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Use different min block size and Rabin break pattern depending on compression algo.

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Cleanup some cruft.
This commit is contained in:
Moinak Ghosh 2012-07-06 23:24:12 +05:30
parent f5ce45b16e
commit ea923b84f0
4 changed files with 11 additions and 15 deletions
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2
main.c
View file

@ -602,7 +602,7 @@ redo:
rbytes = tdat->rbytes;
reset_rabin_context(tdat->rctx);
rctx->cbuf = tdat->uncompressed_chunk;
rabin_index_sz = rabin_dedup(tdat->rctx, tdat->cmp_seg, &(tdat->rbytes), 0, NULL);
rabin_index_sz = rabin_dedup(tdat->rctx, tdat->cmp_seg, &(tdat->rbytes), 0);
if (!rctx->valid) {
memcpy(tdat->uncompressed_chunk, tdat->cmp_seg, rbytes);
tdat->rbytes = rbytes;

12
rabin/rabin_polynomial.c
View file

@ -105,10 +105,12 @@ create_rabin_context(uint64_t chunksize, uint64_t real_chunksize, const char *al
ctx->rabin_poly_min_block_size = RAB_POLYNOMIAL_MIN_BLOCK_SIZE;
ctx->rabin_avg_block_mask = RAB_POLYNOMIAL_AVG_BLOCK_MASK;
ctx->rabin_poly_avg_block_size = RAB_POLYNOMIAL_AVG_BLOCK_SIZE;
ctx->rabin_break_patt = RAB_POLYNOMIAL_CONST;
} else {
ctx->rabin_poly_min_block_size = RAB_POLYNOMIAL_MIN_BLOCK_SIZE2;
ctx->rabin_avg_block_mask = RAB_POLYNOMIAL_AVG_BLOCK_MASK2;
ctx->rabin_poly_avg_block_size = RAB_POLYNOMIAL_AVG_BLOCK_SIZE2;
ctx->rabin_break_patt = 0;
}
blknum = chunksize / ctx->rabin_poly_min_block_size;
@ -196,7 +198,7 @@ cmpblks(const void *a, const void *b)
* the rolling checksum and dedup blocks vary in size from 4K-128K.
*/
uint32_t
rabin_dedup(rabin_context_t *ctx, uchar_t *buf, ssize_t *size, ssize_t offset, ssize_t *rabin_pos)
rabin_dedup(rabin_context_t *ctx, uchar_t *buf, ssize_t *size, ssize_t offset)
{
ssize_t i, last_offset,j;
uint32_t blknum;
@ -214,7 +216,6 @@ rabin_dedup(rabin_context_t *ctx, uchar_t *buf, ssize_t *size, ssize_t offset, s
char cur_byte = buf1[i];
uint64_t pushed_out = ctx->current_window_data[ctx->window_pos];
ctx->current_window_data[ctx->window_pos] = cur_byte;
int msk;
/*
* We want to do:
* cur_roll_checksum = cur_roll_checksum * RAB_POLYNOMIAL_CONST + cur_byte;
@ -238,7 +239,7 @@ rabin_dedup(rabin_context_t *ctx, uchar_t *buf, ssize_t *size, ssize_t offset, s
if (length < ctx->rabin_poly_min_block_size) continue;
// If we hit our special value or reached the max block size update block offset
if ((ctx->cur_roll_checksum & ctx->rabin_avg_block_mask) == RAB_POLYNOMIAL_CONST ||
if ((ctx->cur_roll_checksum & ctx->rabin_avg_block_mask) == ctx->rabin_break_patt ||
length >= rabin_polynomial_max_block_size) {
ctx->blocks[blknum].offset = last_offset;
ctx->blocks[blknum].index = blknum; // Need to store for sorting
@ -252,10 +253,6 @@ rabin_dedup(rabin_context_t *ctx, uchar_t *buf, ssize_t *size, ssize_t offset, s
}
}
if (rabin_pos) {
*rabin_pos = last_offset;
return (0);
}
// If we found at least a few chunks, perform dedup.
if (blknum > 2) {
uint64_t prev_cksum;
@ -388,7 +385,6 @@ rabin_dedup(rabin_context_t *ctx, uchar_t *buf, ssize_t *size, ssize_t offset, s
} else {
prev_index = 0;
prev_length = 0;
blkarr[blk] = htonl(be->index | RABIN_INDEX_FLAG);
rabin_index[pos] = be->index | RABIN_INDEX_FLAG;
trans[blk] = pos;
pos++;

10
rabin/rabin_polynomial.h
View file

@ -74,10 +74,10 @@
#define RAB_POLYNOMIAL_MIN_BLOCK_SIZE RAB_POLYNOMIAL_AVG_BLOCK_SIZE
#define RAB_POLYNOMIAL_MAX_BLOCK_SIZE (128 * 1024)
#define RAB_POLYNOMIAL_AVG_BLOCK_SHIFT2 10
#define RAB_POLYNOMIAL_AVG_BLOCK_SHIFT2 12
#define RAB_POLYNOMIAL_AVG_BLOCK_SIZE2 (1 << RAB_POLYNOMIAL_AVG_BLOCK_SHIFT)
#define RAB_POLYNOMIAL_AVG_BLOCK_MASK2 (RAB_POLYNOMIAL_AVG_BLOCK_SIZE - 1)
#define RAB_POLYNOMIAL_MIN_BLOCK_SIZE2 RAB_POLYNOMIAL_AVG_BLOCK_SIZE
#define RAB_POLYNOMIAL_MIN_BLOCK_SIZE2 2048
#define RAB_POLYNOMIAL_WIN_SIZE 31
#define RAB_POLYNOMIAL_MIN_WIN_SIZE 17
@ -131,6 +131,7 @@ typedef struct {
uint32_t rabin_poly_min_block_size;
uint32_t rabin_poly_avg_block_size;
uint32_t rabin_avg_block_mask;
uint32_t rabin_break_patt;
uint64_t real_chunksize;
int dedup;
int valid;
@ -138,10 +139,11 @@ typedef struct {
int level;
} rabin_context_t;
extern rabin_context_t *create_rabin_context(uint64_t chunksize, uint64_t real_chunksize, const char *algo);
extern rabin_context_t *create_rabin_context(uint64_t chunksize, uint64_t real_chunksize,
const char *algo);
extern void destroy_rabin_context(rabin_context_t *ctx);
extern unsigned int rabin_dedup(rabin_context_t *ctx, unsigned char *buf,
ssize_t *size, ssize_t offset, ssize_t *rabin_pos);
ssize_t *size, ssize_t offset);
extern void rabin_inverse_dedup(rabin_context_t *ctx, uchar_t *buf, ssize_t *size);
extern void rabin_parse_hdr(uchar_t *buf, unsigned int *blknum, ssize_t *rabin_index_sz,
ssize_t *rabin_data_sz, ssize_t *rabin_index_sz_cmp,

2
utils.h
View file

@ -98,8 +98,6 @@ extern int parse_numeric(ssize_t *val, const char *str);
extern char *bytes_to_size(uint64_t bytes);
extern ssize_t Read(int fd, void *buf, size_t count);
extern ssize_t Write(int fd, const void *buf, size_t count);
// extern ssize_t Dedup_Read(int fd, uchar_t **buf, size_t count,
// ssize_t *rabin_count, void *ctx);
/* Pointer type for compress and decompress functions. */
typedef int (*compress_func_ptr)(void *src, size_t srclen, void *dst,