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/*
* Copyright 2013 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "Benchmark.h"
#include "SkCanvas.h"
#include "SkChecksum.h"
#include "SkPaint.h"
#include "SkString.h"
#include "SkTemplates.h"
#include "gUniqueGlyphIDs.h"
#define gUniqueGlyphIDs_Sentinel 0xFFFF
static int count_glyphs(const uint16_t start[]) {
const uint16_t* curr = start;
while (*curr != gUniqueGlyphIDs_Sentinel) {
curr += 1;
}
return static_cast<int>(curr - start);
}
class FontCacheBench : public Benchmark {
public:
FontCacheBench() {}
protected:
const char* onGetName() SK_OVERRIDE {
return "fontcache";
}
void onDraw(const int loops, SkCanvas* canvas) SK_OVERRIDE {
SkPaint paint;
this->setupPaint(&paint);
paint.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
const uint16_t* array = gUniqueGlyphIDs;
while (*array != gUniqueGlyphIDs_Sentinel) {
int count = count_glyphs(array);
for (int i = 0; i < loops; ++i) {
paint.measureText(array, count * sizeof(uint16_t));
}
array += count + 1; // skip the sentinel
}
}
private:
typedef Benchmark INHERITED;
};
///////////////////////////////////////////////////////////////////////////////
static uint32_t rotr(uint32_t value, unsigned bits) {
return (value >> bits) | (value << (32 - bits));
}
typedef uint32_t (*HasherProc)(uint32_t);
static uint32_t hasher0(uint32_t value) {
value = value ^ (value >> 16);
return value ^ (value >> 8);
}
static const struct {
const char* fName;
HasherProc fHasher;
} gRec[] = {
{ "hasher0", hasher0 },
{ "hasher2", SkChecksum::Mix },
};
#define kMaxHashBits 12
#define kMaxHashCount (1 << kMaxHashBits)
static int count_collisions(const uint16_t array[], int count, HasherProc proc,
unsigned hashMask) {
char table[kMaxHashCount];
sk_bzero(table, sizeof(table));
int collisions = 0;
for (int i = 0; i < count; ++i) {
int index = proc(array[i]) & hashMask;
collisions += table[index];
table[index] = 1;
}
return collisions;
}
static void dump_array(const uint16_t array[], int count) {
for (int i = 0; i < count; ++i) {
SkDebugf(" %d,", array[i]);
}
SkDebugf("\n");
}
class FontCacheEfficiency : public Benchmark {
public:
FontCacheEfficiency() {
if (false) dump_array(NULL, 0);
if (false) rotr(0, 0);
}
protected:
const char* onGetName() SK_OVERRIDE {
return "fontefficiency";
}
void onDraw(const int loops, SkCanvas* canvas) SK_OVERRIDE {
static bool gDone;
if (gDone) {
return;
}
gDone = true;
for (int hashBits = 6; hashBits <= 12; hashBits += 1) {
int hashMask = ((1 << hashBits) - 1);
for (int limit = 32; limit <= 1024; limit <<= 1) {
for (size_t i = 0; i < SK_ARRAY_COUNT(gRec); ++i) {
int collisions = 0;
int glyphs = 0;
const uint16_t* array = gUniqueGlyphIDs;
while (*array != gUniqueGlyphIDs_Sentinel) {
int count = SkMin32(count_glyphs(array), limit);
collisions += count_collisions(array, count, gRec[i].fHasher, hashMask);
glyphs += count;
array += count + 1; // skip the sentinel
}
SkDebugf("hashBits [%d] limit [%d] collisions [%d / %d = %1.2g%%] using %s\n", hashBits, limit, collisions, glyphs,
collisions * 100.0 / glyphs, gRec[i].fName);
}
}
}
}
private:
typedef Benchmark INHERITED;
};
///////////////////////////////////////////////////////////////////////////////
DEF_BENCH( return new FontCacheBench(); )
// undefine this to run the efficiency test
//DEF_BENCH( return new FontCacheEfficiency(); )
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