7 * crc_of_blocks - calculate the crc of the blocks.
8 * @data: pointer to the buffer to CRC
9 * @len: length of the buffer
10 * @blocksize: CRC of each block (final block may be shorter)
11 * @crcbits: the number of bits of crc you want (currently 64 maximum)
12 * @crc: the crcs (array will have (len + blocksize-1)/blocksize entries).
14 * Calculates the CRC of each block, and output the lower @crcbits to
17 void crc_of_blocks(const void *data, size_t len, unsigned int blocksize,
18 unsigned int crcbits, uint64_t crc[]);
21 * crc_context_new - allocate and initialize state for crc_find_block
22 * @blocksize: the size of each block
23 * @crcbits: the bits valid in the CRCs (<= 64)
24 * @crc: array of block crcs (including final block, if any)
25 * @num_crcs: number of block crcs
26 * @tail_size: the size of final partial block, if any (< blocksize).
28 * Returns an allocated pointer to the structure for crc_find_block,
29 * or NULL. Makes a copy of @crc.
31 struct crc_context *crc_context_new(size_t blocksize, unsigned crcbits,
32 const uint64_t crc[], unsigned num_crcs,
36 * crc_read_block - search for block matches in the buffer.
37 * @ctx: struct crc_context from crc_context_new.
38 * @result: unmatched bytecount, or crc which matched.
39 * @buf: pointer to bytes
40 * @buflen: length of buffer
42 * Returns the number of bytes of the buffer which have been digested,
43 * and sets @result either to a negagive number (== -crc_number - 1)
44 * to show that a block matched a crc, or zero or more to represent a
45 * length of unmatched data.
47 * Note that multiple lengths of unmatched data might be returned in a row:
48 * you'll probably want to merge them yourself.
50 size_t crc_read_block(struct crc_context *ctx, long *result,
51 const void *buf, size_t buflen);
54 * crc_read_flush - flush any remaining data from crc_read_block.
55 * @ctx: the context passed to crc_read_block.
57 * Matches the final data. This can be used to create a boundary, or
58 * simply flush the final data. Keep calling it until it returns 0.
60 long crc_read_flush(struct crc_context *ctx);
63 * crc_context_free - free a context returned from crc_context_new.
64 * @ctx: the context returned from crc_context_new, or NULL.
66 void crc_context_free(struct crc_context *ctx);
68 #endif /* CCAN_CRCSYNC_H */