1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #include "net/disk_cache/trace.h"
12 #include "base/lazy_instance.h"
13 #include "base/logging.h"
14 #include "base/synchronization/lock.h"
15 #include "net/disk_cache/stress_support.h"
17 // Change this value to 1 to enable tracing on a release build. By default,
18 // tracing is enabled only on debug builds.
19 #define ENABLE_TRACING 0
23 #define ENABLE_TRACING 1
28 const int kEntrySize = 12 * sizeof(size_t);
29 #if defined(NET_BUILD_STRESS_CACHE)
30 const int kNumberOfEntries = 500000;
32 const int kNumberOfEntries = 5000; // 240 KB on 32bit, 480 KB on 64bit
35 bool s_trace_enabled = false;
36 base::LazyInstance<base::Lock>::Leaky s_lock = LAZY_INSTANCE_INITIALIZER;
41 char buffer[kNumberOfEntries][kEntrySize];
45 void DebugOutput(const char* msg) {
47 OutputDebugStringA(msg);
52 #endif // ENABLE_TRACING
56 namespace disk_cache {
58 // s_trace_buffer and s_trace_object are not singletons because I want the
59 // buffer to be destroyed and re-created when the last user goes away, and it
60 // must be straightforward to access the buffer from the debugger.
61 static TraceObject* s_trace_object = NULL;
64 TraceObject* TraceObject::GetTraceObject() {
65 base::AutoLock lock(s_lock.Get());
68 return s_trace_object;
70 s_trace_object = new TraceObject();
71 return s_trace_object;
74 TraceObject::TraceObject() {
78 TraceObject::~TraceObject() {
82 void TraceObject::EnableTracing(bool enable) {
83 base::AutoLock lock(s_lock.Get());
84 s_trace_enabled = enable;
89 static TraceBuffer* s_trace_buffer = NULL;
91 void InitTrace(void) {
92 s_trace_enabled = true;
96 s_trace_buffer = new TraceBuffer;
97 memset(s_trace_buffer, 0, sizeof(*s_trace_buffer));
100 void DestroyTrace(void) {
101 base::AutoLock lock(s_lock.Get());
103 delete s_trace_buffer;
104 s_trace_buffer = NULL;
105 s_trace_object = NULL;
108 void Trace(const char* format, ...) {
109 if (!s_trace_buffer || !s_trace_enabled)
113 va_start(ap, format);
114 char line[kEntrySize + 2];
117 vsprintf_s(line, format, ap);
119 vsnprintf(line, kEntrySize, format, ap);
122 #if defined(DISK_CACHE_TRACE_TO_LOG)
123 line[kEntrySize] = '\0';
130 base::AutoLock lock(s_lock.Get());
131 if (!s_trace_buffer || !s_trace_enabled)
134 memcpy(s_trace_buffer->buffer[s_trace_buffer->current], line, kEntrySize);
136 s_trace_buffer->num_traces++;
137 s_trace_buffer->current++;
138 if (s_trace_buffer->current == kNumberOfEntries)
139 s_trace_buffer->current = 0;
143 // Writes the last num_traces to the debugger output.
144 void DumpTrace(int num_traces) {
145 DCHECK(s_trace_buffer);
146 DebugOutput("Last traces:\n");
148 if (num_traces > kNumberOfEntries || num_traces < 0)
149 num_traces = kNumberOfEntries;
151 if (s_trace_buffer->num_traces) {
152 char line[kEntrySize + 2];
154 int current = s_trace_buffer->current - num_traces;
156 current += kNumberOfEntries;
158 for (int i = 0; i < num_traces; i++) {
159 memcpy(line, s_trace_buffer->buffer[current], kEntrySize);
160 line[kEntrySize] = '\0';
161 size_t length = strlen(line);
164 line[length + 1] = '\0';
169 if (current == kNumberOfEntries)
174 DebugOutput("End of Traces\n");
177 #else // ENABLE_TRACING
179 void InitTrace(void) {
183 void DestroyTrace(void) {
184 s_trace_object = NULL;
187 void Trace(const char* format, ...) {
190 #endif // ENABLE_TRACING
192 } // namespace disk_cache