70 lines
1.6 KiB
C
70 lines
1.6 KiB
C
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#ifndef BCACHE_H
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#define BCACHE_H
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#include <stdint.h>
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/*----------------------------------------------------------------*/
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typedef uint64_t block_address;
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typedef uint64_t sector_t;
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struct block;
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struct bcache;
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// FIXME: allow the cache to be opened read only.
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struct bcache *bcache_create(int fd, sector_t block_size,
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uint64_t on_disk_blocks,
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unsigned nr_cache_blocks);
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/*
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* A simpler way of creating a bcache that assumes 4k block size, and stats to
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* get the file size.
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*/
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struct bcache *bcache_simple(const char *path, unsigned nr_cache_blocks);
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void bcache_destroy(struct bcache *cache);
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uint64_t get_nr_blocks(struct bcache *cache);
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uint64_t get_nr_locked(struct bcache *cache);
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int flush_cache(struct bcache *cache);
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struct bcache;
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struct block {
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/* clients may only access these two fields */
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void *data;
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uint64_t index;
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struct bcache *cache;
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struct list_head list;
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struct list_head hash;
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unsigned flags;
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unsigned ref_count;
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int error;
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};
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enum get_flags {
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/*
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* The block will be zeroed before get_block returns it. This
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* potentially avoids a read if the block is not already in the cache.
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* GF_DIRTY is implicit.
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*/
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GF_ZERO = (1 << 0),
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/*
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* Indicates the caller is intending to change the data in the block, a
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* writeback will occur after the block is released.
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*/
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GF_DIRTY = (1 << 1),
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};
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struct block *get_block(struct bcache *cache, block_address index, unsigned flags);
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void prefetch_block(struct bcache *cache, block_address index);
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void release_block(struct block *b);
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/*----------------------------------------------------------------*/
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#endif
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