1 /*
2 * Copyright 2013 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8 #include "Benchmark.h"
9 #include "SkCanvas.h"
10 #include "SkChecksum.h"
11 #include "SkPaint.h"
12 #include "SkString.h"
13 #include "SkTemplates.h"
14
15 #include "gUniqueGlyphIDs.h"
16 #define gUniqueGlyphIDs_Sentinel 0xFFFF
17
count_glyphs(const uint16_t start[])18 static int count_glyphs(const uint16_t start[]) {
19 const uint16_t* curr = start;
20 while (*curr != gUniqueGlyphIDs_Sentinel) {
21 curr += 1;
22 }
23 return static_cast<int>(curr - start);
24 }
25
26 class FontCacheBench : public Benchmark {
27 public:
FontCacheBench()28 FontCacheBench() {}
29
30 protected:
onGetName()31 const char* onGetName() override {
32 return "fontcache";
33 }
34
onDraw(int loops,SkCanvas * canvas)35 void onDraw(int loops, SkCanvas* canvas) override {
36 SkPaint paint;
37 this->setupPaint(&paint);
38 paint.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
39
40 const uint16_t* array = gUniqueGlyphIDs;
41 while (*array != gUniqueGlyphIDs_Sentinel) {
42 int count = count_glyphs(array);
43 for (int i = 0; i < loops; ++i) {
44 paint.measureText(array, count * sizeof(uint16_t));
45 }
46 array += count + 1; // skip the sentinel
47 }
48 }
49
50 private:
51 typedef Benchmark INHERITED;
52 };
53
54 ///////////////////////////////////////////////////////////////////////////////
55
rotr(uint32_t value,unsigned bits)56 static uint32_t rotr(uint32_t value, unsigned bits) {
57 return (value >> bits) | (value << (32 - bits));
58 }
59
60 typedef uint32_t (*HasherProc)(uint32_t);
61
hasher0(uint32_t value)62 static uint32_t hasher0(uint32_t value) {
63 value = value ^ (value >> 16);
64 return value ^ (value >> 8);
65 }
66
67 static const struct {
68 const char* fName;
69 HasherProc fHasher;
70 } gRec[] = {
71 { "hasher0", hasher0 },
72 { "hasher2", SkChecksum::Mix },
73 };
74
75 #define kMaxHashBits 12
76 #define kMaxHashCount (1 << kMaxHashBits)
77
count_collisions(const uint16_t array[],int count,HasherProc proc,unsigned hashMask)78 static int count_collisions(const uint16_t array[], int count, HasherProc proc,
79 unsigned hashMask) {
80 char table[kMaxHashCount];
81 sk_bzero(table, sizeof(table));
82
83 int collisions = 0;
84 for (int i = 0; i < count; ++i) {
85 int index = proc(array[i]) & hashMask;
86 collisions += table[index];
87 table[index] = 1;
88 }
89 return collisions;
90 }
91
dump_array(const uint16_t array[],int count)92 static void dump_array(const uint16_t array[], int count) {
93 for (int i = 0; i < count; ++i) {
94 SkDebugf(" %d,", array[i]);
95 }
96 SkDebugf("\n");
97 }
98
99 class FontCacheEfficiency : public Benchmark {
100 public:
FontCacheEfficiency()101 FontCacheEfficiency() {
102 if (false) dump_array(nullptr, 0);
103 if (false) rotr(0, 0);
104 }
105
106 protected:
onGetName()107 const char* onGetName() override {
108 return "fontefficiency";
109 }
110
onDraw(int loops,SkCanvas * canvas)111 void onDraw(int loops, SkCanvas* canvas) override {
112 static bool gDone;
113 if (gDone) {
114 return;
115 }
116 gDone = true;
117
118 for (int hashBits = 6; hashBits <= 12; hashBits += 1) {
119 int hashMask = ((1 << hashBits) - 1);
120 for (int limit = 32; limit <= 1024; limit <<= 1) {
121 for (size_t i = 0; i < SK_ARRAY_COUNT(gRec); ++i) {
122 int collisions = 0;
123 int glyphs = 0;
124 const uint16_t* array = gUniqueGlyphIDs;
125 while (*array != gUniqueGlyphIDs_Sentinel) {
126 int count = SkMin32(count_glyphs(array), limit);
127 collisions += count_collisions(array, count, gRec[i].fHasher, hashMask);
128 glyphs += count;
129 array += count + 1; // skip the sentinel
130 }
131 SkDebugf("hashBits [%d] limit [%d] collisions [%d / %d = %1.2g%%] using %s\n", hashBits, limit, collisions, glyphs,
132 collisions * 100.0 / glyphs, gRec[i].fName);
133 }
134 }
135 }
136 }
137
138 private:
139 typedef Benchmark INHERITED;
140 };
141
142 ///////////////////////////////////////////////////////////////////////////////
143
144 DEF_BENCH( return new FontCacheBench(); )
145
146 // undefine this to run the efficiency test
147 //DEF_BENCH( return new FontCacheEfficiency(); )
148