JP2013048336A - Information processor, content deletion method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information processing method, a content deletion method and a program which can automatically delete an unnecessary content from storage means, and with which a user reserving viewing does not need to wait for time when an edge server caches the content again and the user can smoothly view the content.SOLUTION: It is determined whether a content corresponding to content ID which is not included in a lecture schedule is stored or not in a storage section of a broadband router BR1. Content ID different from the content ID which the lecture schedule includes is determined in the content which the broadband router BR1 stores. The determined content ID is determined as a deletion candidate content. The determined deletion candidate content is deleted from the content which the broadband router BR1 stores.

Description

  The present invention relates to a technique for distributing and storing content in a plurality of node devices via a network. Specifically, the present invention relates to a technique for automatically deleting content stored in a distributed manner.

  Conventionally, a technique is known in which each user makes a viewing reservation in advance and acquires content. For example, Patent Document 1 discloses a technique in which content that has been reserved for viewing in advance is distributed to the edge servers at each site and cached in the edge server before viewing.

JP 2011-70557 A

  In the peer-to-peer type distribution device described in Patent Document 1, the content is deleted from the edge server in order from the content that has passed the time since the cache by the LRU (Last Recently Used) method. In the case of this method, the content whose cache time has elapsed in the edge server is deleted from the edge server even though the content is reserved for viewing. For this reason, the user who has reserved viewing needs to wait for the edge server to cache the content again, and the content cannot be viewed smoothly.

  The present invention has been made in view of the above. An object of the present invention is that unnecessary contents can be automatically deleted from the storage means, and a user who has made a viewing reservation does not need to wait for the edge server to cache the contents again, and can smoothly view the contents. An information processing method, a content deletion method, and a program are provided.

  According to the first aspect of the present invention, there is provided the information processing apparatus in an information communication system in which a plurality of contents are transmitted and received by an overlay network composed of a plurality of information processing apparatuses, which is obtained via the overlay network. A viewing schedule including content identification information for identifying the content and time information indicating the time at which the content is viewed is obtained from storage means for storing the content to be stored and a plurality of client devices that acquire the content from the information processing device. Acquiring means, determining means for determining the content identification information not included in the viewing schedule acquired by the acquiring means as a candidate for content to be deleted from the storage means, and the viewing schedule acquired by the acquiring means Content identification information contained in Determining means for determining whether or not the content indicated by the information processing apparatus can be stored in the storage means of the information processing apparatus every predetermined period, and the candidate determined by the determining means if the determination means does not determine that the content can be stored An information processing apparatus comprising: deletion means for deleting content from the information processing apparatus.

  According to the second aspect of the present invention, the determination unit preferentially deletes content not taken during a predetermined period from the current date and time based on the time information included in the viewing schedule. It is characterized by determining.

  According to a third aspect of the present invention, the determining means determines, as the predetermined period, content candidates to be deleted preferentially from content that is not attended from the current date and time until the next day.

  According to the fourth aspect of the present invention, the determination unit preferentially deletes the content of the time information that is a viewing time far from the current date and time based on the time information included in the viewing schedule. It is determined as a candidate.

  According to the fifth aspect of the present invention, there is provided an information communication system in which a plurality of contents are transmitted / received through an overlay network composed of a plurality of information processing apparatuses, and the contents acquired via the overlay network are stored. A content deletion method of the information processing apparatus including a storage unit, wherein content identification information for identifying content from a plurality of client apparatuses that acquire content from the information processing apparatus, and time information indicating a time when the content is viewed An acquisition step that includes a viewing schedule including: a determination step that determines the content identification information that does not include the viewing schedule acquired in the acquisition step as a candidate for content to be deleted from the storage unit; and the acquisition step Obtained by A determination step for determining whether or not the content indicated by the content identification information included in the viewing schedule can be stored in the storage means of the information processing apparatus for each predetermined period, and when the determination step does not determine that the content can be stored, A content deletion method comprising: a deletion step of deleting content from candidates determined in the determination step.

  According to the sixth aspect of the present invention, there is provided an information communication system in which a plurality of contents are transmitted and received through an overlay network composed of a plurality of information processing apparatuses, and the contents acquired via the overlay network are stored. Viewing including content identification information for identifying content and time information indicating the time at which the content is viewed from a plurality of client devices that acquire the content from the information processing device in a computer of the information processing device including a storage unit An acquisition step for acquiring a schedule, a determination step for determining the content identification information not included in the viewing schedule acquired in the acquisition step as a candidate for content to be deleted from the storage means, and an acquisition step acquired The viewing schedule A determination step for determining whether or not the content indicated by the content identification information included in the rule can be stored in the storage unit of the information processing apparatus for each predetermined period, and when the determination step does not determine that the content can be stored, the determination A deletion step of deleting content from candidates determined in steps is executed.

  According to the first aspect of the present invention, the determination unit determines the content identification information that does not include the viewing schedule acquired by the acquisition unit as a content candidate to be deleted from the storage unit. The deletion unit deletes the content from the candidates determined by the determination unit when the determination unit does not determine that the data can be stored. As a result, unnecessary content can be automatically deleted from the storage means, and the user who has reserved viewing does not need to wait for the information processing apparatus as the edge server to cache the content again, and can smoothly view the content. it can.

  According to the second aspect of the present invention, the determination unit determines, based on the time information included in the viewing schedule, content candidates to be deleted preferentially from content that is not attended during a predetermined period from the current date and time. As a result, the information processing device is deleted preferentially from the content that is not attended during a predetermined period, so that the user who reserved viewing does not have to wait for the information processing device as an edge server to cache the content again, The content can be viewed smoothly.

  According to the third aspect of the present invention, the determining unit determines, as a predetermined period, content candidates to be deleted preferentially for content that is not attended from the current date and time to the next day. As a result, since the information processing apparatus preferentially deletes content that is not attended from the current date and time to the next day, the user who has reserved viewing needs to wait for the information processing device as an edge server to cache the content again. Content can be viewed smoothly.

  According to the fourth aspect of the present invention, the determining unit determines, based on the time information included in the viewing schedule, the content of time information that is a viewing time far from the current date and time as a content candidate to be deleted with priority. . As a result, based on the time information included in the viewing schedule, the information processing device preferentially deletes the content of the time information that is the viewing time far from the current date and time, so that the user who reserved viewing is processed as an edge server. There is no need to wait for the device to cache the content again, and the content can be viewed smoothly.

  According to the fifth aspect of the present invention, the determination step determines content identification information that does not include the viewing schedule acquired in the acquisition step as a content candidate to be deleted from the storage unit. The deletion step deletes the content from the candidates determined by the determination step when it is not determined that the data can be stored by the determination step. As a result, unnecessary content can be automatically deleted from the storage means, and the user who has reserved viewing does not need to wait for the information processing apparatus as the edge server to cache the content again, and can smoothly view the content. it can.

  According to the sixth aspect of the present invention, the determination step determines content identification information that does not include the viewing schedule acquired in the acquisition step as a content candidate to be deleted from the storage unit. The deletion step deletes the content from the candidates determined by the determination step when it is not determined that the data can be stored by the determination step. As a result, unnecessary content can be automatically deleted from the storage means, and the user who has reserved viewing does not need to wait for the information processing apparatus as the edge server to cache the content again, and can smoothly view the content. it can.

It is a schematic block diagram of the information communication system S of this embodiment. It is explanatory drawing explaining the content deletion method of this embodiment. It is a conceptual diagram which shows the memory | storage state by which the attendance schedule of this embodiment is memorize | stored in terminal device Tm-n or broadband router BR. It is a block diagram which shows the electric constitution of the broadband router BR of this embodiment. It is a flowchart which shows the process sequence of the main operation | movement in the broadband router BR of this embodiment. It is a flowchart which shows the process sequence of the deletion candidate content determination process of this embodiment. It is a flowchart which shows the process sequence of the modification 1 of the deletion candidate content determination process of this embodiment. It is a flowchart which shows the process sequence of the modification 2 of the deletion candidate content determination process of this embodiment.

[Best Embodiment]
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 peer-to-peer information communication system.

[Outline configuration of information communication system S]
First, the schematic configuration of the information communication system S in the present embodiment will be described with reference to FIG. FIG. 1 is a diagram illustrating an example of a connection mode between the broadband router BR and each terminal device in the information communication system S according to the present embodiment. As shown in FIG. 1, the information communication system S includes a plurality of broadband routers BR (BR1, BR2, BR3) and terminal devices Tm-n (m = 1, 2, 3,..., N = 1. , 2, 3... The terminal devices Tm-n can communicate with each other via the network NW. This network NW is a real-world communication network. For example, the Internet.

The network NW is a network for interconnecting the base networks NLm. This network NW is, for example, the Internet or WAN (Wide Area Network).
) Etc. The network NW is, for example, IX (Internet Exchange), IS
It is constructed by P (Internet Service Provider), DSL (Digital Subscriber Line) line provider apparatus, FTTH (Fiber To The Home) line provider apparatus, communication line, and the like. The network NW may be a network dedicated to the information communication system S.

  In the present embodiment, one or more base networks NLm are formed in the network NW. In addition, a broadband router BR is connected to each base network NLm. A plurality of terminal devices Tm-n are connected to the broadband router BR at each base. Each base network NLm is a network constructed in the site of the base m. The bases include, for example, a company, a school, a hospital, and a cram school. This base network NLm is constructed by a LAN or the like, for example. Alternatively, the base network NLm may be a network constructed by interconnecting a plurality of LANs. In this case, the plurality of LANs are connected via a network device such as a broadband router BR. An example of a network in which a plurality of LANs are interconnected is CAN (Campus Area Network). A broadband router BR is connected to each base network NLm. A firewall may be connected instead of the broadband router BR. The broadband router BR is a communication device that enables communication between the terminal device Tm-n connected in the base and the terminal device Tm-n other than the terminal device Tm-n connected to the base. Since the firewall or the broadband router BR is publicly known, detailed description thereof is omitted. Whether the broadband router BR or the firewall is installed at the base is arbitrarily determined for each base. The base network NLm of this embodiment is, for example, a LAN (Local Area Network).

  A center server SV is connected to the network NW. The center server SV stores an original of content data transmitted / received via an overlay network OL described later. The center server SV transmits content catalog information to the broadband router BR. Details of the content catalog information will be described later. The center server SV manages a content ID used when content data is input to an overlay network OL described later. Here, the input of the content data means that the terminal device Tm-n is in a state where it can be acquired from the broadband router BR. The content data is referred to as “content”. Details of the center server SV will be described later. In the present embodiment, each base is a cram school, and the terminal device Tm-n acquires content to be attended from the broadband router BR in accordance with a schedule for the user of the terminal device Tm-n to attend the cram school. It explains using.

  Each broadband router BR is assigned a unique serial number and an IP (Internet Protocol) address. Each broadband router BR connected to the information communication system S is assigned a node ID, which is unique identification information having a predetermined number of digits. In the information communication system S of the present embodiment, an overlay network OL for content distribution is constructed. The overlay network OL is an overlay network constructed on the network NW. In other words, the overlay network OL is a logical network generated on a physical network. The overlay network OL is realized by a specific algorithm, for example, an algorithm using a distributed hash table. Hereinafter, the distributed hash table is referred to as “DHT (Distributed Hash Table)”. Note that a routing table using DHT is known in Japanese Patent Application Laid-Open No. 2006-197400. Note that the broadband router BR of the present embodiment is an example of an information processing apparatus of the present invention. Further, the terminal device Tm-n of the present embodiment is an example of the client device of the present invention.

[How to participate in Overlay Network OL]
Hereinafter, a method for joining the overlay network OL will be described. In the following description of the overlay network OL participation method, the broadband router BR is simply referred to as a node device. Each node device holds a routing table using DHT (Distributed Hash Table). This routing table defines the transfer destinations of various control messages on the information communication system S. The control message is a message for controlling the operation of the peer-to-peer information communication system. In other words, the control message is a message for use in content search or content acquisition in a peer-to-peer information communication system. The control message is a message transmitted / received according to the DHT routing table. Specifically, a plurality of pieces of node information including node IDs, IP addresses, and port numbers of node devices that are moderately separated in the ID space are registered in this routing table. One node device connected to the information communication system S stores the minimum necessary node information of the node device as a routing table. By transferring control messages between the node devices, node information about node devices that do not store node information is acquired. Further, the information communication system S can operate as a peer-to-peer type information communication system by transmitting and receiving the control message by each node device.

  In connection with the information communication system S, a node device not connected to the information communication system S transmits a participation message indicating a request to participate in the information communication system S to any connected node device. Is done by. Participation in the information communication system S means that the node device is connected to the information communication system S and content can be acquired from the information communication system S. That is, participating in the overlay network OL means operating in a state where various messages can be transmitted to and received from other nodes via the overlay network OL based on a routing table using DHT. The arbitrary node device is, for example, a contact node that is always connected to the information communication system S. The node device that participates in the information communication system S transmits a participation message to the contact node, so that the node device can acquire the DHT routing table from the contact node.

[Outline of content acquisition operation]
In the information communication system S, various contents having different contents are distributed and stored in a plurality of node devices. Each content is given a content ID, which is unique identification information for each content name and content data, by the center server SV. Attribute information such as content name and content ID of each content is described in the content catalog information. The content catalog information is created by the center server SV and distributed to all node devices. Each content is divided into a plurality of data. This divided data is called “chunk”.

<Content ID assignment processing>
When the content input process is executed by the center server SV, first, the center server SV gives a content ID to the content to be input. The content ID assigned at this time may be randomly generated by the node.

<Chunk division processing>
In the present embodiment, each chunk is generated, for example, by dividing the content with a predetermined data size by the center server SV. In the present embodiment, the minimum data size of a chunk is 2 MB (Mega Byte). The maximum data size of the chunk is 128 MB. However, as a result of division into chunks, some chunks may be smaller than 2 MB. In addition, if the data size before being divided into chunks is originally smaller than 2 MB, the chunk may have a data size of less than 2 MB. In the present embodiment, the content data is divided into a plurality of chunks. However, as described in the present embodiment, the content data may not be divided into a plurality of chunks. Content data that is not divided may be applied to the present embodiment. Each chunk is distributed and stored in a plurality of node devices. As a result, the original content is distributed and stored in a plurality of node devices. The original of each chunk is stored in the center server SV.

<Chunk ID assignment process>
Each chunk is given a sequence number and a chunk ID by the center server SV. The sequence number corresponds to, for example, an arrangement order when a plurality of divided chunks are arranged so as to constitute the original content. The chunk ID is identification information unique to each chunk.

<Chunk hash value generation processing>
When the center server SV is given the chunk ID, it generates a hash value of the chunk. The hash value is generated using a predetermined hash function. The hash value is used to check, for example, chunk tampering.

<Meta information file generation processing>
When the chunk ID and the hash value of the chunk are generated by the center server SV, a meta information file is generated. The meta information file is information for searching for content composed of divided chunks. The meta information file includes a given chunk ID, a sequence number, and a hash value of the chunk. The meta information file is given a content ID of content composed of divided chunks. When each node device acquires a content ID of a certain content, it acquires a meta information file. Specifically, the node device acquires the meta information file based on the content ID assigned to the meta information file. When the node device acquires the meta information file, the node device acquires a chunk ID included in the meta information file. Based on the acquired chunk ID, a chunk of content is acquired. Thereby, the chunk ID of each chunk constituting the content can be acquired in association with the sequence number.

  Note that a node device that stores chunks of this embodiment is referred to as a “content holding node”. The location of the chunk is stored as index information by a node device that manages or stores the location of the chunk. Hereinafter, the node device that manages the location of the chunk is referred to as a “root node”. The index information includes a set of node information of the node device that stores the chunk, a chunk ID of the chunk, and the like. Such a root node is determined to be a node having a node ID closest to the chunk ID, for example. The node ID closest to the chunk ID is, for example, a node ID with the highest number of upper digits of the ID.

  The meta information file generated by the above-described processing is stored in one of the plurality of node devices.

<Detailed description of content acquisition operation>
Details of the content acquisition operation of this embodiment will be described below. When a user of a certain node device wants to acquire desired content, the node device searches for a content holding node that stores each chunk constituting the desired content. Hereinafter, a node device that a user desires to acquire a chunk is referred to as a “user node”. Specifically, the user node transmits a search message. This search message includes the content ID of the content desired to be acquired and the node information of the user node. This search message is transmitted to other node devices according to the DHT routing table stored in the user node. That is, the user node transmits a search message toward the root node. As a result, the search message finally arrives at the root node by DHT routing using the content ID as a key. The DHT routing is known in Japanese Patent Application Laid-Open No. 2006-197400 and the like, and thus detailed description thereof is omitted.

  The root node that receives the search message acquires one or more index information corresponding to the content ID included in the search message from the index information cache. The acquired index information is returned to the user node that is the transmission source of the search message based on the node information of the user node. The user node that has acquired the index information in this way acquires or downloads the meta information file corresponding to the content ID based on the index information. Specifically, the user node transmits a content request message to the content holding node based on the IP address and port number of the content holding node included in the index information. The content request message includes the node information of the user node and the content ID of the desired content. When receiving the content request message, the content holding node transmits or uploads a meta information file corresponding to the content ID included in the content request message to the user node. On the other hand, when there is no content holding node that stores the desired meta information file, the user node cannot acquire the index information of the content holding node. In this case, the user node may acquire the meta information file from the center server SV.

  Alternatively, the root node transmits a content transmission request message to the content holding node indicated by the IP address or the like included in the index information. The content transmission request message includes node information of a transmission source of the content request message. The content holding node that has received the content transmission request starts transmitting or uploading the meta information file to the user node indicated by the node information included in the received message. As a result, the user node can acquire the meta information file from the content holding node.

  Then, when the user node acquires and stores the meta information file from the content holding node, the user node releases the meta information file. Release of the meta information file means notifying the root node that the user node has saved the meta information file as a content holding node. By publishing the meta information file, other node devices can acquire the published meta information file from the published content holding node. Specifically, the user node that stores the meta information file transmits a publish message. The publish message includes the content ID of the meta information file and the node information of the user node storing the meta information file. The publish message is sent toward the root node. As a result, the publish message arrives at the root node by DHT routing using the content ID as a key, like the search message. The root node stores index information including a set of node information and content ID included in the received publish message in the index information cache. In this way, the user node becomes a new content holding node for storing the meta information file.

  When the user node acquires the meta information file, the user node transmits a chunk search message based on the chunk ID included in the acquired meta information file. The chunk search message includes node information of the chunk ID user node. The chunk search message is transmitted to other node devices according to the DHT routing table stored in the user node. That is, the user node transmits a chunk search message toward the root node of the chunk. As a result, the chunk search message finally arrives at the root node of the chunk by DHT routing using the chunk ID as a key. The DHT routing is known in Japanese Patent Application Laid-Open No. 2006-197400 and the like, and thus detailed description thereof is omitted.

  The root node that has received the chunk search message acquires one or a plurality of index information corresponding to the chunk IDs included therein from the index information cache. The acquired index information is returned to the user node that is the transmission source of the chunk search message based on the node information of the user node. The user node that has acquired the index information in this way acquires or downloads a chunk based on the index information. Specifically, the user node transmits a chunk request message to the content holding node based on the IP address and port number of the content holding node included in the index information. The chunk request message includes the node information of the user node and the chunk ID of the chunk that is desired to be acquired. The content holding node that has received the chunk request message transmits or uploads a chunk corresponding to the chunk ID included in the chunk request message to the user node. On the other hand, when there is no content holding node that stores a desired chunk, the user node cannot acquire the index information of the content holding node. In this case, the user node may acquire a chunk from the center server SV.

  Alternatively, the root node transmits a chunk transmission request message to the content holding node indicated by the IP address or the like included in the index information. The chunk transmission request message includes node information of a transmission source of the chunk request message. The content holding node that has received the chunk transmission request starts transmitting or uploading the chunk to the user node indicated by the node information included in the received message. As a result, the user node can acquire a chunk from the content holding node.

  Then, when the user node acquires the chunk from the content holding node and stores it, the user node discloses the chunk. Chunk disclosure refers to notifying a root node that a user node has saved a chunk as a content holding node. By publishing the chunk, other node devices can acquire the published chunk from the published content holding node. Specifically, the user node that stores the chunk transmits a publish message. The publish message includes the chunk ID of the chunk and the node information of the user node storing the chunk. The publish message is sent to the root node of the chunk. As a result, the publish message arrives at the root node by DHT routing using the chunk ID as a key, like the search message. The root node stores index information including a set of node information and chunk ID included in the received publish message in the index information cache. Thus, the user node becomes a new content holding node that stores chunks.

[How to delete content]
Hereinafter, the content deletion method of the present embodiment will be described with reference to FIG. In the present embodiment, the content stored by the broadband router BR is deleted based on the attendance schedule for the terminal device Tm-n to attend. FIG. 2 is an explanatory diagram for explaining the content deletion method of the present embodiment. In the present embodiment, the terminal device Tm-n transmits a content acquisition request to the broadband router BR in accordance with the attendance schedule. When the broadband router BR stores the requested content, the terminal device Tm-n acquires the content from the broadband router BR and reproduces it. On the other hand, when the broadband router BR does not store the requested content, the broadband router BR acquires the requested content from another broadband router via the overlay network OL. Then, the broadband router BR causes the terminal device Tm-n to acquire the content acquired from the overlay network OL.

First, the terminal device Tm-n connected to each base transmits a attendance schedule for the terminal device Tm-n to attend to the broadband router BR connected to the base (FIG. 2: (1)). In the example of FIG. 2, the terminal device T1-1 and the terminal device T1-4 transmit the attendance schedule to the broadband router BR. In the present embodiment, each terminal device Tm-n transmits the attendance schedule to the broadband router BR connected to the base at a predetermined timing. The transmitted attendance schedule may be an attendance schedule within a predetermined period from the current date and time. In addition, all of the attendance schedules that the terminal device Tm-n will attend in the future may be transmitted to the broadband router BR1. Hereinafter, the details of the attendance schedule of the present embodiment will be described with reference to FIG. Note that the attendance schedule of this embodiment is an example of the viewing schedule of the present invention.

  FIG. 3 is a conceptual diagram showing a storage state in which the attendance schedule of the present embodiment is stored in the terminal device Tm-n or the broadband router BR. As shown in FIG. 3, the attendance schedule includes a content ID of attendance content, attendance date information, and a user ID. The content ID included in the attendance schedule is a content ID indicating content that the user of the terminal device Tm-n is scheduled to attend.

  The attendance date / time information is information indicating the date and time when the content indicated by the content ID in FIG. 3 is attended by the terminal device Tm-n. The example of FIG. 3 indicates that the date and time when the content indicated by the content ID “1321” is taken is “14:00 on September 23, 2011”. In the example of FIG. 3, an example is shown in which both the date of attendance and the time of attendance are used as the date and time when the content is taken. Only the date of attendance may be used as the attendance date information. As the attendance date / time information, only the attendance time may be used.

  The user ID is information indicating a user who takes the content shown in FIG. In the present embodiment, the terminal device Tm-n is an example shared by a plurality of users. Therefore, in this embodiment, a user who takes a content is set for each content to be taken.

  Next, when receiving the attendance schedule, the broadband router BR1 determines candidate deletion candidate contents to be deleted from the storage unit of the broadband router BR1 (FIG. 2: (2)). Details of the deletion candidate content determination method will be described below.

  In the present embodiment, it is determined whether or not the content corresponding to the content ID not included in the attendance schedule received in FIG. 2 (1) is stored in the storage unit of the broadband router BR1. Specifically, the attendance schedule received in FIG. 2A is stored in a predetermined storage area of the broadband router BR1. Then, a content ID different from the content ID included in the attendance schedule is determined in the content stored in the broadband router BR1. The determined content ID is determined as the deletion candidate content. The determined deletion candidate content is deleted from the content stored in the broadband router BR1. If the content corresponding to the content ID included in the attendance schedule is not stored in the storage unit of the broadband router BR1, the content is acquired from another broadband router BR connected to the overlay network OL. The acquired content is stored in the storage unit of the broadband router BR1.

  In this way, since the terminal device Tm-n connected to each site by the broadband router installed at each site stores the content scheduled to be taken, unnecessary content can be automatically deleted from the storage means, and the terminal at each site The device Tm-n does not have to wait for the time for the broadband router BR1 to acquire content, and can smoothly view the content. Note that the attendance schedule of this embodiment is an example of the viewing schedule of the present invention.

  In addition to the deletion candidate content determination method described above, the following determination method may be used. After the deletion candidate content is determined according to FIG. 2 (2) described above, the content to be taken after the predetermined date and time from the current date and time is further determined as the deletion candidate content from the content ID included in the attendance schedule. Also good. Hereinafter, an example in which the current date and time is “18:00 on September 19, 2011” will be described. Further, the case of “7 days” after the predetermined date will be described as an example. In this case, content IDs scheduled to be taken from “18:00 on September 19, 2011” to “18:00 on September 26, 2011” are determined from the content IDs shown in FIG. Is done. From the content IDs of the attendance schedule shown in FIG. 3, content IDs other than the determined content ID are determined as deletion candidate content. Furthermore, the content IDs determined as deletion candidate contents may be sorted in the order in which the date / time difference between the current date / time and the attendance date / time is large. In this case, a predetermined number of content IDs are determined in order from the content ID having the largest date difference. A predetermined number of content IDs are determined as deletion candidate content. Further, “one day” may be set after the predetermined date and time. In this case, the content scheduled to be taken from the current date to the next day is preferentially stored in the broadband router BR, and the content to be taken after the next day is determined as the candidate content for deletion.

  As a result, since the information processing apparatus preferentially deletes content that is not attended during a predetermined period, unnecessary content can be automatically deleted from the storage means, and the user who has reserved viewing is processed by the information processing apparatus as an edge server Therefore, it is possible to view the content smoothly without waiting for the time to cache the content again. In addition, since the information processing apparatus preferentially deletes content that is not attended from the current date and time to the next day as a predetermined period, the user who made a viewing reservation has time for the information processing device as an edge server to cache the content again. There is no need to wait and content can be viewed smoothly. In addition, the current date and time and the attendance date and time are sorted in descending order, and a predetermined number of content IDs are determined in order from the content ID having the largest date and time difference. The information processing apparatus preferentially deletes the information content. As a result, the user who made a viewing reservation does not need to wait for the information processing apparatus as the edge server to cache the content again, and can view the content smoothly.

[Electric configuration of broadband router BR]
Next, the electrical configuration of the broadband router BR will be described with reference to FIG. FIG. 4 is a block diagram showing an electrical configuration of the broadband router BR of the present embodiment. As shown in FIG. 4, the broadband router BR of the present embodiment includes a CPU 1 that controls the broadband router BR. An HDD 2, a RAM 3, a decoder unit 4, and a communication unit 9 are electrically connected to the CPU 1. The storage means such as the HDD 2 and the RAM 3 and the CPU 1 constitute a computer of the broadband router BR. The timekeeping operation is executed by the computer of the broadband router BR. By the clocking operation, the broadband router BR can measure time. The CPU 1, HDD 2, RAM 3, decoder unit 4, and communication unit 9 are connected to each other via a bus. In addition to the broadband router BR, the present invention can be applied to a personal computer, an STB (Set Top Box), a firewall, or the like.

  The HDD 2 includes a program storage area 21 and a routing table storage area 24. The program storage area 21 includes a main operation processing program storage area 22 and a deletion candidate content determination processing program storage area 23. The main operation processing program storage area 22 stores a main operation processing program. The main operation processing program is a program that causes the broadband router BR to execute main operation processing. The main operation processing program of the broadband router BR may be downloaded from a predetermined server on the network NW, for example, or may be recorded on a recording medium such as a CD-ROM and a drive of the recording medium may be used. You may make it read via.

  The deletion candidate content determination processing program storage area 23 stores a deletion candidate content determination processing program. The deletion candidate content determination processing program is a program that causes the broadband router BR to execute deletion candidate content determination processing. The deletion candidate content determination processing program of the broadband router BR may be downloaded from a predetermined server on the network NW, for example, or recorded on a recording medium such as a CD-ROM and stored in the recording medium. You may make it read via a drive.

  The routing table storage area 24 stores the DHT routing table of the present embodiment.

  The RAM 3 includes a content data temporary storage area 31, a attendance schedule temporary storage area 32, and a deletion candidate content temporary storage area 33. The content data temporary storage area 31 temporarily stores content data transmitted and received in the overlay network OL in association with the content ID. Instead of the RAM 3, a known storage device such as a flash memory may be used.

  The attendance schedule temporary storage area 32 temporarily stores the attendance schedule shown in FIG. The attendance schedule transmitted from each terminal device Tm-n is temporarily stored in the attendance schedule temporary storage area 32. In the deletion candidate content temporary storage area 33, the content ID determined as the deletion candidate content is temporarily stored.

  The communication unit 9 controls communication of information with the broadband router BR or an external device through the network NW.

  The broadband router BR performs reception processing for receiving content, chunks, or meta information files transmitted in response to requests via the communication unit 9. The content, chunk, or meta information file of the present embodiment is packetized and transmitted. Each packet is received through the communication unit 9.

[Main operation of broadband router BR]
The operation and action of the broadband router BR of the present embodiment configured as described above will be described with reference to the accompanying drawings. First, the operation and action of the broadband router BR will be described with reference to the attached drawings. FIG. 5 is a flowchart showing a processing procedure of the main operation in the broadband router BR. The main operation of the broadband router BR is performed by connecting an external power source such as a commercial power source and the broadband router BR via a power source or an outlet. The processing shown below is processed by the CPU 1.

  In step S101, it is determined whether a predetermined time has arrived. In the present embodiment, the predetermined time may be a predetermined time once a day. In addition, the predetermined time may be a predetermined time once every plural days. Further, the predetermined time may be a predetermined time a plurality of times a day. If it is determined that a predetermined time has arrived (step S101: YES), step S102 is executed. If it is not determined that the predetermined time has arrived (step S101: NO), step S108 is executed.

  In step S102, deletion candidate content determination processing is executed. Details of the deletion candidate content determination process will be described later. Note that the computer of this embodiment and step S102 are an example of a determination unit of the present invention. Moreover, step S102 of this embodiment is an example of a determination step of the present invention.

  In step S <b> 103, it is determined whether the content included in the attendance schedule is already stored in the content data temporary storage area 31. Specifically, it is determined whether or not the content corresponding to the content ID included in the attendance schedule stored in the attendance schedule temporary storage area 32 is already stored. If it is determined that it has already been stored (step S103: YES), step S112 is executed. If it is not determined that it is already stored (step S103: NO), step S104 is executed.

  In step S104, it is determined whether the content included in the attendance schedule can be stored. Specifically, it is determined whether or not there is a predetermined free storage area in the content data temporary storage area 31. If it is determined that the content can be stored (step S104: YES), step S105 is executed. If it is not determined that the content can be stored (step S104: NO), step S107 is executed. Note that the computer of this embodiment and step S104 are an example of a determination unit of the present invention. Moreover, step S104 of this embodiment is an example of the determination step of the present invention.

  In step S105, content that is not stored in the content data temporary storage area 31 is requested from the overlay network OL. Among the content IDs included in the attendance schedule, content IDs that are not stored in the content data temporary storage area 31 are determined. Content corresponding to the determined content ID is requested from the overlay network OL.

  In step S106, the content requested in step S105 is acquired via the overlay network OL. Since the content acquisition method has been described above, the details are omitted. The acquired content and content ID are temporarily stored in the content data temporary storage area 31.

  In step S107, a predetermined number of contents are deleted from the content data temporary storage area 31 from the deletion candidate contents determined in step S102. In step S107, all the contents may be deleted from the deletion candidate contents, or some contents may be deleted. Further, the number of contents corresponding to the capacity that can be stored in the content included in the attendance schedule may be determined and deleted from the deletion candidate contents. Note that the computer of this embodiment and step S107 are an example of the deletion unit of the present invention. Moreover, step S107 of this embodiment is an example of the deletion step of the present invention.

  In step S108, it is determined whether a control message has been received. If it is determined that a control message has been received (step S108: YES), step S109 is executed. If it is not determined that the control message has been received (step S108: NO), step S110 is executed. The control message is various messages for operating the overlay network OL.

In step S109, processing corresponding to the control message received in step S108 is executed.

  In step S110, it is determined whether or not the attendance schedule is received from the terminal device Tm-n. If it is determined that the attendance schedule has been received (step S110: YES), step S111 is executed. If it is not determined that the attendance schedule has been received (step S110: NO), step S112 is executed.

  In step S111, the attendance schedule received in step S110 is temporarily stored in the attendance schedule temporary storage area 32. Note that the computer of this embodiment and step S111 are examples of the acquisition unit of the present invention. Moreover, step S111 of this embodiment is an example of the acquisition step of this invention.

  In step S112, it is determined whether the power of the broadband router BR is turned off. If it is determined that the power has been turned off (step S112: YES), the main operation process is terminated. If it is not determined that the power is turned off (step S112: NO), step S101 is executed.

[Delete candidate content decision processing]
Hereinafter, the operation and action of the deletion candidate content determination process of the present embodiment will be described with reference to the accompanying drawings. FIG. 6 is a flowchart showing a processing procedure of deletion candidate content determination processing according to the present embodiment.

  In step S201, it is determined whether or not content not included in the attendance schedule is stored in the content data temporary storage area. When it is determined that content not included in the attendance schedule is stored in the content data temporary storage area (step S201: YES), step S202 is executed. If it is not determined that the content not included in the attendance schedule is stored in the content data temporary storage area (step S201: NO), the deletion candidate content determination process ends.

  In step S202, a content ID that matches the content ID included in the attendance schedule is determined from the content IDs stored in the content data temporary storage area 31. Then, among the content IDs stored in the content data temporary storage area 31, a content ID other than the content ID determined to match the content ID included in the attendance schedule is determined as the deletion candidate content. The determined deletion candidate content is temporarily stored in the deletion candidate content temporary storage area 33.

  Hereinafter, a modified example 1 of the deleted content determination process of the present embodiment will be described. FIG. 7 is a flowchart showing the processing procedure of Modification 1 of the deletion candidate content determination processing of the present embodiment. Note that the flowchart shown in FIG. 7 may be executed after step S201 and step S202 shown in FIG. 6 are executed.

  In step S <b> 301, it is determined whether there is content to be taken after a predetermined date and time from the current date and time among the content IDs included in the attendance schedule. Hereinafter, an example in which the current date and time is “18:00 on September 19, 2011” will be described using FIG. 3. Further, the case of “7 days” after the predetermined date will be described as an example. In this case, content IDs scheduled to be taken from “18:00 on September 19, 2011” to “18:00 on September 26, 2011” are determined from the content IDs shown in FIG. Is done. When a content ID other than the determined content ID is included in the attendance schedule, it is determined that there is content to be attended after a predetermined date and time from the current date and time. On the other hand, when a content ID other than the determined content ID is not included in the attendance schedule, it is determined that there is no content attended after a predetermined date and time from the current date and time. When it is determined that there is content to be taken after the predetermined date and time from the current date and time (step S301: YES), step S302 is executed. If it is not determined that there is content to be taken after the predetermined date and time from the current date and time (step S301: NO), the deletion candidate content determination process is terminated.

  In step S302, from the content IDs included in the attendance schedule, the content ID determined in step S301 as the content to be attended after the predetermined date and time from the current date and time is determined as the deletion candidate content. The determined deletion candidate content is temporarily stored in the deletion candidate content temporary storage area 33.

  Hereinafter, a modified example 2 of the deleted content determination process of the present embodiment will be described. FIG. 8 is a flowchart showing the processing procedure of the modification 2 of the deletion candidate content determination processing of the present embodiment. Note that the flowchart shown in FIG. 8 may be executed after step S201 and step S202 shown in FIG. 6 are executed.

  In step S401, processing similar to that in step S301 in FIG. 7 is executed. If it is determined that there is content to be taken after the predetermined date and time from the current date and time (step S401: YES), step S402 is executed. If it is not determined that there is content to be taken after the predetermined date and time from the current date and time (step S401: NO), the deletion candidate content determination process is terminated.

  In step S402, a content ID included in the attendance schedule and a content ID other than the content ID determined in step S401 are determined. Then, the determined content IDs are sorted in descending order of the date / time difference between the current date / time and the attendance date / time.

  In step S403, as a result of the sorting in step S402, a predetermined number of content IDs are determined in order from the content ID having the largest date difference. A predetermined number of content IDs are determined as deletion candidate content. The determined deletion candidate content is temporarily stored in the deletion candidate content temporary storage area 33.

  In the present embodiment, an example in which the present invention is applied to the broadband router BR is described, but the present invention is not limited to this. For example, in addition to the broadband router BR, the present invention may be applied to an information processing apparatus as an edge server installed at each base.

  In the present embodiment, the terminal device Tm-n transmits the attendance schedule to the broadband router BR at a predetermined timing. As a modification of the present embodiment, a schedule request message may be transmitted from the broadband router BR to the terminal device Tm-n at the base at every predetermined timing. In this case, in response to receiving the schedule request message, the terminal device Tm-n transmits the attendance schedule to the broadband router BR. In addition, although this embodiment described the Example by which content is acquired according to a attendance schedule, it is not limited to this. The present invention may be applied to an information communication system that uses a content viewing schedule instead of the attendance schedule.

  In this embodiment, the peer-to-peer communication system using the DHT routing table is applied to the overlay network OL. However, the present invention is not limited to this. The present invention may be applied to other peer-to-peer communication systems or systems using overlay networks. For example, the present invention may be applied to a communication system using a routing table other than DHT or a peer-to-peer communication system. An example of a peer-to-peer communication system that does not use DHT is a hybrid peer-to-peer communication system. The present invention may be applied to a hybrid peer-to-peer communication system or a pure peer-to-peer communication system. Further, the present invention may be applied to an information communication system that does not use an overlay network. For example, the present invention may be applied to a system in which content is distributed and stored by a plurality of server devices.

1 CPU
2 HDD
3 RAM
DESCRIPTION OF SYMBOLS 9 Communication part 21 Program storage area 22 Main operation | movement process program storage area 23 Delete candidate content determination process program storage area 24 Routing table storage area 31 Content temporary storage area 32 Lecture schedule temporary storage area 33 Delete candidate content temporary storage area Tm-n Terminal Equipment NLm Base NW Network BR, BR1, BR2, BR3 Broadband router S Information communication system OL Overlay network SV Center server

Claims (6)

The information processing apparatus in an information communication system in which a plurality of contents are transmitted and received by an overlay network composed of a plurality of information processing apparatuses,
Storage means for storing content acquired via the overlay network;
Obtaining means for obtaining a viewing schedule including content identification information for identifying the content and time information indicating a time at which the content is viewed from a plurality of client devices that obtain the content from the information processing device;
Determining means for determining the content identification information not included in the viewing schedule acquired by the acquiring means as a candidate for content to be deleted from the storage means;
A determination unit that determines whether or not the content indicated by the content identification information included in the viewing schedule acquired by the acquisition unit can be stored in the storage unit of the information processing apparatus for each predetermined period;
A deletion unit that deletes content from the candidates determined by the determination unit when the determination unit does not determine that storage is possible;
An information processing apparatus comprising:   2. The determination unit according to claim 1, wherein the determination unit determines, based on the time information included in the viewing schedule, a content candidate to be deleted preferentially from a current date and time during a predetermined period. The information processing apparatus described.   The information processing apparatus according to claim 2, wherein the determination unit determines, as the predetermined period, content candidates to be deleted preferentially for content that is not attended from the current date to the next day.   The determination means, based on the time information included in the viewing schedule, determines the content of the time information that is a viewing time far from the current date and time as a content candidate to be preferentially deleted. The information processing apparatus according to any one of 1 to 3. An information communication system in which a plurality of contents are transmitted and received by an overlay network composed of a plurality of information processing devices,
A content deletion method for the information processing apparatus, comprising storage means for storing content acquired via the overlay network,
An acquisition step of acquiring a viewing schedule including content identification information for identifying the content and time information indicating a time at which the content is viewed, from a plurality of client devices that acquire the content from the information processing device;
A determination step of determining the content identification information not included in the viewing schedule acquired by the acquisition step as a content candidate to be deleted from the storage unit;
A determination step of determining whether or not the content indicated by the content identification information included in the viewing schedule acquired in the acquisition step can be stored in a storage unit of the information processing apparatus for each predetermined period;
If it is not determined that the data can be stored in the determination step, a deletion step of deleting content from the candidates determined in the determination step;
Content deletion method. An information communication system in which a plurality of contents are transmitted and received by an overlay network composed of a plurality of information processing devices,
In the computer of the information processing apparatus comprising storage means for storing content acquired via the overlay network,
An acquisition step of acquiring a viewing schedule including content identification information for identifying the content and time information indicating a time at which the content is viewed, from a plurality of client devices that acquire the content from the information processing device;
A determination step of determining the content identification information not included in the viewing schedule acquired by the acquisition step as a content candidate to be deleted from the storage unit;
A determination step of determining whether or not the content indicated by the content identification information included in the viewing schedule acquired in the acquisition step can be stored in a storage unit of the information processing apparatus for each predetermined period;
If it is not determined that the data can be stored in the determination step, a deletion step of deleting content from the candidates determined in the determination step;
A program characterized by having executed.