The kernel of the file system is composed of two parts : the virtual file system and the logic file systems 這樣就為用戶程序提供了一個統(tǒng)一的、抽象的、虛擬的文件系統(tǒng)接口。
There are three layers in deltafile , virtual file system 、 logic file system and buffer cache . besides , deltafile provides the posix api interface 為了對用戶透明的實(shí)現(xiàn)多種不同文件系統(tǒng)支持的功能, deltafile中采用了虛擬文件系統(tǒng)和邏輯文件系統(tǒng)相分離的體系結(jié)構(gòu)。
First it supports the system call interfaces complied with the posix standard , which make convenience to the porting process to delta os for applications . second , delta file 3 . 0 offers the entire supports to the fat logic file system format , and make it suitable in multitasks environment through technique process . once more , delta file 3 . 0 support the flexible virtual file system interface and drive manage interface to make update easier 首先,其系統(tǒng)調(diào)用接口遵循posix規(guī)范,以便于應(yīng)用向deltaos進(jìn)行移植;其次, deltafile3 . 0提供了對fat全系列邏輯文件系統(tǒng)格式(含fat12 、 fat16 、 fat32 )的完全支持,并通過改造將fat這種源于單任務(wù)操作系統(tǒng)dos的文件系統(tǒng)標(biāo)準(zhǔn)應(yīng)用于多任務(wù)環(huán)境;此外, deltafile3 . 0提供了靈活的虛擬文件系統(tǒng)接口和設(shè)備驅(qū)動管理接口,便于未來的升級和擴(kuò)展。
The Logic File System is a research file system which replaces pathnames with expressions in propositional logic. It allows file metadata to be queried with a superset of the Boolean syntax commonly used in modern search engines.