JP2008059398A - Identification information allocation device, information processing method therefor, and program therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the concentration of accesses to a node device by determination of divided content identification information, in accompaniment to control of a plurality of divided content data. <P>SOLUTION: This identification information allocation device determines the divided content identification information to make the content control node devices for the divided content identification information allocated with the respective plurality of divided content data as objects different respectively, when allocating the divided content identification information, using the respective plurality of divided content data with a content data divided into the plurality as the objects, out of an allocation identification information area arranged with node identification information, and a plurality of allocation identification information allocated as content identification information, according to a prescribed rule. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention belongs to the technical field of an identification information allocating device, an information processing method thereof, and a program thereof, and more specifically includes a plurality of node devices distributed on a network, and content data between these node devices. The present invention belongs to the technical field of an identification information allocating apparatus for allocating content identification information of content data in a content distribution system that performs transmission and reception, an information processing method thereof, and a program thereof.

  In recent years, so-called content distribution systems that distribute content data (hereinafter also referred to as “content”) such as music, movies, and talk programs via a network such as the Internet have been actively studied.

  As a basic configuration of a conventional content distribution system, as shown in Patent Document 1, information is efficiently created by logically constructing an overlay network using a distributed hash table (DHT (Distributed Hash Table)). There has been proposed a technique for distributing the load by distributing the load.

  In this system, each node device that is a terminal device does not recognize link information (for example, IP address) to all the node devices participating in the overlay network. Only the link information to some of the obtained node devices is held, and based on such link information, data inquiry or the like is performed.

  In the peer-to-peer type content distribution system of Patent Document 1, each node device is a content distribution server that holds content data, and each node device is also a content distribution request client.

  Also, in such a content distribution system, it is known that not only the node device which is a content distribution server holds content data but also other node devices on the network hold a copy of the content data. ing. Hereinafter, a node device that holds a copy of content data is also referred to as a content holding node device. The node device that is a content distribution request client can also obtain the requested content from such a content holding node device. Therefore, when a distribution request for a certain content increases, the content can be distributed not only from the node device that is the content distribution server but also from the content holding node device that holds a copy of the content device. It is possible to avoid concentration of access. Hereinafter, the content distribution server and the content holding node device are referred to.

  As described above, in a peer-to-peer type content distribution system, a node device (hereinafter referred to as a “root node device”) that stores position information of a plurality of content holding node devices is determined, and the request node device is requested. The index information is obtained by requesting the root node device for location information (hereinafter referred to as “index information”) of the content holding node device that holds the content to be processed, and the content holding node is based on the index information. It is configured to make a content data distribution request to the apparatus.

In addition, an allocation identification information area is set so that it can be allocated as a node ID (node identification information) for the node device and a content ID (content identification information) for the content data. The node ID unique to the node device and the content ID unique to the content data are assigned. Further, the node device is determined as the root node device of the content data on condition that the node ID of the device is close to the content ID. Thereby, it becomes easy to search the node ID of the root node device from the content ID, and the location of the root node device and the location of the content data can be managed more efficiently.
JP 2006-197400 A

  In such a network, content data is divided into a plurality of divided content data, and the plurality of divided content data is distributed and stored in a plurality of node devices, and each of the plurality of divided content data is targeted. A plurality of root node devices are set. Also in this case, a unique divided content ID (divided content identification information) is assigned to each of the plurality of divided content data, and the root node device is determined.

  However, when the unique divided content ID assigned to each of the plurality of divided content data obtained by dividing one content data is determined as an ID close to each other, for example, determined to increase by one. The root node device of the plurality of divided content data may be the same, or the root node device of the plurality of divided content data may be a node device having a node ID close to obtain the location information of the plurality of divided content data For example, there is a risk of concentration of access to the node device including the root node device due to a request for index information and information indicating that the divided content data has been copied.

  The present invention has been made in view of the above-described problems, and it is possible to reduce the concentration of access to a node device by determining divided content identification information as a result of managing a plurality of pieces of divided content data. An object of the present invention is to provide an identification information assigning apparatus, an information processing method thereof, and a program thereof.

  In order to achieve the above object, the present invention provides the following.

  That is, in the present invention according to claim 1, content data held by each node device is transmitted and received between a plurality of node devices respectively connected via a network, whereby the content data is transmitted to the node device. Content identification information for identifying content data is attached to each content data, node identification information for identifying the node device is attached to each node device, and there is a difference from the content identification information. In an identification information allocating apparatus for allocating content data identification information for content data in a content distribution system in which a node apparatus to which small node identification information is allocated is a content management node apparatus for managing content data, the node apparatus is Target node identification information Divided content for each of a plurality of pieces of divided content data obtained by dividing the content data into a plurality of pieces of assignment identification information areas in which a plurality of pieces of assignment identification information that can be assigned as the content identification information are arranged according to a predetermined rule When assigning the identification information, a divided content identification information assigning unit is provided for determining the divided content identification information so that the content management node devices of the divided content identification information assigned to each of the plurality of divided content data are different. It is characterized by that.

  According to a second aspect of the present invention, there is provided the divided content according to the first aspect, wherein the divided content identification information assigned to each of the plurality of divided content data is used to determine whether or not the content management node device is duplicated. The divided content identification information allocating unit has a function of determining divided content identification information determined by the divided content identification information determining unit that content management node devices are not duplicated. Is.

  Further, in the present invention of claim 3, in the invention of claim 2, the node device transmits search information based on the divided content identification information assigned by the divided content identification information assigning means, and It has a function of receiving the node identification information of the node device storing the divided content data corresponding to the divided content identification information from the content management node device of the divided content identification information.

  According to a fourth aspect of the present invention, in the first aspect of the present invention, the divided content identification information provisionally determining means for tentatively determining the divided content identification information from the allocation identification information area, and the divided content identification Divided content identification information determination means for determining whether or not the difference between the divided content identification information determined by the information provisional determination means is a predetermined value or more, and the divided content identification information provisional determination means includes the division When the content identification information determination unit determines that the difference between the divided content identification information is less than a predetermined value, the divided content identification information allocation unit has a function of tentatively determining the divided content identification information again. When the difference between the divided content identification information exceeds a predetermined value by the divided content identification information determination unit If it is constant is characterized in that it has a function of allocating the divided content identification information.

  According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the divided content identification unit includes a divided content data extracting unit that extracts data based on a predetermined extraction condition from the plurality of divided content data. The temporary information determining means has a function of temporarily determining divided content identification information for each of the plurality of divided content data from the data extracted by the divided content data extracting means. .

  Further, in the present invention described in claim 6, in the invention described in claim 5, the divided content identification information provisional determination unit determines that the difference between the divided content identification information is less than a predetermined value by the divided content identification information determination unit. If it is determined that the extracted content data is extracted by the divided content data extracting unit, the divided content data extracting unit is configured to change a predetermined extraction condition for extracting data from the divided content data extracting unit. A function of re-extracting data based on the predetermined extraction condition changed by the extraction condition changing means, and the divided content identification information provisional deciding means again from the data extracted again by the divided content data extracting means A function of temporarily determining the divided content identification information It is.

  According to a seventh aspect of the present invention, in the invention according to the fourth aspect, the plurality of divided content data includes additional information corresponding to the divided content data, and the divided content identification information provisionally determined. The means has a function of temporarily determining the divided content identification information from the additional information.

  Further, in the present invention described in claim 8, in the invention described in claim 7, the plurality of divided content data include a first corresponding to content data including the plurality of divided content data as the additional information. Additional information and second additional information corresponding to each of the plurality of pieces of divided content data are included, and the divided content identification information provisional determination means includes the first additional information and the second additional information. From the above, it has a function of temporarily determining the divided content identification information.

  According to a ninth aspect of the present invention, in the eighth aspect of the invention, the divided content identification information provisional deciding means determines that the divided content identification information determination means determines that the difference between the divided content identification information is less than a predetermined value. If it is determined that the second additional information is changed, the divided content identification information provisional determination unit is changed by the first additional information and the additional information changing unit. The second content information has a function of temporarily determining the divided content identification information again from the second additional information.

  According to a tenth aspect of the present invention, in the invention according to any one of the first to third aspects, the division number determining means for determining the number of divisions of a plurality of pieces of divided content data to which the divided content identification information is assigned, Based on the number of divisions of the plurality of pieces of divided content data determined by the division number determination means, the ratio identification information area is divided into the number of divisions and determined as a plurality of division allocation identification information areas. And the divided content identification information allocating means has a function of allocating the divided content identification information for each of the plurality of divided allocation identification information areas determined by the divided allocation identification information area determining means. To do.

  In the present invention according to claim 11, the content data held by each node device is transmitted / received to / from the node device among a plurality of node devices respectively connected via a network. Content identification information for identifying content data is attached to each content data, node identification information for identifying the node device is attached to each node device, and there is a difference from the content identification information. In the information processing method of the identification information allocating device for allocating content data identification information for the content data in the content distribution system in which the node device to which the small node identification information is allocated is a content management node device that manages the content data. The identification information assigning device A plurality of pieces of content data divided into a plurality of pieces of node identification information targeted at a node device and an assignment identification information area in which a plurality of assignment identification information that can be assigned as the content identification information is arranged according to a predetermined rule When the divided content identification information is assigned to each of the divided content data, the divided content identification information is set so that the content management nodes of the divided content identification information assigned to each of the plurality of divided content data are different. It has the division content identification information allocation step to determine, It is characterized by the above-mentioned.

  According to a twelfth aspect of the present invention, a computer is caused to function as each unit of the identification information allocating device according to any one of the first to tenth aspects.

  According to the first, eleventh, or twelfth aspect of the present invention, a node device to which node identification information having a small difference from the content identification information is assigned becomes a content management node device that manages content data. Targeting each of a plurality of divided content data obtained by dividing content data into a plurality of allocation identification information areas in which a plurality of allocation identification information that can be allocated as node identification information and content identification information are arranged according to a predetermined rule When assigning the divided content identification information, the divided content identification information is determined so that the content management node devices of the divided content identification information assigned to each of the plurality of pieces of divided content data are different. Therefore, since the divided content identification information is determined so that the content management node devices that manage the content data are different from each other, access concentration to the content management node device and relative to the node identification information of the content management node device Access concentration to nearby node devices can be reduced.

  According to the second aspect of the present invention, it is determined whether the content management node devices of the divided content identification information assigned to each of the plurality of divided content data are overlapped, and the content management node devices are determined not to overlap. The divided content identification information is determined. Therefore, by determining whether or not the content management node devices overlap, the content management node devices are surely different from each other to determine the divided content identification information. Concentration of access to a node device that is relatively close to the node identification information of the management node device can be prevented.

  According to the third aspect of the invention, search information is transmitted based on the assigned divided content identification information, and the divided content data corresponding to the divided content identification information is transmitted from the content management node device of the divided content identification information. The node identification information of the stored node device is received. Accordingly, the concentration of access to the content management node device that transmits the node identification information of the node device in which the search information is transmitted and the divided content data is stored, and a node relatively close to the node identification information of the content management node device Access concentration to the device can be prevented.

  According to the fourth aspect of the present invention, when the divided content identification information is provisionally determined from the allocation identification information area and it is determined that the difference between the divided content identification information is less than the predetermined value, the divided content identification information is divided again. If the content identification information is tentatively determined and it is determined that the difference between the divided content identification information is greater than or equal to a predetermined value, the divided content identification information is assigned. Therefore, it is determined whether or not the difference between the divided content identification information is equal to or greater than a predetermined value, and the difference between the divided content identification information is equal to or greater than the predetermined value. Concentration and concentration of access to a node device relatively close to the node identification information of the node device can be reduced.

  According to the fifth aspect of the present invention, data based on a predetermined extraction condition is extracted from the plurality of divided content data, and the divided content identification for each of the plurality of divided content data is performed from the extracted data. Information is temporarily determined. Therefore, for each of the plurality of pieces of divided content data, data based on a predetermined extraction condition is extracted from the plurality of pieces of divided content data, and the divided content identification information is temporarily determined. Therefore, the divided content identification information may be the same. The access concentration to the node device that is the management target of the divided content data and the access concentration to the node device that is relatively close to the node identification information of the node device can be reduced.

  According to the sixth aspect of the present invention, when it is determined that the difference between the divided content identification information is less than the predetermined value, the predetermined extraction condition is changed, and the changed predetermined content is changed from the plurality of divided content data. Data based on the extraction condition is extracted again, and the divided content identification information is temporarily determined again from the extracted data. Therefore, for each of the plurality of divided content data, data based on a predetermined extraction condition is extracted from the plurality of divided content data, and the divided content identification information is provisionally determined. As a result, the difference between the divided content identification information is a predetermined value. If it is determined that the value is less than, the predetermined extraction condition is changed, the data based on the changed predetermined extraction condition is extracted again, and the divided content identification information is tentatively determined again. The access concentration to the node device that is the management target of the divided content data and the access concentration to the node device relatively close to the node identification information of the node device can be reduced.

  According to the seventh aspect of the present invention, the plurality of pieces of divided content data include additional information corresponding to the divided content data, and the divided content identification information is provisionally determined from the additional information. Accordingly, since the divided content identification information is temporarily determined from the additional information corresponding to a plurality of divided content data, the possibility that the divided content identification information is the same is reduced, and access to the node device that is the management target of the divided content data is reduced. Concentration and concentration of access to a node device relatively close to the node identification information of the node device can be reduced.

  According to the invention described in claim 8, the plurality of divided content data includes, as additional information, first additional information corresponding to content data including the plurality of divided content data, and each of the plurality of divided content data. Corresponding second additional information is included, and the divided content identification information is temporarily determined from the first additional information and the second additional information. Accordingly, the divided content identification information is the same because the divided content identification information is temporarily determined from the first additional information corresponding to the content data and the second additional information corresponding to each of the plurality of divided content data. The possibility becomes low, and the concentration of access to the node device that is the management target of the divided content data and the concentration of access to the node device that is relatively close to the node identification information of the node device can be reduced.

  According to the ninth aspect of the present invention, when it is determined that the difference between the divided content identification information is less than the predetermined value, the second additional information is changed to be changed to the first additional information. The divided content identification information is temporarily determined again from the additional information. Accordingly, the divided content identification information is temporarily determined from the first additional information corresponding to the content data and the second additional information corresponding to each of the plurality of divided content data, and as a result, the difference between the divided content identification information is determined. Is determined to be less than the predetermined value, the second additional information is changed, and the divided content identification information is temporarily determined again from the first additional information and the changed second additional information. Therefore, there is no possibility that the divided content identification information is the same, and concentration of access to the node device to be managed of the divided content data and concentration of access to the node device relatively close to the node identification information of the node device are performed. Can be reduced.

  According to the tenth aspect of the present invention, the division number of the plurality of divided content data to which the divided content identification information is assigned is determined, and the ratio identification information area is determined based on the determined division number of the plurality of divided content data. The number of divisions is determined as a plurality of division allocation identification information areas, and divided content identification information is allocated to each of the plurality of division allocation identification information areas. Accordingly, the ratio identification information area is divided into the number of divisions of the plurality of divided content identification information, and the divided content identification information is allocated to each of the divided division allocation identification information areas. The concentration of access to the node device that is the management target of the divided content data and the concentration of access to the node device that is relatively close to the node identification information of the node device can be reduced. .

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, the best embodiment of the invention will be described with reference to the drawings. The embodiment described below is an embodiment when the present invention is applied to a content distribution system in which information to be distributed is content data such as music data and video data.

[1. Content distribution system configuration]
First, a schematic configuration and the like of a content distribution system as an information distribution system will be described with reference to FIG. FIG. 1 is a diagram illustrating an example of a connection mode of each node device that is a terminal device in the content distribution system according to the present embodiment. This content distribution system is composed of a plurality of node devices distributed on a network and transmits / receives content data between the node devices. As will be described in detail later, the content distribution system in the present embodiment includes a plurality of node devices and a content data management device 10 that assigns identification information corresponding to content data and inputs content data.

  As shown in the lower frame of FIG. 1, IX (Internet eXchange) 3, ISP (Internet Service Provider) 4, DSL (Digital Subscriber Line) line operator (device) 5, FTTH (Fiber To The Home) line business A network (real-world network) 8 such as the Internet is constructed by a person (device) 6 and a communication line (for example, a telephone line or an optical cable) 7. Note that the DSL line apparatus includes a RADSL (Rate adaptive Asymmetric Digital Subscriber Line) line apparatus.

  As shown in the upper frame of FIG. 1, the content distribution system S includes a plurality of node devices 1a, 1b, 1c... 1x, 1y, 1z,. And is a peer-to-peer (P2P) network system. Each node device 1a, 1b, 1c... 1x, 1y, 1z... Is assigned a unique manufacturing number (for example, a MAC address) and an IP (Internet Protocol) address as information indicating the node device. . The production number and the IP address are not duplicated among the plurality of node devices 1. In the following description, when any one of the node devices 1a, 1b, 1c... 1x, 1y, 1z.

[1.1. Outline of DHT]
The algorithm using the distributed hash table (hereinafter referred to as “DHT” (Distributed Hash Table)) according to the present embodiment will be described below.

  In the content distribution system S described above, when the node devices 1 exchange information with each other, they must be able to recognize the IP addresses as the position information of each other.

  For example, in a system for sharing content with each other, it is a simple technique for each node device 1 participating in the network 8 to know the IP addresses of all the node devices 1 participating in the network 8. However, when the number of terminals increases to tens of thousands and hundreds of thousands, it is not realistic to remember the IP addresses of all the node devices 1. Also, if the power supply of an arbitrary node device is frequently turned on or off, the IP address of the arbitrary node device stored in each node device 1 is frequently updated, which makes operation difficult.

  Therefore, one node device 1 stores only the minimum necessary IP addresses of some of the node devices 1 participating in the network 8, and stores the IP address. For node devices 1 that are not connected, a system has been devised that supplies content by transferring information between the node devices 1.

  As an example of such a system, an overlay network 9 as shown in the upper frame of FIG. 1 is constructed by an algorithm using DHT. That is, the overlay network 9 means a network that forms a virtual link formed by using the existing network 8.

  In this embodiment, the overlay network 9 constructed by an algorithm using DHT is assumed, and the node device 1 arranged on the overlay network 9 participates in the content distribution system S (in other words, the overlay network 9). The node device 1 participating in the network.

  As the node ID that is the identification number of each node device 1 participating in the content distribution system S, a unique number (unique number) is assigned to each node device 1. This number needs to have a number of bits that can accommodate the maximum number of operating node devices. For example, if the number is 128 bits, 2128 = 340 × 1036 node devices can be operated.

  More specifically, the node ID of each node device 1 is obtained by hashing a unique value for each node device 1 such as the IP address or manufacturing number of each node device 1 with a common hash function (hash algorithm). The obtained hash value is distributed and arranged in one ID space without deviation. Thus, the node ID obtained by hashing with a common hash function has a very low probability of having the same value if the IP address or the manufacturing number is different. Since the hash function is publicly known, detailed description thereof is omitted. In the present embodiment, a node ID is a value obtained by hashing an IP address (global IP address) with a common hash function.

  In addition, the plurality of node devices 1 participating in the content distribution system S include content data (for example, music data, movie data, documents, etc.) shared information distributed from one node device 1 to another node device 1. Data, etc.) are distributed and stored, but the content data is also given a unique identification number (hereinafter referred to as “content ID”) for each content data. Further, this content ID is assigned to content data (including divided divided content data) in the content distribution system S by the content data management apparatus 10 described later.

  The content ID has the same length as the node ID (for example, 128 bits). For example, when a keyword such as a content name (content title) or content outline information (summary) obtains the node ID, Hashed by a common hash function (that is, placed in the same ID space as the hash value of the IP address of the node device 1), and has a node ID closest to the hash value (for example, the higher digits match more) The node device 1 holds link information to the node device 1 that holds content data (hereinafter referred to as “content holding node device”), that is, an IP address that is position information of the content holding node device. That is, in the content distribution system S, the node device 1 to which a node ID having a small difference from the content ID is assigned becomes a root node device (content management node device) that manages content data. The content holding node device is determined under a certain rule (for example, under a rule that the root node device randomly selects). Thereby, the content data is distributed and arranged on the content distribution system S without any bias. Note that even if the content data is different, it is assumed that the same keyword (for example, the name of the content) is used. In this case, the hash value is the same to avoid the same hash value. The keyword may be, for example, a combination of content name and copyright information (for example, performer name, director name, original author name, singer name, composer name, or songwriter name). A method for determining a content ID for a plurality of divided content data obtained by dividing one content data into a plurality of pieces will be described in detail later.

  As described above, since the node ID and the content ID assigned to each node device 1 and each content data are generated by a common hash function, as shown in FIG. It can be thought of as being scattered and present. This figure shows a node ID and content ID assigned in 32 bits. In the figure, a round dot indicates a node ID, a square indicates a content ID, and the ID increases counterclockwise.

  Next, which node device 1 holds which content data is determined under a certain rule. In the present embodiment, the rule is that “a node device 1 that manages content data having a certain content ID is a node device 1 having a node ID close to that content ID”. Here, the definition of “close” does not exceed the content ID, and the difference between the content ID and the node ID is the smallest. In practice, each content data is managed by each node device 1. When allocating, it is only necessary to be consistent. For example, the difference between the content ID and the node ID may be the smallest regardless of whether or not the content ID is exceeded. In the example shown in FIG. 2, based on this definition, the content IDa is managed by the node device 1 having a node ID close to the content IDa (hereinafter referred to as “node IDa”), and the content IDb is the content IDb. Managed by the node device 1 having a node ID close to IDb (hereinafter referred to as “node IDb”), and the content IDc has a node ID close to the content IDc (hereinafter referred to as “node IDc”). Managed by the device 1.

  Here, “management” does not mean that content data is held, but means “recognizes which node device 1 holds content data”. . That is, in FIG. 2, the node device 1 having the node IDa recognizes which node device 1 holds the content data having the content IDa, and has the node device 1 having the node IDb and the node IDc. Similarly, the node device 1 recognizes which node device 1 holds the content data having the content IDb and the content data having the content IDc. Thus, the node device 1 that recognizes which node device 1 holds certain content data is called a root node device (an example of a content management node device) of the content data. That is, the node device 1 having the node IDa is the root node device of the content data having the content IDa, and the node device 1 having the node IDb is the root node device of the content data having the content IDb, and the node IDc Is a root node device for content data having content IDc.

  The content distribution system S also has a function of distributing content data to the root node device in order to make the node device in the content distribution system S a content holding node device, and a function of generating a catalog list and providing it to the node device Is provided.

  As described above, the content distribution system S transmits and receives content data (including divided divided content data) held by each node device between the plurality of node devices. This is a system that enables distribution of content data.

[1.2. Create routing table]
Here, an example of a method for creating a routing table used in DHT will be described with reference to FIG. FIG. 3 is a diagram illustrating an example of how a routing table is created by DHT.

  First, as shown in FIG. 3A, the ID space is divided into several areas. Actually, about 16 divisions are often used, but in order to simplify the explanation, here, it is assumed that the division is four and ID is expressed by a quaternary number having a bit length of 8 bits. An example in which the node ID of the node device 1N is “1133” and the routing table of the node device 1N is created will be described.

(Level 1 routing)
First, when the ID space is divided into four, each area has four areas “0XXX”, “1XXX”, “2XXX”, “3XXX” (where X is a natural number from 0 to 3, The same shall apply hereinafter.) Since the node ID of the node device 1N itself is “1133”, the node device 1N exists in the lower left “1XXX” area in FIG. The node device 1N is a node device existing in an area (that is, an area of “0XXX”, an area of “2XXX”, an area of “3XXX”) other than the area where the node device exists (that is, an area of “1XXX”). 1 is appropriately selected, and the position information of the node ID, that is, the IP address of the node ID is stored in the level 1 table. FIG. 4 is an example of a level 1 table. In this table, “0100” is selected as the node ID of the area “0XXX”, “2133” is selected as the node ID of the area “2XXX”, and “3213” is selected as the node ID of the area “3XXX”. Show. Since the second column of level 1 indicates the node device 1N itself, it is not necessary to store the IP address.

(Level 2 routing)
Next, as shown in FIG. 3B, of the areas divided into four by the routing, the area “11XX” where the user exists is further divided into four, and further four areas “10XX”, “11XX”, “12XX” And “13XX”. Then, similarly to the above, the node device 1 existing in an area other than the area “11XX” in which it exists is appropriately selected, and the IP address which is the position information of the node ID is stored in the level 2 table. FIG. 4 is an example of a level 2 table. In this table, “1003” is selected as the node ID of the area “10XX”, “1221” is selected as the node ID of the area “12XX”, and “1313” is selected as the node ID of the area “13XX”. Is shown. The second column of level 2 is an area “11XX” in which the node device 1N exists, and since it is tabulated at level 3 to be described later, no IP address is stored. If no node device exists in the area, the node ID and IP address fields are blank.

(Level 3 routing)
Further, among the areas divided into four by the routing, the area “113X” in which the user exists is further divided into four, and further divided into four areas “110X”, “111X”, “112X”, and “113X”. Then, similarly to the above, the node device 1 existing in an area other than the area “113X” in which it exists is appropriately selected, and the IP address which is the position information of the node ID is stored in the level 3 table. FIG. 4 is an example of a level 3 table. The fourth column of level 3 is an area where the node device 1N exists, and since it is tabulated at level 4 described later, no IP address is stored. If no node device exists in the area, the node ID and IP address fields are blank.

  In this way, by creating a routing table as shown in FIG. 4 in the same manner up to level 4, all 8-bit IDs can be covered. As the level goes up, white space becomes more noticeable in the table.

  All the node devices 1 each create and own the routing table created according to the method described above. Thus, each node device 1 has a routing table that associates node IDs (identification information) and IP addresses (location information) of some of the node devices 1 among the plurality of node devices 1 in the content distribution system S. This routing table is stored in the routing table storage means described later.

[1.3. Content data search method]
Next, an example of a search method for the node device 1 that holds content data will be described with reference to FIG. FIG. 5 is a diagram illustrating an example of a state in which the node device 1 holding content data is searched by DHT.

  Here, a procedure when the node device 1N having the node ID “1133” searches for content data having the content ID “3020” will be described. In the following, a node device that searches for content data and requests reception of content data will be referred to as a “request node device”.

  The request node device 1N refers to the level 1 table of the routing table held by itself and distributes the content data using the node ID of the node device having the node ID in the same area as the content ID “3020” as the destination identification information. A transmission request (hereinafter referred to as “content search message”) of original information (information including position information of the content holding node device) is transmitted. That is, since the content ID “3020” is an area of “3XXX”, the node device 1 belonging to the area of “3XXX” knows the IP address (that is, the IP address is stored in the routing table held by itself). A content search message is transmitted to node device 1A (node ID “3213”) in which the address is stored. Thus, the content search message includes a content ID that is unique identification information corresponding to the content, and this content ID is used as destination identification information in the content search message.

  According to the example shown in FIG. 5, since the IP address of the node device 1A having the node ID “3213” is stored in the routing table (see FIG. 4) of the request node device 1N, the request node device 1N A content search message is transmitted to the node device 1A whose node ID is “3213”.

  Next, the node device 1A that has received the content search message determines whether or not the content search message is a message addressed to its own node device 1A. Whether the message is addressed to the own node device 1A is determined based on the destination identification information and the routing table. Specifically, it is determined whether the destination identification information is close to the identification information of the own node device 1A. That is, with respect to the destination identification information, the identification information of the closest node device from the identification information of the node device stored in the routing table held by the node device 1A itself is itself or another node device. It is determined whether it is. Here, since the identification information of the other node device is closer to the destination identification information than the identification information of the own node device 1A, the node device 1A is level 2 of the routing table held by the node device 1A itself. The content search message is transferred to the node device 1B (node ID “3031”) that knows the IP address among the node devices 1 belonging to the area “30XX”.

  As described above, when the transfer of the content search message proceeds in the manner of adapting the digits of the content ID in order from the top and finally reaches the node device 1C that manages the content data, that is, the root node device, the route The node device searches the content ID “3020” included in the content search message from index information described later managed by itself, and the IP address of the content holding node device 1 that owns the content data, etc. To the request node device 1N. A mechanism for transferring a message such as a content search message to the target node device as described above is called DHT routing.

  Thus, the request node device 1N receives the location information of the content data with the content ID “3020” from the root node device 1C, that is, the IP address of the content holding node device 1 that holds the content data with the content ID “3020”. Thus, the content data is downloaded and acquired from the content holding node device 1.

[1.4. How to register in the index table]
In the content distribution system S having such a configuration, for example, a method when a certain node device 1 publishes new content data so that it can be searched from other node devices 1 on the content distribution system S will be described. . This node device 1 is a content holding node device that stores and holds content data.

  The content holding node device that stores the content data distributed from the content data management device 10 is directed to the node device having the same node ID as the content ID of the stored content data (whether or not this node device actually exists). Not sure at the moment.) Send a registration message. And this registration message is also transferred one after another according to the routing table in the same manner as the content search message, and when it is transferred to the node device 1 having the node ID closest to the content ID included in the registration message, If the node device 1 determines that there is no other node device 1 as the transfer destination, the node device 1 determines that the node device 1 itself should be the root node device of the content, and the content ID and content included in the registration message. The node ID and IP address of the holding node (hereinafter referred to as “index information”) are stored as index information.

  Furthermore, in the present embodiment, the node device 1 in the middle of the path through which the registration message is transferred to the root node device is configured to hold the index information included in the registration message as a cache. The device is called a cache node device. As a result, the cache node device receives the IP address or node ID of the content holding node device when the content search message is transferred to the cache node device before the root node device receives the content search message for searching for content. Can be returned to the request node device that has searched for the location of the content. In the present embodiment, at least the IP address of the content holding node device is returned in response to the content search message, but the node ID may be returned together with the IP address of the content holding node device.

  When transferring a registration message, the cache node device normally holds index information based on the registration message as described above.

  Here, as illustrated in FIG. 6A, the node device 1M with the node ID “1301” is set as a content holding node device that holds the content with the content ID “3020”, and the node ID is “3011”. Retention of index information when the node device 1C is the root node device of the content with content ID “3020” will be described with reference to FIGS. 6 (a) and 6 (b).

  As shown in FIGS. 6A and 6B, when the node apparatus 1M, which is a content holding node apparatus, transmits a registration message including index information, the node apparatus 1A that has received the message holds the index information. Therefore, it functions as a cache node device (1). The cache node device (1) transfers the registration message. The node device 1B that has received the registration message functions as a cache node device (2) by holding the index information. The cache node device (2) transfers the registration message. The node device 1C that has received the registration message functions as a root node device by holding the index information. In this way, the node devices 1A, 1B, and 1C hold the index information included in the registration message.

  Incidentally, index information is held in the root node device and the cache node device by an index table as shown in FIG. FIG. 7 shows an example of an index table in the root node device 1C, which stores the node ID, IP address, etc. of the content holding node device relating to the content with the content ID “3020” that is managed by the own node device. As the cache node device, the identification information of the content holding node device relating to the content with the content ID “2021” is stored. The index table can also store copyright information in addition to the content ID, the node ID of the content holding node device, and the IP address.

[1.5. Content ID Determination Method]
A content ID is determined and assigned to an ID space for content data distributed in this way, and a content ID determination method in the case where such content data is divided into a plurality of divided content data Will be described below with reference to FIG.

  The plurality of divided content data is content data obtained by dividing one content data into a plurality of pieces. Specifically, when one content data has a large size, the content data is divided and stored as divided content data, or divided into a plurality of pieces of divided content data (for example, The continuous distribution of the content data can be facilitated by storing each of the four pieces of continuous video data separately.

  However, if the content ID is determined by a serial number or determined to be within the same range to some extent, as shown in FIG. 8A, the divided content data (content holding node device storing the divided content data) Content IDs are close, i.e., the root node devices overlap, or the root node devices are arranged close to each other, for example, content holding that actually stores the divided content data Concentration of access to the root node device, such as a registration message issued from the node device toward the root node device, and a content search message for inquiring the location information of the content holding node device to request the divided content data The content ID of the root node device Accessing concentrated to near node device there is a risk of causing.

  Therefore, in the content distribution system S in the present embodiment, as shown in FIG. 8B, by distributing content IDs targeted for a plurality of divided content data, the root node devices are distributed, registration messages and Concentration of access to the root node device such as a content search message and access concentration to a node device relatively close to the node ID of the root node device can be reduced.

[2. Description of Configuration of Content Data Management Device 10]
Next, the configuration and operation of the content data management apparatus 10 will be described with reference to the drawings. FIG. 9 is a diagram showing a schematic configuration of the content data management apparatus 10 in the content distribution system S according to the present embodiment.

  The content data management apparatus 10 can be a general server computer in addition to a dedicated computer. As shown in FIG. 9, the content data management apparatus 10 can be rewritten to store (store) a CPU (Central Processing Unit) 102 and various programs. A first storage unit 103 as a main storage device, a second storage unit 104 composed of an HDD or the like for storing various data, and other node devices 1 participating in the network 8 via the router 120 A network interface 105 for communicating with each other, a mouse 107a and a keyboard 107b as input means for inputting information for controlling the content data management apparatus 10 by an administrator of the content distribution system S, and an input means The peripheral device control chip 106 for processing the input information and the control of the CPU 102 The image data is received, written in an internal video memory (not shown), and the video chip 108 is displayed to display the data written in the video memory on a display 109 described later. They are connected to each other via a system bus 101. In the present embodiment, the CPU 102 and the first storage unit 103 constitute a control unit 114.

(Regarding the first storage unit 103)
The first storage unit 103 also has an operating system (OS) program 110 for providing basic functions of the node device 1 as a computer, a screen control program 111 for controlling the display 109, etc., and content distribution Stores a catalog update program 112 for updating a catalog list, which is a list of contents each time content is input to the system S, a new input content program 113 for newly inputting content to the content distribution system S, and the like. These are read by the CPU 102, and the function according to these programs is executed by the CPU 102. Note that “injecting content into the content distribution system S” means that the content data management device 10 determines a node device 1 that is a content holding node device for a certain content, and distributes the content data to the determined node device 1. Means that.

  Here, the OS program 110 is read and executed by the CPU 102, whereby a function related to the mouse 107 a and the keyboard 107 b and a content data management device such as memory management such as the first storage unit 103 and the second storage unit 104. The basic function of the computer 10 can be executed. Then, with the OS program 110 being executed by the CPU 102, the above-described screen control program 111, catalog update program 112, new input content program 113, etc. are read from the first storage unit 103 and executed.

  The OS program 110, the screen control program 111, the catalog update program 112, the newly input content program 113, and the like are downloaded to the first storage unit 103 via the network interface 105 from, for example, a server connected to the network 8. Alternatively, it may be recorded on a recording medium such as a CD-ROM and then read into the first storage unit 103 via a drive of the recording medium.

(About the second storage unit 104)
The second storage unit 104 includes a catalog list storage area 115 for storing a catalog list in which contents generated by the catalog update program and provided in the content distribution system S are listed, and provided in the content distribution system S. A content data storage area 116 that stores the data of the content that has been stored, and a new content data storage area 117 that serves as content data storage means for storing content data that is newly provided in the content distribution system S. ing.

(Regarding the control means 114)
The control unit 114 includes the CPU 102 and the first storage unit 103 as described above, and the CPU 102 reads out and executes the various programs 110 to 113 stored in the first storage unit 103, whereby the entire node device 1 is configured. General control and later-described display control means, content data identification information determination means, divided content identification information allocation means, divided content identification information provisional determination means, divided content identification information determination means, additional information change means, content holding node device It functions as a determination unit, a content holding request unit, and the like.

  The CPU 102 executes the screen control program 111 as a display control unit or the like, the CPU 102 executes the catalog update program 112 as a catalog update unit or the like, and the CPU 102 executes the new input content program 113. , Content data identification information determining means, divided content identification information assigning means, divided content identification information temporary determining means, divided content identification information determining means, additional information changing means, content holding node device determining means, content holding request means, etc. It is supposed to function.

(Display control means)
The display control means has a function of controlling the video chip 108 and the display 109 to display various video information (image information). In other words, the display control means controls how video is displayed on the display 109.

(About content data identification information determination means)
The content data identification information determination unit has a function of determining a content ID that is identification information of content data to be newly input to the content distribution system S.

  More specifically, the content data identification information determination means calculates a random value by a random calculation, and hashes the value calculated at random in this way with a hash function that is common to when the node ID is obtained. To determine the content ID.

(Divided content identification information allocation means)
In particular, the divided content identification information assigning unit has a function of determining and assigning a content ID for each of a plurality of pieces of divided content data obtained by dividing one piece of content data. The divided content identification information assigning means determines the content ID so that the root node devices of the content ID assigned to each of the plurality of divided content data are different.

(About divided content identification information provisional determination means)
The divided content identification information provisional determination means has a function of temporarily determining a content ID for each of a plurality of pieces of divided content data obtained by dividing one piece of content data.

(Divided content identification information judging means)
The divided content identification information determination unit has a function of determining the duplication of the root node device of the content ID provisionally determined for each of the plurality of divided content data.

(Additional information change means)
The additional information changing means, for each of the plurality of pieces of divided content data, determines that the root node device of the temporarily determined content ID overlaps, or if it is determined that the content ID is less than a predetermined value, It has a function of changing the additional information attached to each of the divided content data.

(About content holding node device determination means)
The content holding node device determination means has a function of determining a node device that holds content data stored in the new content data storage area 117, that is, a content holding node device.

  When determining the content holding node device, the content holding node device determination unit randomly calculates a node ID (identification information), and sets the node device 1 having the calculated node ID as the content holding node device.

(About content retention request means)
The content holding request unit makes a content data holding request to the content holding node device determined by the content holding node device determining unit. In the present embodiment, this content data holding request is a request for holding content data to the node device that should be the content holding node device determined as described above, and is transmitted by DHT routing. In response to this request, the node device that should be the content holding node device extracts the IP address of the content data management device 10 from the content data holding request, and transmits the content data corresponding to the holding request to the IP address. Send a request. When receiving the content data transmission request, the content retention request means transmits the content data to be retained to the transmission request source node device. As described above, in communication between the content data management device 10 and the node device 1, a plurality of types of communication modes such as communication using DHT routing and one-to-one communication can be appropriately used.

[3. Explanation of Configuration of Node Device 1]
Next, the configuration and operation of the node device 1 will be described with reference to the drawings. FIG. 10 is a diagram illustrating a schematic configuration of the node device 1 in the content distribution system S according to the present embodiment.

  The node device 1 can be a general personal computer in addition to a dedicated computer. As shown in FIG. 10, a CPU (Central Processing Unit) 202 and a rewritable main memory that stores (stores) various programs and the like. Between the first storage unit 203 as a storage device, the second storage unit 204 composed of an HDD or the like for storing various data, and other node devices 1 participating in the network 8 via the router 224 A network interface 205 for communicating with the remote controller, a remote controller 206 for transmitting and receiving a predetermined infrared signal to remotely operate the node device 1 by the user, an infrared port 207 for communicating with the remote controller 206 by infrared rays, The peripheral device control chip 208 for controlling the infrared port 207 and the control of the CPU 202 A video chip 209 that receives image data, writes it in an internal video memory (not shown), and displays the data written in the video memory on a display 210 to be described later, and a sound source such as an FM sound source and a Wave Table sound source, A sound source chip 211 that outputs sound waves from the speaker 212 by outputting an audio signal to the speaker 212, and these various components are connected to each other via a system bus 201. In the present embodiment, the CPU 202 and the first storage unit 203 constitute a control unit 213.

(Regarding the first storage unit 203)
The first storage unit 203 also includes an operating system (OS) program 214 for providing basic functions of the node device 1 as a computer, a screen control program 215 for controlling the display 210, and the like, content holding Stream for streaming receiving content data transmitted from another node device functioning as a node device, and streaming distribution of content data stored in the second storage unit 204 when the own node device functions as a content holding node device A control program 216, a message monitoring program 217 for transmitting / receiving messages to / from other node devices, a player program 218 for reproducing distributed content data, and the like are stored in the CPU 202. Read I, and functions according to the program by the CPU202 is executed. The first storage unit 203 is further provided with an index table storage area 219 for storing an index table (see FIG. 7) and a routing table storage area 220 for storing a routing table (see FIG. 4). Yes.

  Here, the OS program 214 is read and executed by the CPU 202, thereby causing the node device 1 such as a function related to input / output of the remote controller 206 or memory management such as the first storage unit 203 and the second storage unit 204. It enables the basic functions of a computer to be executed. Then, with the OS program 214 being executed by the CPU 202, the screen control program 215, the stream control program 216, the message monitoring program 217, the player program 218, etc. are read from the first storage unit 203 and executed. .

  Note that the OS program 214, the screen control program 215, the stream control program 216, the message monitoring program 217, the player program 218, and the like are sent from the first storage unit via the network interface 205 from a server or the like connected to the network 8, for example. Alternatively, it may be downloaded to the storage unit 203 or may be recorded on a recording medium such as a CD-ROM and then read into the first storage unit 203 via a drive of the recording medium.

(About the second storage unit 204)
In the second storage unit 204, a catalog list storage area 222 for storing a catalog list in which contents input from the content data management apparatus 10 and provided in the content distribution system S are listed, and the content data management apparatus The content data storage area 223 and the like function as content data storage means for storing content data distributed from 10 and the like.

(Regarding the control means 213)
The control unit 213 includes the CPU 202 and the first storage unit 203 as described above, and the CPU 202 reads and executes the various programs 214 to 218 stored in the first storage unit 203, whereby the entire node device 1 is configured. Centralized control and display control means, stream control means, message destination determination means, message transfer means, content data acquisition means, registration message generation means, registration message transmission means, deletion message generation means, deletion message transmission means, which will be described later, It functions as content holding node information acquisition means, content holding node request information generation means, content holding node request information transmission means, determination means, node identification information transmission means, decoding means, content reproduction means, and the like.

  It should be noted that the CPU 202 executes the screen control program 215 as a display control unit and the like, and the CPU 202 executes the stream control program 216 and the CPU 202 executes the message monitoring program 217 as the stream control unit and the like. Message destination determination means, message transfer means, content data acquisition means, registration message generation means, registration message transmission means, deletion message generation means, deletion message transmission means, content holding node information acquisition means, content holding node request information generation means , Content holding node request information transmission means, determination means, node identification information transmission means, etc., and when the CPU 202 executes the player program 218, the decoding means and the computer As Ntsu reproduction control unit or the like, and functions, respectively.

(Display control means)
The display control means has a function of controlling the video chip 209 and the display 210 to display various video information (image information). That is, the display control unit controls how the video is displayed on the display 210.

(Stream control means)
The stream control means includes content data receiving means for receiving content data streamed from another node apparatus 1 and content data delivery means for streaming content data stored in the second storage unit 204 to the other node apparatus 1. And so on.

  When it is determined that the packet distributed from the other node device 1 is a content packet, the content data receiving means receives the content packet one by one and temporarily stores it in a ring buffer of the first storage unit 203 (not shown). And then stored in the second storage unit 204. Further, the content distribution unit converts the content data stored in the second storage unit 204 into a content packet, and transmits the content packet to another node device 1 via the network interface 205 one by one. The content data receiving means and the content data distribution means can use a known streaming distribution protocol or a unique dedicated protocol.

(About message destination determination means)
The message destination determination unit determines whether the received message is addressed to the own node device 1 based on the destination identification information of the message received via the network 8 and the routing table. The message determined by the message destination determination means includes a content search message for requesting the identification information of the content holding node device from the root node device, a registration message for registering the identification information of the content holding node device in the root node device, etc. It is.

  Whether or not the received message is addressed to the own node device 1 is determined by taking out a destination node ID (destination identification information) included in the message, and controlling means described later based on the routing table stored in the first storage unit 203 213 determines. That is, when various messages are received via the network interface 205, the message destination determination unit compares the destination identification information included in the received message with the node ID stored in the routing table, and determines the destination identification included in the message. If it is determined that the node ID on the routing table closest to the information is the node ID of the own node device 1, it is determined that the message is addressed to the own node device 1.

(About message transfer means)
When the message transfer means determines that the message received via the network 8 is not addressed to its own node device by the message destination determination means, the node stored in the routing table based on the destination identification information of the received message A destination node device is selected from the device identification information, and the received message is transferred to the destination node device. That is, the message transfer means selects the node ID close to the destination identification information from the node IDs of the node devices stored in the routing table, knows the IP address of the node device corresponding to the node ID thus selected, The message is transferred with the IP address as the destination of the IP packet.

(About content data acquisition means)
When the message received via the network interface 205 is a content data retention request from the content data management device 10, the content data acquisition means sends content data corresponding to the content data retention request to the content data management device 10. Get from. And the acquired content data is memorize | stored in the 2nd memory | storage part 204 which is a content data storage means. As described above, the content data holding request is transmitted and received by DHT routing, and the content data is transmitted and received by one-to-one communication.

(Registration message generation means)
When the content data received from the content data management device 10 is stored in the second storage unit 204 that is the content data storage means, the registration message generation means uses the content ID that is identification information of the content data as destination identification information, and A registration message including a node ID and an IP address that are identification information of the node device 1 is generated. Similarly, when content data is received from another content holding node device, the received content data is stored in the second storage unit 204 as content data storage means, and a registration message is generated.

(Registration message transmission means)
The registration message transmission unit is configured to transmit the registration message generated by the registration message generation unit based on the content ID of the content data stored in the second storage unit 204 based on the identification information of the node device stored in the routing table. Select and send.

(About deletion message generation means)
When the deletion message generation unit deletes the content data stored in the second storage unit 204 that is the content data storage unit, the content ID that is identification information of the content data and the node ID that is identification information of the node device 1 itself And a delete message including the IP address.

(About deletion message sending means)
The deletion message transmission unit is configured to transmit the deletion message generated by the deletion message generation unit based on the content ID of the content data deleted from the second storage unit 204 based on the identification information of the node device stored in the routing table. Select and send.

(About content holding node information acquisition means)
When the received message is a registration message in the own node device 1, the content holding node information acquisition means also includes a node ID, an IP address, etc., which are identification information of the content holding node device included in the registration message, in the same registration message. Index information consisting of a set of included content IDs is acquired. Then, the index information acquired in this way is stored in the index table storage area 219 which is content holding node information storage means.

(About content holding node request information generation means)
The content holding node request information generating unit generates a content search message. For example, after a catalog list received from the content data management apparatus 10 is displayed on the display 210, when a desired content is selected from the catalog list by an operation of the remote controller 206 by the user of the node apparatus 1, a content holding node request The information generation means generates a content search message that is content holding node request information for searching for location information of the content holding node device that holds the selected content. The content search message is a message in which the content ID that is the identification information of the requested content data is the destination identification information, and the node ID that is the identification information of the own node device 1 is the request source identification information.

(About content holding node request information transmission means)
The content holding node request information transmitting means selects the destination node device from the node ID that is the node device identification information stored in the routing table based on the content data identification information that is the destination identification information of the content search message and the predetermined condition. Then, a content search message that is content holding node request information is transmitted. Here, the “predetermined condition” is a condition for selecting a node ID whose upper digits more match the content ID, which is the destination identification information of the content search message, among the node IDs stored in the routing table.

(About judgment means)
When the node device 1 receives a content search message that is content holding node request information via the network interface 205, the determining means is index information stored in an index table that is content holding node information storage means, that is, content. It is determined whether or not the node ID of the holding node device includes information that matches the node ID of the content holding node device for the requested content.

(About node identification information transmission means)
If the node ID of the content holding node device corresponding to the content requested by the content search message is stored, the node identification information transmission means uses the node ID of the content holding node device to transmit the content search message. Send to. The transmission destination node device at this time is a node device selected from the routing table in the same manner as other messages based on the transmission source identification information included in the content search message, that is, the identification information of the request node device. By transmitting in this way, the node ID of the content holding node device is delivered to the transmission source node device of the content search message.

(Decoding means)
The decoding means displays the content data transmitted from the other node device 1 on the display 210 and decodes it for output from the speaker 212. That is, the content data transmitted from the other node device 1 is encoded in a data format for streaming delivery, for example, a data format such as ASF, WMA, WMV, etc., and the encoded content data is displayed on the display 210. And decoding so that it can be output from the speaker 212.

(About content playback means)
The content reproduction means reproduces the content data sequentially stored in the buffer area including the ring buffer of the first storage unit 203 by the content reproduction means. At this time, the control means 213 is based on the stream control program 216. Then, the content data is reproduced by operating the video chip 209 and the sound source chip 211.

[4. Description of processing of content data management apparatus 10]
Hereinafter, the detailed operation of the content data management apparatus 10 will be described more specifically with reference to the flowcharts of FIGS. FIG. 11 is a flowchart showing a main process when a divided content is input in the content data management apparatus, FIG. 12 is a flowchart showing a divided content ID determination process called in the main process, and FIG. 13 is a divided content ID called in the divided content ID determination process. It is a flowchart which shows a confirmation process.

  Note that the control unit 114 performs the main process when a process of inputting a piece of content data as a plurality of divided content data is selected by an operation of the administrator of the content data management apparatus 10 or the like. Will be executed. Specifically, the control means 114 divides the new content data stored in the new content data storage area 117 by operating the input means such as the mouse 107a and the keyboard 107b, and inputs them into the content distribution system S. Therefore, when new content data is designated and the number of content holding node devices to hold the designated content data is designated, it is determined that the main process has been selected.

  First, as shown in FIG. 11, the control unit 114 divides the content by the designated number of divisions (step S11). In this process, the control means 114 determines the number of divisions designated by operating input means such as the mouse 107a and the keyboard 107b. Then, the control means 114 reads the new content data stored in the new content data storage area 117, divides it into the designated number of divisions, and stores it as the divided content data in the new content data storage area 117. And the control means 114 sets "0" to NUM located in the predetermined area | region in the 1st memory | storage part 103 (step S12).

  And the control means 114 determines whether NUM is smaller than the division | segmentation number (step S13). The control unit 114 compares the NUM positioned in the predetermined area in the first storage unit 103 with the number of divisions specified by operating the input unit, thereby determining whether the NUM is smaller than the number of divisions. It will be judged. If it is determined that the NUM is smaller than the number of divisions (step S13: YES), the control unit 114 moves the process to step S14, executes step S15 to step S17 following step S14, and makes this determination again. Will be performed. On the other hand, when it is determined that the NUM is equal to or greater than the number of divisions (step S13: NO), the control unit 114 ends this process without executing steps S14 to S17.

  In step S14, the control unit 114 executes a divided content ID determination process. Although details will be described later with reference to FIG. 12, the control unit 114 determines a content ID for any of the plurality of divided content data divided in step S11. Then, the control unit 114 adds the content ID to the usage list (step S15). In this process, the control unit 114 adds the content ID determined for any of the divided content data divided into a plurality of contents to the use list in the second storage unit 104. Then, the control unit 114 inputs the divided content data to the distributed storage system based on the determined content ID (step S16). Then, the control unit 114 increases the value of the NUM positioned in the predetermined area in the first storage unit 103 by “1” (step S17), and moves the process to step S13 again. As described above, the control unit 114 executes steps S14 to S17 by the designated number of divisions.

(About split content ID determination processing)
Next, the divided content ID determination processing in step S14 will be specifically described with reference to FIG.

  First, as shown in FIG. 12, the control unit 114 adds a salt to the content title (step S31). In this process, the control unit 114 determines a salt corresponding to a value set in a NUM positioned in a predetermined area in the first storage unit 103 among the divided content data divided into a plurality of pieces. This salt is added to the title, and is, for example, “No. 1” or “Vol. 1”. Specifically, the control unit 114 refers to the value of NUM and calculates a value obtained by adding “1” to the value. Then, the control unit 114 adds salt information (for example, “No. 1”) based on the calculated value to the title information attached to the content data before division, and title information corresponding to the divided content data. Is stored and included in the divided content data. The title information corresponding to such divided content data is additional information corresponding to the divided content data. Further, the title information corresponding to the content data before division is the first additional information corresponding to the content data, the salt information corresponding to the divided content data is the second additional information, and the additional information described above is The first additional information and the second additional information are included.

  And the control means 114 reads the title information corresponding to division | segmentation content data, and calculates | requires content ID from a hash function based on the title information (step S32). That is, the control unit 114 (partitioned content identification information provisional determination unit) can add a content ID from the title information of the divided content data (additional information including the first additional information and the second additional information) ( The content ID (divided content identification information) targeted for the divided content data is temporarily determined from the (assignment identification information area). As described above, the divided content identification information is obtained from the additional information corresponding to the plurality of divided content data including the first additional information corresponding to the content data and the second additional information corresponding to each of the plurality of divided content data. Therefore, the divided content identification information is less likely to be the same, the concentration of access to the node device that is the management target of the divided content data, and the node device relatively close to the node identification information of the node device Access concentration can be reduced. As will be described in detail later, the control unit 114 changes the salt information and executes this step S32 again when it is determined that the content ID that has been determined is not an appropriate ID. Become. That is, the control unit 114 (partitioned content identification information provisional determination unit) corresponds to the divided content data, and the salt information (second additional information) changed as will be described later and the title information (first information) corresponding to the content data. The content ID (divided content identification information) corresponding to the divided content data is temporarily determined again.

  And the control means 114 determines whether content ID overlaps with other content ID (step S33). The control unit 114 refers to the content ID corresponding to each of the plurality of divided content data, and obtains the same content data so far as the content ID temporarily determined corresponding to any of the plurality of divided content data in step S32. It is determined whether or not it overlaps with another content ID determined as a target. When it is determined that the content ID overlaps with another content ID (step S33: YES), the control unit 114 moves the process to step S34. On the other hand, when it is determined that the content ID does not overlap with other content IDs (step S33: NO), the control unit 114 moves the process to step S35.

  In step S35, the control unit 114 executes content ID confirmation processing. Although details will be described later with reference to FIG. 13, the control unit 114 determines whether or not the root node devices are duplicated when the temporarily determined content ID is assigned. Then, the control unit 114 determines whether or not the return value is True (step S36). When it is determined that the root node devices overlap (step S36: NO), the control unit 114 moves the process to step S34. On the other hand, if it is determined that the root node devices do not overlap (step S35: YES), the control unit 114 determines the temporarily determined content ID and ends this subroutine.

  On the other hand, in step S34, the control unit 114 changes the salt and moves the process to step S32 again. In this processing, the control unit 114 changes the title information corresponding to the divided content data by changing the salt information corresponding to the temporarily determined divided content data, and determines the content ID so that the root node device does not overlap. Will be allowed to. That is, the control unit 114 (partitioned content identification information provisional determination unit, additional information change unit) that executes such processing determines that the difference in content ID corresponding to the divided content data is less than a predetermined value (including the same). In such a case, the salt information (second additional information) is changed. In this way, the divided content identification information is temporarily determined from the first additional information corresponding to the content data and the second additional information corresponding to each of the plurality of divided content data, and as a result, the divided content identification information is determined. If it is determined that the divided content identification information is not appropriate, for example, the difference between the two is less than a predetermined value, the second additional information is changed, and the first additional information is changed again. Since the divided content identification information is tentatively determined from the additional information, there is no possibility that the divided content identification information is the same, and access concentration to the node device to be managed of the divided content data, and node identification of the node device Concentration of access to a node device that is relatively close to information can be reduced.

(About split content ID confirmation processing)
Next, the divided content ID determination processing in step S35 will be specifically described with reference to FIG.

  First, as shown in FIG. 13, the control unit 114 obtains a root node device having a designated content ID (step S41). In this process, the control unit 114 reads the content ID temporarily determined corresponding to the divided content data in step S32, and searches for the root node device when the content ID is attached. Then, the control unit 114 determines whether or not there is a root node device stored in the root node list indicating the root node device when the content ID is attached, that is, the root node list stored in the second storage unit 104. It is determined whether or not is empty (step S42). When it is determined that the root node list is empty (step S42: YES), the control unit 114 moves the process to step S45. On the other hand, when it is determined that the root node list is not empty (step S42: NO), the control unit 114 sets “0” to I positioned in a predetermined area in the first storage unit 103 (step S43). ), The process proceeds to step S44.

  In step S44, the control means 114 determines whether I is smaller than the number registered in the root node list. The control unit 114 compares the I positioned in the predetermined area in the first storage unit 103 with the number of root node devices registered in the root node list corresponding to the divided content data divided from the same content data. By doing so, it is determined whether I is smaller than the number registered in the root node list. When it is determined that I is smaller than the number registered in the root node list (step S44: YES), the control unit 114 moves the process to step S46. On the other hand, when it is determined that I is equal to or greater than the number registered in the root node list (step S44: NO), the control unit 114 moves the process to step S45.

  In step S46, the control means 114 determines whether or not the I-th root node device is the same as the current root node device. In this process, the control means 114 determines whether or not the I-th root node device is the same as the root node device corresponding to the content ID searched in step S41 and determined this time. That is, the control unit 114 (divided content identification information determination unit) determines the duplication of the root node device (content management node device) of the content ID (divided content identification information) assigned to each of the plurality of divided content data. Will be. When it is determined that the I-th root node device is the same as the current root node device (step S45: YES), the control unit 114 sets the return value to False and ends the present subroutine. As a result, in step S32 described above, the content ID is temporarily determined again. On the other hand, when it is determined that the I-th root node device is not the same as the current root node device (step S44: NO), the control unit 114 is positioned in a predetermined area in the first storage unit 103. The value of I is incremented by “1” (step S47), and the process again proceeds to step S44. As described above, the control unit 114 executes steps S44 to S47 by a certain number registered in the root node list.

  In step S45, the control means 114 adds to the root node list, sets the return value to True, and ends this subroutine. As a result, the content ID temporarily determined in step S32 described above is determined. In other words, the control unit 114 (divided content identification information allocating unit) is required when the root node device (content management node device) of the content ID (divided content identification information) allocated to each of the plurality of divided content data does not overlap. The content ID (divided content identification information) to be determined is determined. In other words, when the control unit 114 assigns a content ID (divided content identification information) to each of the plurality of divided content data, the route of the divided content identification information assigned to each of the plurality of divided content data. The content ID (divided content identification information) is determined so that the node devices (content management node devices) are different.

  Therefore, since the divided content identification information is determined so that the content management node devices that manage the content data are different from each other, access concentration to the content management node device and relative to the node identification information of the content management node device Access concentration to nearby node devices can be reduced. In addition, by determining whether the content management node devices are duplicated, the content management node devices are surely different from each other to determine the divided content identification information. Concentration of access to a node device that is relatively close to the node identification information of the management node device can be prevented.

[5. Description of processing of node device 1]
Hereinafter, the detailed operation of the node device 1 will be described more specifically with reference to the flowcharts of FIGS. 14 and 15. FIG. 14 is a flowchart showing a main process for determining a node ID when the node apparatus 1 participates in the system, and FIG. 15 is a flowchart showing a node ID determination process called in the main process.

  Note that the control unit 213 executes the main process when a process to participate in the system is selected by an operation of the user of the node device 1 or the like. Specifically, the control unit 213 determines that the main process has been selected to participate in the content distribution system S by operating an input unit such as the remote controller 206. Description of other processes is omitted.

  First, as shown in FIG. 14, the control means 213 executes a node ID determination process (step S61). Although details will be described later with reference to FIG. 15, the control unit 213 determines a unique node ID for the node device 1. Then, the control unit 213 stores the determined node ID in the nonvolatile memory of the node device 1 (step S62). When this process ends, the main process ends.

(About node ID determination processing)
Next, the node ID determination process in step S61 will be specifically described with reference to FIG.

  First, as shown in FIG. 15, the control means 213 acquires a value specific to the terminal (step S66). In this process, the control unit 213 acquires a unique value (for example, an IP address or a manufacturing number) of the node device 1. Then, the control means 213 determines the node ID from the unique value acquired in step S66 (step S67). In this processing, the control unit 213 determines a node ID by hashing a unique value for each node device 1 such as the IP address or manufacturing number of each node device 1 with a common hash function (hash algorithm). Then, the control unit 213 determines whether or not the node ID overlaps with another node ID (step S68). When it is determined that the node ID overlaps with another node ID, the control unit 213 changes the unique value (step S69) and moves the process to step S67 again. On the other hand, if the control means 213 determines that the node ID does not overlap with other node IDs, the determined node ID is determined and this subroutine is terminated. As a result, the control means 213 determines a unique node ID for each node device 1.

(Other embodiments)
In the above-described embodiment, it is determined whether or not the root node device based on the content ID corresponding to each of the plurality of pieces of divided content data is duplicated. It may be determined whether or not the difference between the content IDs corresponding to each of them is a predetermined value or more.

  Specific embodiments will be described below. Here, configurations and the like different from the above-described embodiment will be described below, and descriptions of other configurations and the like will be omitted.

(About split content ID confirmation processing)
The divided content ID confirmation processing in step S35 will be specifically described with reference to FIG. FIG. 16 is a flowchart showing a divided content ID confirmation process called in the divided content ID determination process.

  First, the control means 114 determines whether or not a content ID is stored in the content ID list in which the content ID temporarily determined this time is registered in the content ID list corresponding to each of the divided content data, that is, in the second storage. It is determined whether or not the content ID list stored in the unit 104 is empty (step S51). When it is determined that the content ID list is empty (step S51: YES), the control unit 114 moves the process to step S54. On the other hand, when it is determined that the content ID list is not empty (step S51: NO), the control unit 114 sets “0” to I positioned in a predetermined area in the first storage unit 103 (step S52). ), The process proceeds to step S53.

  In step S53, the control means 114 determines whether I is smaller than the number registered in the content ID list. The control unit 114 compares I positioned in a predetermined area in the first storage unit 103 with the number of content IDs registered in the content ID list corresponding to the divided content data divided from the same content data. Thus, it is determined whether I is smaller than the number registered in the content ID list. When it is determined that I is smaller than the number registered in the content ID list (step S53: YES), the control unit 114 moves the process to step S55. On the other hand, when it is determined that I is equal to or greater than the number registered in the content ID list (step S53: NO), the control unit 114 moves the process to step S54.

  In step S55, the control unit 114 determines whether or not there is a certain difference between the I-th content ID and the current content ID. In this process, the control unit 114 refers to the I-th content ID and the content ID determined in step S32 in the above-described embodiment, and determines whether or not the difference between them is greater than or equal to a certain value. It becomes. That is, the control unit 114 (divided content identification information determination unit) determines whether or not the difference between the content IDs (divided content identification information) assigned to each of the plurality of divided content data is greater than or equal to a predetermined value. It will be. When it is determined that the I-th content ID and the current content ID have a certain difference or more (step S55: YES), the control unit 114 is positioned in a predetermined area in the first storage unit 103. The value of I is incremented by “1” (step S56), and the process proceeds to step S53 again. As described above, the control unit 114 executes steps S53 to S56 by a certain number registered in the content ID list. On the other hand, if the control means 114 determines that the difference between the I-th content ID and the current content ID does not exceed a certain value (step S55: NO), the return value is set to False and the present subroutine is terminated. To do. As a result, in step S32 described above, the content ID is temporarily determined again.

  In step S54, the control unit 114 adds the content ID corresponding to the divided content data to the content ID list, sets the return value to True, and ends the present subroutine. As a result, the content ID temporarily determined in step S32 described above is determined. That is, the control unit 114 (divided content identification information allocating unit) determines that the difference between content IDs (divided content identification information) allocated to each of the plurality of divided content data is equal to or greater than a predetermined value. The content ID is assigned. In other words, when the control unit 114 assigns a content ID (divided content identification information) to each of the plurality of divided content data, the route of the divided content identification information assigned to each of the plurality of divided content data. The content ID (divided content identification information) is determined so that the node devices (content management node devices) are different.

  Therefore, since the divided content identification information is determined so that the content management node devices that manage the content data are different from each other, access concentration to the content management node device and relative to the node identification information of the content management node device Access concentration to nearby node devices can be reduced. In addition, since it is determined whether or not the difference between the divided content identification information is equal to or greater than a predetermined value, and the difference between the divided content identification information is equal to or greater than the predetermined value, access to the node device that is the management target of the divided content data Concentration and concentration of access to a node device relatively close to the node identification information of the node device can be reduced.

  In the above-described embodiment, the content ID corresponding to each of the plurality of pieces of divided content data is determined based on the additional information such as the title information corresponding to the divided content data. A content ID corresponding to each of the plurality of divided content data may be determined based on a part of the data extracted from the data.

  Specific embodiments will be described below. Here, configurations and the like different from the above-described embodiment will be described below, and descriptions of other configurations and the like will be omitted.

(About split content ID determination processing)
The divided content ID determination process in step S35 will be specifically described with reference to FIG. FIG. 17 is a flowchart showing the divided content ID determination process called in the main process.

  First, as shown in FIG. 17, the control unit 114 acquires several bytes of the history book of divided content (step S37). In this process, the control unit 114 calculates the first few bytes of the divided content data corresponding to the value set in the NUM positioned in the predetermined area in the first storage unit 103 among the divided content data divided into a plurality of pieces. Extract and get. That is, the control unit 114 (divided content data extracting unit) extracts data based on a predetermined extraction condition such as the first few bytes from a plurality of divided content data.

  And the control means 114 calculates | requires content ID from a hash function based on the data of the first several bytes extracted from division | segmentation content data (step S32). That is, the control unit 114 (provisional content identification information provisional determination unit) determines each of a plurality of pieces of divided content data from among the regions (allocation identification information regions) to which content IDs can be added from the data extracted from the divided content data. The content ID (divided content identification information) targeted for is determined temporarily. In this way, for each of the plurality of pieces of divided content data, data based on a predetermined extraction condition is extracted from the plurality of pieces of divided content data, and the pieces of divided content identification information are provisionally determined. Therefore, the pieces of divided content identification information can be the same. Therefore, it is possible to reduce concentration of access to a node device that is a management target of divided content data and concentration of access to a node device that is relatively close to the node identification information of the node device. As will be described in detail later, if it is determined that the content ID that has been determined is not an appropriate ID, the control unit 114 changes the condition for extracting this data, and again executes step S32. Will be executed. That is, the control unit 114 (partitioned content identification information provisional determination unit) temporarily determines the content ID (partitioned content identification information) corresponding to the divided content data again from the extracted data.

  And the control means 114 determines whether content ID overlaps with other content ID (step S33). If the control unit 114 determines that the content ID overlaps with another content ID (step S33: YES), the control unit 114 moves the process to step S38. On the other hand, when it is determined that the content ID does not overlap with other content IDs (step S33: NO), the control unit 114 moves the process to step S35.

  In step S35, the control unit 114 executes the content ID confirmation process as described above in detail with reference to FIG. Then, the control unit 114 determines whether or not the return value is True (step S36). If it is determined that the root node devices overlap (step S36: NO), the control unit 114 moves the process to step S38. On the other hand, if it is determined that the root node devices do not overlap (step S35: YES), the control unit 114 determines the temporarily determined content ID and ends this subroutine.

  On the other hand, in step S38, the control unit 114 changes the extraction condition, acquires data again, and moves the process to step S32 again. In this process, the control unit 114 changes the extraction condition for extracting from the divided content data. Specifically, the control unit 114 extracts the first few bytes of the divided content data, but extracts several bytes after the first several bytes from the beginning of the divided content data, or extracts the first few bytes of the divided content data. Dozens of bytes may be extracted. In other words, the control unit 114 changes the extraction position and the extraction size extracted from the divided content data. That is, the control unit 114 (extraction condition changing unit) that executes such processing determines that the root node device (content management node device) corresponding to the content ID (divided content identification information) is duplicated, or the content When it is determined that the ID difference is less than a predetermined value, the predetermined extraction condition for extracting data is changed. And the control means 114 extracts a part of data again from division | segmentation content data based on the extraction conditions changed in this way. In other words, the control unit 114 (divided content data extracting unit) that executes such processing again extracts data based on the changed predetermined extraction condition from the plurality of divided content data. As described above, for each of the plurality of divided content data, data based on a predetermined extraction condition is extracted from the plurality of divided content data, and the divided content identification information is provisionally determined. As a result, the divided content identification information corresponds to the divided content identification information. When it is determined that the content management node devices overlap, or when it is determined that the difference between the divided content identification information is less than a predetermined value, the predetermined extraction condition is changed and the changed predetermined extraction condition is set. Based on this, the divided content identification information is not the same, and the concentration of access to the node device that is the management target of the divided content data is reduced. Concentration of access to node devices that are relatively close to the node identification information can be reduced.

  In the embodiment described above, when assigning a content ID to each of a plurality of divided content data, the root node device corresponding to the content ID targeted for the divided content data is duplicated or the divided content data is targeted. The content ID is determined so that the root node device assigned to each of the plurality of divided content data is different depending on whether the difference between the content IDs is equal to or greater than a predetermined value. Based on the number of divisions of the plurality of divided content data, the ratio identification information area arranged so as to be assignable as a node ID and content ID is divided into the number of divisions, and determined as a plurality of division allocation identification information areas. Multiple divided content data for each divided allocation identification information area By assigning a content ID of interest, respectively, the root node apparatus which is assigned a respective as the target of the plurality of divided content data may determine the content ID as different.

  Specific embodiments will be described below. Here, configurations and the like different from the above-described embodiment will be described below, and descriptions of other configurations and the like will be omitted.

(About split content ID determination processing)
The divided content ID determination process in step S14 will be specifically described with reference to FIG. FIG. 18 is a flowchart showing the divided content ID determination process called in the main process.

  First, as shown in FIG. 18, the control means 114 determines whether or not NUM is “0” (step S21). In this process, the control unit 114 reads the value of the NUM positioned in the predetermined area in the first storage unit 103 and determines whether or not the NUM is “0”. When it is determined that the NUM is “0” (step S21: YES), the control unit 114 divides the content ID space by the content division number (step S22), and moves the process to step S23. In this process, the control means 114 determines the number of divisions of the divided content data determined in step S11. That is, the control unit 114 (number of division determination unit) determines the number of divisions of the plurality of pieces of divided content data to which content IDs targeted for each of the plurality of pieces of divided content data are assigned. Then, the control unit 114 divides the ID space by the number of divisions and stores the divided ID space in a predetermined area in the first storage unit 103. In this way, the control unit 114 (divided allocation identification information area determining unit) divides the ID area (ratio identification information area) into the number of divisions based on the number of divisions of the plurality of divided content data, and thereby creates a plurality of division IDs It is determined as an area (division allocation identification information area). On the other hand, when it is determined that the NUM is not “0” (step S21: NO), the control unit 114 moves the process to step S23 without executing step S22.

  In step S23, the control unit 114 determines whether or not there is an ID space in the NUM-th area. In this process, the control unit 114 determines whether or not there is a space for setting the content ID in the NUM-th divided ID space (area). If the control means 114 determines that there is a free ID in the NUM-th area (step S23: YES), it moves the process to step S24. When it is determined that there is no ID space in the NUM-th area (step S23: NO), the control unit 114 moves the process to step S26.

  In step S24, the control means 114 determines a content ID at random within the NUM-th divided area. In other words, the control unit 114 (divided content identification information determination unit) determines the divided content from the determined divided ID space (any one of the plurality of divided allocation identification information areas) in the ID space (any of the assigned identification information areas). A content ID (divided content identification information) targeted for any of the data is temporarily determined. Then, the control unit 114 determines whether the content ID targeted for any of the divided content data temporarily determined in step S24 overlaps with the content ID targeted for other content data (including the divided content data). Is determined (step S25). When it is determined that the content ID overlaps with another content ID (step S25: YES), the control unit 114 moves the process to step S24 again. As a result, the control unit 114 (divided content identification information determination unit) determines the duplication of the content IDs assigned to each of the plurality of divided content data. Then, the content ID is determined again, and the content ID that does not overlap is determined. On the other hand, if the control unit 114 determines that the content ID does not overlap with other content IDs (step S25: NO), the temporarily determined content ID is determined, and this subroutine is terminated.

  On the other hand, in step S26, the control unit 114 randomly determines a content ID from the entire ID space. That is, the control unit 114 (partitioned content identification information provisional determination unit) provisionally determines a content ID (partitioned content identification information) targeted for any one of the divided content data from the ID space (assignment identification information area). It will be. Then, the control unit 114 determines whether the content ID targeted for any of the divided content data temporarily determined in step S26 overlaps with the content ID targeted for other content data (including the divided content data). Is determined (step S27). When it is determined that the content ID overlaps with another content ID (step S27: YES), the control unit 114 moves the process to step S26 again. As a result, the control unit 114 (divided content identification information determination unit) determines the duplication of the content IDs assigned to each of the plurality of divided content data. Then, the content ID is determined again, and a content ID that does not overlap is determined. On the other hand, if the control unit 114 determines that the content ID does not overlap with other content IDs (step S27: NO), the temporarily determined content ID is determined, and this subroutine is terminated.

  As described above, the control unit 114 (divided content identification information allocating unit) performs the content ID (divided content identification information) targeted for the divided content data for each of the determined plurality of divided ID spaces (divided allocation identification information area). Will be assigned. Accordingly, the ratio identification information area is divided into the number of divisions of the plurality of divided content identification information, and the divided content identification information is allocated to each of the divided division allocation identification information areas. The concentration of access to the node device that is the management target of the divided content data and the concentration of access to the node device that is relatively close to the node identification information of the node device can be reduced. .

  In the above-described embodiment, the node device 1 determines the node ID. However, the present invention is not limited to this, and for example, a system including a device such as a node ID determination server that determines the node ID may be used. . Of course, the content data management apparatus 10 in the above-described embodiment may determine the node ID.

  Specific embodiments will be described below. Here, configurations and the like different from the above-described embodiment will be described below, and descriptions of other configurations and the like will be omitted.

(Main processing for determining node ID in node device)
First, as shown in FIG. 19, the control means 213 determines whether or not a node ID is stored (step S71). The control unit 213 determines whether or not the node ID is stored depending on whether or not the node ID is already stored in the nonvolatile memory or the like of the node device 1. When it is determined that the node ID is stored, the control unit 213 moves the process to step S74 without executing steps S72 and S73 described later. On the other hand, when it is determined that the node ID is not stored, the control unit 213 moves the process to step S72.

  In step S72, the control means 213 transmits a node ID acquisition request message to a node ID determination server (not shown). The node ID acquisition request message includes a unique value (for example, IP address or manufacturing number) of the node device 1. And the control means 213 receives node ID from a node ID determination server (step S73). If this process ends, the process moves to a step S74.

  In step S74, the control means 213 executes a system participation process. Thereby, the node device 1 participates in the content distribution system S with the node ID received from the node ID determination server in step S73. When this process ends, the main process ends.

(Regarding the main process of the node ID determination server)
First, the control means (not shown) of the node ID determination server determines whether or not the power is off as shown in FIG. 20 (step S81). In this process, if the control means determines that the power is off, the main process ends. On the other hand, when it is determined that the power is not turned off, the control unit moves the process to step S82.

  In step S <b> 82, the control unit determines whether a node ID acquisition request message has been received from the node device 1. In this process, when it is determined that the node ID acquisition request message has been received from the node device 1, the control means executes a node ID determination process (step S84), and the node device 1 that has been requested for the determined node ID. (Step S85). In the node ID determination process, the control unit of the node ID determination server executes a process as shown in FIG. On the other hand, when it is determined that the node ID acquisition request message has not been received from the node device 1, the control means executes other processing (step S83) and moves the processing to step S82 again. In this way, the node ID determination server determines that the node IDs of the node devices 1 do not overlap.

  In the above-described embodiment, in order to recognize the node ID of the content holding node device that holds the content data, an inquiry about search information or the like is made to the root node device of the content data. The content data management apparatus 10 may store the node ID of the content holding node apparatus in advance, and the node apparatus 1 may inquire the content data management apparatus 10 about search information and the like.

  As described above, some of the embodiments of the present invention have been described in detail with reference to the drawings. However, these are merely examples, and the knowledge of those skilled in the art including the aspects described in the above [Disclosure of the Invention] section. It is possible to implement the present invention in other forms in which various modifications and improvements are made based on the above.

It is a figure which shows an example of the connection aspect of each node apparatus in the content delivery system which concerns on this embodiment. It is explanatory drawing of ID space. It is a figure which shows an example of a mode that a routing table is produced by DHT. It is an example of the routing table of the node apparatus which concerns on this embodiment. It is a figure which shows an example of a mode that the node apparatus 1 which is the holding | maintenance source of content data is searched by DHT. It is the figure which represented a mode that the registration message of a content holding node was transferred in the spanning tree shape. It is an example of the index table of the node apparatus which concerns on this embodiment. It is a figure which shows the determination method of content ID. It is a figure which shows the example of schematic structure of the content data management apparatus in this embodiment. It is a figure which shows the example of schematic structure of the node apparatus in this embodiment. It is a flowchart which shows the process performed in a content data management apparatus. It is a flowchart which shows the process performed in a content data management apparatus. It is a flowchart which shows the process performed in a content data management apparatus. It is a flowchart which shows the process performed in a node apparatus. It is a flowchart which shows the process performed in a node apparatus. It is a flowchart which shows the process performed in a content data management apparatus. It is a flowchart which shows the process performed in a content data management apparatus. It is a flowchart which shows the process performed in a content data management apparatus. It is a flowchart which shows the process performed in a node apparatus. It is a flowchart which shows the process performed in a node ID determination server.

Explanation of symbols

S Content Distribution System 1 Node Device 10 Content Data Management Device 114, 213 Control Unit

Claims (12)

By transmitting / receiving content data held by each node device to / from each other among a plurality of node devices connected via a network, the content data can be distributed to the node device. Content identification information for identifying content data is attached, and each node device is assigned with node identification information for identifying the node device, and assigned with node identification information having a small difference from the content identification information. In an identification information assigning device that assigns content data identification information to the content data in a content distribution system that is a content management node device that manages content data.
A plurality of pieces of content data divided into a plurality of pieces of assignment identification information areas in which a plurality of pieces of assignment identification information that can be assigned as node identification information and content identification information are arranged according to a predetermined rule. When the divided content identification information is assigned to each of the divided content data, the divided content identification information is set so that the content management node devices of the divided content identification information assigned to each of the plurality of divided content data are different. An identification information allocating device comprising divided content identification information allocating means for determining A divided content identification information judging unit for judging the duplication of the content management node device of the divided content identification information assigned to each of the plurality of divided content data;
2. The identification according to claim 1, wherein the divided content identification information allocating unit has a function of determining divided content identification information determined by the divided content identification information determining unit that content management node devices are not duplicated. Information allocation device.   The node device transmits search information based on the divided content identification information assigned by the divided content identification information assigning unit, and the divided content corresponding to the divided content identification information is transmitted from the content management node device of the divided content identification information. The identification information allocating device according to claim 2, further comprising a function of receiving node identification information of a node device in which data is stored. Divided content identification information provisionally determining means for temporarily determining the divided content identification information from the allocation identification information area;
Divided content identification information determination means for determining whether or not a difference between the divided content identification information determined by the divided content identification information provisional determination means is a predetermined value or more,
The divided content identification information provisional determination unit temporarily determines the divided content identification information again when the divided content identification information determination unit determines that the difference between the divided content identification information is less than a predetermined value. Have
The divided content identification information allocating unit has a function of allocating the divided content identification information when the divided content identification information determining unit determines that the difference between the divided content identification information is a predetermined value or more. The identification information allocating device according to claim 1. A divided content data extracting means for extracting data based on a predetermined extraction condition from the plurality of divided content data;
The divided content identification information provisional determination unit has a function of temporarily determining divided content identification information for each of the plurality of divided content data from the data extracted by the divided content data extraction unit. The identification information allocating device according to claim 4. The divided content identification information provisional determination means extracts data by the divided content data extraction means when the divided content identification information determination means determines that the difference between the divided content identification information is less than a predetermined value. An extraction condition changing means for changing a predetermined extraction condition;
The divided content data extracting unit has a function of extracting again data based on a predetermined extraction condition changed by the extraction condition changing unit from the plurality of divided content data,
6. The identification according to claim 5, wherein the divided content identification information provisional determination unit has a function of temporarily determining the divided content identification information again from the data extracted again by the divided content data extraction unit. Information allocation device. The plurality of divided content data includes additional information corresponding to the divided content data,
5. The identification information allocation apparatus according to claim 4, wherein the divided content identification information provisional determination unit has a function of temporarily determining divided content identification information from the additional information. In the plurality of divided content data, as the additional information, first additional information corresponding to content data including the plurality of divided content data, and second additional information corresponding to the plurality of divided content data, , And
8. The identification information assigning apparatus according to claim 7, wherein the divided content identification information provisional determination means has a function of temporarily determining divided content identification information from the first additional information and the second additional information. . The divided content identification information provisional deciding means changes the additional information changing means for changing the second additional information when the divided content identification information judging means judges that the difference of the divided content identification information is less than a predetermined value. With
The divided content identification information provisional determination means has a function of temporarily determining the divided content identification information again from the first additional information and the second additional information changed by the additional information changing means. The identification information assigning apparatus according to claim 8, wherein: Division number determination means for determining the number of divisions of a plurality of pieces of divided content data to which the divided content identification information is assigned;
Based on the number of divisions of the plurality of pieces of divided content data determined by the division number determination unit, the division identification information area is determined by dividing the ratio identification information area into the number of divisions and determining the plurality of division allocation identification information areas. Means, and
2. The divided content identification information allocating unit has a function of allocating the divided content identification information for each of a plurality of divided allocation identification information areas determined by the divided allocation identification information area determining unit. 4. The identification information allocation device according to any one of 3. By transmitting / receiving content data held by each node device to / from each other among a plurality of node devices connected via a network, the content data can be distributed to the node device. Content identification information for identifying content data is attached, and each node device is assigned with node identification information for identifying the node device, and assigned with node identification information having a small difference from the content identification information. In an information processing method of an identification information assigning device that assigns content data identification information to the content data in a content distribution system that is a content management node device that manages content data.
The identification information assigning device
A plurality of pieces of content data divided into a plurality of pieces of assignment identification information areas in which a plurality of pieces of assignment identification information that can be assigned as node identification information and content identification information are arranged according to a predetermined rule. When the divided content identification information is assigned to each of the divided content data, the divided content identification information is set so that the content management nodes of the divided content identification information assigned to each of the plurality of divided content data are different. An information processing method for an identification information allocating apparatus in a content distribution system, comprising a divided content identification information allocating step for determining.   A program for causing a computer to function as each unit of the identification information assigning device according to any one of claims 1 to 10.

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