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Diffstat (limited to 'src/core/common/Logger.hpp')
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diff --git a/src/core/common/Logger.hpp b/src/core/common/Logger.hpp new file mode 100644 index 0000000..e6b97f4 --- /dev/null +++ b/src/core/common/Logger.hpp @@ -0,0 +1,609 @@ +/* + Ousía + Copyright (C) 2014, 2015 Benjamin Paaßen, Andreas Stöckel + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +/** + * @file Logger.hpp + * + * Contains classes for logging messages in Ousía. Provides a generic Logger + * class, and TerminalLogger, an extension of Logger which logs do an output + * stream. + * + * @author Andreas Stöckel (astoecke@techfak.uni-bielefeld.de) + */ + +#ifndef _OUSIA_LOGGER_HPP_ +#define _OUSIA_LOGGER_HPP_ + +#include <ostream> +#include <stack> +#include <string> +#include <vector> + +#include "Exceptions.hpp" + +namespace ousia { + +/** + * Enum containing the severities used for logging errors and debug messages. + */ +enum class Severity : int { + /** + * Indicates that this message was only printed for debugging. Note that + * in release builds messages with this severity are discarded. + */ + DEBUG = 0, + + /** + * A message which might provide additional information to the user. + */ + NOTE = 1, + + /** + * A message which warns of possible mistakes by the user which might not be + * actual errors but may lead to unintended behaviour. + */ + WARNING = 2, + + /** + * An error occurred while processing, however program execution continues, + * trying to deal with the error situation (graceful degradation). However, + * messages with this severity may be followed up by fatal errors. + */ + ERROR = 3, + + /** + * A fatal error occurred. Program execution cannot continue. + */ + FATAL_ERROR = 4 +}; + +#ifdef NDEBUG +static constexpr Severity DEFAULT_MIN_SEVERITY = Severity::NOTE; +#else +static constexpr Severity DEFAULT_MIN_SEVERITY = Severity::DEBUG; +#endif + +/** + * The Logger class is the base class the individual logging systems should + * derive from. It provides a simple interface for logging errors, warnings and + * notes and filters these according to the set minimum severity. Additionally + * a stack of file names is maintained in order to allow simple descent into + * included files. Note however, that this base Logger class simply discards the + * incomming log messages. Use one of the derived classes to actually handle the + * log messages. + */ +class Logger { +public: + /** + * The message struct represents a single log message and all information + * attached to it. + */ + struct Message { + /** + * Severity of the log message. + */ + Severity severity; + + /** + * Actual log message. + */ + std::string msg; + + /** + * Refers to the file which provides the context for this error message. + * May be empty. + */ + std::string file; + + /** + * Line in the above file the error message refers to. Ignored if + * smaller than zero. + */ + int line; + + /** + * Column in the above file the error message refers to. Ignored if + * smaller than zero. + */ + int column; + + /** + * Constructor of the Message struct. + * + * @param severity describes the message severity. + * @param msg contains the actual message. + * @param file provides the context the message refers to. May be empty. + * @param line is the line in the above file the message refers to. + * @param column is the column in the above file the message refers to. + */ + Message(Severity severity, std::string msg, std::string file, int line, + int column) + : severity(severity), + msg(std::move(msg)), + file(std::move(file)), + line(line), + column(column){}; + + /** + * Returns true if the file string is set. + * + * @return true if the file string is set. + */ + bool hasFile() const { return !file.empty(); } + + /** + * Returns true if the line is set. + * + * @return true if the line number is a non-negative integer. + */ + bool hasLine() const { return line >= 0; } + + /** + * Returns true if column and line are set (since a column has no + * significance without a line number). + * + * @return true if line number and column number are non-negative + * integers. + */ + bool hasColumn() const { return hasLine() && column >= 0; } + }; + +private: + /** + * Minimum severity a log message should have before it is discarded. + */ + Severity minSeverity; + + /** + * Maximum encountered log message severity. + */ + Severity maxEncounteredSeverity; + + /** + * Stack containing the current file names that have been processed. + */ + std::stack<std::string> filenameStack; + +protected: + /** + * Function to be overriden by child classes to actually display or store + * the messages. The default implementation just discards all incomming + * messages. + * + * @param msg is an instance of the Message struct containing the data that + * should be logged. + */ + virtual void process(const Message &msg){}; + +public: + /** + * Constructor of the Logger class. + * + * @param minSeverity is the minimum severity a log message should have. + * Messages below this severity are discarded. + */ + Logger(Severity minSeverity = DEFAULT_MIN_SEVERITY) + : minSeverity(minSeverity), maxEncounteredSeverity(Severity::DEBUG) + { + } + + Logger(const Logger &) = delete; + + /** + * Virtual destructor. + */ + virtual ~Logger(){}; + + /** + * Logs the given message. Most generic log function. + * + * @param severity is the severity of the log message. + * @param msg is the actual log message. + * @param file is the name of the file the message refers to. May be empty. + * @param line is the line in the above file at which the error occured. + * Ignored if negative. + * @param column is the column in the above file at which the error occured. + * Ignored if negative. + */ + void log(Severity severity, const std::string &msg, const std::string &file, + int line = -1, int column = -1); + + /** + * Logs the given message. The file name is set to the topmost file name on + * the file name stack. + * + * @param severity is the severity of the log message. + * @param msg is the actual log message. + * @param line is the line in the above file at which the error occured. + * Ignored if negative. + * @param column is the column in the above file at which the error occured. + * Ignored if negative. + */ + void log(Severity severity, const std::string &msg, int line = -1, + int column = -1) + { + log(severity, msg, currentFilename(), line, column); + } + + /** + * Logs the given message. The file name is set to the topmost file name on + * the file name stack. + * + * @param severity is the severity of the log message. + * @param msg is the actual log message. + * @param pos is a const reference to a variable which provides position + * information. + * @tparam PosType is the actual type of pos and must implement a getLine + * and getColumn function. + */ + template <class PosType> + void logAt(Severity severity, const std::string &msg, const PosType &pos) + { + log(severity, msg, pos.getLine(), pos.getColumn()); + } + + /** + * Logs the given loggable exception. + * + * @param ex is the exception that should be logged. + */ + void log(const LoggableException &ex) + { + log(Severity::ERROR, ex.msg, + ex.file.empty() ? currentFilename() : ex.file, ex.line, ex.column); + } + + /** + * Logs a debug message. The file name is set to the topmost file name on + * the file name stack. + * + * @param msg is the actual log message. + * @param file is the name of the file the message refers to. May be empty. + * @param line is the line in the above file at which the error occured. + * Ignored if negative. + * @param column is the column in the above file at which the error occured. + * Ignored if negative. + */ + void debug(const std::string &msg, const std::string &file, int line = -1, + int column = -1) + { + log(Severity::DEBUG, msg, file, line, column); + } + + /** + * Logs a debug message. The file name is set to the topmost file name on + * the file name stack. + * + * @param msg is the actual log message. + * @param line is the line in the above file at which the error occured. + * Ignored if negative. + * @param column is the column in the above file at which the error occured. + * Ignored if negative. + */ + void debug(const std::string &msg, int line = -1, int column = -1) + { + debug(msg, currentFilename(), line, column); + } + + /** + * Logs a debug message. The file name is set to the topmost file name on + * the file name stack. + * + * @param severity is the severity of the log message. + * @param msg is the actual log message. + * @param pos is a const reference to a variable which provides position + * information. + */ + template <class PosType> + void debugAt(const std::string &msg, const PosType &pos) + { + debug(msg, pos.getLine(), pos.getColumn()); + } + + /** + * Logs a note. The file name is set to the topmost file name on + * the file name stack. + * + * @param msg is the actual log message. + * @param file is the name of the file the message refers to. May be empty. + * @param line is the line in the above file at which the error occured. + * Ignored if negative. + * @param column is the column in the above file at which the error occured. + * Ignored if negative. + */ + void note(const std::string &msg, const std::string &file, int line = -1, + int column = -1) + { + log(Severity::NOTE, msg, file, line, column); + } + + /** + * Logs a note. The file name is set to the topmost file name on + * the file name stack. + * + * @param msg is the actual log message. + * @param line is the line in the above file at which the error occured. + * Ignored if negative. + * @param column is the column in the above file at which the error occured. + * Ignored if negative. + */ + void note(const std::string &msg, int line = -1, int column = -1) + { + note(msg, currentFilename(), line, column); + } + + /** + * Logs a note. The file name is set to the topmost file name on + * the file name stack. + * + * @param msg is the actual log message. + * @param pos is a const reference to a variable which provides position + * information. + */ + template <class PosType> + void noteAt(const std::string &msg, const PosType &pos) + { + note(msg, pos.getLine(), pos.getColumn()); + } + + /** + * Logs a warning. The file name is set to the topmost file name on + * the file name stack. + * + * @param msg is the actual log message. + * @param file is the name of the file the message refers to. May be empty. + * @param line is the line in the above file at which the error occured. + * Ignored if negative. + * @param column is the column in the above file at which the error occured. + * Ignored if negative. + */ + void warning(const std::string &msg, const std::string &file, int line = -1, + int column = -1) + { + log(Severity::WARNING, msg, file, line, column); + } + + /** + * Logs a warning. The file name is set to the topmost file name on + * the file name stack. + * + * @param msg is the actual log message. + * @param pos is a const reference to a variable which provides position + * information. + */ + template <class PosType> + void warningAt(const std::string &msg, const PosType &pos) + { + warning(msg, pos.getLine(), pos.getColumn()); + } + + /** + * Logs a warning. The file name is set to the topmost file name on + * the file name stack. + * + * @param msg is the actual log message. + * @param line is the line in the above file at which the error occured. + * Ignored if negative. + * @param column is the column in the above file at which the error occured. + * Ignored if negative. + */ + void warning(const std::string &msg, int line = -1, int column = -1) + { + warning(msg, currentFilename(), line, column); + } + + /** + * Logs an error message. The file name is set to the topmost file name on + * the file name stack. + * + * @param msg is the actual log message. + * @param file is the name of the file the message refers to. May be empty. + * @param line is the line in the above file at which the error occured. + * Ignored if negative. + * @param column is the column in the above file at which the error occured. + * Ignored if negative. + */ + void error(const std::string &msg, const std::string &file, int line = -1, + int column = -1) + { + log(Severity::ERROR, msg, file, line, column); + } + + /** + * Logs an error message. The file name is set to the topmost file name on + * the file name stack. + * + * @param msg is the actual log message. + * @param line is the line in the above file at which the error occured. + * Ignored if negative. + * @param column is the column in the above file at which the error occured. + * Ignored if negative. + */ + void error(const std::string &msg, int line = -1, int column = -1) + { + error(msg, currentFilename(), line, column); + } + + /** + * Logs an error message. The file name is set to the topmost file name on + * the file name stack. + * + * @param msg is the actual log message. + * @param pos is a const reference to a variable which provides position + * information. + */ + template <class PosType> + void errorAt(const std::string &msg, const PosType &pos) + { + error(msg, pos.getLine(), pos.getColumn()); + } + + /** + * Logs a fatal error. The file name is set to the topmost file name on + * the file name stack. + * + * @param msg is the actual log message. + * @param file is the name of the file the message refers to. May be empty. + * @param line is the line in the above file at which the error occured. + * Ignored if negative. + * @param column is the column in the above file at which the error occured. + * Ignored if negative. + */ + void fatalError(const std::string &msg, const std::string &file, + int line = -1, int column = -1) + { + log(Severity::FATAL_ERROR, msg, file, line, column); + } + + /** + * Logs a fatal error. The file name is set to the topmost file name on + * the file name stack. + * + * @param msg is the actual log message. + * @param line is the line in the above file at which the error occured. + * Ignored if negative. + * @param column is the column in the above file at which the error occured. + * Ignored if negative. + */ + void fatalError(const std::string &msg, int line = -1, int column = -1) + { + fatalError(msg, currentFilename(), line, column); + } + + /** + * Logs a fatal error. The file name is set to the topmost file name on + * the file name stack. + * + * @param msg is the actual log message. + * @param pos is a const reference to a variable which provides position + * information. + */ + template <class PosType> + void fatalErrorAt(const std::string &msg, const PosType &pos) + { + fatalError(msg, pos.getLine(), pos.getColumn()); + } + + /** + * Pushes a new file name onto the internal filename stack. + * + * @param name is the name of the file that should be added to the filename + * stack. + * @return the size of the filename stack. This number can be passed to the + * "unwindFilenameStack" method in order to return the stack to state it was + * in after this function has been called. + */ + unsigned int pushFilename(const std::string &name); + + /** + * Pops the filename from the internal filename stack. + * + * @return the current size of the filename stack. + */ + unsigned int popFilename(); + + /** + * Pops elements from the filename stack while it has more elements than + * the given number and the stack is non-empty. + * + * @param pos is the position the filename stack should be unwound to. Use + * a number returned by pushFilename. + */ + void unwindFilenameStack(unsigned int pos); + + /** + * Returns the topmost filename from the internal filename stack. + * + * @return the topmost filename from the filename stack or an empty string + * if the filename stack is empty. + */ + std::string currentFilename() + { + return filenameStack.empty() ? std::string{} : filenameStack.top(); + } + + /** + * Returns the maximum severity that was encountered by the Logger but at + * least Severity::DEBUG. + * + * @return the severity of the most severe log message but at least + * Severity::DEBUG. + */ + Severity getMaxEncounteredSeverity() { return maxEncounteredSeverity; } + + /** + * Returns the minimum severity. Messages with a smaller severity are + * discarded. + * + * @return the minimum severity. + */ + Severity getMinSeverity() { return minSeverity; } + + /** + * Sets the minimum severity. Messages with a smaller severity will be + * discarded. Only new messages will be filtered according to the new value. + * + * @param severity is the minimum severity for new log messages. + */ + void setMinSeverity(Severity severity) { minSeverity = severity; } +}; + +/** + * Class extending the Logger class and printing the log messages to the given + * stream. + */ +class TerminalLogger : public Logger { +private: + /** + * Reference to the target output stream. + */ + std::ostream &os; + + /** + * If true, the TerminalLogger will use colors to make the log messages + * prettier. + */ + bool useColor; + +protected: + /** + * Implements the process function and logs the messages to the output. + */ + void process(const Message &msg) override; + +public: + /** + * Constructor of the TerminalLogger class. + * + * @param os is the output stream the log messages should be logged to. + * Should be set to std::cerr in most cases. + * @param useColor if true, the TerminalLogger class will do its best to + * use ANSI/VT100 control sequences for colored log messages. + * @param minSeverity is the minimum severity below which log messages are + * discarded. + */ + TerminalLogger(std::ostream &os, bool useColor = false, + Severity minSeverity = DEFAULT_MIN_SEVERITY) + : Logger(minSeverity), os(os), useColor(useColor) + { + } +}; +} + +#endif /* _OUSIA_LOGGER_HPP_ */ + |