Data storage method and device for flash memory

Abstract

The invention discloses a data storage method and a data storage device for a flash memory. By the invention, the toerase frequency of the flash memory equipment is reduced greatly and reliable point-to-point (P2P) video on demand service can be provided for users. The technical scheme is that: the data storage method comprises the following steps of: checking whether a page file exists; if a page file is absent, establishing a page file, otherwise, opening the page file; reading data in a file information region of the page file and caching the data into a memory of a client; after the client clicks a video on demand button of the file, downloading a data branch block from a server; storing the downloaded data branch block into the client and updating the data, which is cached in the memory, of the file information region; transferring the cached data of the file information region into the page file if the number of the stored data branch blocks is greater than a threshold value; and closing the page file.

Description

technical field [0001] The invention relates to a memory data storage technology, in particular to a data storage method and device applied in a flash memory (Flash) memory. Background technique [0002] The multimedia on-demand system based on the P2P network protocol (hereinafter referred to as the P2P on-demand system) requires each terminal connected to the system to store the downloaded and played multimedia data in the local storage device, and at the same time share and upload the data to other terminals in the network Use; when each terminal downloads media data, it can request and obtain the data they have downloaded and stored from other terminals, so that data can be shared between terminals, and while greatly reducing the pressure on server access, it can also provide terminals with Efficient streaming service. [0003] In the application of P2P on-demand system in the past, local data is usually stored in non-fragile hard disk, but with the development of semic...

AI Technical Summary

Problems solved by technology

[0004] Due to the characteristics of IC manufacturing process, flash memory has great limitations in use compared with random read and write and non-fragility of hard disk: the physical storage unit inside flash memory does not support random write operations, but needs to follow the " Write-erase-rewrite" logic is carried out. When a "write" operation is performed on a certain storage unit, to modify the data in it, an "erase" operation must be performed before "rewrite "In the same storage unit; [2]. Each physical storage unit can only be "erased" for a limited number of times under the premise of ensuring stable data storage (generally, SLC: <100000 times, MLC: <10000 times ), if the number of erasing and writing of a storage unit exceeds this limit value, the storage unit will no longer guarantee the correctness of the stored data. Generally speaking, this situation is called "writable"

[0005] Usually, before using flash memory to store data, it will be formatted into a specific file system. In addition to storing user-visible media data on the storage device, these file systems also need to store system information used by the file system to mark files. Including the file name, storage path, file size, modification time and other information, each time the downloaded media data is stored in the file, in addition to the update of the media data, the corresponding file system information will also be updated, which will involve the The physical storage unit of the flash memory performs the operation of "write-erase-rewrite". The impact of a single file is relatively small, but as the number of media files requested by users increases, the accumulation of such operations will cause damage to the physical storage inside the flash memory. The number of "erasing" of the unit cannot be ignored, and each time a user orders a file, a file is correspondingly reserved on the storage device, especially when the user frequently switches on-demand files, the amount of data downloaded by each file Small, but the number of files can become very large, which makes managing these files extremely complicated

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