Updated memory provider to support feature source (untested yet)

qgis · Dec 3, 2013 · b99e93c · b99e93c
1 parent 5386324
commit b99e93c
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Showing 4 changed files with 67 additions and 33 deletions.
diff --git a/src/providers/memory/qgsmemoryfeatureiterator.cpp b/src/providers/memory/qgsmemoryfeatureiterator.cpp
@@ -21,12 +21,11 @@
 #include "qgsmessagelog.h"
 
 
-QgsMemoryFeatureIterator::QgsMemoryFeatureIterator( QgsMemoryProvider* p, const QgsFeatureRequest& request )
-    : QgsAbstractFeatureIterator( request )
-    , P( p )
+
+QgsMemoryFeatureIterator::QgsMemoryFeatureIterator( QgsMemoryFeatureSource* source, bool ownSource, const QgsFeatureRequest& request )
+    : QgsAbstractFeatureIteratorFromSource( source, ownSource, request )
     , mSelectRectGeom( 0 )
 {
-  P->mActiveIterators << this;
 
   if ( mRequest.filterType() == QgsFeatureRequest::FilterRect && mRequest.flags() & QgsFeatureRequest::ExactIntersect )
   {
@@ -35,17 +34,17 @@ QgsMemoryFeatureIterator::QgsMemoryFeatureIterator( QgsMemoryProvider* p, const
 
   // if there's spatial index, use it!
   // (but don't use it when selection rect is not specified)
-  if ( mRequest.filterType() == QgsFeatureRequest::FilterRect && P->mSpatialIndex )
+  if ( mRequest.filterType() == QgsFeatureRequest::FilterRect && mSource->mSpatialIndex )
   {
     mUsingFeatureIdList = true;
-    mFeatureIdList = P->mSpatialIndex->intersects( mRequest.filterRect() );
+    mFeatureIdList = mSource->mSpatialIndex->intersects( mRequest.filterRect() );
     QgsDebugMsg( "Features returned by spatial index: " + QString::number( mFeatureIdList.count() ) );
   }
   else if ( mRequest.filterType() == QgsFeatureRequest::FilterFid )
   {
     mUsingFeatureIdList = true;
-    QgsFeatureMap::iterator it = P->mFeatures.find( mRequest.filterFid() );
-    if ( it != P->mFeatures.end() )
+    QgsFeatureMap::const_iterator it = mSource->mFeatures.find( mRequest.filterFid() );
+    if ( it != mSource->mFeatures.end() )
       mFeatureIdList.append( mRequest.filterFid() );
   }
   else
@@ -81,12 +80,12 @@ bool QgsMemoryFeatureIterator::nextFeatureUsingList( QgsFeature& feature )
   bool hasFeature = false;
 
   // option 1: we have a list of features to traverse
-  while ( mFeatureIdListIterator != mFeatureIdList.end() )
+  while ( mFeatureIdListIterator != mFeatureIdList.constEnd() )
   {
     if ( mRequest.filterType() == QgsFeatureRequest::FilterRect && mRequest.flags() & QgsFeatureRequest::ExactIntersect )
     {
       // do exact check in case we're doing intersection
-      if ( P->mFeatures[*mFeatureIdListIterator].geometry()->intersects( mSelectRectGeom ) )
+      if ( mSource->mFeatures[*mFeatureIdListIterator].geometry()->intersects( mSelectRectGeom ) )
         hasFeature = true;
     }
     else
@@ -101,14 +100,14 @@ bool QgsMemoryFeatureIterator::nextFeatureUsingList( QgsFeature& feature )
   // copy feature
   if ( hasFeature )
   {
-    feature = P->mFeatures[*mFeatureIdListIterator];
+    feature = mSource->mFeatures[*mFeatureIdListIterator];
     mFeatureIdListIterator++;
   }
   else
     close();
 
   if ( hasFeature )
-    feature.setFields( &P->mFields ); // allow name-based attribute lookups
+    feature.setFields( &mSource->mFields ); // allow name-based attribute lookups
 
   return hasFeature;
 }
@@ -119,7 +118,7 @@ bool QgsMemoryFeatureIterator::nextFeatureTraverseAll( QgsFeature& feature )
   bool hasFeature = false;
 
   // option 2: traversing the whole layer
-  while ( mSelectIterator != P->mFeatures.end() )
+  while ( mSelectIterator != mSource->mFeatures.constEnd() )
   {
     if ( mRequest.filterType() != QgsFeatureRequest::FilterRect )
     {
@@ -154,7 +153,7 @@ bool QgsMemoryFeatureIterator::nextFeatureTraverseAll( QgsFeature& feature )
     feature = mSelectIterator.value();
     mSelectIterator++;
     feature.setValid( true );
-    feature.setFields( &P->mFields ); // allow name-based attribute lookups
+    feature.setFields( &mSource->mFields ); // allow name-based attribute lookups
   }
   else
     close();
@@ -168,9 +167,9 @@ bool QgsMemoryFeatureIterator::rewind()
     return false;
 
   if ( mUsingFeatureIdList )
-    mFeatureIdListIterator = mFeatureIdList.begin();
+    mFeatureIdListIterator = mFeatureIdList.constBegin();
   else
-    mSelectIterator = P->mFeatures.begin();
+    mSelectIterator = mSource->mFeatures.constBegin();
 
   return true;
 }
@@ -180,11 +179,30 @@ bool QgsMemoryFeatureIterator::close()
   if ( mClosed )
     return false;
 
-  P->mActiveIterators.remove( this );
+  iteratorClosed();
 
   delete mSelectRectGeom;
   mSelectRectGeom = NULL;
 
   mClosed = true;
   return true;
 }
+
+// -------------------------
+
+QgsMemoryFeatureSource::QgsMemoryFeatureSource( const QgsMemoryProvider* p )
+  : mFields( p->mFields )
+  , mFeatures( p->mFeatures )
+  , mSpatialIndex( p->mSpatialIndex ? new QgsSpatialIndex( *p->mSpatialIndex ) : 0 )  // just shallow copy
+{
+}
+
+QgsMemoryFeatureSource::~QgsMemoryFeatureSource()
+{
+  delete mSpatialIndex;
+}
+
+QgsFeatureIterator QgsMemoryFeatureSource::getFeatures( const QgsFeatureRequest& request )
+{
+  return QgsFeatureIterator( new QgsMemoryFeatureIterator( this, false, request ) );
+}
diff --git a/src/providers/memory/qgsmemoryfeatureiterator.h b/src/providers/memory/qgsmemoryfeatureiterator.h
@@ -21,11 +21,30 @@ class QgsMemoryProvider;
 
 typedef QMap<QgsFeatureId, QgsFeature> QgsFeatureMap;
 
+class QgsSpatialIndex;
 
-class QgsMemoryFeatureIterator : public QgsAbstractFeatureIterator
+
+class QgsMemoryFeatureSource : public QgsAbstractFeatureSource
+{
+public:
+  QgsMemoryFeatureSource( const QgsMemoryProvider* p );
+  ~QgsMemoryFeatureSource();
+
+  virtual QgsFeatureIterator getFeatures( const QgsFeatureRequest& request );
+
+protected:
+  QgsFields mFields;
+  QgsFeatureMap mFeatures;
+  QgsSpatialIndex* mSpatialIndex;
+
+  friend class QgsMemoryFeatureIterator;
+};
+
+
+class QgsMemoryFeatureIterator : public QgsAbstractFeatureIteratorFromSource<QgsMemoryFeatureSource>
 {
   public:
-    QgsMemoryFeatureIterator( QgsMemoryProvider* p, const QgsFeatureRequest& request );
+    QgsMemoryFeatureIterator( QgsMemoryFeatureSource* source, bool ownSource, const QgsFeatureRequest& request );
 
     ~QgsMemoryFeatureIterator();
 
@@ -43,13 +62,11 @@ class QgsMemoryFeatureIterator : public QgsAbstractFeatureIterator
     bool nextFeatureUsingList( QgsFeature& feature );
     bool nextFeatureTraverseAll( QgsFeature& feature );
 
-    QgsMemoryProvider* P;
-
     QgsGeometry* mSelectRectGeom;
-    QgsFeatureMap::iterator mSelectIterator;
+    QgsFeatureMap::const_iterator mSelectIterator;
     bool mUsingFeatureIdList;
     QList<QgsFeatureId> mFeatureIdList;
-    QList<QgsFeatureId>::iterator mFeatureIdListIterator;
+    QList<QgsFeatureId>::const_iterator mFeatureIdListIterator;
 
 };
 

diff --git a/src/providers/memory/qgsmemoryprovider.cpp b/src/providers/memory/qgsmemoryprovider.cpp
@@ -151,16 +151,14 @@ QgsMemoryProvider::QgsMemoryProvider( QString uri )
 
 QgsMemoryProvider::~QgsMemoryProvider()
 {
-  while ( !mActiveIterators.empty() )
-  {
-    QgsMemoryFeatureIterator *it = *mActiveIterators.begin();
-    QgsDebugMsg( "closing active iterator" );
-    it->close();
-  }
-
   delete mSpatialIndex;
 }
 
+QgsAbstractFeatureSource* QgsMemoryProvider::featureSource() const
+{
+  return new QgsMemoryFeatureSource( this );
+}
+
 QString QgsMemoryProvider::dataSourceUri() const
 {
   QUrl uri( "memory" );
@@ -238,7 +236,7 @@ QString QgsMemoryProvider::storageType() const
 
 QgsFeatureIterator QgsMemoryProvider::getFeatures( const QgsFeatureRequest& request )
 {
-  return QgsFeatureIterator( new QgsMemoryFeatureIterator( this, request ) );
+  return QgsFeatureIterator( new QgsMemoryFeatureIterator( new QgsMemoryFeatureSource( this ), true, request ) );
 }
 
 

diff --git a/src/providers/memory/qgsmemoryprovider.h b/src/providers/memory/qgsmemoryprovider.h
@@ -34,6 +34,8 @@ class QgsMemoryProvider : public QgsVectorDataProvider
 
     /* Implementation of functions from QgsVectorDataProvider */
 
+    virtual QgsAbstractFeatureSource* featureSource() const;
+
     /**
      * Returns the permanent storage type for this layer as a friendly name.
      */
@@ -168,6 +170,5 @@ class QgsMemoryProvider : public QgsVectorDataProvider
     // indexing
     QgsSpatialIndex* mSpatialIndex;
 
-    friend class QgsMemoryFeatureIterator;
-    QSet< QgsMemoryFeatureIterator *> mActiveIterators;
+    friend class QgsMemoryFeatureSource;
 };