magma_flare_dir_t Struct Reference
Detailed Descriptioncast structure for directory flares
counter for mmap()ped pages
directories are implemented using mmap() system call to reduce possibility of data loss. mmap() simply bind a memory region to a file, loading file contents in memory and saving it back to disk while munmap() or msync() are called. Directories are entierly mapped in memory (i.e. when a directory is accessed and loaded in magma cache system, the whole file "contents" is mapped in memory). If directory needs to grow, this field is incremented and a new page is mapped in memory.
next field is used by mmap()ped system to access directory pages by offsets of 4096 bytes (which is Linux page size). When a new page is added, first null entry in this array should be pointed to new page. Directories are saved as a sequence of null terminated strings.
this is the filedescriptor used to mmap() dirctory contents on memory.
UPDATE: mmap() operations does not require the filedescriptor to remain open. This field will be removed somewhere in the future.
|unsigned int magma_flare_dir_t::entries|
number of entries present
The documentation for this struct was generated from the following file: