ddidderr/zstd-rs
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Address comments, clean up interface/internals

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This commit is contained in:
senhuang42
2021-01-07 12:29:12 -05:00
parent 22b7bff2bc
commit c2c9b8a7ec
1 changed files with 20 additions and 15 deletions
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lib/decompress/zstd_decompress.c
+20 -15
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@@ -62,6 +62,7 @@
#include "../common/fse.h"
#define HUF_STATIC_LINKING_ONLY
#include "../common/huf.h"
#include "../common/xxhash.h" /* XXH64_reset, XXH64_update, XXH64_digest, XXH64 */
#include "../common/zstd_internal.h" /* blockProperties_t */
#include "zstd_decompress_internal.h" /* ZSTD_DCtx */
#include "zstd_ddict.h" /* ZSTD_DDictDictContent */
@@ -77,7 +78,13 @@
* Multiple DDicts Hashset internals *
*************************************/
#define DDICT_HASHSET_MAX_LOAD_FACTOR 0.75
#define DDICT_HASHSET_MAX_LOAD_FACTOR_COUNT_MULT 4
#define DDICT_HASHSET_MAX_LOAD_FACTOR_SIZE_MULT 3 /* These two constants represent SIZE_MULT/COUNT_MULT load factor without using a float.
* Currently, that means a 0.75 load factor.
* So, if count * COUNT_MULT / size * SIZE_MULT != 0, then we've exceeded
* the load factor of the ddict hash set.
*/
#define DDICT_HASHSET_TABLE_BASE_SIZE 64
#define DDICT_HASHSET_RESIZE_FACTOR 2
@@ -90,17 +97,19 @@ static size_t ZSTD_DDictHashSet_getIndex(const ZSTD_DDictHashSet* hashSet, U32 d
return hash & (hashSet->ddictPtrTableSize - 1);
}
/* Adds ddict to a hashset resizing it
* Returns 0 if successful (ddict may or may not have actually been added), or a zstd error code if something went wrong
/* Adds DDict to a hashset without resizing it.
* If inserting a DDict with a dictID that already exists in the set, replaces the one in the set.
* Returns 0 if successful, or a zstd error code if something went wrong.
*/
static size_t ZSTD_DDictHashSet_emplaceDDict(ZSTD_DDictHashSet* hashSet, const ZSTD_DDict* ddict, U32 dictID) {
static size_t ZSTD_DDictHashSet_emplaceDDict(ZSTD_DDictHashSet* hashSet, const ZSTD_DDict* ddict) {
U32 dictID = ZSTD_getDictID_fromDDict(ddict);
size_t idx = ZSTD_DDictHashSet_getIndex(hashSet, dictID);
RETURN_ERROR_IF(hashSet->ddictPtrCount == hashSet->ddictPtrTableSize, GENERIC, "Hash set is full!");
DEBUGLOG(4, "Hashed index: for dictID: %u is %zu", dictID, idx);
while (hashSet->ddictPtrTable[idx] != NULL) {
/* Replace existing ddict if inserting ddict with same dictID */
if (ZSTD_getDictID_fromDDict(hashSet->ddictPtrTable[idx]) == dictID) {
DEBUGLOG(2, "DictID already exists, replacing rather than adding");
DEBUGLOG(4, "DictID already exists, replacing rather than adding");
hashSet->ddictPtrTable[idx] = ddict;
return 0;
}
@@ -134,7 +143,7 @@ static size_t ZSTD_DDictHashSet_expand(ZSTD_DDictHashSet* hashSet, ZSTD_customMe
hashSet->ddictPtrCount = 0;
for (i = 0; i < oldTableSize; ++i) {
if (oldTable[i] != NULL) {
FORWARD_IF_ERROR(ZSTD_DDictHashSet_emplaceDDict(hashSet, oldTable[i], ZSTD_getDictID_fromDDict(oldTable[i])), "");
FORWARD_IF_ERROR(ZSTD_DDictHashSet_emplaceDDict(hashSet, oldTable[i]), "");
}
}
ZSTD_customFree(oldTable, customMem);
@@ -154,10 +163,7 @@ static const ZSTD_DDict* ZSTD_DDictHashSet_getDDict(ZSTD_DDictHashSet* hashSet,
/* currDictID == 0 implies a NULL ddict entry */
break;
} else {
if (idx == hashSet->ddictPtrTableSize - 1) {
idx = 0;
continue;
}
idx &= (hashSet->ddictPtrTableSize - 1); /* Goes to start of table when we reach the end */
idx++;
}
}
@@ -197,12 +203,12 @@ static void ZSTD_freeDDictHashSet(ZSTD_DDictHashSet* hashSet, ZSTD_customMem cus
/* Public function: Adds a DDict into the ZSTD_DDictHashSet, possibly triggering a resize of the hash set.
* Returns 0 on success, or a ZSTD error.
*/
static size_t ZSTD_DDictHashSet_addDDict(ZSTD_DDictHashSet* hashSet, const ZSTD_DDict* ddict, U32 dictID, ZSTD_customMem customMem) {
static size_t ZSTD_DDictHashSet_addDDict(ZSTD_DDictHashSet* hashSet, const ZSTD_DDict* ddict, ZSTD_customMem customMem) {
DEBUGLOG(4, "Adding dict ID: %d to hashset with - Count: %zu Tablesize: %zu", dictID, hashSet->ddictPtrCount, hashSet->ddictPtrTableSize);
if ((float)hashSet->ddictPtrCount / (float)hashSet->ddictPtrTableSize >= DDICT_HASHSET_MAX_LOAD_FACTOR) {
if (hashSet->ddictPtrCount * DDICT_HASHSET_MAX_LOAD_FACTOR_COUNT_MULT / hashSet->ddictPtrTableSize * DDICT_HASHSET_MAX_LOAD_FACTOR_SIZE_MULT != 0) {
FORWARD_IF_ERROR(ZSTD_DDictHashSet_expand(hashSet, customMem), "");
}
FORWARD_IF_ERROR(ZSTD_DDictHashSet_emplaceDDict(hashSet, ddict, dictID), "");
FORWARD_IF_ERROR(ZSTD_DDictHashSet_emplaceDDict(hashSet, ddict), "");
return 0;
}
@@ -1568,8 +1574,7 @@ size_t ZSTD_DCtx_refDDict(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict)
}
}
assert(!dctx->staticSize); /* Impossible: ddictSet cannot have been allocated if static dctx */
FORWARD_IF_ERROR(ZSTD_DDictHashSet_addDDict(dctx->ddictSet, ddict,
ZSTD_getDictID_fromDDict(ddict), dctx->customMem), "");
FORWARD_IF_ERROR(ZSTD_DDictHashSet_addDDict(dctx->ddictSet, ddict, dctx->customMem), "");
}
}
return 0;