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// Copyright 2006-2009 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef V8_LOG_UTILS_H_
#define V8_LOG_UTILS_H_
#include <stdio.h>
#include <cstdarg>
#include "src/allocation.h"
#include "src/base/compiler-specific.h"
#include "src/base/platform/mutex.h"
#include "src/flags.h"
#include "src/ostreams.h"
namespace v8 {
namespace internal {
class Logger;
enum class LogSeparator { kSeparator };
// Functions and data for performing output of log messages.
class Log {
public:
Log(Logger* log, const char* log_file_name);
// Disables logging, but preserves acquired resources.
void stop() { is_stopped_ = true; }
static bool InitLogAtStart() {
return FLAG_log || FLAG_log_api || FLAG_log_code || FLAG_log_gc ||
FLAG_log_handles || FLAG_log_suspect || FLAG_ll_prof ||
FLAG_perf_basic_prof || FLAG_perf_prof || FLAG_log_source_code ||
FLAG_log_internal_timer_events || FLAG_prof_cpp || FLAG_trace_ic ||
FLAG_log_function_events;
}
// Frees all resources acquired in Initialize and Open... functions.
// When a temporary file is used for the log, returns its stream descriptor,
// leaving the file open.
FILE* Close();
// Returns whether logging is enabled.
bool IsEnabled() { return !is_stopped_ && output_handle_ != nullptr; }
// Size of buffer used for formatting log messages.
static const int kMessageBufferSize = 2048;
// This mode is only used in tests, as temporary files are automatically
// deleted on close and thus can't be accessed afterwards.
static const char* const kLogToTemporaryFile;
static const char* const kLogToConsole;
// Utility class for formatting log messages. It fills the message into the
// static buffer in Log.
class MessageBuilder BASE_EMBEDDED {
public:
// Create a message builder starting from position 0.
// This acquires the mutex in the log as well.
explicit MessageBuilder(Log* log);
~MessageBuilder() { }
// Append string data to the log message.
void PRINTF_FORMAT(2, 3) Append(const char* format, ...);
// Append string data to the log message.
void PRINTF_FORMAT(2, 0) AppendVA(const char* format, va_list args);
void AppendSymbolName(Symbol* symbol);
void AppendDetailed(String* str, bool show_impl_info);
// Append and escape a full string.
void AppendString(String* source);
void AppendString(const char* string);
// Append and escpae a portion of a string.
void AppendStringPart(String* source, int len);
void AppendStringPart(const char* str, size_t len);
void AppendCharacter(const char character);
// Delegate insertion to the underlying {log_}.
// All appened srings are escaped to maintain one-line log entries.
template <typename T>
MessageBuilder& operator<<(T value) {
log_->os_ << value;
return *this;
}
// Finish the current log line an flush the it to the log file.
void WriteToLogFile();
private:
Log* log_;
base::LockGuard<base::Mutex> lock_guard_;
};
private:
static FILE* CreateOutputHandle(const char* file_name);
// Implementation of writing to a log file.
int WriteToFile(const char* msg, int length) {
DCHECK_NOT_NULL(output_handle_);
os_.write(msg, length);
DCHECK(!os_.bad());
return length;
}
// Whether logging is stopped (e.g. due to insufficient resources).
bool is_stopped_;
// When logging is active output_handle_ is used to store a pointer to log
// destination. mutex_ should be acquired before using output_handle_.
FILE* output_handle_;
OFStream os_;
// mutex_ is a Mutex used for enforcing exclusive
// access to the formatting buffer and the log file or log memory buffer.
base::Mutex mutex_;
// Buffer used for formatting log messages. This is a singleton buffer and
// mutex_ should be acquired before using it.
char* format_buffer_;
Logger* logger_;
friend class Logger;
};
template <>
Log::MessageBuilder& Log::MessageBuilder::operator<<<LogSeparator>(
LogSeparator separator);
template <>
Log::MessageBuilder& Log::MessageBuilder::operator<<<void*>(void* pointer);
template <>
Log::MessageBuilder& Log::MessageBuilder::operator<<<const char*>(
const char* string);
template <>
Log::MessageBuilder& Log::MessageBuilder::operator<<<char>(char c);
template <>
Log::MessageBuilder& Log::MessageBuilder::operator<<<String*>(String* string);
template <>
Log::MessageBuilder& Log::MessageBuilder::operator<<<Symbol*>(Symbol* symbol);
template <>
Log::MessageBuilder& Log::MessageBuilder::operator<<<Name*>(Name* name);
} // namespace internal
} // namespace v8
#endif // V8_LOG_UTILS_H_
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