Add log file rotation support based on ExceptionFault's work.

This patch adds options to enable log rotations
base on files size and or change of date.

Note: Zip support will be added in a second commit.

Reviewed-by: CodyMartin, Thorbjorn.

3 files changed, 192 insertions, 19 deletions

diff --git a/src/utils/logger.cpp b/src/utils/logger.cpp
index 71f92a8..45a68eb 100644
--- a/src/utils/logger.cpp
+++ b/src/utils/logger.cpp
@@ -1,6 +1,7 @@
 /*
  *  The Mana Server
  *  Copyright (C) 2004-2010  The Mana World Development Team
+ *  Copyright (C) 2010  The Mana Development Team
  *
  *  This file is part of The Mana Server.
  *
@@ -19,6 +20,8 @@
  */
 
 #include "logger.h"
+#include "common/resourcemanager.hpp"
+#include "utils/string.hpp"
 
 #include <ctime>
 #include <fstream>
@@ -31,11 +34,24 @@
 
 namespace utils
 {
-
-static std::ofstream mLogFile;     /**< Log file. */
-bool Logger::mHasTimestamp = true; /**< Timestamp flag. */
-bool Logger::mTeeMode = false;     /**< Tee mode flag. */
-Logger::Level Logger::mVerbosity = Logger::Info; /**< Verbosity level. */
+/** Log file. */
+static std::ofstream mLogFile;
+/** current log filename */
+std::string Logger::mFilename = "";
+/** Timestamp flag. */
+bool Logger::mHasTimestamp = true;
+/** Tee mode flag. */
+bool Logger::mTeeMode = false;
+/** Verbosity level. */
+Logger::Level Logger::mVerbosity = Logger::Info;
+/** Enables logrotation by size of the logfile. */
+bool Logger::mLogRotation = false;
+/** Maximum size of current logfile. */
+long Logger::mMaxFileSize = 1024; // 1 Mb
+/** Switch log file each day. */
+bool Logger::mSwitchLogEachDay = false;
+/** Last call date */
+static std::string mLastCallDate = "";
 
 /**
   * Gets the current time.
@@ -47,29 +63,72 @@ static std::string getCurrentTime()
     time_t now;
     tm local;
 
-    // get current time_t value
+    // Get current time_t value
     time(&now);
 
-    // convert time_t to tm struct to break the time into individual
-    // constituents
+    // Convert time_t to tm struct to break the time into individual
+    // constituents.
     local = *(localtime(&now));
 
-    // stringify the time, the format is: [hh:mm:ss]
+    // Stringify the time, the format is: [hh-mm-ss]
     using namespace std;
     ostringstream os;
-    os << "[" << setw(2) << setfill('0') << local.tm_hour
-       << ":" << setw(2) << setfill('0') << local.tm_min
-       << ":" << setw(2) << setfill('0') << local.tm_sec
-       << "]";
+    os << setw(2) << setfill('0') << local.tm_hour
+       << "-" << setw(2) << setfill('0') << local.tm_min
+       << "-" << setw(2) << setfill('0') << local.tm_sec;
 
     return os.str();
 }
 
+/**
+  * Gets the current date.
+  *
+  * @return the current date as string.
+  */
+static std::string getCurrentDate()
+{
+    time_t now;
+    tm local;
+
+    // Get current time_t value
+    time(&now);
+
+    // Convert time_t to tm struct to break the time into individual
+    // constituents.
+    local = *(localtime(&now));
+
+    // Stringify the time, the format is: yyyy-mm-dd
+    using namespace std;
+    ostringstream os;
+    os << setw(4) << setfill('0') << (local.tm_year + 1900)
+       << "-" << setw(2) << setfill('0') << local.tm_mon
+       << "-" << setw(2) << setfill('0') << local.tm_mday;
+
+    return os.str();
+}
+
+/**
+  * Check whether the day has changed since the last call.
+  *
+  * @return whether the day has changed.
+  */
+static bool getDayChanged()
+{
+    static std::string date = getCurrentDate();
+    if (mLastCallDate.compare(date))
+    {
+        // Reset the current date for next call.
+        mLastCallDate = date;
+        return true;
+    }
+    return false;
+}
+
 void Logger::output(std::ostream &os, const std::string &msg, const char *prefix)
 {
     if (mHasTimestamp)
     {
-        os << getCurrentTime() << ' ';
+        os << "[" << getCurrentTime() << "]" << ' ';
     }
 
     if (prefix)
@@ -80,7 +139,7 @@ void Logger::output(std::ostream &os, const std::string &msg, const char *prefix
     os << msg << std::endl;
 }
 
-void Logger::setLogFile(const std::string &logFile)
+void Logger::setLogFile(const std::string &logFile, bool append)
 {
     // Close the current log file.
     if (mLogFile.is_open())
@@ -88,8 +147,12 @@ void Logger::setLogFile(const std::string &logFile)
         mLogFile.close();
     }
 
-    // Open the file for output and remove the former file contents.
-    mLogFile.open(logFile.c_str(), std::ios::trunc);
+    // Open the file for output
+    // and remove the former file contents depending on the append flag.
+    mLogFile.open(logFile.c_str(),
+                  append ? std::ios::ate : std::ios::trunc);
+    mFilename = logFile;
+    mLastCallDate = getCurrentDate();
 
     if (!mLogFile.is_open())
     {
@@ -97,7 +160,7 @@ void Logger::setLogFile(const std::string &logFile)
     }
     else
     {
-        // by default the streams do not throw any exception
+        // By default the streams do not throw any exception
         // let std::ios::failbit and std::ios::badbit throw exceptions.
         mLogFile.exceptions(std::ios::failbit | std::ios::badbit);
     }
@@ -127,6 +190,7 @@ void Logger::output(const std::string &msg, Level atVerbosity)
         if (open)
         {
             output(mLogFile, msg, prefixes[atVerbosity]);
+            switchLogs();
         }
 
         if (!open || mTeeMode)
@@ -137,4 +201,58 @@ void Logger::output(const std::string &msg, Level atVerbosity)
     }
 }
 
+void Logger::switchLogs()
+{
+    // Handles logswitch if enabled
+    // and if at least one switch condition permits it.
+    if (!mLogRotation || (mMaxFileSize <= 0 && !mSwitchLogEachDay))
+        return;
+
+    // Update current filesize
+    long mFileSize = mLogFile.tellp();
+
+    if ((mFileSize >= mMaxFileSize * 1024)
+        || (mSwitchLogEachDay && getDayChanged()))
+    {
+        // Close logfile, rename it and open a new one
+        mLogFile.flush();
+        mLogFile.close();
+
+        // Stringify the time, the format is: yyyy-mm-dd_hh-mm-ss-logFilename.
+        using namespace std;
+        ostringstream os;
+        os << getCurrentDate();
+
+        int fileNum = 1;
+        std::string newFileName = os.str() + "-" + toString<int>(fileNum)
+                                  +  "_" + mFilename;
+        // Keeping a hard limit of 100 files per day.
+        while (ResourceManager::exists(newFileName) && fileNum < 100)
+        {
+            fileNum++;
+            newFileName = os.str() + "-" + toString<int>(fileNum)
+                          +  "_" + mFilename;
+        }
+
+        if (rename(mFilename.c_str(), newFileName.c_str()))
+        {
+            ostringstream errorOs;
+            errorOs << "Error renaming file: " << mFilename << " to: "
+            << newFileName << std::endl << "Continuing on the same log file.";
+            perror(errorOs.str().c_str());
+
+            // Continue appending on the original file.
+            setLogFile(mFilename, true);
+        }
+        else
+        {
+            // Keep the logging after emptying the original log file.
+            setLogFile(mFilename);
+        }
+
+        mLogFile << "---- Continue logging from former file " << os.str()
+                 << " ----" << std::endl;
+    }
+}
+
 } // namespace utils
diff --git a/src/utils/logger.h b/src/utils/logger.h
index 473e025..ba64b10 100644
--- a/src/utils/logger.h
+++ b/src/utils/logger.h
@@ -1,6 +1,7 @@
 /*
  *  The Mana Server
  *  Copyright (C) 2004-2010  The Mana World Development Team
+ *  Copyright (C) 2010  The Mana Development Team
  *
  *  This file is part of The Mana Server.
  *
@@ -88,10 +89,11 @@ class Logger
          * contents are removed.
          *
          * @param logFile the log file name (may include path).
+         * @param append whether the file is cleaned up before logging in.
          *
          * @exception std::ios::failure if the log file could not be opened.
          */
-        static void setLogFile(const std::string &logFile);
+        static void setLogFile(const std::string &logFile, bool append = false);
 
         /**
          * Add/removes the timestamp.
@@ -120,6 +122,31 @@ class Logger
         { mVerbosity = verbosity; }
 
         /**
+         * Enable logrotation based on the maximum filesize given in
+         * setMaxLogfileSize.
+         *
+         * @param enable Set to true to enable logrotation.
+         */
+        static void enableLogRotation(bool enable = true)
+        { mLogRotation = enable; }
+
+        /**
+         * Sets the maximum size of a logfile before logrotation occurs.
+         *
+         * @param kiloBytes Maximum size of logfile in bytes. Defaults to 1MB.
+         */
+        static void setMaxLogfileSize(long kiloBytes = 1024)
+        { mMaxFileSize = kiloBytes; }
+
+        /**
+         * Sets whether the logfile switches when changing date.
+         *
+         * @param switchLogEachDay Keeps whether the parameter is activated.
+         */
+        static void setSwitchLogEachDay(bool switchLogEachDay)
+        { mSwitchLogEachDay = switchLogEachDay; }
+
+        /**
          * Logs a generic message.
          *
          * @param msg the message to log.
@@ -136,6 +163,14 @@ class Logger
         static bool mHasTimestamp; /**< Timestamp flag. */
         static bool mTeeMode;      /**< Tee mode flag. */
 
+        static std::string mFilename; /**< Name of the current logfile. */
+        /** Enable rotation of logfiles by size. */
+        static bool mLogRotation;
+        /** Maximum size of current logfile in bytes */
+        static long mMaxFileSize;
+        /** Sets whether the logfile switches when changing date. */
+        static bool mSwitchLogEachDay;
+
         /**
          * Logs a generic message.
          *
@@ -147,6 +182,12 @@ class Logger
          */
         static void output(std::ostream &os, const std::string &msg,
                            const char *prefix);
+
+        /**
+         * Switch the log file based on a maximum size
+         * and/or and a date change.
+         */
+        static void switchLogs();
 };
 
 
diff --git a/src/utils/string.hpp b/src/utils/string.hpp
index 9f2b4ac..6127bfe 100644
--- a/src/utils/string.hpp
+++ b/src/utils/string.hpp
@@ -22,6 +22,7 @@
 #define UTILS_STRING_H
 
 #include <string>
+#include <sstream>
 
 namespace utils
 {
@@ -67,6 +68,19 @@ namespace utils
      * @param str the string to trim spaces off
      */
     void trim(std::string &str);
+
+    /**
+     * Converts the given value to a string using std::stringstream.
+     *
+     * @param arg the value to convert to a string
+     * @return the string representation of arg
+     */
+    template<typename T> std::string toString(const T &arg)
+    {
+        std::stringstream ss;
+        ss << arg;
+        return ss.str();
+    }
 }
 
 #endif // UTILS_STRING_H