Aegisub/libaegisub/include/libaegisub/log.h
Thomas Goyne d615dcb30a Replace all uses of strstream and stringstream with bufferstream
istringstream makes a copy of its input, which is not very nice for
performance. strstream doesn't do bounds checking, which is not very
nice for safety (and is deprecated).
2014-03-21 13:50:28 -07:00

150 lines
4.4 KiB
C++

// Copyright (c) 2010, Amar Takhar <verm@aegisub.org>
//
// Permission to use, copy, modify, and distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
// OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
/// @file log.h
/// @brief Logging
/// @ingroup libaegisub
#include <libaegisub/fs_fwd.h>
#include <libaegisub/time.h>
#include <ctime>
#include <boost/circular_buffer.hpp>
#include <boost/interprocess/streams/bufferstream.hpp>
#include <iosfwd>
#include <memory>
#include <vector>
// These macros below aren't a perm solution, it will depend on how annoying they are through
// actual usage, and also depends on msvc support.
#define LOG_SINK(section, severity) agi::log::Message(section, severity, __FILE__, __FUNCTION__, __LINE__).stream()
#define LOG_E(section) LOG_SINK(section, agi::log::Exception)
#define LOG_A(section) LOG_SINK(section, agi::log::Assert)
#define LOG_W(section) LOG_SINK(section, agi::log::Warning)
#define LOG_I(section) LOG_SINK(section, agi::log::Info)
#define LOG_D(section) LOG_SINK(section, agi::log::Debug)
#define LOG_W_IF(cond, section) if (cond) LOG_SINK(section, agi::log::Warning)
#define LOG_I_IF(cond, section) if (cond) LOG_SINK(section, agi::log::Info)
#define LOG_D_IF(cond, section) if (cond) LOG_SINK(section, agi::log::Debug)
namespace agi {
namespace dispatch { class Queue; }
namespace log {
class LogSink;
/// Severity levels
enum Severity {
Exception, ///< Used when exceptions are thrown
Assert, ///< Fatal and non-fatal assert logging
Warning, ///< Warnings
Info, ///< Information only
Debug ///< Enabled by default when compiled in debug mode.
};
/// Short Severity ID
/// Set in common/log.cpp, keep this ordered the same as Severity.
extern const char *Severity_ID;
/// Global log sink.
extern LogSink *log;
/// Container to hold a single message
struct SinkMessage {
std::string message; ///< Formatted message
agi_timeval tv; ///< Time at execution
const char *section; ///< Section info eg "video/open" "video/seek" etc
const char *file; ///< Source file
const char *func; ///< Function name
Severity severity; ///< Severity
int line; ///< Source line
};
class Emitter;
/// Log sink, single destination for all messages
class LogSink {
boost::circular_buffer<SinkMessage> messages{250};
std::unique_ptr<dispatch::Queue> queue;
/// List of pointers to emitters
std::vector<std::unique_ptr<Emitter>> emitters;
public:
LogSink();
~LogSink();
/// Insert a message into the sink.
void Log(SinkMessage const& sm);
/// @brief Subscribe an emitter
/// @param em Emitter to add
void Subscribe(std::unique_ptr<Emitter> em);
/// @brief Unsubscribe and delete an emitter
/// @param em Emitter to delete
void Unsubscribe(Emitter *em);
/// @brief @get the complete (current) log.
/// @return Const pointer to internal sink.
decltype(messages) GetMessages() const;
};
/// An emitter to produce human readable output for a log sink.
class Emitter {
public:
/// Destructor
virtual ~Emitter() { }
/// Accept a single log entry
virtual void log(SinkMessage *sm)=0;
};
/// A simple emitter which writes the log to a file in json format
class JsonEmitter final : public Emitter {
std::unique_ptr<std::ostream> fp;
void WriteTime(const char *key);
public:
/// Constructor
/// @param directory Directory to write the log file in
JsonEmitter(fs::path const& directory);
/// Destructor
~JsonEmitter();
void log(SinkMessage *) override;
};
/// Generates a message and submits it to the log sink.
class Message {
boost::interprocess::obufferstream msg;
SinkMessage sm;
char buffer[2048];
public:
Message(const char *section, Severity severity, const char *file, const char *func, int line);
~Message();
std::ostream& stream() { return msg; }
};
/// Emit log entries to stdout.
class EmitSTDOUT: public Emitter {
public:
void log(SinkMessage *sm) override;
};
} // namespace log
} // namespace agi