xref: /aosp_15_r20/external/regex-re2/util/benchmark.cc (revision ccdc9c3e24c519bfa4832a66aa2e83a52c19f295)
1 // Copyright 2009 The RE2 Authors.  All Rights Reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
4 
5 #include <stdint.h>
6 #include <stdio.h>
7 #include <stdlib.h>
8 #include <algorithm>
9 #include <chrono>
10 #include <thread>
11 
12 #include "util/util.h"
13 #include "util/flags.h"
14 #include "util/benchmark.h"
15 #include "re2/re2.h"
16 
17 DEFINE_string(test_tmpdir, "/var/tmp", "temp directory");
18 
19 #ifdef _WIN32
20 #define snprintf _snprintf
21 #endif
22 
23 using testing::Benchmark;
24 
25 static Benchmark* benchmarks[10000];
26 static int nbenchmarks;
27 
Register()28 void Benchmark::Register() {
29 	benchmarks[nbenchmarks] = this;
30 	if(lo < 1)
31 		lo = 1;
32 	if(hi < lo)
33 		hi = lo;
34 	nbenchmarks++;
35 }
36 
nsec()37 static int64_t nsec() {
38 	return std::chrono::duration_cast<std::chrono::nanoseconds>(
39 		std::chrono::steady_clock::now().time_since_epoch()).count();
40 }
41 
42 static int64_t bytes;
43 static int64_t ns;
44 static int64_t t0;
45 static int64_t items;
46 
SetBenchmarkBytesProcessed(int64_t x)47 void SetBenchmarkBytesProcessed(int64_t x) {
48 	bytes = x;
49 }
50 
StopBenchmarkTiming()51 void StopBenchmarkTiming() {
52 	if(t0 != 0)
53 		ns += nsec() - t0;
54 	t0 = 0;
55 }
56 
StartBenchmarkTiming()57 void StartBenchmarkTiming() {
58 	if(t0 == 0)
59 		t0 = nsec();
60 }
61 
SetBenchmarkItemsProcessed(int n)62 void SetBenchmarkItemsProcessed(int n) {
63 	items = n;
64 }
65 
BenchmarkMemoryUsage()66 void BenchmarkMemoryUsage() {
67 	// TODO(rsc): Implement.
68 }
69 
NumCPUs()70 int NumCPUs() {
71 	return static_cast<int>(std::thread::hardware_concurrency());
72 }
73 
runN(Benchmark * b,int n,int siz)74 static void runN(Benchmark *b, int n, int siz) {
75 	bytes = 0;
76 	items = 0;
77 	ns = 0;
78 	t0 = nsec();
79 	if(b->fn)
80 		b->fn(n);
81 	else if(b->fnr)
82 		b->fnr(n, siz);
83 	else {
84 		fprintf(stderr, "%s: missing function\n", b->name);
85 		abort();
86 	}
87 	if(t0 != 0)
88 		ns += nsec() - t0;
89 }
90 
round(int n)91 static int round(int n) {
92 	int base = 1;
93 
94 	while(base*10 < n)
95 		base *= 10;
96 	if(n < 2*base)
97 		return 2*base;
98 	if(n < 5*base)
99 		return 5*base;
100 	return 10*base;
101 }
102 
RunBench(Benchmark * b,int nthread,int siz)103 void RunBench(Benchmark* b, int nthread, int siz) {
104 	int n, last;
105 
106 	// TODO(rsc): Threaded benchmarks.
107 	if(nthread != 1)
108 		return;
109 
110 	// run once in case it's expensive
111 	n = 1;
112 	runN(b, n, siz);
113 	while(ns < (int)1e9 && n < (int)1e9) {
114 		last = n;
115 		if(ns/n == 0)
116 			n = (int)1e9;
117 		else
118 			n = (int)1e9 / static_cast<int>(ns/n);
119 
120 		n = std::max(last+1, std::min(n+n/2, 100*last));
121 		n = round(n);
122 		runN(b, n, siz);
123 	}
124 
125 	char mb[100];
126 	char suf[100];
127 	mb[0] = '\0';
128 	suf[0] = '\0';
129 	if(ns > 0 && bytes > 0)
130 		snprintf(mb, sizeof mb, "\t%7.2f MB/s", ((double)bytes/1e6)/((double)ns/1e9));
131 	if(b->fnr || b->lo != b->hi) {
132 		if(siz >= (1<<20))
133 			snprintf(suf, sizeof suf, "/%dM", siz/(1<<20));
134 		else if(siz >= (1<<10))
135 			snprintf(suf, sizeof suf, "/%dK", siz/(1<<10));
136 		else
137 			snprintf(suf, sizeof suf, "/%d", siz);
138 	}
139 	printf("%s%s\t%8lld\t%10lld ns/op%s\n", b->name, suf, (long long)n, (long long)ns/n, mb);
140 	fflush(stdout);
141 }
142 
match(const char * name,int argc,const char ** argv)143 static int match(const char* name, int argc, const char** argv) {
144 	if(argc == 1)
145 		return 1;
146 	for(int i = 1; i < argc; i++)
147 		if(RE2::PartialMatch(name, argv[i]))
148 			return 1;
149 	return 0;
150 }
151 
main(int argc,const char ** argv)152 int main(int argc, const char** argv) {
153 	for(int i = 0; i < nbenchmarks; i++) {
154 		Benchmark* b = benchmarks[i];
155 		if(match(b->name, argc, argv))
156 			for(int j = b->threadlo; j <= b->threadhi; j++)
157 				for(int k = std::max(b->lo, 1); k <= std::max(b->hi, 1); k<<=1)
158 					RunBench(b, j, k);
159 	}
160 }
161 
162