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BLOF:A Binary Group List based Low Overhead Index Structure and Fast File Management Method
Time
Location
Event Type
Designer, IP and Embedded Systems Track Presentations
Virtual Programs
Hosted in Virtual Platform
Topics
Embedded Systems
DescriptionThe computing,storage and other resources of spacecraft are greatly restricted,and ordinary embedded file systems can not satisfy performance requirements in memory usage and file operation time.In order to meet special requirements of spacecraft,and resolve the problem that the space occupied by file index structure in memory increases linearly with file size in YAFFS2,a new index method called BLOF is proposed that continuous FLASH pages are indexed uniformly by introducing binary group structure based on B+ tree, and the corresponding algorithms are designed. So that the file system can implements fast file reading and writing,unmounting and mounting.The experimental results show that:1)when the number of FLASH pages for storing file data reaches an average of six or more consecutive pages,BLOF takes less memory footprint than YAFFS2;2) when the file size is greater than 512KB,the file writing time of the BLOF method is always less than that of YAFFS2,and the value of YAFFS2 file writing time minus BLOF file writing time increases linearly with file size;3) when the file size is larger than 1024KB,BLOF method takes lower time than YAFFS2 in unmounting operation;4) when the file size is larger than 2048KB,BLOF method takes less time than YAFFS2 method in mounting operation.