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Refactor VP8LColorCacheContains()

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Return key/index if the query is found, and -1 otherwise.
The benefit of this is to save a hashing computation.

Change-Id: Iff056be330f5fb8204011259ac814f7677dd40fe
This commit is contained in:
hui su 2016-08-12 15:16:06 -07:00
parent 40872fb2e6
commit 1269dc7cfb
2 changed files with 12 additions and 7 deletions
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16
src/enc/backward_references.c
View File

@ -598,9 +598,10 @@ static void AddSingleLiteralWithCostModel(const uint32_t* const argb,
uint16_t* const dist_array) { uint16_t* const dist_array) {
double cost_val = prev_cost; double cost_val = prev_cost;
const uint32_t color = argb[0]; const uint32_t color = argb[0];
if (use_color_cache && VP8LColorCacheContains(hashers, color)) { const int ix = use_color_cache ? VP8LColorCacheContains(hashers, color) : -1;
if (ix >= 0) {
// use_color_cache is true and hashers contains color
const double mul0 = 0.68; const double mul0 = 0.68;
const int ix = VP8LColorCacheGetIndex(hashers, color);
cost_val += GetCacheCost(cost_model, ix) * mul0; cost_val += GetCacheCost(cost_model, ix) * mul0;
} else { } else {
const double mul1 = 0.82; const double mul1 = 0.82;
@ -1410,9 +1411,11 @@ static int BackwardReferencesHashChainFollowChosenPath(
i += len; i += len;
} else { } else {
PixOrCopy v; PixOrCopy v;
if (use_color_cache && VP8LColorCacheContains(&hashers, argb[i])) { const int idx =
use_color_cache ? VP8LColorCacheContains(&hashers, argb[i]) : -1;
if (idx >= 0) {
// use_color_cache is true and hashers contains argb[i]
// push pixel as a color cache index // push pixel as a color cache index
const int idx = VP8LColorCacheGetIndex(&hashers, argb[i]);
v = PixOrCopyCreateCacheIdx(idx); v = PixOrCopyCreateCacheIdx(idx);
} else { } else {
if (use_color_cache) VP8LColorCacheInsert(&hashers, argb[i]); if (use_color_cache) VP8LColorCacheInsert(&hashers, argb[i]);
@ -1601,8 +1604,9 @@ static int BackwardRefsWithLocalCache(const uint32_t* const argb,
PixOrCopy* const v = c.cur_pos; PixOrCopy* const v = c.cur_pos;
if (PixOrCopyIsLiteral(v)) { if (PixOrCopyIsLiteral(v)) {
const uint32_t argb_literal = v->argb_or_distance; const uint32_t argb_literal = v->argb_or_distance;
if (VP8LColorCacheContains(&hashers, argb_literal)) { const int ix = VP8LColorCacheContains(&hashers, argb_literal);
const int ix = VP8LColorCacheGetIndex(&hashers, argb_literal); if (ix >= 0) {
// hashers contains argb_literal
*v = PixOrCopyCreateCacheIdx(ix); *v = PixOrCopyCreateCacheIdx(ix);
} else { } else {
VP8LColorCacheInsert(&hashers, argb_literal); VP8LColorCacheInsert(&hashers, argb_literal);

3
src/utils/color_cache.h
View File

@ -53,10 +53,11 @@ static WEBP_INLINE int VP8LColorCacheGetIndex(const VP8LColorCache* const cc,
return (kHashMul * argb) >> cc->hash_shift_; return (kHashMul * argb) >> cc->hash_shift_;
} }
// Return the key if cc contains argb, and -1 otherwise.
static WEBP_INLINE int VP8LColorCacheContains(const VP8LColorCache* const cc, static WEBP_INLINE int VP8LColorCacheContains(const VP8LColorCache* const cc,
uint32_t argb) { uint32_t argb) {
const uint32_t key = (kHashMul * argb) >> cc->hash_shift_; const uint32_t key = (kHashMul * argb) >> cc->hash_shift_;
return (cc->colors_[key] == argb); return (cc->colors_[key] == argb) ? (int)key : -1;
} }
//------------------------------------------------------------------------------ //------------------------------------------------------------------------------