suyu/src/common/logging/backend.h
Yuri Kunde Schlesner 616d874443 New logging system
2014-12-13 01:59:52 -02:00

134 lines
3.9 KiB
C++

// Copyright 2014 Citra Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.
#pragma once
#include <cstdarg>
#include <memory>
#include <vector>
#include "common/concurrent_ring_buffer.h"
#include "common/logging/log.h"
namespace Log {
/**
* A log entry. Log entries are store in a structured format to permit more varied output
* formatting on different frontends, as well as facilitating filtering and aggregation.
*/
struct Entry {
std::chrono::microseconds timestamp;
Class log_class;
Level log_level;
std::string location;
std::string message;
Entry() = default;
// TODO(yuriks) Use defaulted move constructors once MSVC supports them
#define MOVE(member) member(std::move(o.member))
Entry(Entry&& o)
: MOVE(timestamp), MOVE(log_class), MOVE(log_level),
MOVE(location), MOVE(message)
{}
#undef MOVE
Entry& operator=(const Entry&& o) {
#define MOVE(member) member = std::move(o.member)
MOVE(timestamp);
MOVE(log_class);
MOVE(log_level);
MOVE(location);
MOVE(message);
#undef MOVE
return *this;
}
};
struct ClassInfo {
Class log_class;
/**
* Total number of (direct or indirect) sub classes this class has. If any, they follow in
* sequence after this class in the class list.
*/
unsigned int num_children = 0;
ClassInfo(Class log_class) : log_class(log_class) {}
};
/**
* Logging management class. This class has the dual purpose of acting as an exchange point between
* the logging clients and the log outputter, as well as containing reflection info about available
* log classes.
*/
class Logger {
private:
using Buffer = Common::ConcurrentRingBuffer<Entry, 16 * 1024 / sizeof(Entry)>;
public:
static const size_t QUEUE_CLOSED = Buffer::QUEUE_CLOSED;
Logger();
/**
* Returns a list of all vector classes and subclasses. The sequence returned is a pre-order of
* classes and subclasses, which together with the `num_children` field in ClassInfo, allows
* you to recover the hierarchy.
*/
const std::vector<ClassInfo>& GetClasses() const { return all_classes; }
/**
* Returns the name of the passed log class as a C-string. Subclasses are separated by periods
* instead of underscores as in the enumeration.
*/
static const char* GetLogClassName(Class log_class);
/**
* Returns the name of the passed log level as a C-string.
*/
static const char* GetLevelName(Level log_level);
/**
* Appends a messages to the log buffer.
* @note This function is thread safe.
*/
void LogMessage(Entry entry);
/**
* Retrieves a batch of messages from the log buffer, blocking until they are available.
* @note This function is thread safe.
*
* @param out_buffer Destination buffer that will receive the log entries.
* @param buffer_len The maximum size of `out_buffer`.
* @return The number of entries stored. In case the logger is shutting down, `QUEUE_CLOSED` is
* returned, no entries are stored and the logger should shutdown.
*/
size_t GetEntries(Entry* out_buffer, size_t buffer_len);
/**
* Initiates a shutdown of the logger. This will indicate to log output clients that they
* should shutdown.
*/
void Close() { ring_buffer.Close(); }
/**
* Returns true if Close() has already been called on the Logger.
*/
bool IsClosed() const { return ring_buffer.IsClosed(); }
private:
Buffer ring_buffer;
std::vector<ClassInfo> all_classes;
};
/// Creates a log entry by formatting the given source location, and message.
Entry CreateEntry(Class log_class, Level log_level,
const char* filename, unsigned int line_nr, const char* function,
const char* format, va_list args);
/// Initializes the default Logger.
std::shared_ptr<Logger> InitGlobalLogger();
}