greg/pcompress
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

Many optimizations to segmented global dedupe.

Browse source 
Use chunk hash based cumulative similarity matching instead of chunk content.
This commit is contained in:
Moinak Ghosh 2013-04-19 22:51:51 +05:30
parent 2f6ccca6e5
commit 3b8a5813fd
4 changed files with 82 additions and 95 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

4
rabin/global/index.c
View file

@ -316,7 +316,7 @@ db_segcache_pos(archive_config_t *cfg, int tid)
* Mmap the requested segment metadata array.
*/
int
db_segcache_map(archive_config_t *cfg, int tid, uint32_t *blknum, uint64_t *offset, uchar_t *blocks)
db_segcache_map(archive_config_t *cfg, int tid, uint32_t *blknum, uint64_t *offset, uchar_t **blocks)
{
uchar_t *mapbuf, *hdr;
int fd;
@ -349,7 +349,7 @@ db_segcache_map(archive_config_t *cfg, int tid, uint32_t *blknum, uint64_t *offs
hdr = mapbuf + adj;
*blknum = *((uint32_t *)(hdr));
*offset = *((uint64_t *)(hdr + 4));
memcpy(blocks, hdr + SEGCACHE_HDR_SZ, *blknum * sizeof (global_blockentry_t));
*blocks = hdr + SEGCACHE_HDR_SZ;
cfg->seg_fd_r[tid].mapping = mapbuf;
cfg->seg_fd_r[tid].len = len + adj;

2
rabin/global/index.h
View file

@ -56,7 +56,7 @@ void destroy_global_db_s(archive_config_t *cfg);
int db_segcache_write(archive_config_t *cfg, int tid, uchar_t *buf, uint32_t len, uint32_t blknum, uint64_t file_offset);
int db_segcache_pos(archive_config_t *cfg, int tid);
int db_segcache_map(archive_config_t *cfg, int tid, uint32_t *blknum, uint64_t *offset, uchar_t *blocks);
int db_segcache_map(archive_config_t *cfg, int tid, uint32_t *blknum, uint64_t *offset, uchar_t **blocks);
int db_segcache_unmap(archive_config_t *cfg, int tid);
#ifdef __cplusplus

188
rabin/rabin_dedup.c
View file

@ -212,7 +212,7 @@ create_dedupe_context(uint64_t chunksize, uint64_t real_chunksize, int rab_blk_s
get_sys_limits(&msys_info);
arc = init_global_db_s(NULL, "/tmp", rab_blk_sz, chunksize, 0,
algo, props->cksum, CKSUM_CRC64, file_size,
algo, props->cksum, GLOBAL_SIM_CKSUM, file_size,
msys_info.freeram, props->nthreads);
if (arc == NULL) {
pthread_mutex_unlock(&init_lock);
@ -662,6 +662,7 @@ process_blocks:
uint64_t dedupe_index_sz = 0;
rabin_blockentry_t *be;
DEBUG_STAT_EN(uint32_t delta_calls, delta_fails, merge_count, hash_collisions);
DEBUG_STAT_EN(double w1, w2);
DEBUG_STAT_EN(delta_calls = 0);
DEBUG_STAT_EN(delta_fails = 0);
DEBUG_STAT_EN(hash_collisions = 0);
@ -712,7 +713,9 @@ process_blocks:
* threads without locking.
*/
length = 0;
DEBUG_STAT_EN(w1 = get_wtime_millis());
sem_wait(ctx->index_sem);
DEBUG_STAT_EN(w2 = get_wtime_millis());
for (i=0; i<blknum; i++) {
hash_entry_t *he;
@ -793,11 +796,9 @@ process_blocks:
* ======================================================================
*/
cfg = ctx->arc;
seg_heap = (uchar_t *)(ctx->g_blocks) - cfg->segment_sz_bytes;
seg_heap = (uchar_t *)(ctx->g_blocks) - cfg->segment_sz * cfg->chunk_cksum_sz;
ary_sz = cfg->segment_sz * sizeof (global_blockentry_t **);
htab = (global_blockentry_t **)(seg_heap - ary_sz);
seg_blocks = (global_blockentry_t *)(seg_heap - ary_sz - \
cfg->segment_sz * sizeof (global_blockentry_t));
for (i=0; i<blknum;) {
uint64_t crc;
length = 0;
@ -808,12 +809,12 @@ process_blocks:
blks = cfg->segment_sz;
if (blks > blknum-i) blks = blknum-i;
len = 0;
length = 0;
tgt = seg_heap;
for (j=0; j<blks; j++) {
len += ctx->g_blocks[j+i].length;
if (len > cfg->segment_sz_bytes) {
break;
}
length = len;
memcpy(tgt, ctx->g_blocks[j+i].cksum, cfg->chunk_cksum_sz);
length += cfg->chunk_cksum_sz;
tgt += cfg->chunk_cksum_sz;
}
blks = j+i;
@ -821,9 +822,6 @@ process_blocks:
* Compute the cumulative similarity minhashes.
*/
sim_ck = ctx->similarity_cksums;
src = buf1 + ctx->g_blocks[i].offset;
tgt = seg_heap;
memcpy(tgt, src, length);
crc = 0;
increment = (length / cfg->intervals) / cfg->sub_intervals;
len = increment;
@ -836,7 +834,6 @@ process_blocks:
sim_ck += cfg->similarity_cksum_sz;
}
len -= increment;
increment = length / cfg->intervals;
len = increment * 2;
for (j=0; j<cfg->intervals-1; j++) {
@ -852,7 +849,11 @@ process_blocks:
* Begin shared index access and write segment metadata to cache
* first.
*/
if (i == 0) sem_wait(ctx->index_sem);
if (i == 0) {
DEBUG_STAT_EN(w1 = get_wtime_millis());
sem_wait(ctx->index_sem);
DEBUG_STAT_EN(w2 = get_wtime_millis());
}
sim_ck -= cfg->similarity_cksum_sz;
seg_offset = db_segcache_pos(cfg, ctx->id);
src = (uchar_t *)&(ctx->g_blocks[i]);
@ -861,77 +862,14 @@ process_blocks:
ctx->file_offset + ctx->g_blocks[i].offset);
/*
* Now lookup the similarity minhashes starting at the highest
* significance level.
*/
for (j=cfg->intervals + cfg->sub_intervals; j > 0; j--) {
hash_entry_t *he;
he = db_lookup_insert_s(cfg, sim_ck, j-1, seg_offset, 0, 1);
if (he) {
/*
* Match found. Load segment metadata from disk and perform
* identity deduplication with the segment chunks.
* Insert current segment blocks into local hashtable and do partial
* in-segment deduplication.
*/
be = NULL;
memset(htab, 0, ary_sz);
offset = he->item_offset;
if (db_segcache_map(cfg, ctx->id, &o_blks, &offset,
(uchar_t *)seg_blocks) == -1) {
fprintf(stderr, "Segment cache mmap failed.\n");
ctx->valid = 0;
return (0);
}
/*
* First insert all the unique blocks from the mapped segment
* blocks(chunks) array into the hashtable.
*/
for (k=0; k<o_blks; k++) {
uint32_t hent;
hent = XXH32(&(seg_blocks[k].cksum[0]), cfg->chunk_cksum_sz, 0);
hent ^= (hent / cfg->chunk_cksum_sz);
hent = hent % cfg->segment_sz;
if (htab[hent] == NULL) {
htab[hent] = &(seg_blocks[k]);
seg_blocks[k].offset += offset;
seg_blocks[k].next = NULL;
} else {
be = htab[hent];
do {
if (memcmp(seg_blocks[k].cksum,
be->cksum, cfg->chunk_cksum_sz) == 0 &&
seg_blocks[k].length == be->length) {
be = NULL;
break;
}
if (be->next)
be = be->next;
else
break;
} while(1);
/*
* be will be non-NULL if no match was found.
* It will the last bucket in the hash slot.
*/
if (be) {
be->next = &(seg_blocks[k]);
seg_blocks[k].offset += offset;
seg_blocks[k].next = NULL;
}
}
}
/*
* Now lookup current segment blocks(chunks) in the hashtable and
* perform the actual deduplication.
*/
be = NULL;
for (k=i; k<blks; k++) {
uint32_t hent;
if (ctx->g_blocks[k].length & RABIN_INDEX_FLAG) continue;
hent = XXH32(ctx->g_blocks[k].cksum, cfg->chunk_cksum_sz, 0);
hent ^= (hent / cfg->chunk_cksum_sz);
hent = hent % cfg->segment_sz;
@ -947,27 +885,8 @@ process_blocks:
if (memcmp(ctx->g_blocks[k].cksum,
be->cksum, cfg->chunk_cksum_sz) == 0 &&
ctx->g_blocks[k].length == be->length) {
break;
}
if (be->next) {
be = be->next;
} else {
be->next = &(ctx->g_blocks[k]);
be->next->offset +=
ctx->file_offset;
be->next->next = NULL;
be = NULL;
break;
}
} while(1);
}
/*
* be will be non-NULL if match was found. It will
* point to the matching bucket.
*/
if (be) {
global_blockentry_t *en;
/*
* Block match in index was found. Update g_blocks
* array.
@ -976,6 +895,73 @@ process_blocks:
en->length = (en->length | RABIN_INDEX_FLAG) &
CLEAR_SIMILARITY_FLAG;
en->offset = be->offset;
break;
}
if (be->next) {
be = be->next;
} else {
be->next = &(ctx->g_blocks[k]);
be->next->offset += ctx->file_offset;
be->next->next = NULL;
break;
}
} while(1);
}
}
/*
* Now lookup the similarity minhashes starting at the highest
* significance level.
*/
for (j=cfg->intervals + cfg->sub_intervals; j > 0; j--) {
hash_entry_t *he;
he = db_lookup_insert_s(cfg, sim_ck, j-1, seg_offset, 0, 1);
if (he) {
/*
* Match found. Load segment metadata from disk and perform
* identity deduplication with the segment chunks.
*/
offset = he->item_offset;
if (db_segcache_map(cfg, ctx->id, &o_blks, &offset,
(uchar_t **)&seg_blocks) == -1) {
fprintf(stderr, "Segment cache mmap failed.\n");
ctx->valid = 0;
return (0);
}
/*
* Now lookup loaded segment blocks in hashtable. If match is
* found then the hashtable entry is updated to point to the
* loaded segment block.
*/
for (k=0; k<o_blks; k++) {
uint32_t hent;
hent = XXH32(&(seg_blocks[k].cksum[0]), cfg->chunk_cksum_sz, 0);
hent ^= (hent / cfg->chunk_cksum_sz);
hent = hent % cfg->segment_sz;
if (htab[hent] != NULL) {
be = htab[hent];
do {
if (be->length & RABIN_INDEX_FLAG)
goto next_ent;
if (memcmp(seg_blocks[k].cksum,
be->cksum, cfg->chunk_cksum_sz) == 0 &&
seg_blocks[k].length == be->length) {
be->length = (be->length |
RABIN_INDEX_FLAG) &
CLEAR_SIMILARITY_FLAG;
be->offset = seg_blocks[k].offset +
offset;
break;
}
next_ent:
if (be->next)
be = be->next;
else
break;
} while(1);
}
}
break;
@ -1058,7 +1044,7 @@ process_blocks:
if (matchlen < dedupe_index_sz) {
DEBUG_STAT_EN(en = get_wtime_millis());
DEBUG_STAT_EN(fprintf(stderr, "Chunking speed %.3f MB/s, Overall Dedupe speed %.3f MB/s\n",
get_mb_s(*size, strt, en_1), get_mb_s(*size, strt, en)));
get_mb_s(*size, strt, en_1), get_mb_s(*size, strt, en - (w2 - w1))));
DEBUG_STAT_EN(fprintf(stderr, "No Dedupe possible.\n"));
ctx->valid = 0;
return (0);

1
rabin/rabin_dedup.h
View file

@ -137,6 +137,7 @@
#define SIMILAR_EXACT 1
#define SIMILAR_PARTIAL 2
#define SIMILAR_REF 3
#define GLOBAL_SIM_CKSUM CKSUM_CRC64
/*
* TYpes of delta operations.