Merge

YACReaderLibrary/server/lib/logging/filelogger.h

@@ -0,0 +1,123 @@
+/**
+  @file
+  @author Stefan Frings
+*/
+
+#ifndef FILELOGGER_H
+#define FILELOGGER_H
+
+#include <QtGlobal>
+#include <QSettings>
+#include <QFile>
+#include <QMutex>
+#include <QBasicTimer>
+#include "logglobal.h"
+#include "logger.h"
+
+/**
+  Logger that uses a text file for output. Settings are read from a
+  config file using a QSettings object. Config settings can be changed at runtime.
+  <p>
+  Example for the configuration settings:
+  <code><pre>
+  fileName=logs/QtWebApp.log
+  maxSize=1000000
+  maxBackups=2
+  minLevel=0
+  msgformat={timestamp} {typeNr} {type} thread={thread}: {msg}
+  timestampFormat=dd.MM.yyyy hh:mm:ss.zzz
+  bufferSize=0
+  </pre></code>
+
+  - fileName is the name of the log file, relative to the directory of the settings file.
+    In case of windows, if the settings are in the registry, the path is relative to the current
+    working directory.
+  - maxSize is the maximum size of that file in bytes. The file will be backed up and
+    replaced by a new file if it becomes larger than this limit. Please note that
+    the actual file size may become a little bit larger than this limit. Default is 0=unlimited.
+  - maxBackups defines the number of backup files to keep. Default is 0=unlimited.
+  - minLevel defines the minimum type of messages that are written (together with buffered messages) into the file. Defaults is 0=debug.
+  - msgFormat defines the decoration of log messages, see LogMessage class. Default is "{timestamp} {type} {msg}".
+  - timestampFormat defines the format of timestamps, see QDateTime::toString(). Default is "yyyy-MM-dd hh:mm:ss.zzz".
+  - bufferSize defines the size of the buffer. Default is 0=disabled.
+
+  @see set() describes how to set logger variables
+  @see LogMessage for a description of the message decoration.
+  @see Logger for a descrition of the buffer.
+*/
+
+class DECLSPEC FileLogger : public Logger {
+    Q_OBJECT
+    Q_DISABLE_COPY(FileLogger)
+public:
+
+    /**
+      Constructor.
+      @param settings Configuration settings, usually stored in an INI file. Must not be 0.
+      Settings are read from the current group, so the caller must have called settings->beginGroup().
+      Because the group must not change during runtime, it is recommended to provide a
+      separate QSettings instance to the logger that is not used by other parts of the program.
+      @param refreshInterval Interval of checking for changed config settings in msec, or 0=disabled
+      @param parent Parent object
+    */
+    FileLogger(QSettings* settings, const int refreshInterval=10000, QObject* parent = 0);
+
+    /**
+      Destructor. Closes the file.
+    */
+    virtual ~FileLogger();
+
+    /** Write a message to the log file */
+    virtual void write(const LogMessage* logMessage);
+
+protected:
+
+    /**
+      Handler for timer events.
+      Refreshes config settings or synchronizes I/O buffer, depending on the event.
+      This method is thread-safe.
+      @param event used to distinguish between the two timers.
+    */
+    void timerEvent(QTimerEvent* event);
+
+private:
+
+    /** Configured name of the log file */
+    QString fileName;
+
+    /** Configured  maximum size of the file in bytes, or 0=unlimited */
+    long maxSize;
+
+    /** Configured maximum number of backup files, or 0=unlimited */
+    int maxBackups;
+
+    /** Pointer to the configuration settings */
+    QSettings* settings;
+
+    /** Output file, or 0=disabled */
+    QFile* file;
+
+    /** Timer for refreshing configuration settings */
+    QBasicTimer refreshTimer;
+
+    /** Timer for flushing the file I/O buffer */
+    QBasicTimer flushTimer;
+
+    /** Open the output file */
+    void open();
+
+    /** Close the output file */
+    void close();
+
+    /** Rotate files and delete some backups if there are too many */
+    void rotate();
+
+    /**
+      Refreshes the configuration settings.
+      This method is thread-safe.
+    */
+    void refreshSettings();
+
+};
+
+#endif // FILELOGGER_H