This source file includes following definitions.
- DebugOutput
- GetTraceObject
- EnableTracing
- InitTrace
- DestroyTrace
- Trace
- DumpTrace
- InitTrace
- DestroyTrace
- Trace
#include "net/disk_cache/blockfile/trace.h"
#include <stdio.h>
#if defined(OS_WIN)
#include <windows.h>
#endif
#include "base/lazy_instance.h"
#include "base/logging.h"
#include "base/synchronization/lock.h"
#include "net/disk_cache/blockfile/stress_support.h"
#define ENABLE_TRACING 0
#ifndef NDEBUG
#undef ENABLE_TRACING
#define ENABLE_TRACING 1
#endif
namespace {
const int kEntrySize = 12 * sizeof(size_t);
#if defined(NET_BUILD_STRESS_CACHE)
const int kNumberOfEntries = 500000;
#else
const int kNumberOfEntries = 5000;
#endif
bool s_trace_enabled = false;
base::LazyInstance<base::Lock>::Leaky s_lock = LAZY_INSTANCE_INITIALIZER;
struct TraceBuffer {
int num_traces;
int current;
char buffer[kNumberOfEntries][kEntrySize];
};
#if ENABLE_TRACING
void DebugOutput(const char* msg) {
#if defined(OS_WIN)
OutputDebugStringA(msg);
#else
NOTIMPLEMENTED();
#endif
}
#endif
}
namespace disk_cache {
static TraceObject* s_trace_object = NULL;
TraceObject* TraceObject::GetTraceObject() {
base::AutoLock lock(s_lock.Get());
if (s_trace_object)
return s_trace_object;
s_trace_object = new TraceObject();
return s_trace_object;
}
TraceObject::TraceObject() {
InitTrace();
}
TraceObject::~TraceObject() {
DestroyTrace();
}
void TraceObject::EnableTracing(bool enable) {
base::AutoLock lock(s_lock.Get());
s_trace_enabled = enable;
}
#if ENABLE_TRACING
static TraceBuffer* s_trace_buffer = NULL;
void InitTrace(void) {
s_trace_enabled = true;
if (s_trace_buffer)
return;
s_trace_buffer = new TraceBuffer;
memset(s_trace_buffer, 0, sizeof(*s_trace_buffer));
}
void DestroyTrace(void) {
base::AutoLock lock(s_lock.Get());
delete s_trace_buffer;
s_trace_buffer = NULL;
s_trace_object = NULL;
}
void Trace(const char* format, ...) {
if (!s_trace_buffer || !s_trace_enabled)
return;
va_list ap;
va_start(ap, format);
char line[kEntrySize + 2];
#if defined(OS_WIN)
vsprintf_s(line, format, ap);
#else
vsnprintf(line, kEntrySize, format, ap);
#endif
#if defined(DISK_CACHE_TRACE_TO_LOG)
line[kEntrySize] = '\0';
LOG(INFO) << line;
#endif
va_end(ap);
{
base::AutoLock lock(s_lock.Get());
if (!s_trace_buffer || !s_trace_enabled)
return;
memcpy(s_trace_buffer->buffer[s_trace_buffer->current], line, kEntrySize);
s_trace_buffer->num_traces++;
s_trace_buffer->current++;
if (s_trace_buffer->current == kNumberOfEntries)
s_trace_buffer->current = 0;
}
}
void DumpTrace(int num_traces) {
DCHECK(s_trace_buffer);
DebugOutput("Last traces:\n");
if (num_traces > kNumberOfEntries || num_traces < 0)
num_traces = kNumberOfEntries;
if (s_trace_buffer->num_traces) {
char line[kEntrySize + 2];
int current = s_trace_buffer->current - num_traces;
if (current < 0)
current += kNumberOfEntries;
for (int i = 0; i < num_traces; i++) {
memcpy(line, s_trace_buffer->buffer[current], kEntrySize);
line[kEntrySize] = '\0';
size_t length = strlen(line);
if (length) {
line[length] = '\n';
line[length + 1] = '\0';
DebugOutput(line);
}
current++;
if (current == kNumberOfEntries)
current = 0;
}
}
DebugOutput("End of Traces\n");
}
#else
void InitTrace(void) {
return;
}
void DestroyTrace(void) {
s_trace_object = NULL;
}
void Trace(const char* format, ...) {
}
#endif
}