Further work on the svg cache

Author: Marco Hugentobler

src/core/symbology-ng/qgssvgcache.cpp

@@ -16,6 +16,41 @@
  ***************************************************************************/
 
 #include "qgssvgcache.h"
+#include <QDomDocument>
+#include <QFile>
+#include <QImage>
+#include <QPicture>
+
+QgsSvgCacheEntry::QgsSvgCacheEntry(): file( QString() ), size( 0 ), outlineWidth( 0 ), widthScaleFactor( 1.0 ), rasterScaleFactor( 1.0 ), fill( Qt::black ),
+outline( Qt::black ), image( 0 ), picture( 0 )
+{
+}
+
+QgsSvgCacheEntry::QgsSvgCacheEntry( const QString& f, double s, double ow, double wsf, double rsf, const QColor& fi, const QColor& ou ): file( f ), size( s ), outlineWidth( ow ),
+widthScaleFactor( wsf ), rasterScaleFactor( rsf ), fill( fi ), outline( ou ), image( 0 ), picture( 0 )
+{
+}
+
+
+QgsSvgCacheEntry::~QgsSvgCacheEntry()
+{
+  delete image;
+  delete picture;
+}
+
+bool QgsSvgCacheEntry::operator==( const QgsSvgCacheEntry& other ) const
+{
+  return ( other.file == file && other.size == size && other.outlineWidth == outlineWidth && other.widthScaleFactor == widthScaleFactor
+           && other.rasterScaleFactor == rasterScaleFactor && other.fill == fill && other.outline == outline );
+}
+
+QString file;
+double size;
+double outlineWidth;
+double widthScaleFactor;
+double rasterScaleFactor;
+QColor fill;
+QColor outline;
 
 QgsSvgCache* QgsSvgCache::mInstance = 0;
 
@@ -37,23 +72,93 @@ QgsSvgCache::~QgsSvgCache()
 }
 
 
-const QImage& QgsSvgCache::svgAsImage( const QString& file, double size, const QColor& fill, const QColor& outline, double outlineWidth ) const
+const QImage& QgsSvgCache::svgAsImage( const QString& file, double size, const QColor& fill, const QColor& outline, double outlineWidth,
+                                       double widthScaleFactor, double rasterScaleFactor )
+{
+
+}
+
+const QPicture& QgsSvgCache::svgAsPicture( const QString& file, double size, const QColor& fill, const QColor& outline, double outlineWidth,
+                                           double widthScaleFactor, double rasterScaleFactor )
 {
+  //search entries in mEntryLookup
+  QgsSvgCacheEntry* currentEntry = 0;
+  QList<QgsSvgCacheEntry*> entries = mEntryLookup.values( file );
+
+  QList<QgsSvgCacheEntry*>::iterator entryIt = entries.begin();
+  for(; entryIt != entries.end(); ++entryIt )
+  {
+    QgsSvgCacheEntry* cacheEntry = *entryIt;
+    if( cacheEntry->file == file && cacheEntry->size == size && cacheEntry->fill == fill && cacheEntry->outline == outline &&
+        cacheEntry->outlineWidth == outlineWidth && cacheEntry->widthScaleFactor == widthScaleFactor && cacheEntry->rasterScaleFactor == rasterScaleFactor)
+    {
+      currentEntry = cacheEntry;
+      break;
+    }
+  }
+
+
+  //if not found: create new entry
+  //cache and replace params in svg content
+  if( !currentEntry )
+  {
+    currentEntry = insertSVG( file, size, fill, outline, outlineWidth, widthScaleFactor, rasterScaleFactor );
+  }
+
+  //if current entry image is 0: cache image for entry
+  //update stats for memory usage
+  if( !currentEntry->picture )
+  {
+    cachePicture( currentEntry );
+  }
+
+  //update lastUsed with current date time
+
+  return *( currentEntry->picture );
 }
 
-const QPicture& QgsSvgCache::svgAsPicture( const QString& file, double size, const QColor& fill, const QColor& outline, double outlineWidth ) const
+QgsSvgCacheEntry* QgsSvgCache::insertSVG( const QString& file, double size, const QColor& fill, const QColor& outline, double outlineWidth,
+                                          double widthScaleFactor, double rasterScaleFactor )
 {
+  QgsSvgCacheEntry* entry = new QgsSvgCacheEntry( file, size, outlineWidth, widthScaleFactor, rasterScaleFactor, fill, outline );
+  entry->lastUsed = QDateTime::currentDateTime();
+
+  replaceParamsAndCacheSvg( entry );
+
+  mEntries.insert( entry->lastUsed, entry );
+  mEntryLookup.insert( file, entry );
+  return entry;
 }
 
-void QgsSvgCache::insertSVG( const QString& file, double size, const QColor& fill, const QColor& outline, double outlineWidth )
+void QgsSvgCache::replaceParamsAndCacheSvg( QgsSvgCacheEntry* entry )
 {
+  if( !entry )
+  {
+    return;
+  }
+
+  QFile svgFile( entry->file );
+  if( !svgFile.open( QIODevice::ReadOnly ) )
+  {
+    return;
+  }
+
+  QDomDocument svgDoc;
+  if( !svgDoc.setContent( &svgFile ) )
+  {
+    return;
+  }
+
+  //todo: replace params here
+
+  entry->svgContent = svgDoc.toByteArray();
 }
 
-void QgsSvgCache::cacheImage( QgsSvgCacheEntry )
+void QgsSvgCache::cacheImage( QgsSvgCacheEntry* entry )
 {
 }
 
-void QgsSvgCache::cachePicture( QgsSvgCacheEntry )
+void QgsSvgCache::cachePicture( QgsSvgCacheEntry *entry )
 {
 }
 

src/core/symbology-ng/qgssvgcache.h

@@ -29,14 +29,25 @@ class QPicture;
 
 struct QgsSvgCacheEntry
 {
+  QgsSvgCacheEntry();
+  QgsSvgCacheEntry( const QString& file, double size, double outlineWidth, double widthScaleFactor, double rasterScaleFctor, const QColor& fill, const QColor& outline );
+  ~QgsSvgCacheEntry();
+
   QString file;
   double size;
   double outlineWidth;
+  double widthScaleFactor;
+  double rasterScaleFactor;
   QColor fill;
   QColor outline;
   QImage* image;
   QPicture* picture;
   QDateTime lastUsed;
+  //content (with params replaced)
+  QByteArray svgContent;
+
+  /**Don't consider image, picture, last used timestamp for comparison*/
+  bool operator==( const QgsSvgCacheEntry& other ) const;
 };
 
 /**A cache for images / pictures derived from svg files. This class supports parameter replacement in svg files
@@ -49,21 +60,27 @@ class QgsSvgCache
     static QgsSvgCache* instance();
     ~QgsSvgCache();
 
-    const QImage& svgAsImage( const QString& file, double size, const QColor& fill, const QColor& outline, double outlineWidth ) const;
-    const QPicture& svgAsPicture( const QString& file, double size, const QColor& fill, const QColor& outline, double outlineWidth ) const;
+    const QImage& svgAsImage( const QString& file, double size, const QColor& fill, const QColor& outline, double outlineWidth,
+                              double widthScaleFactor, double rasterScaleFactor );
+    const QPicture& svgAsPicture( const QString& file, double size, const QColor& fill, const QColor& outline, double outlineWidth,
+                                  double widthScaleFactor, double rasterScaleFactor );
 
   protected:
     QgsSvgCache();
 
-    void insertSVG( const QString& file, double size, const QColor& fill, const QColor& outline, double outlineWidth );
-    void cacheImage( QgsSvgCacheEntry );
-    void cachePicture( QgsSvgCacheEntry );
+    /**Creates new cache entry and returns pointer to it*/
+    QgsSvgCacheEntry* insertSVG( const QString& file, double size, const QColor& fill, const QColor& outline, double outlineWidth,
+                                 double widthScaleFactor, double rasterScaleFactor );
+
+    void replaceParamsAndCacheSvg( QgsSvgCacheEntry* entry );
+    void cacheImage( QgsSvgCacheEntry* entry );
+    void cachePicture( QgsSvgCacheEntry* entry );
 
   private:
     static QgsSvgCache* mInstance;
 
     /**Entries sorted by last used time*/
-    QMap< QDateTime, QgsSvgCacheEntry > mEntries;
+    QMap< QDateTime, QgsSvgCacheEntry* > mEntries;
     /**Entry pointers accessible by file name*/
     QMultiHash< QString, QgsSvgCacheEntry* > mEntryLookup;
     /**Estimated total size of all images and pictures*/