JP5557192B2 - Content receiving apparatus, content distribution system, and program - Google Patents

Description

  The present invention relates to a content receiving device, a content distribution system, and a program.

  With the progress of communication technology in recent years, IPTV services for distributing content via an IP network, such as video on demand and multi-channel IP broadcasting, are becoming widespread. In this type of service, in order to improve the convenience of the user at the time of program search or the like, metadata regarding the content being distributed is transmitted from the meta server to the content receiving device via the network. The content receiving device constructs a GUI screen such as a video genre list based on the metadata received from the network and displays it on the display device.

  Note that the operation regulations regarding IPTV are disclosed in Non-Patent Document 1, for example.

IPTV specification CDN scope service approach specification IPTVFJSTD-0006 version 1.0, IPTV Forum, limited liability intermediary corporation, September 11, 2008

  In the content receiving device, in order to omit the server search for each user operation, the metadata described in the catalog information provided from the distribution source is acquired in advance and stored in the storage unit in the content receiving device. Processing (catalog cache) is performed. When displaying a desired screen in accordance with a user operation, if necessary metadata is already stored in the storage unit by the catalog cache, the desired screen is created and displayed using the metadata.

  By the way, since the storage capacity of the storage unit for storing metadata is physically finite, when the number of contents to be distributed becomes enormous, it is not possible to store metadata for all contents in the storage unit. It becomes difficult. Therefore, the number of contents that can be distributed from the distribution source is limited by the storage capacity of the storage unit included in the content receiving apparatus.

  As a measure for releasing this restriction, when the amount of metadata stored in the storage unit approaches the maximum storage capacity of the storage unit, the metadata is physically deleted in a batch or partially. A method can be considered.

  However, when the metadata stored in the storage unit is physically deleted in a lump, the user must wait until the physical deletion is completed. Since it takes a certain amount of time to physically delete a large amount of metadata at once, the waiting time becomes long and user convenience is poor.

  In addition, when part of the metadata stored in the storage unit is physically deleted, it is possible to reduce the waiting time of the user, but only a part of a plurality of mutually related metadata is deleted. Inconsistency occurs in the display. In order to avoid display inconsistency, it is necessary to specify metadata to be deleted in consideration of the relationship between metadata, and the processing becomes complicated.

  The present invention has been made in view of such circumstances, and the number of contents that can be distributed from the distribution source is not limited by the storage capacity of the storage unit included in the content receiving apparatus, and further, the waiting time of the user is shortened. An object of the present invention is to obtain a content receiving device, a content distribution system, and a program that can avoid display inconsistency.

  The content receiving apparatus according to the first aspect of the present invention includes a storage unit that stores content attribute data and a process of acquiring attribute data described in content catalog information from a server and storing the attribute data in the storage unit. A catalog cache processing unit that executes a certain catalog cache, a user cache processing unit that executes a user cache that is a process of acquiring attribute data required in response to a user operation from a server and storing the attribute data in a storage unit, and a predetermined cache When the condition is satisfied, the logical deletion processing unit that logically deletes the attribute data stored in the storage unit collectively and the attribute data logically deleted by the logical deletion processing unit are not operated by a user. However, a physical deletion processing unit that physically deletes from the storage unit is provided.

  According to the content receiving device of the first aspect, the logical deletion processing unit logically deletes the attribute data stored in the storage unit when the predetermined condition is satisfied, and the physical deletion processing unit The attribute data logically deleted by the logical deletion processing unit is physically deleted from the storage unit after the logical deletion. By logically deleting the attribute data stored in the storage unit collectively, the amount of data stored in the storage unit is apparently zero, and the attribute data that has been logically deleted is stored in the storage unit after the logical deletion. Since it is physically deleted, it is possible to avoid a situation where the number of contents that can be distributed from the distribution source is limited by the storage capacity of the storage unit. In addition, the time required for logical deletion is extremely short, and physical deletion is sequentially performed in the background even if no user operation is performed. Therefore, it is possible to reduce the waiting time of the user. Furthermore, since the attribute data stored in the storage unit is logically deleted in a lump, it is possible to avoid display inconsistencies associated with deleting some of the attribute data.

  The content receiving device according to the second aspect of the present invention is the content receiving device according to the first aspect, in particular, the logical deletion processing unit is configured to store attribute data stored in the storage unit as the predetermined condition. When the total data amount exceeds a predetermined threshold value set to a value smaller than the storage capacity of the storage unit and larger than the data amount of attribute data described in the catalog information, and then a user operation is performed , Logical deletion is performed.

  According to the content receiving device according to the second aspect, the logical deletion processing unit, when the total data amount of the attribute data stored in the storage unit exceeds a predetermined threshold, and then a user operation is performed, Perform a logical delete. Therefore, for example, after the catalog cache after the content receiving device is turned on is completed, the amount of data acquired in the user cache becomes enormous due to frequent user operations, and the total amount of attribute data is a predetermined threshold value. When the value exceeds, logical deletion can be appropriately executed.

  The content receiving device according to a third aspect of the present invention is the content receiving device according to the first aspect, in which the logical deletion processing unit is configured to perform a user operation after a predetermined periodic update time as the predetermined condition. When it is performed, logical deletion is executed.

  According to the content receiving device of the third aspect, the logical deletion processing unit executes logical deletion when a user operation is performed after a predetermined periodic update time has elapsed. Therefore, it is possible to appropriately execute periodic update of the attribute data stored in the storage unit.

  The content receiving device according to the fourth aspect of the present invention is the content receiving device according to the second or third aspect, in particular, the catalog cache processing unit is described in the catalog information when logical deletion is executed. The physical deletion processing unit starts physical deletion of the attribute data stored in the storage unit before the reacquisition when the reacquisition of the attribute data is completed. It is a feature.

  According to the content receiving device of the fourth aspect, the physical deletion processing unit starts physical deletion of the attribute data when the reacquisition of the attribute data is completed. By executing physical deletion as background processing in this way, it is possible to avoid the occurrence of user waiting time associated with physical deletion. Also, since attribute data stored in the storage unit before reacquisition is physically deleted, attribute data reacquired in the catalog cache and attribute data acquired in the user cache after reacquisition are not physically deleted. Can be left in the storage unit. As a result, it is possible to shorten the time required to display a screen with a high reference frequency, and thus it is possible to improve user convenience.

  The content reception device according to a fifth aspect of the present invention is the content reception device according to the first aspect, in which the logical deletion processing unit is configured to use the catalog cache after the content reception device is turned on as the predetermined condition. Is completed, the total data amount of the attribute data stored in the storage unit is set to a value smaller than the storage capacity of the storage unit and larger than the data amount of the attribute data described in the catalog information. When a predetermined threshold value is exceeded and a user operation is subsequently performed, logical deletion is performed.

  According to the content receiving device of the fifth aspect, the logical deletion processing unit determines that the total amount of attribute data stored in the storage unit is predetermined before the catalog cache after the content receiving device is powered on is completed. The logical deletion is executed when the user's operation is performed after the above threshold is exceeded. Therefore, for example, the amount of acquired data in the user cache becomes enormous due to frequent user operations after the content receiving device is turned on, and the total amount of attribute data reaches a predetermined threshold before the catalog cache is completed. When it exceeds, logical deletion can be appropriately executed.

  The content receiving device according to a sixth aspect of the present invention is the content receiving device according to the fifth aspect, in which the physical deletion processing unit starts physical deletion after completion of logical deletion. is there.

  According to the content receiving device of the sixth aspect, the physical deletion processing unit starts physical deletion after completion of logical deletion. By executing physical deletion as background processing in this way, it is possible to avoid the occurrence of user waiting time associated with physical deletion. In addition, physical deletion is started upon completion of logical deletion without waiting for completion of reacquisition of attribute data by the catalog cache after logical deletion. Therefore, since physical deletion can be started at an early stage, it is possible to avoid a situation in which the total amount of attribute data stored in the storage unit approaches the maximum storage capacity of the storage unit due to the subsequent catalog cache.

  The content receiving device according to the seventh aspect of the present invention is the content receiving device according to the fifth or sixth aspect, in which the physical deletion processing unit is acquired by the user cache rather than the attribute data acquired by the catalog cache. The physical deletion is performed with priority given to the attribute data.

  According to the content receiving device of the seventh aspect, the physical deletion processing unit performs physical deletion by giving priority to the attribute data acquired by the user cache over the attribute data acquired by the catalog cache. Thereby, the attribute data acquired in the catalog cache can be left in the storage unit without being physically deleted. As a result, when the attribute data is reacquired by the next catalog cache, the attribute data that is the same as the attribute data already stored in the storage unit can be omitted from the storage unit, so that the storage process can be omitted. The required time can be shortened.

  The content reception device according to an eighth aspect of the present invention is the content reception device according to the first aspect, in which the logical deletion processing unit is configured to store attribute data stored in the storage unit as the predetermined condition. When the total amount of data exceeds a predetermined threshold set according to the upper limit value of the storage capacity of the storage unit, logical deletion is executed.

  According to the content reception device of the eighth aspect, the logical deletion processing unit has a predetermined amount in which the total amount of attribute data stored in the storage unit is set according to the upper limit value of the storage capacity of the storage unit When the threshold is exceeded, logical deletion is executed. Therefore, for example, when the amount of acquired data in the catalog cache or the user cache becomes enormous and the total amount of attribute data approaches the upper limit of the storage capacity of the storage unit, logical deletion can be appropriately executed. Become.

  The content receiving device according to the ninth aspect of the present invention is the content receiving device according to the eighth aspect, in which the physical deletion processing unit starts physical deletion together with the start of logical deletion. is there.

  According to the content receiving device of the ninth aspect, the physical deletion processing unit starts physical deletion together with the start of logical deletion. Since physical deletion can be started early by starting physical deletion at the same time as logical deletion starts without waiting for completion of reacquisition of attribute data by the catalog cache after logical deletion, the attribute data stored in the storage unit The total amount of data can be reduced quickly.

  The content receiving device according to the tenth aspect of the present invention is the content receiving device according to any one of the first to ninth aspects, particularly further comprising a management unit for managing attribute data stored in the storage unit. The management unit manages the generation of each attribute data by allocating generation information representing the generation of the attribute data to the attribute data when storing the acquired attribute data in the storage unit. Is.

  According to the content receiving device of the tenth aspect, when storing the acquired attribute data in the storage unit, the management unit assigns generation information representing the generation of the attribute data to the attribute data, thereby Manage generations. Thereby, it becomes possible to easily specify the attribute data to be physically deleted from the plurality of attribute data stored in the storage unit based on the generation information.

  The content reception device according to an eleventh aspect of the present invention is the content reception device according to the tenth aspect, in which the physical deletion processing unit performs physical deletion on the old generation attribute data, The physical deletion is stopped when the attribute data no longer exists in the storage unit.

  According to the content receiving device of the eleventh aspect, the physical deletion processing unit performs physical deletion on the old generation attribute data, and when the old generation attribute data no longer exists in the storage unit, the physical deletion processing unit Stop the deletion. As a result, the latest generation attribute data can be left in the storage unit without being physically deleted. As a result, it is possible to shorten the time required to display a screen with a high reference frequency, and thus it is possible to improve user convenience.

  The content reception device according to the twelfth aspect of the present invention is the content reception device according to the tenth or eleventh aspect, in particular, the catalog cache processing unit is described in the catalog information when logical deletion is executed. If the old generation attribute data having the same identification information and version information as the reacquired attribute data is stored in the storage unit, the management unit The generation information of the attribute data is rewritten with the latest generation information.

  According to the content receiving device of the twelfth aspect, when the old generation attribute data having the same identification information and version information as the reacquired attribute data is stored in the storage unit, the management unit Rewrite the generation information of the attribute data of the previous generation to the latest generation information. As a result, with respect to the same attribute data as the attribute data already stored in the storage unit, it is only necessary to rewrite the generation information, and the storage process in the storage unit can be omitted. Is possible.

  The content receiving device according to the thirteenth aspect of the present invention is the content receiving device according to the tenth or eleventh aspect, in particular, the catalog cache processing unit is described in the catalog information when logical deletion is executed. The management unit re-acquires the attribute data of the previous generation whose identification information and version information are the same as the re-acquired attribute data and are not stored in the storage unit. The attribute data is stored in the storage unit.

  According to the content receiving device of the thirteenth aspect, the management unit re-executes the re-acquired attribute data when the old generation attribute data having the same identification information and version information is not stored in the storage unit. The acquired attribute data is stored in the storage unit. As a result, the latest attribute data including update data and additional data that were not acquired in the previous catalog cache can be stored in the storage unit.

  In the content receiving device according to the fourteenth aspect of the present invention, in particular, in the content receiving device according to the tenth or eleventh aspect, the catalog cache processing unit stores the latest catalog information when logical deletion is executed. The list information of the described attribute data is acquired from the server, and the management unit stores attribute data in which the identification information and version information are the same as each attribute data described in the list information. If it is, the generation information of the attribute data is rewritten to the latest generation information.

  According to the content receiving device of the fourteenth aspect, the catalog cache processing unit acquires, from the server, the list information of the attribute data described in the latest catalog information when the logical deletion is executed. When the attribute data having the same identification information and version information as the attribute data described in the list information is stored in the storage unit, the management unit updates the generation information of the attribute data. Rewrite to generation information. Thereby, for the same attribute data as the attribute data already stored in the storage unit, it is only necessary to rewrite the generation information, and it is possible to omit re-acquisition processing from the server and re-storage processing to the storage unit. The load on the server and the network can be reduced, and the time required for processing can be shortened.

  In the content receiving device according to the fifteenth aspect of the present invention, in particular, in the content receiving device according to the tenth or eleventh aspect, the catalog cache processing unit updates the latest catalog information when logical deletion is executed. The list information of the described attribute data is acquired from the server, and the management unit stores attribute data in which the identification information and version information are the same as each attribute data described in the list information. If not, the attribute data is acquired from the server and stored in the storage unit.

  According to the content receiving device of the fifteenth aspect, the management unit, when attribute data having the same identification information and version information as each attribute data described in the list information is not stored in the storage unit The attribute data is acquired from the server and stored in the storage unit. As a result, the latest attribute data including update data and additional data that were not acquired in the previous catalog cache can be stored in the storage unit.

  A content delivery system according to a sixteenth aspect of the present invention includes a content transmission device, a content reception device, and a server that holds attribute data of the content transmitted from the content transmission device, and the content reception device includes: A storage unit that stores attribute data, a catalog cache processing unit that executes a catalog cache, which is a process of acquiring attribute data described in content catalog information from the server and storing the attribute data in the storage unit, and a user operation And a user cache processing unit that executes a user cache, which is a process of acquiring attribute data necessary for the server from the server and storing the attribute data in the storage unit, and when the predetermined condition is satisfied, the attribute data is stored in the storage unit. A logical deletion processing unit that logically deletes the attribute data in batch and the logical deletion processing unit Attribute data that is logically deleted, and is characterized in that it has a physical deletion processing unit to physical deleted from the storage unit in the logical delete after.

  According to the content delivery system of the sixteenth aspect, the logical deletion processing unit logically deletes the attribute data stored in the storage unit when the predetermined condition is satisfied, and the physical deletion processing unit The attribute data logically deleted by the logical deletion processing unit is physically deleted from the storage unit without any user operation. By logically deleting the attribute data stored in the storage unit collectively, the amount of data stored in the storage unit is apparently zero, and the attribute data that has been logically deleted is stored in the storage unit after the logical deletion. Since it is physically deleted, it is possible to avoid a situation where the number of contents that can be distributed from the distribution source is limited by the storage capacity of the storage unit. In addition, the time required for logical deletion is extremely short, and physical deletion is sequentially performed in the background even if no user operation is performed. Therefore, it is possible to reduce the waiting time of the user. Furthermore, since the attribute data stored in the storage unit is logically deleted in a lump, it is possible to avoid display inconsistencies associated with deleting some of the attribute data.

  According to a seventeenth aspect of the present invention, there is provided a program for storing a catalog cache, which is a process in which a computer installed in a content receiving device acquires attribute data described in content catalog information from a server and stores the attribute data in a storage unit. A catalog cache processing unit to be executed, a user cache processing unit to execute a user cache, which is a process of acquiring attribute data required in response to a user operation from a server and storing it in the storage unit, and a predetermined condition is satisfied In this case, the logical deletion processing means for logically deleting the attribute data stored in the storage unit and the attribute data logically deleted by the logical deletion processing means can be stored even if no user operation is performed. A program for causing a computer to function as a physical deletion processing means for performing physical deletion from a copy.

  According to the program according to the seventeenth aspect, the logical deletion processing means collectively deletes the attribute data stored in the storage unit when the predetermined condition is satisfied, and the physical deletion processing means The attribute data logically deleted by the deletion processing means is physically deleted from the storage unit after the logical deletion. By logically deleting the attribute data stored in the storage unit collectively, the amount of data stored in the storage unit is apparently zero, and the attribute data that has been logically deleted is stored in the storage unit after the logical deletion. Since it is physically deleted, it is possible to avoid a situation where the number of contents that can be distributed from the distribution source is limited by the storage capacity of the storage unit. In addition, the time required for logical deletion is extremely short, and physical deletion is sequentially performed in the background even if no user operation is performed. Therefore, it is possible to reduce the waiting time of the user. Furthermore, since the attribute data stored in the storage unit is logically deleted in a lump, it is possible to avoid display inconsistencies associated with deleting some of the attribute data.

  According to the present invention, the number of contents that can be distributed from the distribution source is not limited by the storage capacity of the storage unit included in the content receiving apparatus, and it is possible to avoid display inconsistency while reducing the waiting time of the user. Content receiving apparatus, content distribution system, and program can be obtained.

It is a figure which shows the whole structure of the content delivery system which concerns on embodiment of this invention. It is a figure which shows the structure of the computer mounted in the content receiver. It is a block diagram which shows a part of function implement | achieved by a process part by running a program. It is a figure which shows an example of a management table. It is a figure which shows the 1st operation example of a content receiver. It is a figure which shows the 2nd operation example of a content receiver. It is a figure which shows the 3rd operation example of a content receiver. It is a figure which shows the 4th operation example of a content receiver.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the element which attached | subjected the same code | symbol in different drawing shall show the same or corresponding element.

  FIG. 1 is a diagram showing an overall configuration of a content distribution system 1 according to an embodiment of the present invention. As shown in FIG. 1, a content distribution system 1 includes a content transmission device 2 such as a VOD (Video On Demand) server or a multi-channel IP broadcast server, a network 3 such as an IP network, and a content reception device 4 such as a set top box. And a meta server 6 that holds metadata (attribute data) related to the content transmitted from the content transmitting device 2. The meta server 6 may be implemented in the content transmission device 2 as a part of the functions of the content transmission device 2.

  The content receiving device 4 is connected to an arbitrary display device 5 such as a liquid crystal display or a plasma display. Although only one content receiving device 4 is shown in FIG. 1, a large number of content receiving devices 4 are connected to the network 3.

  FIG. 2 is a diagram illustrating a configuration of a computer installed in the content receiving device 4. As shown in FIG. 2, the computer includes a processing unit 10 such as a CPU and a storage unit 11 such as a semiconductor memory or a hard disk. A predetermined program 12 is stored in the storage unit 11. The processing unit 10 reads the program 12 from the storage unit 11 and executes it.

  FIG. 3 is a block diagram showing a part of functions realized in the processing unit 10 by executing the program 12. As illustrated in FIG. 3, the processing unit 10 includes a communication unit 20, a catalog cache processing unit 21, a user cache processing unit 22, a management unit 23, a logical deletion processing unit 24, a physical deletion processing unit 25, and a screen display data generation unit 26. have. In other words, the program 12 includes a computer mounted on the content receiving device 4 as a communication unit 20, a catalog cache processing unit 21, a user cache processing unit 22, a management unit 23, a logical deletion processing unit 24, and a physical deletion processing unit. 25 and a program for causing the screen display data generation unit 26 to function.

  The storage unit 30 is a storage medium that is common or separate from the storage unit 11 illustrated in FIG. 2, and includes a metadata storage area 31 and a management table storage area 32. Metadata is stored in the metadata storage area 31. A management table 40 described later is stored in the management table storage area 32.

  The communication unit 20 transmits and receives various data to and from the meta server 6 via the network 3 using a network interface.

  The catalog cache processing unit 21 acquires metadata described in catalog information provided from a content distribution source from the meta server 6 and stores the acquired metadata in the metadata storage area 31 (catalog cache). Execute.

  When a user operation such as screen transition is performed by the user of the content receiving device 4, the user cache processing unit 22 acquires metadata necessary for screen construction from the meta server 6 according to the user operation. Then, a process (user cache) for storing the acquired metadata in the metadata storage area 31 is executed.

  The logical deletion processing unit 24 logically deletes the metadata stored in the metadata storage area 31 collectively when a predetermined condition described later is satisfied.

  The physical deletion processing unit 25 physically deletes the metadata logically deleted by the logical deletion processing unit 24 from the metadata storage area 31 after the logical deletion.

  The management unit 23 manages the metadata stored in the metadata storage area 31 and the management table 40 stored in the management table storage area 32.

  The screen display data generation unit 26 generates display data for constructing a screen such as a video genre list to be displayed on the display device 5 based on the metadata stored in the metadata storage area 31.

  FIG. 4 is a diagram illustrating an example of the management table 40. In the management table 40, for each of a plurality of metadata stored in the metadata storage area 31, a CRID (content reference ID) that is identification information of the metadata and a fragment version that is a description unit of the metadata. It manages the fragment version that is information, the generation information that indicates the generation of the metadata that is updated each time logical deletion is performed, and the information that indicates whether the acquisition of the metadata is from the catalog cache or the user cache The In the management table 40, generation information representing the current generation (that is, the latest generation) is managed.

  Hereinafter, the operation of the content receiving device 4 according to the present embodiment will be described in detail. In the content receiving device 4, thresholds TH1 and TH2 relating to the total amount of metadata stored in the metadata storage area 31 are set. The threshold value TH2 is set to a value slightly smaller than the upper limit value according to the upper limit value of the storage capacity of the metadata storage area 31. The threshold value TH1 is set to a value smaller than the threshold value TH2 and larger than the total data amount of a plurality of metadata described in the catalog information.

<First operation example>
FIG. 5 is a diagram illustrating a first operation example of the content receiving device 4. Here, the total data amount of the metadata stored in the metadata storage area 31 is set to the threshold value TH1 because the user operation is performed after the initial catalog cache after the power-on of the content receiving device 4 is completed. The operation when exceeding is described.

  At time T01, the content receiving device 4 is powered on. As a result, the catalog cache processing unit 21 starts catalog caching, and the total amount of metadata stored in the metadata storage area 31 gradually increases. The catalog cache is completed at time T02. Here, the management unit 23 describes the CRID and fragment version of each metadata acquired by the catalog cache in the management table 40. Further, the management unit 23 assigns generation information “1” to each metadata, and describes the generation information in the item “generation” of the management table 40. Further, the management unit 23 describes information representing the catalog cache in the item “catalog / user” of the management table 40. Further, the management unit 23 describes the generation information “1” in the item “current generation” of the management table 40.

  When the user operation is performed at each time T03, T05, and T07, the user cache processing unit 22 starts the user cache, and the total data amount of the metadata stored in the metadata storage area 31 further increases. . Each user cache is completed at times T04, T06, and T09. Here, the management unit 23 describes the CRID and fragment version of each metadata acquired by the user cache in the management table 40. Further, the management unit 23 assigns generation information “1” to each metadata, and describes the generation information in the item “generation” of the management table 40. In addition, the management unit 23 describes information representing the user cache in the item “catalog / user” of the management table 40.

  At time T08, the total amount of metadata stored in the metadata storage area 31 exceeds the threshold value TH1. As a result, a predetermined deletion flag that can be referred to by the logical deletion processing unit 24 is set to “True”.

  At time T10, a user operation is performed. The logical deletion processing unit 24 starts logical deletion when a user operation is performed in a state where the deletion flag is set to “True”. The logical deletion is completed at time T11. In the present embodiment, the generation information described in the item “current generation” in the management table 40 is updated from “1” to “2” representing the next generation, thereby generating “1” generation information. All metadata stored in the metadata storage area 31 is apparently deleted (logically deleted) at once. As the metadata stored in the metadata storage area 31 is logically deleted in a lump, the amount of stored data on management becomes zero as shown by a thick broken line in the figure. Note that the thick solid line in the figure indicates the actual amount of stored data.

  At time T11, the user cache processing unit 22 starts user cache, and the total amount of metadata stored in the metadata storage area 31 increases. The user cache is completed at time T12. Here, the management unit 23 describes the CRID and fragment version of each metadata acquired by the user cache in the management table 40. Further, the management unit 23 assigns generation information “2” to each metadata, and describes the generation information in the item “generation” of the management table 40. In addition, the management unit 23 describes information representing the user cache in the item “catalog / user” of the management table 40. When the user displays a screen such as a video genre list on the display device 5, the metadata stored in the meta server 6 is stored in the metadata storage area 31 so as to correspond to an operation mode in which the metadata is frequently updated in a short period of time. It is also possible to set so that the latest metadata is acquired from the meta server 6 each time and the screen is generated using the latest metadata, instead of using the metadata that has been set. Even when such a setting is made, by acquiring information representing the setting from the meta server 6 in advance, the updated or added metadata can be acquired and used for screen generation.

  As a result of the logical deletion, the catalog cache processing unit 21 starts catalog caching again at time T12. As a result, the total amount of metadata stored in the metadata storage area 31 gradually increases. The catalog cache is completed at time T13. Here, the management unit 23 describes the CRID and fragment version of each metadata acquired by the catalog cache in the management table 40. Also, the management unit 23 assigns the generation information “2” acquired from the current generation to each metadata, and describes the generation information in the item “generation” of the management table 40. Further, the management unit 23 describes information representing the catalog cache in the item “catalog / user” of the management table 40.

  Here, the catalog cache processing unit 21 reacquires metadata described in the catalog information from the meta server 6. The management unit 23 refers to the management table 40, and the metadata of the old generation (generation “1” in this example) whose CRID and fragment version are the same as the reacquired metadata is stored in the metadata storage area 31. It is determined whether it is already stored. If the old generation metadata exists, the process of storing the reacquired metadata in the metadata storage area 31 is omitted, and the generation information of the old generation metadata is updated to the latest generation information ( In this example, it is rewritten to generation “2”). On the other hand, when the old generation metadata does not exist, a process of storing the reacquired metadata in the metadata storage area 31 is executed.

  Alternatively, the catalog cache processing unit 21 acquires metadata list information (list information) described in the latest catalog information from the meta server 6 prior to the reacquisition of metadata. When the metadata having the same CRID and fragment version as each metadata described in the list information is already stored in the metadata storage area 31, the management unit 23, The re-acquisition processing from the meta server 6 and the storage processing in the metadata storage area 31 are omitted, and the generation information of the metadata is rewritten to the latest generation information (generation “2” in this example). On the other hand, when metadata having the same CRID and fragment version as each metadata described in the list information is not stored in the metadata storage area 31, the metadata is acquired from the metadata server 6. Then, the process of storing in the metadata storage area 31 is executed. Thereby, since the data amount of the metadata transmitted from the meta server 6 to the content receiving device 4 is reduced, the load on the network 3 can be reduced and the time required for obtaining the metadata can be shortened. This process can also be performed for the user cache.

  Returning to the description of FIG. 5, when the catalog cache is completed at time T <b> 13, the physical deletion processing unit 25 starts physical deletion. Here, the physical deletion processing unit 25 refers to the management table 40, and among all the metadata stored in the metadata storage area 31 at this time, the metadata whose generation information is different from the latest generation. The physical deletion is executed on the target (that is, the metadata to which the generation information of the previous generation is assigned). In this example, metadata to which generation information “1” is assigned is physically deleted. As physical deletion progresses, the total amount of metadata stored in the metadata storage area 31 gradually decreases.

  At time T14, when a user operation is performed, the physical deletion processing unit 25 interrupts the physical deletion, and the user cache processing unit 22 starts the user cache. As a result, the total amount of metadata stored in the metadata storage area 31 increases. The user cache is completed at time T15. Here, the management unit 23 describes the CRID and fragment version of each metadata acquired by the user cache in the management table 40. Further, the management unit 23 assigns generation information “2” to each metadata, and describes the generation information in the item “generation” of the management table 40. In addition, the management unit 23 describes information representing the user cache in the item “catalog / user” of the management table 40.

  When the user cache is completed at time T15, the physical deletion processing unit 25 resumes physical deletion. As a result, the total amount of metadata stored in the metadata storage area 31 gradually decreases.

  At time T <b> 16, the physical deletion processing unit 25 stops the physical deletion when the old generation metadata no longer exists in the metadata storage area 31, and sets the deletion flag to “False”. At this point, the actual (physical) stored data amount matches the apparent stored data amount.

<Second operation example>
FIG. 6 is a diagram illustrating a second operation example of the content receiving device 4. Here, an operation at the time of updating metadata that is performed periodically (for example, once a day) will be described.

  The logical deletion processing unit 24 starts logical deletion at time T22 when the first user operation is performed after the time T21, which is a specific periodic update time at midnight, has been performed. That is, by updating the generation information described in the item “current generation” of the management table 40, the metadata of the previous generation is logically deleted collectively. The logical deletion is completed at time T23. Since the metadata stored in the metadata storage area 31 is logically deleted at once, the apparent amount of stored data becomes zero.

  When the logical deletion is executed, the catalog cache processing unit 21 starts catalog caching at time T23. The catalog cache is completed at time T24. Here, the management unit 23 describes the CRID and fragment version of each metadata acquired by the catalog cache in the management table 40. Further, the management unit 23 assigns the latest generation information acquired from the management table 40 to each metadata, and describes the generation information in the item “generation” of the management table 40. Further, the management unit 23 describes information representing the catalog cache in the item “catalog / user” of the management table 40.

  Here, the catalog cache processing unit 21 reacquires metadata described in the catalog information from the meta server 6. The management unit 23 refers to the management table 40 to determine whether or not old-generation metadata having the same CRID and fragment version as the re-acquired metadata is already stored in the metadata storage area 31. To do. If the old generation metadata exists, the process of storing the reacquired metadata in the metadata storage area 31 is omitted, and the generation information of the old generation metadata is changed to the latest generation information. rewrite. On the other hand, when the old generation metadata does not exist, a process of storing the reacquired metadata in the metadata storage area 31 is executed.

  Alternatively, the catalog cache processing unit 21 acquires metadata list information (list information) described in the latest catalog information from the meta server 6 prior to the reacquisition of metadata. When the metadata having the same CRID and fragment version as each metadata described in the list information is already stored in the metadata storage area 31, the management unit 23, The re-acquisition process from the meta server 6 and the storage process to the metadata storage area 31 are omitted, and the generation information of the metadata is rewritten to the latest generation information. On the other hand, when metadata having the same CRID and fragment version as each metadata described in the list information is not stored in the metadata storage area 31, the metadata is acquired from the metadata server 6. Then, the process of storing in the metadata storage area 31 is executed. Thereby, since the data amount of the metadata transmitted from the meta server 6 to the content receiving device 4 is reduced, the load on the network 3 can be reduced and the time required for obtaining the metadata can be shortened.

  Returning to the description of FIG. 6, when the catalog cache is completed at time T <b> 24, the physical deletion processing unit 25 starts physical deletion. Here, the physical deletion processing unit 25 refers to the management table 40, and among all the metadata stored in the metadata storage area 31 at this time, the metadata whose generation information is different from the latest generation. The physical deletion is executed on the target (that is, the metadata to which the generation information of the previous generation is assigned). As physical deletion progresses, the total amount of metadata stored in the metadata storage area 31 gradually decreases.

  At time T <b> 25, the physical deletion processing unit 25 stops the physical deletion when the old generation metadata no longer exists in the metadata storage area 31.

<Third operation example>
FIG. 7 is a diagram illustrating a third operation example of the content receiving device 4. Here, the total amount of metadata stored in the metadata storage area 31 is determined by frequent user operations before the first catalog cache after the power-on of the content receiving device 4 is completed. An operation when the threshold value TH1 is exceeded will be described.

  At time T31, the content receiving device 4 is powered on. As a result, the catalog cache processing unit 21 starts catalog caching, and the total amount of metadata stored in the metadata storage area 31 gradually increases. Here, the management unit 23 describes the CRID and fragment version of each metadata acquired by the catalog cache in the management table 40. Further, the management unit 23 assigns generation information “1” to each metadata, and describes the generation information in the item “generation” of the management table 40. Further, the management unit 23 describes information representing the catalog cache in the item “catalog / user” of the management table 40. Further, the management unit 23 describes the generation information “1” in the item “current generation” of the management table 40.

  In addition, since the user operation is frequently performed after the power of the content receiving device 4 is turned on at time T31, the user cache processing unit 22 repeats the user cache and stores the metadata stored in the metadata storage area 31. The total amount of data increases dramatically. Here, the management unit 23 describes the CRID and fragment version of each metadata acquired by the user cache in the management table 40. Further, the management unit 23 assigns generation information “1” to each metadata, and describes the generation information in the item “generation” of the management table 40. In addition, the management unit 23 describes information representing the user cache in the item “catalog / user” of the management table 40.

  At time T32, before the catalog cache is completed, the total amount of metadata stored in the metadata storage area 31 exceeds the threshold value TH1. As a result, a predetermined deletion flag that can be referred to by the logical deletion processing unit 24 is set to “True”. Further, the catalog cache processing unit 21 stops the incomplete catalog cache at time T32.

  At time T <b> 33, the logical deletion processing unit 24 starts logical deletion when a user operation is performed after the deletion flag is set to “True” in a state where the catalog cache is incomplete. That is, by updating the generation information described in the item “current generation” of the management table 40 from “1” to “2”, the metadata of the previous generation is logically deleted collectively. The logical deletion is completed at time T34. As a result of logical deletion of the metadata stored in the metadata storage area 31 as a whole, the apparent amount of stored data becomes zero as shown by the thick broken line in the figure.

  At time T34, when the logical deletion is completed, the user cache processing unit 22 starts user cache, and the total amount of metadata stored in the metadata storage area 31 increases. The user cache is completed at time T35. Here, the management unit 23 describes the CRID and fragment version of each metadata acquired by the user cache in the management table 40. Further, the management unit 23 assigns generation information “2” to each metadata, and describes the generation information in the item “generation” of the management table 40. In addition, the management unit 23 describes information representing the user cache in the item “catalog / user” of the management table 40.

  When the logical deletion is executed, the catalog cache processing unit 21 starts the catalog cache again at time T35. The catalog cache is completed at time T36. Here, the management unit 23 describes the CRID and fragment version of each metadata acquired by the catalog cache in the management table 40. Further, the management unit 23 assigns generation information “2” to each metadata, and describes the generation information in the item “generation” of the management table 40. Further, the management unit 23 describes information representing the catalog cache in the item “catalog / user” of the management table 40.

  Here, the catalog cache processing unit 21 reacquires metadata described in the catalog information from the meta server 6. The management unit 23 refers to the management table 40, and the metadata of the old generation (generation “1” in this example) whose CRID and fragment version are the same as the reacquired metadata is stored in the metadata storage area 31. It is determined whether it is already stored. If the old generation metadata exists, the process of storing the reacquired metadata in the metadata storage area 31 is omitted, and the generation information of the old generation metadata is updated to the latest generation information ( In this example, it is rewritten to generation “2”). On the other hand, when the old generation metadata does not exist, a process of storing the reacquired metadata in the metadata storage area 31 is executed.

  Alternatively, the catalog cache processing unit 21 acquires metadata list information (list information) described in the latest catalog information from the meta server 6 prior to the reacquisition of metadata. When the metadata having the same CRID and fragment version as each metadata described in the list information is already stored in the metadata storage area 31, the management unit 23, The re-acquisition processing from the meta server 6 and the storage processing in the metadata storage area 31 are omitted, and the generation information of the metadata is rewritten to the latest generation information (generation “2” in this example). On the other hand, when metadata having the same CRID and fragment version as each metadata described in the list information is not stored in the metadata storage area 31, the metadata is acquired from the metadata server 6. Then, the process of storing in the metadata storage area 31 is executed. Thereby, since the data amount of the metadata transmitted from the meta server 6 to the content receiving device 4 is reduced, the load on the network 3 can be reduced and the time required for obtaining the metadata can be shortened.

  Returning to the description of FIG. 7, when the user cache is completed at time T <b> 35, the physical deletion processing unit 25 starts physical deletion. Here, the physical deletion processing unit 25 refers to the management table 40, and among all the metadata stored in the metadata storage area 31 at this time, the metadata whose generation information is different from the latest generation. The physical deletion is executed on the target (that is, the metadata to which the generation information of the previous generation is assigned). In this example, metadata to which generation information “1” is assigned is physically deleted. At this time, the physical deletion processing unit 25 performs the physical deletion by giving priority to the metadata acquired from the user cache over the metadata acquired from the catalog cache. Specifically, by referring to the item “catalog / user” in the management table 40, the metadata in which information representing the user cache is described in the item is preferentially physically deleted. When the physical deletion of the old generation metadata acquired in the user cache is completed, the physical deletion of the old generation metadata acquired in the catalog cache is started. As physical deletion progresses, the total amount of metadata stored in the metadata storage area 31 gradually decreases.

  At time T <b> 37, the physical deletion processing unit 25 stops the physical deletion when the old generation metadata no longer exists in the metadata storage area 31, and sets the deletion flag to “False”.

<Fourth operation example>
FIG. 8 is a diagram illustrating a fourth operation example of the content receiving device 4. Here, the operation when the total amount of metadata stored in the metadata storage area 31 exceeds the threshold value TH2 will be described.

  When a user operation is performed at time T41, the user cache processing unit 22 starts user cache, and the total amount of metadata stored in the metadata storage area 31 increases. The user cache is completed at time T43. Here, the management unit 23 describes the CRID and fragment version of each metadata acquired by the user cache in the management table 40. In addition, the management unit 23 assigns the latest generation information at that time to each metadata, and describes the generation information in the item “generation” of the management table 40. In addition, the management unit 23 describes information representing the user cache in the item “catalog / user” of the management table 40.

  At time T42, the total amount of metadata stored in the metadata storage area 31 exceeds the threshold value TH1. As a result, a predetermined deletion flag that can be referred to by the logical deletion processing unit 24 is set to “True”.

  At time T44, a user operation is performed. The logical deletion processing unit 24 starts logical deletion when a user operation is performed in a state where the deletion flag is set to “True”. That is, by updating the generation information described in the item “current generation” of the management table 40, the metadata of the previous generation is logically deleted collectively. The logical deletion is completed at time T45. As a result of logical deletion of the metadata stored in the metadata storage area 31 as a whole, the apparent amount of stored data becomes zero as shown by the thick broken line in the figure.

  At time T45, the user cache processing unit 22 starts user cache, and the total amount of metadata stored in the metadata storage area 31 increases. Here, the management unit 23 describes the CRID and fragment version of each metadata acquired by the user cache in the management table 40. In addition, the management unit 23 assigns the latest generation information at that time to each metadata, and describes the generation information in the item “generation” of the management table 40. In addition, the management unit 23 describes information representing the user cache in the item “catalog / user” of the management table 40.

  Further, when the logical deletion is executed, the catalog cache processing unit 21 starts the catalog cache again at time T45. As a result, the total amount of metadata stored in the metadata storage area 31 gradually increases. Here, the management unit 23 describes the CRID and fragment version of each metadata acquired by the catalog cache in the management table 40. In addition, the management unit 23 assigns the latest generation information at that time to each metadata, and describes the generation information in the item “generation” of the management table 40. Further, the management unit 23 describes information representing the catalog cache in the item “catalog / user” of the management table 40.

  Here, the catalog cache processing unit 21 reacquires metadata described in the catalog information from the meta server 6. The management unit 23 refers to the management table 40 to determine whether or not old-generation metadata having the same CRID and fragment version as the re-acquired metadata is already stored in the metadata storage area 31. To do. If the old generation metadata exists, the process of storing the reacquired metadata in the metadata storage area 31 is omitted, and the generation information of the old generation metadata is changed to the latest generation information. rewrite. On the other hand, when the old generation metadata does not exist, a process of storing the reacquired metadata in the metadata storage area 31 is executed.

  Alternatively, the catalog cache processing unit 21 acquires metadata list information (list information) described in the latest catalog information from the meta server 6 prior to the reacquisition of metadata. When the metadata having the same CRID and fragment version as each metadata described in the list information is already stored in the metadata storage area 31, the management unit 23, The re-acquisition process from the meta server 6 and the storage process to the metadata storage area 31 are omitted, and the generation information of the metadata is rewritten to the latest generation information. On the other hand, when metadata having the same CRID and fragment version as each metadata described in the list information is not stored in the metadata storage area 31, the metadata is acquired from the metadata server 6. Then, the process of storing in the metadata storage area 31 is executed. Thereby, since the data amount of the metadata transmitted from the meta server 6 to the content receiving device 4 is reduced, the load on the network 3 can be reduced and the time required for obtaining the metadata can be shortened.

  Returning to FIG. 8, at time T46, the total amount of metadata stored in the metadata storage area 31 exceeds the threshold value TH2.

  At time T47, the logical deletion processing unit 24 starts logical deletion when the total amount of metadata stored in the metadata storage area 31 exceeds the threshold value TH2. At the same time, the physical deletion processing unit 25 receives all metadata stored in the metadata storage area 31 when the total amount of metadata stored in the metadata storage area 31 exceeds the threshold value TH2. Start physical deletion of data. The physical deletion processing unit 25 stops the physical deletion when the metadata no longer exists in the metadata storage area 31 and sets the above-described deletion flag to “False”. The logical deletion and the physical deletion are completed at time T48. However, the logical deletion completion time and the physical deletion completion time do not necessarily match.

  As a result of the logical deletion, the catalog cache processing unit 21 starts catalog caching again at time T48. As a result, the total amount of metadata stored in the metadata storage area 31 gradually increases. Here, the management unit 23 describes the CRID and fragment version of each metadata acquired by the catalog cache in the management table 40. In addition, the management unit 23 assigns the latest generation information at that time to each metadata, and describes the generation information in the item “generation” of the management table 40. Further, the management unit 23 describes information representing the catalog cache in the item “catalog / user” of the management table 40. The catalog cache is completed at time T49.

<Summary>
According to the content receiving device 4 (content distribution system 1, program 12) according to the present embodiment, the logical deletion processing unit 24 stores data in the storage unit 30 (metadata storage area 31) when a predetermined condition is satisfied. The stored metadata is logically deleted at once, and the physical deletion processing unit 25 physically deletes the metadata logically deleted by the logical deletion processing unit 24 from the storage unit 30 after the logical deletion. By logically deleting the metadata stored in the storage unit 30 at once, the amount of data stored in the storage unit 30 is apparently zero, and the logically deleted metadata is stored after the logical deletion. Since it is physically deleted from the unit 30, it is possible to avoid a situation where the number of contents that can be distributed from the distribution source is limited by the storage capacity of the storage unit 30. In addition, the time required for logical deletion is extremely short, and physical deletion is sequentially performed in the background even if no user operation is performed. Therefore, it is possible to reduce the waiting time of the user. Furthermore, since the metadata stored in the storage unit 30 is logically deleted in a lump, it is possible to avoid display inconsistencies associated with deleting some of the metadata.

  Further, as shown in FIG. 5, according to the content receiving device 4 according to the present embodiment, the logical deletion processing unit 24 has the total data amount of the metadata stored in the storage unit 30 exceeding the threshold value TH1. When a user operation is subsequently performed, logical deletion is executed. Therefore, for example, after the catalog cache after power-on of the content receiving device 4 is completed, the amount of acquired data in the user cache becomes enormous due to frequent user operations, and the total amount of metadata is the threshold TH1. When the value exceeds, logical deletion can be appropriately executed.

  In addition, as shown in FIG. 6, according to the content receiving device 4 according to the present embodiment, the logical deletion processing unit 24 performs logical deletion when a user operation is performed after a predetermined periodic update time has elapsed. Run. Therefore, it is possible to appropriately execute the periodic update of the metadata stored in the storage unit 30.

  5 and 6, according to the content receiving device 4 according to the present embodiment, the physical deletion processing unit 25 starts physical deletion of metadata when the reacquisition of metadata is completed. To do. By executing physical deletion as background processing in this way, it is possible to avoid the occurrence of user waiting time associated with physical deletion. In addition, in order to physically delete the metadata stored in the storage unit 30 before the reacquisition, the metadata reacquired in the catalog cache and the metadata acquired in the user cache after the reacquisition are physically deleted. Without being stored in the storage unit 30. As a result, it is possible to shorten the time required to display a screen with a high reference frequency, and thus it is possible to improve user convenience.

  As shown in FIG. 7, according to the content receiving device 4 according to the present embodiment, the logical deletion processing unit 24 stores the storage unit 30 before the catalog cache after the content receiving device 4 is powered on is completed. When the total data amount of the metadata stored in exceeds the threshold value TH1, and a user operation is performed thereafter, logical deletion is executed. Therefore, for example, the amount of data acquired in the user cache becomes enormous due to frequent user operations after the content receiving device 4 is turned on, and the total data amount of the metadata becomes the threshold value TH1 before the catalog cache is completed. When it exceeds, logical deletion can be appropriately executed.

  As shown in FIG. 7, according to the content receiving device 4 according to the present embodiment, the physical deletion processing unit 25 starts physical deletion after the logical deletion is completed. By executing physical deletion as background processing in this way, it is possible to avoid the occurrence of user waiting time associated with physical deletion. In addition, physical deletion is started upon completion of logical deletion without waiting for completion of reacquisition of metadata by the catalog cache after logical deletion. Therefore, since physical deletion can be started at an early stage, it is possible to avoid a situation in which the total data amount of metadata stored in the storage unit 30 approaches the maximum storage capacity of the storage unit 30 due to a subsequent catalog cache. Become.

  Also, as shown in FIG. 7, according to the content receiving device 4 according to the present embodiment, the physical deletion processing unit 25 prioritizes the metadata acquired by the user cache over the metadata acquired by the catalog cache. And perform physical deletion. Thereby, the metadata acquired in the catalog cache can be left in the storage unit 30 without being physically deleted. As a result, when the metadata is reacquired by the next catalog cache, the storage process in the storage unit 30 can be omitted for the same metadata already stored in the storage unit 30. It is possible to reduce the time required for processing.

  Further, as shown in FIG. 8, according to the content receiving device 4 according to the present embodiment, the logical deletion processing unit 24 has a total data amount of metadata stored in the storage unit 30 of the storage unit 30. When the threshold TH2 set according to the upper limit value of the storage capacity is exceeded, logical deletion is executed. Therefore, for example, when the amount of acquired data in the catalog cache or the user cache becomes enormous and the total amount of metadata approaches the upper limit value of the storage capacity of the storage unit 30, logical deletion can be appropriately executed. It becomes.

  Also, as shown in FIG. 8, according to the content receiving device 4 according to the present embodiment, the physical deletion processing unit 25 starts physical deletion together with the start of logical deletion. Since the physical deletion can be started at an early stage by starting the physical deletion together with the start of the logical deletion without waiting for completion of the reacquisition of the metadata by the catalog cache after the logical deletion, the metadata stored in the storage unit 30 It is possible to reduce the total amount of data immediately.

  Further, according to the content receiving device 4 according to the present embodiment, the management unit 23 assigns generation information representing the generation of metadata to the metadata when storing the acquired metadata in the storage unit 30. , Manage the generation of each metadata. As a result, it is possible to easily specify the metadata to be physically deleted from the plurality of metadata stored in the storage unit 30 based on the generation information.

  Further, according to the content reception device 4 according to the present embodiment, the physical deletion processing unit 25 performs physical deletion on the old generation metadata, and the old generation metadata exists in the storage unit 30. Stop physical deletion when there is no more. As a result, the latest generation of metadata can be left in the storage unit 30 without being physically deleted. As a result, it is possible to shorten the time required to display a screen with a high reference frequency, and thus it is possible to improve user convenience.

  Further, according to the content reception device 4 according to the present embodiment, the management unit 23 stores the old generation metadata having the same CRID and fragment version as the reacquired metadata stored in the storage unit 30. The generation information of the old generation metadata is rewritten to the latest generation information. As a result, for the same metadata as the metadata already stored in the storage unit 30, it is only necessary to rewrite the generation information, and the storage process in the storage unit 30 can be omitted. It can be shortened.

  Further, according to the content receiving device 4 according to the present embodiment, the management unit 23 does not store the old generation metadata having the same CRID and fragment version as the reacquired metadata in the storage unit 30. The re-acquired metadata is stored in the storage unit 30. As a result, the latest metadata including update data and additional data that have not been acquired in the previous catalog cache can be stored in the storage unit 30.

  Further, according to the content receiving device 4 according to the present embodiment, the catalog cache processing unit 21 receives the metadata list information described in the latest catalog information from the meta server 6 when the logical deletion is executed. get. When the metadata having the same CRID and fragment version as that of each metadata described in the list information is stored in the storage unit 30, the management unit 23 updates the generation information of the metadata. Rewrite the generation information. As a result, with respect to the same metadata as the metadata already stored in the storage unit 30, it is only necessary to rewrite the generation information. Since it can be omitted, the load on the meta server 6 and the network 3 can be reduced and the time required for processing can be shortened.

  Further, according to the content receiving device 4 according to the present embodiment, the management unit 23 stores in the storage unit 30 metadata that has the same CRID and fragment version as each metadata described in the list information. If not, the metadata is acquired from the meta server 6 and stored in the storage unit 30. As a result, the latest metadata including update data and additional data that have not been acquired in the previous catalog cache can be stored in the storage unit 30.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined not by the above-mentioned meaning but by the scope of claims for patent, and is intended to include all modifications within the scope and meaning equivalent to the scope of claims for patent. For example, in the above-described embodiment, logical deletion and physical deletion are performed using generation information, but those targets may be specified by update time or the like.

DESCRIPTION OF SYMBOLS 1 Content delivery system 2 Content transmission apparatus 3 Network 4 Content reception apparatus 6 Meta server 12 Program 21 Catalog cache processing part 22 User cache processing part 23 Management part 24 Logical deletion processing part 25 Physical deletion processing part 30 Storage part 31 Metadata storage area 32 Management table storage area 40 Management table

Claims (17)

And serial憶部,
And catalog cache processing unit for executing a catalog cache is a process of storing predetermined and attribute data in the storage unit and obtained from the server for the screen construction related content,
A user cache processing unit that executes a user cache that is a process of acquiring attribute data necessary for the screen construction according to a user operation related to the content from a server and storing the attribute data in the storage unit;
When a predetermined condition is satisfied, a logical deletion processing unit that executes logical deletion to exclude the attribute data stored in the storage unit from the target used for the screen construction ;
A physical deletion processing unit that performs a physical delete for deleting the attribute data the logical deletion is performed by the logical deletion processing unit, wherein even without the user operation is performed from the storage unit,
A content receiving device. The logical deletion processing section, as the predetermined condition, the total data amount of the attribute data stored in the storage unit, the predetermined attribute data to a storage capacity smaller than value of the storage unit of greater than a predetermined threshold which is set to a value larger than the data amount of total, if subsequently the user operation is performed, the performing a logical deletion, the content receiving apparatus according to claim 1. The logical deletion processing unit, as the predetermined condition, when the user operation is performed after a predetermined periodic update time, executes the logical deletion, the content receiving apparatus according to claim 1. The catalog cache processing unit, when the logical deletion is performed, re-acquires the predetermined attribute data,
The physical deletion processing unit, when the re-acquisition of the predetermined attribute data is completed, initiates the physical deletion of the attribute data stored in the storage unit before reacquired to claim 2 or 3 The content receiving device described. The logical deletion processing section, as the predetermined condition, before the catalog cache after power of the content receiving apparatus is complete, the total data amount of the attribute data stored in the storage unit , exceeds a predetermined threshold value a storage capacity smaller value is set to a value larger than the total data amount of the predetermined attribute data of the storage unit, when subsequently the user operation is performed, the The content receiving apparatus according to claim 1, wherein logical deletion is executed. The physical deletion processing section starts the physical removed after completion of the logical deletion, the content receiving apparatus according to claim 5. The physical deletion processing unit executes the physical deletion preferentially to the attribute data acquired by the user cache than obtaining said predetermined attribute data was by the catalog cache to claim 5 or 6 The content receiving device described. The logical deletion processing section, as the predetermined condition, the total data amount of the attribute data stored in the storage unit, a predetermined set according to the upper limit of the storage capacity of the storage unit The content receiving apparatus according to claim 1, wherein the logical deletion is executed when a threshold value is exceeded. The physical deletion processing unit starts said physical deletion with the start of the logical deletion, the content receiving apparatus according to claim 8. Further comprising a management unit for managing the current generation representing the target to be used for the attribute data, and the screen construction has been stored in the storage unit,
The management unit, when storing the attribute data acquired in the storage unit, the current based on the generation, by allocating the generation information indicating the generation of the attribute data on the attribute data, for each said attribute data The content receiving apparatus according to claim 1, which manages generations. The physical deletion processing unit, the currently running the physical delete the previous older generation of the attribute data as a target from the generation, wherein the physical deleted when older generation of the attribute data is no longer present in the storage portion The content receiving device according to claim 10, wherein the content receiving device is stopped. The logical deletion processing unit sets the next generation of the current generation as a new current generation as the logical deletion,
The catalog cache processing unit, when the logical deletion is performed, re-acquires the predetermined attribute data,
The management unit re-acquires when the attribute data of the previous generation before the current generation whose identification information and version information are the same as the predetermined attribute data re-acquired is stored in the storage unit. The content receiving apparatus according to claim 10 or 11, wherein the generation information of the attribute data of the old generation is rewritten to the current generation instead of storing the attribute data that has been generated in the storage unit. The catalog cache processing unit, when the logical deletion is performed, re-acquires the predetermined attribute data,
The management unit re-acquires when the attribute data of the previous generation before the current generation whose identification information and version information are the same as the predetermined attribute data acquired again is not stored in the storage unit. is the attribute data stored in the storage unit has, content receiving apparatus according to claim 10 or 11. The catalog cache processing unit obtains the latest list information of the predetermined attribute data from the server when the logical deletion is executed,
The management unit, if the attribute data the predetermined attribute data and identification information and version information that is described in the list information is the same are stored in the storage unit, the newest predetermined attribute data The content receiving device according to claim 10 or 11, wherein the generation information of the attribute data stored in the storage unit is rewritten to the current generation instead of acquisition of the information. The catalog cache processing unit obtains the latest list information of the predetermined attribute data from the server when the logical deletion is executed,
The management unit, when the attribute data the predetermined attribute data and identification information and version information that is described in the list information is the same is not stored in the storage unit, the newest predetermined attribute The content receiving device according to claim 10 or 11, wherein data is acquired from a server and stored in the storage unit. A content transmission device;
A content receiving device;
A server holding attribute data for screen construction related to the content transmitted from the content transmission device;
With
The content receiving device is:
And serial憶部,
A catalog cache processing unit that executes a catalog cache that is a process of acquiring predetermined attribute data from the server and storing the predetermined attribute data in the storage unit;
A user cache processing unit that executes a user cache that is a process of acquiring attribute data required for the screen construction according to a user operation from the server and storing the attribute data in the storage unit;
When a predetermined condition is satisfied, a logical deletion processing unit that executes logical deletion to exclude the attribute data stored in the storage unit from the target used for the screen construction ;
A physical deletion processing unit that performs a physical delete for deleting the attribute data the logical deletion is performed by the logical deletion processing unit, wherein even without the user operation is performed from the storage unit,
A content distribution system. The computer installed in the content receiving device
And catalog cache processing means for performing a catalog cache is a process of storing to the serial憶部acquire predetermined attribute data from the server for the screen construction related content,
User cache processing means for executing user cache, which is processing for acquiring attribute data necessary for the screen construction according to a user operation related to the content from a server and storing the attribute data in the storage unit;
Logical deletion processing means for performing logical deletion to exclude the attribute data stored in the storage unit from the target used for screen construction when a predetermined condition is satisfied;
The logical deletion processing said attribute data to which the logical deletion is performed by means, physical deletion processing means for performing a physical delete for deleting from said memory unit even if the user operation is not performed,
Program to function as.

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