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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"
namespace v8 {
namespace internal {
class Logger;
// Functions and data for performing output of log messages.
class Log {
public:
// Performs process-wide initialization.
void Initialize(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_internal_timer_events || FLAG_prof_cpp;
}
// 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_ != NULL;
}
// 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);
// Append a character to the log message.
void Append(const char c);
// Append double quoted string to the log message.
void AppendDoubleQuotedString(const char* string);
// Append a heap string.
void Append(String* str);
// Appends an address.
void AppendAddress(Address addr);
void AppendSymbolName(Symbol* symbol);
void AppendDetailed(String* str, bool show_impl_info);
// Append a portion of a string.
void AppendStringPart(const char* str, int len);
// Write the log message to the log file currently opened.
void WriteToLogFile();
private:
Log* log_;
base::LockGuard<base::Mutex> lock_guard_;
int pos_;
};
private:
explicit Log(Logger* logger);
// Opens stdout for logging.
void OpenStdout();
// Opens file for logging.
void OpenFile(const char* name);
// Opens a temporary file for logging.
void OpenTemporaryFile();
// Implementation of writing to a log file.
int WriteToFile(const char* msg, int length) {
DCHECK(output_handle_ != NULL);
size_t rv = fwrite(msg, 1, length, output_handle_);
DCHECK(static_cast<size_t>(length) == rv);
USE(rv);
fflush(output_handle_);
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_;
// 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* message_buffer_;
Logger* logger_;
friend class Logger;
};
} // namespace internal
} // namespace v8
#endif // V8_LOG_UTILS_H_
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