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Simplify segment lookup loop.

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Fix assertion.
This commit is contained in:
Moinak Ghosh 2013-04-26 10:56:29 +05:30
parent 5bb028fe03
commit 75f62d6a36
1 changed files with 32 additions and 37 deletions
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63
rabin/rabin_dedup.c
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@ -866,7 +866,7 @@ process_blocks:
*/
cfg = ctx->arc;
assert(cfg->similarity_cksum_sz >= sizeof (uint64_t));
assert(cfg->similarity_cksum_sz == sizeof (uint64_t));
seg_heap = (uchar_t *)(ctx->g_blocks) - cfg->segment_sz * cfg->chunk_cksum_sz;
ary_sz = (cfg->sub_intervals * cfg->similarity_cksum_sz + sizeof (blks) + 1) *
((blknum+1) / cfg->segment_sz) + 3;
@ -935,47 +935,49 @@ process_blocks:
* Now lookup all the similarity hashes. We sort the hashes first so that
* all duplicate hash values can be easily eliminated.
*
* The matching segment offsets in the segcache are stored in a list.
* The matching segment offsets in the segcache are stored in a list. Entries
* that were not found are stored with offset of UINT64_MAX.
*/
if (cfg->similarity_cksum_sz == 8) {
isort_uint64((uint64_t *)(ctx->similarity_cksums), sub_i);
} else {
fprintf(stderr, "Similarity Checksum Size: %d not implemented.\n",
cfg->similarity_cksum_sz);
ctx->valid = 0;
sem_post(ctx->index_sem_next);
return (0);
}
sim_ck = ctx->similarity_cksums;
tgt = src + 1; // One byte for number of entries
crc = 0;
off1 = UINT64_MAX;
k = 0;
for (j=0; j < sub_i; j++) {
hash_entry_t *he = NULL;
/*
* Check for duplicate checksum which need not be looked up
* again.
*/
if (crc == *((uint64_t *)sim_ck)) {
he = NULL;
} else {
if (j > 0 && crc != *((uint64_t *)sim_ck)) {
he = db_lookup_insert_s(cfg, sim_ck, 0, seg_offset, 0, 1);
/*
* Check for different checksum but same segment match.
* This is not a complete check but does help to reduce
* wasted processing.
*/
if (he && off1 == he->item_offset) {
crc = *((uint64_t *)sim_ck);
} else {
he = NULL;
}
}
if (he) {
*((uint64_t *)tgt) = he->item_offset;
} else {
*((uint64_t *)tgt) = UINT64_MAX;
}
crc = *((uint64_t *)sim_ck);
off1 = he->item_offset;
sim_ck += cfg->similarity_cksum_sz;
tgt += cfg->similarity_cksum_sz;
}
/*
* At this point we have a list of segment offsets from the segcache
* file. Sort the offsets to avoid subsequent random access.
*/
tgt = src + 1;
isort_uint64((uint64_t *)tgt, k);
/*
* Now eliminate duplicate offsets and UINT64_MAX offset entries which
* indicate entries that were not found.
*/
sim_ck = tgt;
for (j=0; j < sub_i; j++) {
if (off1 != *((uint64_t *)sim_ck) && *((uint64_t *)sim_ck) != UINT64_MAX) {
off1 = *((uint64_t *)sim_ck);
*((uint64_t *)tgt) = off1;
tgt += cfg->similarity_cksum_sz;
k++;
@ -983,13 +985,6 @@ process_blocks:
sim_ck += cfg->similarity_cksum_sz;
}
*src = k; // Number of entries
src++;
/*
* At this point we have a list of segment offsets from the segcache
* file. Sort the offsets to avoid subsequent random access.
*/
isort_uint64((uint64_t *)src, k);
src = tgt;
i = blks;
}