Merge pull request #2060 from manisandro/ogrpool

Add connection pool for OGR provider (followup 0b9d1dc)

Author: jef-n

src/providers/ogr/CMakeLists.txt

@@ -1,7 +1,7 @@
 
-SET (OGR_SRCS qgsogrprovider.cpp qgsogrdataitems.cpp qgsogrfeatureiterator.cpp qgsogrgeometrysimplifier.cpp)
+SET (OGR_SRCS qgsogrprovider.cpp qgsogrdataitems.cpp qgsogrfeatureiterator.cpp qgsogrgeometrysimplifier.cpp qgsogrconnpool.cpp)
 
-SET(OGR_MOC_HDRS qgsogrprovider.h qgsogrdataitems.h)
+SET(OGR_MOC_HDRS qgsogrprovider.h qgsogrdataitems.h qgsogrconnpool.h)
 
 ########################################################
 # Build

src/providers/ogr/qgsogrconnpool.cpp

@@ -0,0 +1,34 @@
+/***************************************************************************
+    qgsogrconnpool.cpp
+    ---------------------
+    begin                : May 2015
+    copyright            : (C) 2015 by Sandro Mani
+    email                : smani at sourcepole dot ch
+ ***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+#include "qgsogrconnpool.h"
+
+
+QgsOgrConnPool* QgsOgrConnPool::instance()
+{
+  static QgsOgrConnPool sInstance;
+  return &sInstance;
+}
+
+QgsOgrConnPool::QgsOgrConnPool() : QgsConnectionPool<QgsOgrConn*, QgsOgrConnPoolGroup>()
+{
+  QgsDebugCall;
+}
+
+QgsOgrConnPool::~QgsOgrConnPool()
+{
+  QgsDebugCall;
+}
+

src/providers/ogr/qgsogrconnpool.h

@@ -0,0 +1,80 @@
+/***************************************************************************
+    qgsogrconnpool.h
+    ---------------------
+    begin                : May 2015
+    copyright            : (C) 2015 by Sandro Mani
+    email                : smani at sourcepole dot ch
+ ***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+#ifndef QGSOGRCONNPOOL_H
+#define QGSOGRCONNPOOL_H
+
+#include "qgsconnectionpool.h"
+#include <ogr_api.h>
+
+
+struct QgsOgrConn
+{
+  QString path;
+  OGRDataSourceH ds;
+};
+
+inline QString qgsConnectionPool_ConnectionToName( QgsOgrConn* c )
+{
+  return c->path;
+}
+
+inline void qgsConnectionPool_ConnectionCreate( QString connInfo, QgsOgrConn*& c )
+{
+  c = new QgsOgrConn;
+  c->ds = OGROpen( connInfo.toUtf8().constData(), false, NULL );
+  c->path = connInfo;
+}
+
+inline void qgsConnectionPool_ConnectionDestroy( QgsOgrConn* c )
+{
+  OGR_DS_Destroy( c->ds );
+  delete c;
+}
+
+
+class QgsOgrConnPoolGroup : public QObject, public QgsConnectionPoolGroup<QgsOgrConn*>
+{
+    Q_OBJECT
+
+  public:
+    QgsOgrConnPoolGroup( QString name ) : QgsConnectionPoolGroup<QgsOgrConn*>( name ) { initTimer( this ); }
+
+  protected slots:
+    void handleConnectionExpired() { onConnectionExpired(); }
+    void startExpirationTimer() { expirationTimer->start(); }
+    void stopExpirationTimer() { expirationTimer->stop(); }
+
+  protected:
+    Q_DISABLE_COPY( QgsOgrConnPoolGroup )
+
+};
+
+/** Ogr connection pool - singleton */
+class QgsOgrConnPool : public QgsConnectionPool<QgsOgrConn*, QgsOgrConnPoolGroup>
+{
+  public:
+    static QgsOgrConnPool* instance();
+
+  protected:
+    Q_DISABLE_COPY( QgsOgrConnPool )
+
+  private:
+    QgsOgrConnPool();
+    ~QgsOgrConnPool();
+};
+
+
+#endif // QGSOGRCONNPOOL_H

src/providers/ogr/qgsogrfeatureiterator.cpp

@@ -35,27 +35,26 @@
 
 QgsOgrFeatureIterator::QgsOgrFeatureIterator( QgsOgrFeatureSource* source, bool ownSource, const QgsFeatureRequest& request )
     : QgsAbstractFeatureIteratorFromSource<QgsOgrFeatureSource>( source, ownSource, request )
-    , ogrDataSource( 0 )
     , ogrLayer( 0 )
     , mSubsetStringSet( false )
     , mGeometrySimplifier( NULL )
 {
   mFeatureFetched = false;
 
-  ogrDataSource = OGROpen( TO8F( mSource->mFilePath ), false, NULL );
+  mConn = QgsOgrConnPool::instance()->acquireConnection( mSource->mFilePath );
 
   if ( mSource->mLayerName.isNull() )
   {
-    ogrLayer = OGR_DS_GetLayer( ogrDataSource, mSource->mLayerIndex );
+    ogrLayer = OGR_DS_GetLayer( mConn->ds, mSource->mLayerIndex );
   }
   else
   {
-    ogrLayer = OGR_DS_GetLayerByName( ogrDataSource, TO8( mSource->mLayerName ) );
+    ogrLayer = OGR_DS_GetLayerByName( mConn->ds, TO8( mSource->mLayerName ) );
   }
 
   if ( !mSource->mSubsetString.isEmpty() )
   {
-    ogrLayer = QgsOgrUtils::setSubsetString( ogrLayer, ogrDataSource, mSource->mEncoding, mSource->mSubsetString );
+    ogrLayer = QgsOgrUtils::setSubsetString( ogrLayer, mConn->ds, mSource->mEncoding, mSource->mSubsetString );
     mSubsetStringSet = true;
   }
 
@@ -218,13 +217,13 @@ bool QgsOgrFeatureIterator::close()
 
   if ( mSubsetStringSet )
   {
-    OGR_DS_ReleaseResultSet( ogrDataSource, ogrLayer );
+    OGR_DS_ReleaseResultSet( mConn->ds, ogrLayer );
   }
 
-  OGR_DS_Destroy( ogrDataSource );
+  QgsOgrConnPool::instance()->releaseConnection( mConn );
+  mConn = 0;
 
   mClosed = true;
-  ogrDataSource = 0;
   return true;
 }
 

src/providers/ogr/qgsogrfeatureiterator.h

@@ -16,6 +16,7 @@
 #define QGSOGRFEATUREITERATOR_H
 
 #include "qgsfeatureiterator.h"
+#include "qgsogrconnpool.h"
 
 #include <ogr_api.h>
 
@@ -71,7 +72,7 @@ class QgsOgrFeatureIterator : public QgsAbstractFeatureIteratorFromSource<QgsOgr
 
     bool mFeatureFetched;
 
-    OGRDataSourceH ogrDataSource;
+    QgsOgrConn* mConn;
     OGRLayerH ogrLayer;
 
     bool mSubsetStringSet;