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 "SkFontHost.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 virtual const char* onGetName() SK_OVERRIDE {
32 return "fontcache";
33 }
34
onDraw(const int loops,SkCanvas * canvas)35 virtual void onDraw(const int loops, SkCanvas* canvas) SK_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
hasher2(uint32_t h)67 static uint32_t hasher2(uint32_t h) {
68 h ^= h >> 16;
69 h *= 0x85ebca6b;
70 h ^= h >> 13;
71 h *= 0xc2b2ae35;
72 h ^= h >> 16;
73
74 h ^= (h >> 8);
75 return h;
76 }
77
78 static const struct {
79 const char* fName;
80 HasherProc fHasher;
81 } gRec[] = {
82 { "hasher0", hasher0 },
83 { "hasher2", hasher2 },
84 };
85
86 #define kMaxHashBits 12
87 #define kMaxHashCount (1 << kMaxHashBits)
88
count_collisions(const uint16_t array[],int count,HasherProc proc,unsigned hashMask)89 static int count_collisions(const uint16_t array[], int count, HasherProc proc,
90 unsigned hashMask) {
91 char table[kMaxHashCount];
92 sk_bzero(table, sizeof(table));
93
94 int collisions = 0;
95 for (int i = 0; i < count; ++i) {
96 int index = proc(array[i]) & hashMask;
97 collisions += table[index];
98 table[index] = 1;
99 }
100 return collisions;
101 }
102
dump_array(const uint16_t array[],int count)103 static void dump_array(const uint16_t array[], int count) {
104 for (int i = 0; i < count; ++i) {
105 SkDebugf(" %d,", array[i]);
106 }
107 SkDebugf("\n");
108 }
109
110 class FontCacheEfficiency : public Benchmark {
111 public:
FontCacheEfficiency()112 FontCacheEfficiency() {
113 if (false) dump_array(NULL, 0);
114 if (false) rotr(0, 0);
115 }
116
117 protected:
onGetName()118 virtual const char* onGetName() SK_OVERRIDE {
119 return "fontefficiency";
120 }
121
onDraw(const int loops,SkCanvas * canvas)122 virtual void onDraw(const int loops, SkCanvas* canvas) SK_OVERRIDE {
123 static bool gDone;
124 if (gDone) {
125 return;
126 }
127 gDone = true;
128
129 for (int hashBits = 6; hashBits <= 12; hashBits += 1) {
130 int hashMask = ((1 << hashBits) - 1);
131 for (int limit = 32; limit <= 1024; limit <<= 1) {
132 for (size_t i = 0; i < SK_ARRAY_COUNT(gRec); ++i) {
133 int collisions = 0;
134 int glyphs = 0;
135 const uint16_t* array = gUniqueGlyphIDs;
136 while (*array != gUniqueGlyphIDs_Sentinel) {
137 int count = SkMin32(count_glyphs(array), limit);
138 collisions += count_collisions(array, count, gRec[i].fHasher, hashMask);
139 glyphs += count;
140 array += count + 1; // skip the sentinel
141 }
142 SkDebugf("hashBits [%d] limit [%d] collisions [%d / %d = %1.2g%%] using %s\n", hashBits, limit, collisions, glyphs,
143 collisions * 100.0 / glyphs, gRec[i].fName);
144 }
145 }
146 }
147 }
148
149 private:
150 typedef Benchmark INHERITED;
151 };
152
153 ///////////////////////////////////////////////////////////////////////////////
154
155 DEF_BENCH( return new FontCacheBench(); )
156
157 // undefine this to run the efficiency test
158 //DEF_BENCH( return new FontCacheEfficiency(); )
159