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Use pre-increment for shorter instruction length and slight speed.

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This commit is contained in:
Moinak Ghosh 2013-01-17 22:54:30 +05:30
parent 49ec3a054d
commit 455c8107d5
1 changed files with 14 additions and 14 deletions
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28
rabin/rabin_dedup.c
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@ -214,7 +214,7 @@ create_dedupe_context(uint64_t chunksize, uint64_t real_chunksize, int rab_blk_s
ctx->blknum = chunksize / ctx->rabin_poly_avg_block_size; ctx->blknum = chunksize / ctx->rabin_poly_avg_block_size;
if (chunksize % ctx->rabin_poly_min_block_size) if (chunksize % ctx->rabin_poly_min_block_size)
ctx->blknum++; ++(ctx->blknum);
if (ctx->blknum > RABIN_MAX_BLOCKS) { if (ctx->blknum > RABIN_MAX_BLOCKS) {
fprintf(stderr, "Chunk size too large for dedup.\n"); fprintf(stderr, "Chunk size too large for dedup.\n");
@ -313,7 +313,7 @@ dedupe_compress(dedupe_context_t *ctx, uchar_t *buf, uint64_t *size, uint64_t of
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) if (j)
blknum++; ++blknum;
else else
j = ctx->rabin_poly_avg_block_size; j = ctx->rabin_poly_avg_block_size;
@ -369,7 +369,7 @@ dedupe_compress(dedupe_context_t *ctx, uchar_t *buf, uint64_t *size, uint64_t of
cur_pos_checksum = cur_roll_checksum ^ ir[pushed_out]; cur_pos_checksum = cur_roll_checksum ^ ir[pushed_out];
ctx->window_pos = (ctx->window_pos + 1) & (RAB_POLYNOMIAL_WIN_SIZE-1); ctx->window_pos = (ctx->window_pos + 1) & (RAB_POLYNOMIAL_WIN_SIZE-1);
length++; ++length;
if (length < ctx->rabin_poly_min_block_size) continue; if (length < ctx->rabin_poly_min_block_size) continue;
// If we hit our special value update block offset // If we hit our special value update block offset
@ -404,7 +404,7 @@ dedupe_compress(dedupe_context_t *ctx, uchar_t *buf, uint64_t *size, uint64_t of
* to be power of 2 * to be power of 2
*/ */
ctx->window_pos = (ctx->window_pos + 1) & (RAB_POLYNOMIAL_WIN_SIZE-1); ctx->window_pos = (ctx->window_pos + 1) & (RAB_POLYNOMIAL_WIN_SIZE-1);
length++; ++length;
if (length < ctx->rabin_poly_min_block_size) continue; 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 we hit our special value or reached the max block size update block offset
@ -416,7 +416,7 @@ dedupe_compress(dedupe_context_t *ctx, uchar_t *buf, uint64_t *size, uint64_t of
ctx->blocks[blknum]->offset = last_offset; ctx->blocks[blknum]->offset = last_offset;
ctx->blocks[blknum]->index = blknum; // Need to store for sorting ctx->blocks[blknum]->index = blknum; // Need to store for sorting
ctx->blocks[blknum]->length = length; ctx->blocks[blknum]->length = length;
DEBUG_STAT_EN(if (length >= ctx->rabin_poly_max_block_size) max_count++); DEBUG_STAT_EN(if (length >= ctx->rabin_poly_max_block_size) ++max_count);
/* /*
* Reset the heap structure and find the K min values if Delta Compression * Reset the heap structure and find the K min values if Delta Compression
@ -443,7 +443,7 @@ dedupe_compress(dedupe_context_t *ctx, uchar_t *buf, uint64_t *size, uint64_t of
ctx->blocks[blknum]->similarity_hash = ctx->blocks[blknum]->similarity_hash =
XXH32((const uchar_t *)ctx_heap, pc[ctx->delta_flag]*8, 0); XXH32((const uchar_t *)ctx_heap, pc[ctx->delta_flag]*8, 0);
} }
blknum++; ++blknum;
last_offset = i+1; last_offset = i+1;
length = 0; length = 0;
j = 0; j = 0;
@ -482,7 +482,7 @@ dedupe_compress(dedupe_context_t *ctx, uchar_t *buf, uint64_t *size, uint64_t of
ctx->blocks[blknum]->similarity_hash = cur_sketch; ctx->blocks[blknum]->similarity_hash = cur_sketch;
} }
} }
blknum++; ++blknum;
last_offset = *size; last_offset = *size;
} }
@ -614,7 +614,7 @@ process_blocks:
ctx->blocks[i]->next = 0; ctx->blocks[i]->next = 0;
ctx->blocks[i]->similar = 0; ctx->blocks[i]->similar = 0;
be->next = ctx->blocks[i]; be->next = ctx->blocks[i];
DEBUG_STAT_EN(hash_collisions++); DEBUG_STAT_EN(++hash_collisions);
} }
} }
} }
@ -641,19 +641,19 @@ process_blocks:
for (i=0; i<blknum;) { for (i=0; i<blknum;) {
dedupe_index[pos] = i; dedupe_index[pos] = i;
ctx->blocks[i]->index = pos; ctx->blocks[i]->index = pos;
pos++; ++pos;
length = 0; length = 0;
j = i; j = i;
if (ctx->blocks[i]->similar == 0) { if (ctx->blocks[i]->similar == 0) {
while (i< blknum && ctx->blocks[i]->similar == 0 && while (i< blknum && ctx->blocks[i]->similar == 0 &&
length < RABIN_MAX_BLOCK_SIZE) { length < RABIN_MAX_BLOCK_SIZE) {
length += ctx->blocks[i]->length; length += ctx->blocks[i]->length;
i++; ++i;
DEBUG_STAT_EN(merge_count++); DEBUG_STAT_EN(++merge_count);
} }
ctx->blocks[j]->length = length; ctx->blocks[j]->length = length;
} else { } else {
i++; ++i;
} }
} }
DEBUG_STAT_EN(fprintf(stderr, "Merge count: %u\n", merge_count)); DEBUG_STAT_EN(fprintf(stderr, "Merge count: %u\n", merge_count));
@ -684,12 +684,12 @@ process_blocks:
*/ */
oldbuf = buf1 + be->other->offset; oldbuf = buf1 + be->other->offset;
newbuf = buf1 + be->offset; newbuf = buf1 + be->offset;
DEBUG_STAT_EN(delta_calls++); DEBUG_STAT_EN(++delta_calls);
bsz = bsdiff(oldbuf, be->other->length, newbuf, be->length, bsz = bsdiff(oldbuf, be->other->length, newbuf, be->length,
ctx->cbuf + pos1, buf1 + *size, matchlen); ctx->cbuf + pos1, buf1 + *size, matchlen);
if (bsz == 0) { if (bsz == 0) {
DEBUG_STAT_EN(delta_fails++); DEBUG_STAT_EN(++delta_fails);
memcpy(ctx->cbuf + pos1, newbuf, be->length); memcpy(ctx->cbuf + pos1, newbuf, be->length);
dedupe_index[i] = htonl(be->length); dedupe_index[i] = htonl(be->length);
pos1 += be->length; pos1 += be->length;