CN114647625A - A method, device and storage medium for data caching - Google Patents

Abstract

The embodiment of the application discloses a data caching method, a data caching device and a storage medium, which are applied to a caching node comprising a general node and a service node, wherein the method comprises the following steps: when the service operates the data of the bottom layer, judging whether the cache node is hit; when the cache node is hit, if the periodic service hits the universal node, selecting the service node, copying the content of the hit universal node into the selected service node, and releasing the hit universal node; when the cache node is not hit, if the service is a general service, selecting the general node, and copying the data targeted by the operation to the selected general node; and if the service is a periodic service, selecting a service node, and copying data needing to be cached by the periodic service to the selected service node. By the scheme, the cache data of the periodic service can be maximally persisted.

Description

A method, device and storage medium for data caching

technical field

The embodiments of the present application relate to, but are not limited to, the field of caching, and in particular, relate to a method, an apparatus, and a storage medium for data caching.

Background technique

Cache node types are generally divided into file types and directory types. From the actual usage scenario, access to files and directories is the most frequent. The data in the monitoring field has a very significant feature, the amount of data is large and growing steadily. Due to the limited space, a full coverage strategy will be formulated to protect the recording retention period, and at the same time, business operations such as retrieval and playback are also interspersed. For cache nodes, services such as retrieval and playback are irregular, and the data accessed is also relatively random. ; However, for periodic services such as full coverage services, as a persistently running service, the access data area of this service is relatively fixed, that is to say, when accessing data, the oldest user directory and file are deleted. In normal business logic, scan the bottom layer to obtain the oldest files and directories and store them in the cache information, which will be occupied by services such as retrieval or playback later. As a result, when the next full coverage occurs, there will be no results from the previous scan in the cache node. , the underlying files need to be rescanned, and the cache cannot combine the actual business needs to persist the node information required by some businesses.

SUMMARY OF THE INVENTION

The following is an overview of the topics detailed in this article. This summary is not intended to limit the scope of protection of the claims.

The embodiments of the present disclosure disclose a method, an apparatus and a storage medium for data caching, which can achieve maximum persistence of cached data for periodic services.

The present disclosure provides a method for data caching, which is applied to data caching for a cache node including a general node and a service node. The method includes:

When the business operates on the underlying data, determine whether the cache node is hit;

When hitting the cache node, if the periodic service hits the general node, select the business node, copy the content of the hit general node to the selected business node, and release the hit general node;

When the cache node is not hit, if the service is a general service, a general node is selected, and the data targeted by the operation is copied to the selected general node; if the service is a periodic service, a service node is selected, and the periodic service is selected. Sexual business needs to copy the cached data to the selected business node.

In an exemplary embodiment, a plurality of general nodes are connected in sequence to form a general node segment, and a plurality of service nodes are connected in sequence to form a service node segment; wherein, the cache nodes in the general node segment and the service node segment respectively follow a first-in-first-out order. out the principle;

The cache node further includes a head node for storing address information of the cache node.

In an exemplary embodiment, the cache nodes form a linked list of nodes;

The head node includes a linked list header and a service head node, and the address information is the address of the service head node; the linked list header is used to store the address of the service head node; the node linked list sequentially includes a linked list header, a general node segment, Service head node and service node segment.

In an exemplary embodiment, the selecting a service node includes:

According to the address information in the head node, select one or more service nodes located at the beginning of the service node segment;

The selection of general nodes includes:

According to the address information in the head node, one or more general nodes located at the beginning of the general node segment are selected.

In an exemplary embodiment, copying the content in the hit general node to the selected service node, and releasing the hit general node includes:

Use the content in the hit general node to update the selected service node, and move the selected service node to the end of the service node segment;

The contents of the hit general node are cleared, and the hit general node is moved to the beginning of the general node segment.

In an exemplary embodiment, the copying of the data targeted by the operation to the selected general node includes:

updating the content of the generic node with the data targeted by the operation, moving the generic node to the end of the generic node segment;

The copying of the data that needs to be cached for the periodic service to the selected service node includes:

The service node is updated using the data that the periodic service needs to cache, and the service node is moved to the end of the service node segment.

In an exemplary embodiment, when the cache node is hit, the method further includes:

If the general service hits the general node or service node, then judge the type of the general service, if it is a write operation, update the content of the hit cache node; if it is a delete operation, clear the content of the hit cache node; if it is a read operation Then access the content of the hit cache node;

If the periodic service hits the service node, the content of the hit service node is accessed.

In an exemplary embodiment, the cache node is divided into multiple node linked lists according to different data types; each node linked list includes a general node and a service node;

When the business operates on the underlying data, determining whether to hit the cache node includes:

When the business operates the underlying data, select the corresponding node list according to the data type of the data to be operated, traverse the selected node list, and determine whether the cache node is hit;

The selecting a service node includes: selecting a service node in the selected node linked list;

The selecting a general node includes: selecting a general node in the selected node linked list.

The present disclosure also provides an apparatus including a memory and a processor; it is applied to data caching for a cache node including a general node and a service node, the memory is used for storing a program for data caching, and the processor is used for data caching The program for data caching is read and executed, and the method described in any one of the foregoing embodiments is executed.

The present disclosure also provides a storage medium, where a program for data caching based on a cache node including a general node and a service node is stored in the storage medium, and the program is configured to execute any one of the foregoing embodiments at runtime method described in item.

The embodiment of the present disclosure discloses a data cache method, device and storage medium, which are applied to a cache node including a general node and a service node. The method includes: when a service operates on underlying data, judging whether the cache is hit or not node; when hitting the cache node, if the periodic business hits the general node, select the business node, copy the content of the hit general node to the selected business node, and release the hit general node; When caching a node, if the business is a general business, select a general node, and copy the data for the operation to the selected general node; if the business is a periodic business, select a business node, and the periodic business needs The cached data is copied to the selected business node. With the solution of the present disclosure, it is possible to ensure that the cached data of the periodic service is not covered by the general service without occupying more caches, thereby ensuring that the cached data of the periodic service can be persisted to the greatest extent.

Other aspects will become apparent upon reading and understanding of the drawings and detailed description.

Description of drawings

1 is a flowchart of a method for data caching according to an embodiment of the present application;

FIG. 2 is a schematic diagram of a hierarchical structure of cache nodes in some exemplary embodiments;

FIG. 3 is a schematic diagram of a segmented organization of a singly linked list in some exemplary embodiments;

Figure 4a is a schematic diagram of a node moving in a linked list of nodes used in some exemplary embodiments;

4b is a schematic diagram of the node linked list after the node used in some exemplary embodiments is moved;

5 is a process flow diagram of data caching performed by periodic services in some exemplary embodiments;

FIG. 6 is a process flow diagram of data caching performed by a general service in some exemplary embodiments;

FIG. 7 is a schematic diagram of a cache node after initialization layering and segmentation in some exemplary embodiments;

FIG. 8 is a schematic diagram of a directory node linked list in some exemplary embodiments;

9 is a schematic diagram of a file node linked list in some exemplary embodiments;

FIG. 10 is a schematic diagram of a changed directory node linked list in some exemplary embodiments;

11 is a schematic diagram of a changed file node linked list in some exemplary embodiments;

FIG. 12 is a schematic diagram of an apparatus according to an embodiment of the present application.

Detailed ways

Hereinafter, the embodiments of the present application will be described in detail with reference to the accompanying drawings. It should be noted that, in the case of no conflict, the embodiments of the present application and the features in the embodiments may be arbitrarily combined with each other.

The steps shown in the flowcharts of the figures may be performed in a computer system, such as a set of computer-executable instructions. Also, although a logical order is shown in the flowcharts, in some cases the steps shown or described may be performed in an order different from that herein.

In one solution, a cache is specially allocated for periodic services, and the newly developed cache is dedicated to serving periodic services and not provided for general services. However, since the newly opened cache space is not provided for general services, when accessing the general services, even if the data to be accessed by the general services is already cached in the newly opened cache space, the general services still need to check the underlying data, and then The general cache is then occupied, that is, there will be two caches for the same underlying data, resulting in a waste of cache space resources; and when the general business needs to write the underlying data corresponding to the newly opened cache, the general cache needs to be updated at the same time. and the corresponding content in the newly developed cache, otherwise the cache and the bottom layer will be inconsistent, and the process of protection is more complicated.

An embodiment of the present disclosure provides a method for data caching, which is applied to a cache node including a general node and a service node. As shown in FIG. 1 , the method includes:

S100, when the business operates on the underlying data, determine whether the cache node is hit;

Step S210 is performed when the cache node is hit, and step S220 is performed when the cache node is not hit.

S210, if the periodic service hits the general node, then select the service node, copy the content in the hit general node to the selected service node, and release the hit general node;

S220. If the service is a general service, select a general node, and copy the data targeted by the operation to the selected general node; if the service is a periodic service, select a service node, and the periodic service needs to be cached The data is copied to the selected business node.

In this embodiment, the hit cache node may refer to the data targeted by the general service operation, or the data that needs to be cached for the periodic service has been stored in the cache node, which is used to save the data targeted by the general service operation, or the periodic service The cache node of the data that needs to be cached, that is, the hit cache node.

In this embodiment, the underlying data may, but is not limited to, refer to data on a hard disk.

In this embodiment, since the cache nodes are divided into general nodes and service nodes, and when a new cache needs to be added (ie, the cache node is not hit), the corresponding cache nodes are selected for the general service and the periodic service respectively, so the general service can be avoided. When using the cache, the existing cached data of the periodic service is overwritten, which can ensure the maximum persistence of the cached data of the periodic service; when the periodic service hits the general node, the content in the general node is replaced with the service node, which can Avoiding the existence of two caches for the same data saves cache resources and makes it easier to ensure the consistency of cache and underlying data.

In this embodiment, during the service operation, search is performed in all the cache nodes, that is, both the general service and the periodic service can access each other's cache nodes, so the cache hit rate of the periodic service is increased, and the general service is also guaranteed. Cache hit rate.

In this embodiment, the respective proportions of service nodes and general-purpose nodes in the total cache nodes can be set by themselves according to requirements.

In an exemplary embodiment, a plurality of general nodes are connected in sequence to form a general node segment, and a plurality of service nodes are connected in sequence to form a service node segment; wherein, the cache nodes in the general node segment and the service node segment follow a first-in-first-out sequence, respectively. in principle;

The cache node further includes a head node for storing address information of the cache node.

Wherein, the head node may include two parts, which are respectively located at the beginning of the general node segment and the service node segment. Or there is only one head node, which is located at the beginning of any node segment in the general node segment and the service node segment, and uses address information to indicate the address of the other node segment.

In this embodiment, for example, the cache node may be placed in a node linked list, and the head node may include a linked list header and a service header node, and the node linked list sequentially includes: a linked list header, a general node segment, a service header node, and a service node segment. Alternatively, the service node segment can be placed in front of the general node segment, and the head node correspondingly includes a linked list header and a general head node located between the service node segment and the general node segment.

In this embodiment, the cache nodes in the general node segment and the service node segment respectively follow the first-in-first-out principle may refer to:

After accessing a general node or updating the content of a general node, move the general node to the end of the general node segment where the general node is located; after clearing the content of a general node, move the general node to the location where the general node is located The beginning of the general node segment; when the general node needs to be selected, it is selected from the beginning of the general node segment;

After accessing a service node or updating the content of a service node, move the service node to the end of the service node segment where the service node is located; after clearing the content of a service node, move the service node to where the service node is located The beginning of the business node segment; when the business node needs to be selected, it is selected from the beginning of the business node segment.

In other embodiments, multiple general-purpose nodes/service nodes are not necessarily adjacent to each other to form a node segment, as long as the address of each general-purpose node/service node is recorded; if FIFO (First In First Out, first in first out) is to be satisfied In principle, the latest usage (including access and update) time of each general node/service node can be recorded, and the FIFO is executed according to the time.

In this embodiment, the cache nodes may form a node linked list; or the cache nodes may be organized according to other storage structures.

When a node linked list is formed, the head node includes a linked list header and a service head node, and the address information is the address of the service head node; the linked list header is used to store the address of the service head node; the node linked list sequentially includes a linked list Header, general node segment, service header node, and service node segment.

In this embodiment, the selecting a service node may include:

According to the address information in the head node, select one or more service nodes located at the beginning of the service node segment;

The selection of general nodes includes:

According to the address information in the head node, one or more general nodes located at the beginning of the general node segment are selected.

In this embodiment, copying the content of the hit general node to the selected service node, and releasing the hit general node may include:

Use the content in the hit general node to update the selected service node, and move the selected service node to the end of the service node segment;

The contents of the hit general node are cleared, and the hit general node is moved to the beginning of the general node segment.

In this embodiment, the copying of the data targeted by the operation to the selected general node may include:

updating the content of the generic node with the data targeted by the operation, moving the generic node to the end of the generic node segment;

The copying of the data that needs to be cached for the periodic service to the selected service node includes:

The service node is updated using the data that the periodic service needs to cache, and the service node is moved to the end of the service node segment.

Among them, when updating the content of a cache node (general node or service node), if the cache node is idle (that is, there is no content in it), the corresponding data can be directly copied to the cache node; if the cache node is not idle, Then, it is necessary to clear the content of the cache node and then copy the corresponding data to the cache node.

In an exemplary embodiment, the step S210 further includes:

If the general service hits the general node or service node, then judge the type of the general service, if it is a write operation, update the content of the hit cache node; if it is a delete operation, clear the content of the hit cache node; if it is a read operation Then access the content of the hit cache node;

If the periodic service hits the service node, the content of the hit cache node is accessed.

In this embodiment, if the general node and the service node respectively constitute the general node segment and the service node segment, after updating or accessing, the updated or accessed cache node can be moved to the end of the corresponding node segment; after clearing the cache node, the Place the cache node at the beginning of the corresponding node segment.

In an exemplary embodiment, the cache node is divided into multiple node linked lists according to different data types; each node linked list includes a general node and a service node;

When the business operates on the underlying data, determining whether to hit the cache node includes:

When the business operates the underlying data, select the corresponding node list according to the data type of the data to be operated, traverse the selected node list, and determine whether the cache node is hit;

The selecting a service node includes: selecting a service node in the selected node linked list;

The selecting a general node includes: selecting a general node from the selected node linked list.

In this embodiment, the data types may include, but are not limited to, formats, directories, and files; correspondingly, the node linked list may include a format node linked list, a directory node linked list, and a file node linked list. In practical applications, you can set the number of node linked lists according to your needs.

In this embodiment, the general node and the service node in each node linked list can respectively form a general node segment and a general node segment, and each follow the FIFO principle; when selecting the location of the cache node or mobile cache node in the node segment, it is In the corresponding node segment in the corresponding node linked list. For example, if a general business wants to write a file, it is to check whether the cache node is hit in the file node linked list. If there is no hit, the general node is selected at the beginning of the general node segment of the file node linked list; if the general node is hit, it is updated. After the hit common node, put the hit common node at the end of the common node segment of the file node linked list; if the business node is hit, update the hit common node and put the hit common node in the file node The last of the business node segment of the linked list.

In this embodiment, the cache node may further include a cache node header, which is used to store addresses of node linked lists corresponding to different data types.

The above-described embodiments are described below with three examples.

Example 1

This example presents a solution for dividing cache nodes according to data types and service types, and organizes cache nodes in a hierarchical + segmented mode.

Among them, the layering is shown in Figure 2, which means that the cache nodes are divided into multiple node linked lists according to data types, such as the file node linked list and the directory node linked list in Figure 2, and each node linked list has multiple cache nodes. The headers of different node linked lists are stored hierarchically in the cache node header. When a service request is received, according to the data type for which the request is directed, the cache node is searched in the node list corresponding to the data type.

Segmentation means that in each node linked list, the cache nodes are divided into general node segments and service node segments according to the corresponding service type; for example, a node linked list contains 3 general nodes and 2 service nodes, the node linked list As shown in Figure 3, the first is the head of the linked list, followed by the general node 1, the general node 2, the general node 3, the service head node, the service node 1, the service node 2 and the tail of the linked list.

Among them, the head of the linked list is used to record the address of the service head node, which is convenient for the release of the general node and the service node. The different node segments in the cache node each satisfy the FIFO (first in first out) principle. The tail here does not refer to the tail of the entire linked list, but to the tail of the node segment (for example, in Figure 3, the tail of the general node segment is the service head node. , the tail of the business node is the tail of the linked list), the general node segment and the business node segment follow this rule, which satisfies the principle of software local access.

A schematic diagram of the FIFO principle is shown in Figure 4a and Figure 4b. Fig. 4a is a schematic diagram of the used node moving in the node linked list, and Fig. 4b is a schematic diagram of the node linked list after the movement.

For a service node, when applying for a service node, obtain a service node (such as node 5 in Figure 4a) after the service head node according to the address of the service head node recorded in the head; after the use (update or access) is completed, The business node needs to be released to the end of the overall linked list, that is, at the end of the business node segment. For example, as shown by the arrow in Figure 4a, node 5 needs to be moved to the end of the business node segment, as shown in Figure 4b.

For a general node, when applying for a general node, a general node (such as node 1 in Figure 4a) is taken from the head. After the use is completed, the general node needs to be released before the service head node, that is, the general node segment. The tail, for example, as shown by the arrow in Figure 4a, needs to move node 1 to the tail of the general node segment, as shown in Figure 4b after the movement.

In this example, all services involving the cache need to traverse the entire linked list, so as to improve the reusability of the cache and ensure the consistency between the cache and the underlying layer; when a cache node is hit, if it is a write operation, the hit cache is updated The content of the node, and the cache node is placed at the end of the corresponding node segment of the corresponding linked list; if it is a delete operation, the content of the hit cache node is cleared, and the cache node is placed at the head of the corresponding node segment of the corresponding linked list; if it is For read operations, the content of the hit cache node is not modified, and after access, the cache node is placed at the end of the corresponding node segment of the corresponding linked list.

In this example, according to the actual business requirements, how to design the layer and segment can be specified by the user. For example, it can be calculated by the calculation method specified by the user. The calculation method of the cache size can also be calculated by the user specified algorithm. An exemplary calculation method can be : (capacity (bytes)>>40)*1MB.

Example 2

This example presents the processing flow of data caching for different types of services, which is implemented based on the layered + segmented structure in Example 1.

The processing flow of data caching for periodic services is shown in Figure 5, including:

501. Acquire the head of the corresponding node linked list according to the data type involved in the business.

The subsequent steps are all performed in the corresponding node linked list, and the general node segment and the service node segment mentioned are both node segments in the node linked list.

502. Determine whether the cache node is hit; if there is no hit, go to step 503, and if it hits, go to step 504.

503. Select a service node from the beginning of the service node segment, update the service node with data that needs to be cached for the periodic service (data obtained by scanning the hard disk), and then place the service node at the end of the service node segment.

504. Determine whether the hit is a general node; if so, go to 505, and if not, go to 506.

505. Select a business node from the beginning of the business node segment, update the selected business node with the content in the hit general node, and then place the selected business node at the end of the business node segment; put the hit general node After emptying, put it at the beginning of the general node segment.

506. Put the hit service node at the end of the service node segment.

The processing flow of data caching for general services is shown in Figure 6, including:

601. Acquire a corresponding node linked list according to the data type involved in the service.

The subsequent steps are all performed in the corresponding node linked list, and the general node segment and the service node segment mentioned are both node segments in the node linked list.

602. Determine whether the cache node is hit; if there is no hit, go to step 603, and if it hits (whether it is a general node or a service node), go to step 604.

603. Select a general node from the beginning of the general node segment, update the general node with the data targeted by the general service (data obtained by scanning the hard disk), and then place the general node at the end of the general node segment.

604. Determine the operation type of the general service, if it is a write operation, go to 605, if it is a delete operation, go to 606, and if it is a read operation, go to 607.

605. Update the hit cache node according to the data targeted by the write operation, and then place the cache node at the end of the corresponding node segment.

606. Clear the content of the hit cache node, and then place the cache node at the beginning of the corresponding node segment.

607. After accessing the hit cache node, place the cache node at the end of the corresponding node segment.

Example three

This example uses the actual stored procedure of a camera as an example to illustrate the process of data caching.

In the cloud storage system, assume that a certain camera name is Tmpipc123, the file storage directory rule is Tmpipc123 as the root directory, and the first subdirectory named after the year (such as 2020) is established below, and the first subdirectory is established under the name of the month In the second subdirectory (such as 10), a third subdirectory named after the day (such as 01, 02, . , named file X, where X is the serial number starting from 1. For example, the first file collected on October 1, 2020 is Tmpipc123/2020/10/01/file1, with an average of one file every 2 hours and 12 files per day.

First, the cache nodes allocated in the cloud storage system are hierarchically set according to a given business type, and different layers cache data of different data types; in this example, the data types include: files, directories, and formats;

When performing hierarchical setting, the cache nodes allocated in the cloud storage system are divided into multi-layer node linked lists according to different data types, including: file node linked list, directory node linked list and format node linked list.

Set the allocation ratio of cache space according to the cache size occupied by different data types during layering;

It can be set according to requirements, for example: the camera configuration retention period is 30 days, the cache size is specified as 1MB, and a single cache node is 4KB; the cache node of the file type is accessed the most, so the cache node of the file type is set to account for 50% of the overall cache space. , the cache nodes of directory type and format type are allocated 3:1 in the remaining cache space, and the cache size is calculated by the calculation method specified by the user. The cache size calculation strategy adopted in this example is:

(Camera capacity (bytes)>>40)*1MB.

After the cache nodes are layered, the situation is as follows:

Format layer: 32 nodes for caching file system index format information;

Directory layer: 96 nodes for caching directory node information;

File layer: 128 nodes for caching file index information;

After layering, each layer of nodes is segmented, and the node segments in each node linked list include: general node segments and business node segments;

In this example, the general node is used to cache the relevant data of the general service; the service node is used to cache the relevant data of the periodic service specially serving a specific service; in this example, the periodic service is designated as a full coverage service. It can be set according to the user's needs. The general node segment is set to account for 75%; the business node segment is set to account for 25%; that is, the business nodes in the format node list are 8 nodes, and the directory node list is 24. There are 32 business nodes in the file node linked list.

After the initialization process including the above layering and segmentation, the cache node is shown in Figure 7.

After the camera starts to work, the data within the preset time period is stored;

In this example, it is assumed that the work starts from 2020/10/1, and the cache node has stored the camera's photos for one month on 2020/10/30, that is, the current camera has been stored from 2020/10/01 to 2020/10/30, A total of 12*30=360 files, directory 3 (one for each of the root directory, the first subdirectory, and the second subdirectory)+30 (30 third subdirectories)=33;

On 2020/10/30, the storage of the node list of each layer is as follows (the format data can be used to record the basic information such as the overall capacity and time of the current camera, and can be used for business query. In order to simplify the description, the format node list will not be shown later):

The list of directory nodes is shown in Figure 8. Currently, there is no data in the business node segment. In the general node segment: 33 general nodes are used. It is also accessed when the file of 2020/10/30 is updated, so the third subdirectory corresponding to date 30 is placed at the end of the general node segment) and the third subdirectory corresponding to date 30.

The file node list is shown in Figure 9. Currently, there is no data in the business node segment. In the general node segment, all general nodes are used, and 96 files for 8 days from 2020/10/23-2020/10/30 are saved.

When a file is continued to be stored, the execution of the full coverage service is triggered, and after the full coverage service deletes a file, the cache distribution changes, and the situation after the directory node linked list changes is shown in Figure 10. For the full coverage task, you need to scan the oldest directory and put it into the business node, that is, you need to put the four directories of Tmpipc123, 2020, 10, and 01 into the business node; the scan will find that these four directories are in the general node, then Four business nodes are selected, the four directories in the general node are copied to the four business nodes respectively, and then the four general nodes originally used to save the four directories are released.

The situation after the file node linked list changes is shown in Figure 11. For file type data, since the full coverage task is performed, the oldest files (ie, 12 files of 2020/10/01) need to be scanned and put into the business node , because these files are not in the cache node of the file node linked list, they can be scanned from the bottom and put into the business node.

In this example, only one day's video is scanned for the full coverage service as an example. If the service node has enough space, it can be set to cache the oldest several days of video at a time for full coverage.

In addition, if the operation of deleting the oldest file and directory is triggered when a service other than the full coverage service is executed, it is determined whether the deletion is triggered because the service needs to perform a write operation or a delete operation, and if it is determined to perform a write operation (such as Modify or replace the oldest file and directory), and hit the business node in the directory node linked list and the file node linked list, then update the content of the hit business node and place the business node at the end of the business node segment; if the judgment is yes When the delete operation is performed and the service node in the directory node list and the file node list is hit, the content of the hit service node is cleared and the service node is placed at the beginning of the service node segment.

In this example, after the full coverage service is executed, the oldest directory and file are cached in the service node of the corresponding node list. In the cases shown in Figures 10 and 11, if the retrieval and playback service is triggered, it will be carried out in different situations. processing, as follows:

If it is to retrieve the latest video, it will hit the general node in the directory node linked list and the file node linked list. You can directly access the hit general node to get the search result. After accessing, put the hit general node at the end of the general node segment. ;

If it is to retrieve the oldest video, it will hit the business node in the directory node list and file node list, and directly access the hit general node to get the search result. After accessing, the hit business node will be placed in the business node segment at last;

If the retrieved video (including directories and files) is not in any cache node, and the common nodes are already occupied, select the common nodes in the common node segments of the directory node linked list and the file node linked list respectively, and select the distance from the current operation. The most distant general node (ie, the general node at the beginning of the general node segment) copies the retrieved data to the selected general node.

It can be seen that any non-deleted access to the oldest data will not cause the content in the business node to be deleted, and the content of the business node will not be updated without involving a write operation, but accessing the business node will reset the location of the business node, which will It is moved to the end of the business node segment (ie, the most recently accessed business node is persisted at the end). For retrieval and playback services, if a new cache node needs to be added, the newly added cache node is selected in the general node segment and will not occupy the service node used by the full coverage service; this will wait until the next time the full coverage service is executed. , the oldest files and directories are still stored in the cache. At the end of each day, wait until the data of the day is completely cleaned up, scan it again, and then continue with the next full coverage service. Most persistent save.

An embodiment of the present disclosure also provides an apparatus, as shown in FIG. 12 , including a memory 1210 and a processor 1220; it is applied to data caching for a cache node including a general node and a service node, and the memory is used for storing data for performing data caching. A program for data caching, where the processor is configured to read and execute the program for data caching, and execute the data caching method described in any of the foregoing embodiments.

An embodiment of the present disclosure further provides a storage medium, where a program for data caching based on a cache node including a general node and a service node is stored in the storage medium, and the program is configured to execute any one of the above implementations at runtime The method for data caching described in the example.

Those of ordinary skill in the art can understand that all or some of the steps in the methods disclosed above, functional modules/units in the systems, and devices can be implemented as software, firmware, hardware, and appropriate combinations thereof. In a hardware implementation, the division between functional modules/units mentioned in the above description does not necessarily correspond to the division of physical components; for example, one physical component may have multiple functions, or one function or step may be composed of several physical components Components execute cooperatively. Some or all of the components may be implemented as software executed by a processor, such as a digital signal processor or microprocessor, or as hardware, or as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on computer-readable media, which may include computer storage media (or non-transitory media) and communication media (or transitory media). As is known to those of ordinary skill in the art, the term computer storage media includes both volatile and nonvolatile implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data flexible, removable and non-removable media. Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disk (DVD) or other optical disk storage, magnetic cartridges, magnetic tape, magnetic disk storage or other magnetic storage devices, or may Any other medium used to store desired information and which can be accessed by a computer. In addition, communication media typically embodies computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and can include any information delivery media, as is well known to those of ordinary skill in the art .

Claims (10)

1. a method for carrying out data cache, is characterized in that, is applied on the cache node comprising general node and service node, and described method comprises: When the business operates on the underlying data, determine whether the cache node is hit; When hitting the cache node, if the periodic service hits the general node, select the business node, copy the content of the hit general node to the selected business node, and release the hit general node; When the cache node is not hit, if the service is a general service, a general node is selected, and the data targeted by the operation is copied to the selected general node; if the service is a periodic service, a service node is selected, and the periodic service is selected. Sexual business needs to copy the cached data to the selected business node. 2. the method for carrying out data cache according to claim 1 is characterized in that: A plurality of general nodes are connected in sequence to form a general node segment, and a plurality of service nodes are connected in sequence to form a service node segment; wherein, the general node segment and the cache nodes in the service node segment respectively follow the first-in-first-out principle; The cache node further includes a head node for storing address information of the cache node. 3. the method for carrying out data cache according to claim 2, is characterized in that: The cache node forms a node linked list; The head node includes a linked list header and a service head node, and the address information is the address of the service head node; the linked list header is used to store the address of the service head node; the node linked list sequentially includes a linked list header, a general node segment, Service head node and service node segment. 4. The method for performing data caching according to claim 2, wherein the selecting a service node comprises: According to the address information in the head node, select one or more service nodes located at the beginning of the service node segment; The selection of general nodes includes: According to the address information in the head node, one or more general nodes located at the beginning of the general node segment are selected. 5. The method for carrying out data caching according to claim 2, wherein the content in the hit general node is copied to the selected service node, and releasing the hit general node comprises: Use the content in the hit general node to update the selected service node, and move the selected service node to the end of the service node segment; The contents of the hit general node are cleared, and the hit general node is moved to the beginning of the general node segment. 6. The method for data caching according to claim 2, wherein the copying of the data targeted by the operation to the selected general node comprises: updating the content of the generic node with the data targeted by the operation, moving the generic node to the end of the generic node segment; The copying of the data that needs to be cached for the periodic service to the selected service node includes: The service node is updated using the data that the periodic service needs to cache, and the service node is moved to the end of the service node segment. 7. The method for data caching according to claim 1, wherein when a cache node is hit, the method further comprises: If the general service hits the general node or service node, then judge the type of the general service, if it is a write operation, update the content of the hit cache node; if it is a delete operation, clear the content of the hit cache node; if it is a read operation Then access the content of the hit cache node; If the periodic service hits the service node, the content of the hit service node is accessed. 8. the method for carrying out data cache according to claim 1 is characterized in that: The cache node is divided into multiple node linked lists according to different data types; each node linked list includes a general node and a service node; When the business operates on the underlying data, determining whether to hit the cache node includes: When the business operates the underlying data, select the corresponding node list according to the data type of the data to be operated, traverse the selected node list, and determine whether the cache node is hit; The selecting a service node includes: selecting a service node in the selected node linked list; The selecting a general node includes: selecting a general node in the selected node linked list. 9. A device comprising a memory and a processor; it is characterized in that, it is applied to cache data for a cache node including a general node and a service node, and the memory is used to save a program for performing data cache, and the processor is used for data caching. The method described in any one of claims 1-8 is executed by reading and executing the program for performing data caching. 10. A storage medium, wherein a program for data caching based on a cache node comprising a general node and a service node is stored in the storage medium, and the program is configured to execute claims 1-8 at runtime The method of any one.

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