implemented faster logging

include/ACGL/Utils/Log.hh

@@ -58,29 +58,31 @@ class CoutLikeStreamBuffer : public std::basic_streambuf<char, std::char_traits<
 
 public:
     CoutLikeStreamBuffer();
-
     ~CoutLikeStreamBuffer();
 
+    //! sets the prefix of each line
     void setPrefix( const std::string &_prefix );
 
+    //! sets the filename of the file to mirror everything into, set to "" to disable mirroring
     void setFilename( const std::string &_filename);
-private:
 
-    //virtual std::streamsize xsputn(const base_type::char_type* s, std::streamsize n)
-    //{
-        // TODO: implement me for better performance
-    //}
+private:
+    //! gets called when multiple chars should get written
+    virtual std::streamsize xsputn(const base_type::char_type* s, std::streamsize n);
 
+    //! gets called when the buffer is full ans a single char gets written
     virtual base_type::int_type overflow(base_type::int_type ch);
 
-    // for each endl:
+    //! gets called for each endl:
     virtual int sync();
 
+    //! used to mirror the output also into a file
     void mirrorToFile( const std::string &_token );
+
 private:
-    char  *mBuffer;
-	std::string mPrefix;
-    size_t mBufferSize;    // how many bytes are used
+    char  *mBuffer;        // string buffer
+    std::string mPrefix;   // prefix used for each new line of this stream
+    size_t mBufferSize;    // how many bytes are used in the buffer
     size_t mBufferMaxSize; // size of the buffer
 
     bool  mNewLineIsAboutToStart;
@@ -138,6 +140,7 @@ public:
         delete mStreamBuffer;
     }
 
+    //! sets the prefix of each line
     void setPrefix( const std::string &_prefix ) {
         if (mStreamBuffer) {
             mStreamBuffer->setPrefix(_prefix);
@@ -151,7 +154,11 @@ public:
             mStreamBuffer->setFilename(_filename);
         }
     }
+
+    //! disable all output from this stream
     void mute()   { rdbuf( NULL ); }
+
+    //! reenable all output
     void unmute() { rdbuf( mStreamBuffer ); }
 private:
     CoutLikeStreamBuffer *mStreamBuffer;

src/ACGL/Utils/Log.cc

@@ -5,6 +5,7 @@
  **********************************************************************/
 
 #include <ACGL/Utils/Log.hh>
+#include <ACGL/Math/Math.hh>
 
 #include <cstdio>
 #include <iostream>
@@ -54,6 +55,25 @@ void CoutLikeStreamBuffer::mirrorToFile( const std::string &_token ) {
     file.close();
 }
 
+std::streamsize CoutLikeStreamBuffer::xsputn(const base_type::char_type* s, std::streamsize n) {
+    size_t charsWritten = 0;
+
+    while (charsWritten < (size_t)n) {
+        int maxToCopy = std::min( (size_t) n-charsWritten, mBufferMaxSize-mBufferSize );
+
+        memcpy( mBuffer+mBufferSize, s+charsWritten, maxToCopy );
+        charsWritten += maxToCopy;
+        mBufferSize  += maxToCopy;
+
+        if (charsWritten < (size_t)n) {
+            overflow( (base_type::int_type) s[charsWritten] );
+            charsWritten++;
+        }
+    };
+
+    return n;
+}
+
 CoutLikeStreamBuffer::base_type::int_type CoutLikeStreamBuffer::overflow(base_type::int_type ch) {
     // print buffer
     if ((mBufferSize >= mBufferMaxSize) || ( base_type::traits_type::eq_int_type(ch, base_type::traits_type::eof()))) {