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Fix polynomial computation.

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Fix incorrect block length when doing fixed-block dedupe.
This commit is contained in:
Moinak Ghosh 2012-10-02 00:20:44 +05:30
parent 0019efbadb
commit 9475ccc3d6
1 changed files with 9 additions and 4 deletions
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13
rabin/rabin_dedup.c
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@ -129,7 +129,7 @@ create_dedupe_context(uint64_t chunksize, uint64_t real_chunksize, int rab_blk_s
*/ */
pthread_mutex_lock(&init_lock); pthread_mutex_lock(&init_lock);
if (!inited) { if (!inited) {
int term, j; int term, pow, j;
uint64_t val, poly_pow; uint64_t val, poly_pow;
poly_pow = 1; poly_pow = 1;
@ -139,13 +139,15 @@ create_dedupe_context(uint64_t chunksize, uint64_t real_chunksize, int rab_blk_s
for (j = 0; j < 256; j++) { for (j = 0; j < 256; j++) {
term = 1; term = 1;
pow = 1;
val = 1; val = 1;
out[j] = (j * poly_pow) & POLY_MASK; out[j] = (j * poly_pow) & POLY_MASK;
for (i=0; i<RAB_POLYNOMIAL_WIN_SIZE; i++) { for (i=0; i<RAB_POLYNOMIAL_WIN_SIZE; i++) {
if (term & FP_POLY) { if (term & FP_POLY) {
val += ((term * j) & POLY_MASK); val += ((pow * j) & POLY_MASK);
} }
term = (term * RAB_POLYNOMIAL_CONST) & POLY_MASK; pow = (pow * RAB_POLYNOMIAL_CONST) & POLY_MASK;
term <<= 1;
} }
ir[j] = val; ir[j] = val;
} }
@ -304,7 +306,10 @@ dedupe_compress(dedupe_context_t *ctx, uchar_t *buf, ssize_t *size, ssize_t offs
if (ctx->fixed_flag) { if (ctx->fixed_flag) {
blknum = *size / ctx->rabin_poly_avg_block_size; blknum = *size / ctx->rabin_poly_avg_block_size;
j = *size % ctx->rabin_poly_avg_block_size; j = *size % ctx->rabin_poly_avg_block_size;
if (j) blknum++; if (j)
blknum++;
else
j = ctx->rabin_poly_avg_block_size;
last_offset = 0; last_offset = 0;
length = ctx->rabin_poly_avg_block_size; length = ctx->rabin_poly_avg_block_size;