CacheDigest *
cacheDigestClone(const CacheDigest * cd)
{
CacheDigest *clone;
assert(cd);
clone = cacheDigestCreate(cd->capacity, cd->bits_per_entry);
clone->count = cd->count;
clone->del_count = cd->del_count;
assert(cd->mask_size == clone->mask_size);
xmemcpy(clone->mask, cd->mask, cd->mask_size);
return clone;
}
void
storeDigestInit(void)
{
#if USE_CACHE_DIGESTS
const int cap = storeDigestCalcCap();
if (!Config.onoff.digest_generation) {
store_digest = NULL;
debug(71, 3) ("Local cache digest generation disabled\n");
return;
}
store_digest = cacheDigestCreate(cap, Config.digest.bits_per_entry);
debug(71, 1) ("Local cache digest enabled; rebuild/rewrite every %d/%d sec\n",
(int) Config.digest.rebuild_period, (int) Config.digest.rewrite_period);
memset(&sd_state, 0, sizeof(sd_state));
cachemgrRegister("store_digest", "Store Digest",
storeDigestReport, 0, 1);
#else
store_digest = NULL;
debug(71, 3) ("Local cache digest is 'off'\n");
#endif
}
/* re-digests currently hashed entries */
static void
cacheResetDigest(Cache * cache)
{
CacheEntry *e = NULL;
hash_table *hash;
struct timeval t_start, t_end;
assert(cache);
fprintf(stderr, "%s: init-ing digest with %d entries\n", cache->name, cache->count);
if (cache->digest)
cacheDigestDestroy(cache->digest);
hash = cache->hash;
cache->digest = cacheDigestCreate(cache->count + 1, 6);
if (!cache->count)
return;
gettimeofday(&t_start, NULL);
hash_first(hash);
while (e = hash_next(hash)) {
cacheDigestAdd(cache->digest, e->key);
}
gettimeofday(&t_end, NULL);
assert(cache->digest->count == cache->count);
fprintf(stderr, "%s: init-ed digest with %d entries\n",
cache->name, cache->digest->count);
fprintf(stderr, "%s: init took: %f sec, %f sec/M\n",
cache->name,
tvSubDsec(t_start, t_end),
(double) 1e6 * tvSubDsec(t_start, t_end) / cache->count);
/* check how long it takes to traverse the hash */
gettimeofday(&t_start, NULL);
for (e = hash_first(hash); e; e = hash_next(hash)) {
}
gettimeofday(&t_end, NULL);
fprintf(stderr, "%s: hash scan took: %f sec, %f sec/M\n",
cache->name,
tvSubDsec(t_start, t_end),
(double) 1e6 * tvSubDsec(t_start, t_end) / cache->count);
}
static int
peerDigestSetCBlock(PeerDigest * pd, const char *buf)
{
StoreDigestCBlock cblock;
int freed_size = 0;
const char *host = strBuf(pd->host);
xmemcpy(&cblock, buf, sizeof(cblock));
/* network -> host conversions */
cblock.ver.current = ntohs(cblock.ver.current);
cblock.ver.required = ntohs(cblock.ver.required);
cblock.capacity = ntohl(cblock.capacity);
cblock.count = ntohl(cblock.count);
cblock.del_count = ntohl(cblock.del_count);
cblock.mask_size = ntohl(cblock.mask_size);
debug(72, 2) ("got digest cblock from %s; ver: %d (req: %d)\n",
host, (int) cblock.ver.current, (int) cblock.ver.required);
debug(72, 2) ("\t size: %d bytes, e-cnt: %d, e-util: %d%%\n",
cblock.mask_size, cblock.count,
xpercentInt(cblock.count, cblock.capacity));
/* check version requirements (both ways) */
if (cblock.ver.required > CacheDigestVer.current) {
debug(72, 1) ("%s digest requires version %d; have: %d\n",
host, cblock.ver.required, CacheDigestVer.current);
return 0;
}
if (cblock.ver.current < CacheDigestVer.required) {
debug(72, 1) ("%s digest is version %d; we require: %d\n",
host, cblock.ver.current, CacheDigestVer.required);
return 0;
}
/* check consistency */
if (cblock.ver.required > cblock.ver.current ||
cblock.mask_size <= 0 || cblock.capacity <= 0 ||
cblock.bits_per_entry <= 0 || cblock.hash_func_count <= 0) {
debug(72, 0) ("%s digest cblock is corrupted.\n", host);
return 0;
}
/* check consistency further */
if (cblock.mask_size != cacheDigestCalcMaskSize(cblock.capacity, cblock.bits_per_entry)) {
debug(72, 0) ("%s digest cblock is corrupted (mask size mismatch: %d ? %d).\n",
host, cblock.mask_size, cacheDigestCalcMaskSize(cblock.capacity, cblock.bits_per_entry));
return 0;
}
/* there are some things we cannot do yet */
if (cblock.hash_func_count != CacheDigestHashFuncCount) {
debug(72, 0) ("%s digest: unsupported #hash functions: %d ? %d.\n",
host, cblock.hash_func_count, CacheDigestHashFuncCount);
return 0;
}
/*
* no cblock bugs below this point
*/
/* check size changes */
if (pd->cd && cblock.mask_size != pd->cd->mask_size) {
debug(72, 2) ("%s digest changed size: %d -> %d\n",
host, cblock.mask_size, pd->cd->mask_size);
freed_size = pd->cd->mask_size;
cacheDigestDestroy(pd->cd);
pd->cd = NULL;
}
if (!pd->cd) {
debug(72, 2) ("creating %s digest; size: %d (%+d) bytes\n",
host, cblock.mask_size, (int) (cblock.mask_size - freed_size));
pd->cd = cacheDigestCreate(cblock.capacity, cblock.bits_per_entry);
if (cblock.mask_size >= freed_size)
kb_incr(&Counter.cd.memory, cblock.mask_size - freed_size);
}
assert(pd->cd);
/* these assignments leave us in an inconsistent state until we finish reading the digest */
pd->cd->count = cblock.count;
pd->cd->del_count = cblock.del_count;
return 1;
}
