Merge pull request #33 from vikramrajkumar/master

Implement log file rotation

include/fc/log/file_appender.hpp

@@ -2,6 +2,7 @@
 #include <fc/log/appender.hpp>
 #include <fc/log/logger.hpp>
 #include <fc/filesystem.hpp>
+#include <fc/time.hpp>
 
 namespace fc {
 
@@ -16,10 +17,13 @@ class file_appender : public appender {
             fc::path                           filename;
             bool                               flush;
             bool                               truncate;
+            bool                               rotate;
+            microseconds                       rotation_interval;
+            microseconds                       rotation_limit;
          };
          file_appender( const variant& args );
          ~file_appender();
-         virtual void log( const log_message& m );
+         virtual void log( const log_message& m )override;
 
       private:
          class impl;
@@ -28,4 +32,4 @@ class file_appender : public appender {
 } // namespace fc
 
 #include <fc/reflect/reflect.hpp>
-FC_REFLECT( fc::file_appender::config, (format)(filename)(flush)(truncate) )
+FC_REFLECT( fc::file_appender::config, (format)(filename)(flush)(truncate)(rotate)(rotation_interval)(rotation_limit) )

src/log/file_appender.cpp

@@ -16,19 +16,42 @@ namespace fc {
          config              cfg;
          ofstream            out;
          boost::mutex        slock;
+         time_point_sec      current_file_start_time;
+
+         time_point_sec get_file_start_time( const time_point_sec& timestamp, const microseconds& interval )
+         {
+             const auto interval_seconds = interval.to_seconds();
+             const auto file_number = timestamp.sec_since_epoch() / interval_seconds;
+             return time_point_sec( file_number * interval_seconds );
+         }
    };
    file_appender::config::config( const fc::path& p  )
    :format( "${timestamp} ${thread_name} ${context} ${file}:${line} ${method} ${level}]  ${message}" ),
-   filename(p),flush(true),truncate(true){}
+   filename(p),flush(true),truncate(true),rotate(false){}
 
    file_appender::file_appender( const variant& args )
    :my( new impl() )
    {
-      try {
+      std::string log_filename;
+      try
+      {
          my->cfg = args.as<config>(); 
-         fc::create_directories( fc::path( my->cfg.filename.string() ).parent_path() );
-         my->out.open( my->cfg.filename.string().c_str() );
-      } catch ( ... ) {
+         log_filename = my->cfg.filename.string();
+
+         fc::create_directories( fc::path( log_filename ).parent_path() );
+
+         if( my->cfg.rotate )
+         {
+             const auto start_time = my->get_file_start_time( time_point::now(), my->cfg.rotation_interval );
+             // TODO: Convert to proper timestamp string
+             log_filename += "." + std::to_string( start_time.sec_since_epoch() );
+             my->current_file_start_time = start_time;
+         }
+
+         my->out.open( log_filename.c_str() );
+      }
+      catch( ... )
+      {
          std::cerr << "error opening log file: " << my->cfg.filename.string() << "\n";
          //elog( "%s", fc::except_str().c_str() );
       }
@@ -38,6 +61,7 @@ namespace fc {
    // MS THREAD METHOD  MESSAGE \t\t\t File:Line
    void file_appender::log( const log_message& m )
    {
+      const auto now = time_point::now();
       std::stringstream line;
       //line << (m.get_context().get_timestamp().time_since_epoch().count() % (1000ll*1000ll*60ll*60))/1000 <<"ms ";
       line << std::string(m.get_context().get_timestamp()) << " ";
@@ -60,14 +84,53 @@ namespace fc {
       fc::string message = fc::format_string( m.get_format(), m.get_data() );
       line << message.c_str();
 
-
       //fc::variant lmsg(m);
 
-     // fc::string fmt_str = fc::format_string( my->cfg.format, mutable_variant_object(m.get_context())( "message", message)  );
+      // fc::string fmt_str = fc::format_string( my->cfg.format, mutable_variant_object(m.get_context())( "message", message)  );
+
+      /* Write to log file (rotating file beforehand if necessary) */
       {
-        fc::scoped_lock<boost::mutex> lock(my->slock);
+        fc::scoped_lock<boost::mutex> lock( my->slock );
+
+        if( my->cfg.rotate )
+        {
+            const auto start_time = my->get_file_start_time( now, my->cfg.rotation_interval );
+            if( start_time > my->current_file_start_time )
+            {
+               my->out.close();
+               auto log_filename = my->cfg.filename.string();
+
+               /* Delete old log files */
+               // TODO: Delete on startup as well
+               const auto limit_time = now - my->cfg.rotation_limit;
+               auto itr = directory_iterator( fc::path( log_filename ).parent_path() );
+               for( ; itr != directory_iterator(); itr++ )
+               {
+                   const auto current_filename = itr->string();
+                   const auto current_pos = current_filename.find( log_filename );
+                   if( current_pos != 0 ) continue;
+                   const auto current_timestamp = current_filename.substr( log_filename.size() + 1 );
+                   try
+                   {
+                       if( std::stoi( current_timestamp ) < limit_time.sec_since_epoch() )
+                           remove_all( current_filename );
+                       //else compress if not already compressed
+                   }
+                   catch( ... )
+                   {
+                   }
+               }
+
+               // TODO: Convert to proper timestamp string
+               log_filename += "." + std::to_string( start_time.sec_since_epoch() );
+               my->out.open( log_filename.c_str() );
+
+               my->current_file_start_time = start_time;
+            }
+        }
+
         my->out << line.str() << "\t\t\t" << m.get_context().get_file() <<":"<<m.get_context().get_line_number()<<"\n";
+        if( my->cfg.flush ) my->out.flush();
       }
-      if( my->cfg.flush ) my->out.flush();
    }
 }