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/*
* libjingle
* Copyright 2004--2005, Google Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
// LOG(...) an ostream target that can be used to send formatted
// output to a variety of logging targets, such as debugger console, stderr,
// file, or any StreamInterface.
// The severity level passed as the first argument to the LOGging
// functions is used as a filter, to limit the verbosity of the logging.
// Static members of LogMessage documented below are used to control the
// verbosity and target of the output.
// There are several variations on the LOG macro which facilitate logging
// of common error conditions, detailed below.
// LOG(sev) logs the given stream at severity "sev", which must be a
// compile-time constant of the LoggingSeverity type, without the namespace
// prefix.
// LOG_V(sev) Like LOG(), but sev is a run-time variable of the LoggingSeverity
// type (basically, it just doesn't prepend the namespace).
// LOG_F(sev) Like LOG(), but includes the name of the current function.
// LOG_T(sev) Like LOG(), but includes the this pointer.
// LOG_T_F(sev) Like LOG_F(), but includes the this pointer.
// LOG_GLE(M)(sev [, mod]) attempt to add a string description of the
// HRESULT returned by GetLastError. The "M" variant allows searching of a
// DLL's string table for the error description.
// LOG_ERRNO(sev) attempts to add a string description of an errno-derived
// error. errno and associated facilities exist on both Windows and POSIX,
// but on Windows they only apply to the C/C++ runtime.
// LOG_ERR(sev) is an alias for the platform's normal error system, i.e. _GLE on
// Windows and _ERRNO on POSIX.
// (The above three also all have _EX versions that let you specify the error
// code, rather than using the last one.)
// LOG_E(sev, ctx, err, ...) logs a detailed error interpreted using the
// specified context.
// LOG_CHECK_LEVEL(sev) (and LOG_CHECK_LEVEL_V(sev)) can be used as a test
// before performing expensive or sensitive operations whose sole purpose is
// to output logging data at the desired level.
// Lastly, PLOG(sev, err) is an alias for LOG_ERR_EX.
#ifndef TALK_BASE_LOGGING_H_
#define TALK_BASE_LOGGING_H_
#ifdef HAVE_CONFIG_H
#include "config.h" // NOLINT
#endif
#include <list>
#include <sstream>
#include <string>
#include <utility>
#include "talk/base/basictypes.h"
#include "talk/base/criticalsection.h"
namespace talk_base {
class StreamInterface;
///////////////////////////////////////////////////////////////////////////////
// ConstantLabel can be used to easily generate string names from constant
// values. This can be useful for logging descriptive names of error messages.
// Usage:
// const ConstantLabel LIBRARY_ERRORS[] = {
// KLABEL(SOME_ERROR),
// KLABEL(SOME_OTHER_ERROR),
// ...
// LASTLABEL
// }
//
// int err = LibraryFunc();
// LOG(LS_ERROR) << "LibraryFunc returned: "
// << ErrorName(err, LIBRARY_ERRORS);
struct ConstantLabel { int value; const char * label; };
#define KLABEL(x) { x, #x }
#define TLABEL(x, y) { x, y }
#define LASTLABEL { 0, 0 }
const char * FindLabel(int value, const ConstantLabel entries[]);
std::string ErrorName(int err, const ConstantLabel* err_table);
//////////////////////////////////////////////////////////////////////
// Note that the non-standard LoggingSeverity aliases exist because they are
// still in broad use. The meanings of the levels are:
// LS_SENSITIVE: Information which should only be logged with the consent
// of the user, due to privacy concerns.
// LS_VERBOSE: This level is for data which we do not want to appear in the
// normal debug log, but should appear in diagnostic logs.
// LS_INFO: Chatty level used in debugging for all sorts of things, the default
// in debug builds.
// LS_WARNING: Something that may warrant investigation.
// LS_ERROR: Something that should not have occurred.
enum LoggingSeverity { LS_SENSITIVE, LS_VERBOSE, LS_INFO, LS_WARNING, LS_ERROR,
INFO = LS_INFO,
WARNING = LS_WARNING,
LERROR = LS_ERROR };
// LogErrorContext assists in interpreting the meaning of an error value.
enum LogErrorContext {
ERRCTX_NONE,
ERRCTX_ERRNO, // System-local errno
ERRCTX_HRESULT, // Windows HRESULT
ERRCTX_OSSTATUS, // MacOS OSStatus
// Abbreviations for LOG_E macro
ERRCTX_EN = ERRCTX_ERRNO, // LOG_E(sev, EN, x)
ERRCTX_HR = ERRCTX_HRESULT, // LOG_E(sev, HR, x)
ERRCTX_OS = ERRCTX_OSSTATUS, // LOG_E(sev, OS, x)
};
class LogMessage {
public:
static const int NO_LOGGING;
static const uint32 WARN_SLOW_LOGS_DELAY = 50; // ms
LogMessage(const char* file, int line, LoggingSeverity sev,
LogErrorContext err_ctx = ERRCTX_NONE, int err = 0,
const char* module = NULL);
~LogMessage();
static inline bool Loggable(LoggingSeverity sev) { return (sev >= min_sev_); }
std::ostream& stream() { return print_stream_; }
// Returns the time at which this function was called for the first time.
// The time will be used as the logging start time.
// If this is not called externally, the LogMessage ctor also calls it, in
// which case the logging start time will be the time of the first LogMessage
// instance is created.
static uint32 LogStartTime();
// Returns the wall clock equivalent of |LogStartTime|, in seconds from the
// epoch.
static uint32 WallClockStartTime();
// These are attributes which apply to all logging channels
// LogContext: Display the file and line number of the message
static void LogContext(int min_sev);
// LogThreads: Display the thread identifier of the current thread
static void LogThreads(bool on = true);
// LogTimestamps: Display the elapsed time of the program
static void LogTimestamps(bool on = true);
// These are the available logging channels
// Debug: Debug console on Windows, otherwise stderr
static void LogToDebug(int min_sev);
static int GetLogToDebug() { return dbg_sev_; }
// Stream: Any non-blocking stream interface. LogMessage takes ownership of
// the stream. Multiple streams may be specified by using AddLogToStream.
// LogToStream is retained for backwards compatibility; when invoked, it
// will discard any previously set streams and install the specified stream.
// GetLogToStream gets the severity for the specified stream, of if none
// is specified, the minimum stream severity.
// RemoveLogToStream removes the specified stream, without destroying it.
static void LogToStream(StreamInterface* stream, int min_sev);
static int GetLogToStream(StreamInterface* stream = NULL);
static void AddLogToStream(StreamInterface* stream, int min_sev);
static void RemoveLogToStream(StreamInterface* stream);
// Testing against MinLogSeverity allows code to avoid potentially expensive
// logging operations by pre-checking the logging level.
static int GetMinLogSeverity() { return min_sev_; }
static void SetDiagnosticMode(bool f) { is_diagnostic_mode_ = f; }
static bool IsDiagnosticMode() { return is_diagnostic_mode_; }
// Parses the provided parameter stream to configure the options above.
// Useful for configuring logging from the command line. If file logging
// is enabled, it is output to the specified filename.
static void ConfigureLogging(const char* params, const char* filename);
// Convert the string to a LS_ value; also accept numeric values.
static int ParseLogSeverity(const std::string& value);
private:
typedef std::list<std::pair<StreamInterface*, int> > StreamList;
// Updates min_sev_ appropriately when debug sinks change.
static void UpdateMinLogSeverity();
// These assist in formatting some parts of the debug output.
static const char* Describe(LoggingSeverity sev);
static const char* DescribeFile(const char* file);
// These write out the actual log messages.
static void OutputToDebug(const std::string& msg, LoggingSeverity severity_);
static void OutputToStream(StreamInterface* stream, const std::string& msg);
// The ostream that buffers the formatted message before output
std::ostringstream print_stream_;
// The severity level of this message
LoggingSeverity severity_;
// String data generated in the constructor, that should be appended to
// the message before output.
std::string extra_;
// If time it takes to write to stream is more than this, log one
// additional warning about it.
uint32 warn_slow_logs_delay_;
// Global lock for the logging subsystem
static CriticalSection crit_;
// dbg_sev_ is the thresholds for those output targets
// min_sev_ is the minimum (most verbose) of those levels, and is used
// as a short-circuit in the logging macros to identify messages that won't
// be logged.
// ctx_sev_ is the minimum level at which file context is displayed
static int min_sev_, dbg_sev_, ctx_sev_;
// The output streams and their associated severities
static StreamList streams_;
// Flags for formatting options
static bool thread_, timestamp_;
// are we in diagnostic mode (as defined by the app)?
static bool is_diagnostic_mode_;
DISALLOW_EVIL_CONSTRUCTORS(LogMessage);
};
//////////////////////////////////////////////////////////////////////
// Logging Helpers
//////////////////////////////////////////////////////////////////////
class LogMultilineState {
public:
size_t unprintable_count_[2];
LogMultilineState() {
unprintable_count_[0] = unprintable_count_[1] = 0;
}
};
// When possible, pass optional state variable to track various data across
// multiple calls to LogMultiline. Otherwise, pass NULL.
void LogMultiline(LoggingSeverity level, const char* label, bool input,
const void* data, size_t len, bool hex_mode,
LogMultilineState* state);
//////////////////////////////////////////////////////////////////////
// Macros which automatically disable logging when LOGGING == 0
//////////////////////////////////////////////////////////////////////
// If LOGGING is not explicitly defined, default to enabled in debug mode
#if !defined(LOGGING)
#if defined(_DEBUG) && !defined(NDEBUG)
#define LOGGING 1
#else
#define LOGGING 0
#endif
#endif // !defined(LOGGING)
#ifndef LOG
#if LOGGING
// The following non-obvious technique for implementation of a
// conditional log stream was stolen from google3/base/logging.h.
// This class is used to explicitly ignore values in the conditional
// logging macros. This avoids compiler warnings like "value computed
// is not used" and "statement has no effect".
class LogMessageVoidify {
public:
LogMessageVoidify() { }
// This has to be an operator with a precedence lower than << but
// higher than ?:
void operator&(std::ostream&) { }
};
#define LOG_SEVERITY_PRECONDITION(sev) \
!(talk_base::LogMessage::Loggable(sev)) \
? (void) 0 \
: talk_base::LogMessageVoidify() &
#define LOG(sev) \
LOG_SEVERITY_PRECONDITION(talk_base::sev) \
talk_base::LogMessage(__FILE__, __LINE__, talk_base::sev).stream()
// The _V version is for when a variable is passed in. It doesn't do the
// namespace concatination.
#define LOG_V(sev) \
LOG_SEVERITY_PRECONDITION(sev) \
talk_base::LogMessage(__FILE__, __LINE__, sev).stream()
// The _F version prefixes the message with the current function name.
#if (defined(__GNUC__) && defined(_DEBUG)) || defined(WANT_PRETTY_LOG_F)
#define LOG_F(sev) LOG(sev) << __PRETTY_FUNCTION__ << ": "
#else
#define LOG_F(sev) LOG(sev) << __FUNCTION__ << ": "
#endif
#define LOG_CHECK_LEVEL(sev) \
talk_base::LogCheckLevel(talk_base::sev)
#define LOG_CHECK_LEVEL_V(sev) \
talk_base::LogCheckLevel(sev)
inline bool LogCheckLevel(LoggingSeverity sev) {
return (LogMessage::GetMinLogSeverity() <= sev);
}
#define LOG_E(sev, ctx, err, ...) \
LOG_SEVERITY_PRECONDITION(talk_base::sev) \
talk_base::LogMessage(__FILE__, __LINE__, talk_base::sev, \
talk_base::ERRCTX_ ## ctx, err , ##__VA_ARGS__) \
.stream()
#define LOG_T(sev) LOG(sev) << this << ": "
#define LOG_T_F(level) LOG_F(level) << this << ": "
#else // !LOGGING
// Hopefully, the compiler will optimize away some of this code.
// Note: syntax of "1 ? (void)0 : LogMessage" was causing errors in g++,
// converted to "while (false)"
#define LOG(sev) \
while (false)talk_base:: LogMessage(NULL, 0, talk_base::sev).stream()
#define LOG_V(sev) \
while (false) talk_base::LogMessage(NULL, 0, sev).stream()
#define LOG_F(sev) LOG(sev) << __FUNCTION__ << ": "
#define LOG_CHECK_LEVEL(sev) \
false
#define LOG_CHECK_LEVEL_V(sev) \
false
#define LOG_E(sev, ctx, err, ...) \
while (false) talk_base::LogMessage(__FILE__, __LINE__, talk_base::sev, \
talk_base::ERRCTX_ ## ctx, err , ##__VA_ARGS__) \
.stream()
#define LOG_T(sev) LOG(sev) << this << ": "
#define LOG_T_F(level) LOG_F(level) << this << " "
#endif // !LOGGING
#define LOG_ERRNO_EX(sev, err) \
LOG_E(sev, ERRNO, err)
#define LOG_ERRNO(sev) \
LOG_ERRNO_EX(sev, errno)
#ifdef WIN32
#define LOG_GLE_EX(sev, err) \
LOG_E(sev, HRESULT, err)
#define LOG_GLE(sev) \
LOG_GLE_EX(sev, GetLastError())
#define LOG_GLEM(sev, mod) \
LOG_E(sev, HRESULT, GetLastError(), mod)
#define LOG_ERR_EX(sev, err) \
LOG_GLE_EX(sev, err)
#define LOG_ERR(sev) \
LOG_GLE(sev)
#define LAST_SYSTEM_ERROR \
(::GetLastError())
#elif POSIX
#define LOG_ERR_EX(sev, err) \
LOG_ERRNO_EX(sev, err)
#define LOG_ERR(sev) \
LOG_ERRNO(sev)
#define LAST_SYSTEM_ERROR \
(errno)
#endif // WIN32
#define PLOG(sev, err) \
LOG_ERR_EX(sev, err)
// TODO(?): Add an "assert" wrapper that logs in the same manner.
#endif // LOG
} // namespace talk_base
#endif // TALK_BASE_LOGGING_H_