Change READ_LINE classes to use less virtual functions, and READ_LINE::ReadLine() to return char*

which can eliminate a subsequent call to READ_LINE::Line() for a small performance gain.

common/filter_reader.cpp

@@ -27,14 +27,41 @@
 #include <richio.h>
 #include <filter_reader.h>
 
-unsigned FILTER_READER::ReadLine() throw( IO_ERROR )
+
+FILTER_READER::FILTER_READER( LINE_READER& aReader ) :
+    LINE_READER( 1 ),
+    reader( aReader )
 {
-    unsigned ret;
+    // Not using our own line buffer, will be using aReader's.  This changes
+    // the meaning of this->line to be merely a pointer to aReader's line, which of course
+    // is not owned here.
+    delete [] line;
+
+    line = 0;
+}
+
+
+FILTER_READER::~FILTER_READER()
+{
+    // Our 'line' points to aReader's, and he will delete that buffer.
+    // Prevent subsequent call to ~LINE_READER() from deleting a buffer we do not own.
+    line = 0;
+}
 
-    while( ( ret = reader.ReadLine() ) != 0 )
+
+char* FILTER_READER::ReadLine() throw( IO_ERROR )
+{
+    char* s;
+
+    while( ( s = reader.ReadLine() ) != NULL )
     {
-        if( !strchr( "#\n\r", reader[0] ) )
+        if( !strchr( "#\n\r", s[0] ) )
             break;
     }
-    return ret;
+
+    line   = reader.Line();
+    length = reader.Length();
+
+    return length ? line : NULL;
 }
+

common/richio.cpp

@@ -64,6 +64,12 @@ LINE_READER::LINE_READER( unsigned aMaxLineLength )
 }
 
 
+LINE_READER::~LINE_READER()
+{
+    delete[] line;
+}
+
+
 void LINE_READER::expandCapacity( unsigned newsize )
 {
     // length can equal maxLineLength and nothing breaks, there's room for
@@ -134,40 +140,8 @@ FILE_LINE_READER::~FILE_LINE_READER()
         fclose( fp );
 }
 
-#if 0
 
-// The strlen() will trip on embedded nuls which can come in via bad data files.
-// Try an alternate technique below.
-
-unsigned FILE_LINE_READER::ReadLine() throw( IO_ERROR )
-{
-    length  = 0;
-    line[0] = 0;
-
-    // fgets always puts a terminating nul at end of its read.
-    while( fgets( line + length, capacity - length, fp ) )
-    {
-        length += strlen( line + length );
-
-        if( length >= maxLineLength )
-            THROW_IO_ERROR( _("Line length exceeded") );
-
-        // a normal line breaks here, once through while loop
-        if( length+1 < capacity || line[length-1] == '\n' )
-            break;
-
-        expandCapacity( capacity * 2 );
-    }
-
-    // lineNum is incremented even if there was no line read, because this
-    // leads to better error reporting when we hit an end of file.
-    ++lineNum;
-
-    return length;
-}
-
-#else
-unsigned FILE_LINE_READER::ReadLine() throw( IO_ERROR )
+char* FILE_LINE_READER::ReadLine() throw( IO_ERROR )
 {
     length = 0;
 
@@ -196,9 +170,8 @@ unsigned FILE_LINE_READER::ReadLine() throw( IO_ERROR )
     // leads to better error reporting when we hit an end of file.
     ++lineNum;
 
-    return length;
+    return length ? line : NULL;
 }
-#endif
 
 
 STRING_LINE_READER::STRING_LINE_READER( const std::string& aString, const wxString& aSource ) :
@@ -224,7 +197,8 @@ STRING_LINE_READER::STRING_LINE_READER( const STRING_LINE_READER& aStartingPoint
     lineNum = aStartingPoint.lineNum;
 }
 
-unsigned STRING_LINE_READER::ReadLine() throw( IO_ERROR )
+
+char* STRING_LINE_READER::ReadLine() throw( IO_ERROR )
 {
     size_t  nlOffset = lines.find( '\n', ndx );
 
@@ -252,7 +226,7 @@ unsigned STRING_LINE_READER::ReadLine() throw( IO_ERROR )
 
     line[length] = 0;
 
-    return length;
+    return length ? line : NULL;
 }
 
 
@@ -263,7 +237,7 @@ INPUTSTREAM_LINE_READER::INPUTSTREAM_LINE_READER( wxInputStream* aStream ) :
 }
 
 
-unsigned INPUTSTREAM_LINE_READER::ReadLine() throw( IO_ERROR )
+char* INPUTSTREAM_LINE_READER::ReadLine() throw( IO_ERROR )
 {
     length  = 0;
 
@@ -293,7 +267,7 @@ unsigned INPUTSTREAM_LINE_READER::ReadLine() throw( IO_ERROR )
     // leads to better error reporting when we hit an end of file.
     ++lineNum;
 
-    return length;
+    return length ? line : NULL;
 }
 
 

include/dsnlexer.h

@@ -117,7 +117,9 @@ protected:
     {
         if( reader )
         {
-            unsigned len = reader->ReadLine();
+            reader->ReadLine();
+
+            unsigned len = reader->Length();
 
             // start may have changed in ReadLine(), which can resize and
             // relocate reader's line buffer.

include/filter_reader.h

@@ -45,32 +45,21 @@ public:
      * Constructor ( LINE_READER& )
      * does not take ownership over @a aReader, so will not destroy it.
      */
-    FILTER_READER( LINE_READER& aReader ) :
-       reader( aReader )
-    {
-    }
+    FILTER_READER( LINE_READER& aReader );
+
+    ~FILTER_READER();
 
-    unsigned ReadLine() throw( IO_ERROR );
+    char* ReadLine() throw( IO_ERROR );
 
     const wxString& GetSource() const
     {
         return reader.GetSource();
     }
 
-    char* Line() const
-    {
-        return reader.Line();
-    }
-
     unsigned LineNumber() const
     {
         return reader.LineNumber();
     }
-
-    unsigned Length() const
-    {
-        return reader.Length();
-    }
 };
 
 #endif // FILTER_READER_H_

include/richio.h

@@ -227,20 +227,17 @@ public:
      */
     LINE_READER( unsigned aMaxLineLength = LINE_READER_LINE_DEFAULT_MAX );
 
-    virtual ~LINE_READER()
-    {
-        delete[] line;
-    }
+    virtual ~LINE_READER();
 
     /**
      * Function ReadLine
      * reads a line of text into the buffer and increments the line number
      * counter.  If the line is larger than aMaxLineLength passed to the
      * constructor, then an exception is thrown.  The line is nul terminated.
-     * @return unsigned - The number of bytes read, 0 at end of file.
+     * @return char* - The beginning of the read line, or NULL if EOF.
      * @throw IO_ERROR when a line is too long.
      */
-    virtual unsigned ReadLine() throw( IO_ERROR ) = 0;
+    virtual char* ReadLine() throw( IO_ERROR ) = 0;
 
     /**
      * Function GetSource
@@ -258,7 +255,7 @@ public:
      * Function Line
      * returns a pointer to the last line that was read in.
      */
-    virtual char* Line() const
+    char* Line() const
     {
         return line;
     }
@@ -287,7 +284,7 @@ public:
      * Function Length
      * returns the number of bytes in the last line read from this LINE_READER.
      */
-    virtual unsigned Length() const
+    unsigned Length() const
     {
         return length;
     }
@@ -354,7 +351,7 @@ public:
      */
     ~FILE_LINE_READER();
 
-    unsigned ReadLine() throw( IO_ERROR );   // see LINE_READER::ReadLine() description
+    char* ReadLine() throw( IO_ERROR );   // see LINE_READER::ReadLine() description
 
     /**
      * Function Rewind
@@ -401,7 +398,7 @@ public:
      */
     STRING_LINE_READER( const STRING_LINE_READER& aStartingPoint );
 
-    unsigned ReadLine() throw( IO_ERROR );    // see LINE_READER::ReadLine() description
+    char* ReadLine() throw( IO_ERROR );    // see LINE_READER::ReadLine() description
 };
 
 
@@ -423,7 +420,7 @@ public:
      */
     INPUTSTREAM_LINE_READER( wxInputStream* aStream );
 
-    unsigned ReadLine() throw( IO_ERROR );    // see LINE_READER::ReadLine() description
+    char* ReadLine() throw( IO_ERROR );    // see LINE_READER::ReadLine() description
 };
 
 

pcbnew/netlist_reader_firstformat.cpp

@@ -365,25 +365,24 @@ bool NETLIST_READER::SetPadNetName( char* aText )
  */
 bool NETLIST_READER::ReadOldFmtFootprintFilterList(  FILE_LINE_READER& aNetlistReader )
 {
-    wxString     cmpRef;
+    wxString        cmpRef;
     COMPONENT_INFO* cmp_info = NULL;
+    char*           line;
 
-    while( aNetlistReader.ReadLine() )
+    while( ( line = aNetlistReader.ReadLine() ) != NULL )
     {
-        const char* Line = aNetlistReader.Line();
-
-        if( strnicmp( Line, "$endlist", 8 ) == 0 ) // end of list for the current component
+        if( strnicmp( line, "$endlist", 8 ) == 0 ) // end of list for the current component
         {
             cmp_info = NULL;
             continue;
         }
-        if( strnicmp( Line, "$endfootprintlist", 4 ) == 0 )
+        if( strnicmp( line, "$endfootprintlist", 4 ) == 0 )
             // End of this section
             return 0;
 
-        if( strnicmp( Line, "$component", 10 ) == 0 ) // New component reference found
+        if( strnicmp( line, "$component", 10 ) == 0 ) // New component reference found
         {
-            cmpRef = FROM_UTF8( Line + 11 );
+            cmpRef = FROM_UTF8( line + 11 );
             cmpRef.Trim( true );
             cmpRef.Trim( false );
 
@@ -400,7 +399,7 @@ bool NETLIST_READER::ReadOldFmtFootprintFilterList(  FILE_LINE_READER& aNetlistR
         else if( cmp_info )
         {
             // Add new filter to list
-            wxString fp = FROM_UTF8( Line + 1 );
+            wxString fp = FROM_UTF8( line + 1 );
             fp.Trim( false );
             fp.Trim( true );
             cmp_info->m_FootprintFilter.Add( fp );