Move memory provider to core

This commit introduces basic support for non-library based data providers, and moves the memory provider from a library based provider to a core provider. The memory provider is used so frequently throughout QGIS that it has become integral to QGIS functionality and must be available wherever the QGIS core library is used. The changes here (while not exposed yet to Python) could potentially be built on to allow creation of pure Python data providers.
qgis · May 6, 2017 · 5511b07 · 5511b07
1 parent 5e3c6e5
commit 5511b07
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Showing 15 changed files with 225 additions and 93 deletions.
diff --git a/doc/CMakeLists.txt b/doc/CMakeLists.txt
@@ -66,6 +66,8 @@ IF(WITH_APIDOC)
       ${CMAKE_SOURCE_DIR}/src/core/metadata
       ${CMAKE_SOURCE_DIR}/src/core/pal
       ${CMAKE_SOURCE_DIR}/src/core/processing
+      ${CMAKE_SOURCE_DIR}/src/core/providers
+      ${CMAKE_SOURCE_DIR}/src/core/providers/memory
       ${CMAKE_SOURCE_DIR}/src/core/raster
       ${CMAKE_SOURCE_DIR}/src/core/scalebar
       ${CMAKE_SOURCE_DIR}/src/core/symbology-ng

diff --git a/python/core/providers/memory/qgsmemoryproviderutils.sip b/python/core/providers/memory/qgsmemoryproviderutils.sip
@@ -0,0 +1,34 @@
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/core/providers/memory/qgsmemoryproviderutils.h                   *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/
+
+
+
+
+class QgsMemoryProviderUtils
+{
+%Docstring
+ Utility functions for use with the memory vector data provider.
+.. versionadded:: 3.0
+%End
+
+%TypeHeaderCode
+#include "qgsmemoryproviderutils.h"
+%End
+  public:
+
+};
+
+
+
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/core/providers/memory/qgsmemoryproviderutils.h                   *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/
diff --git a/src/core/CMakeLists.txt b/src/core/CMakeLists.txt
@@ -92,6 +92,9 @@ SET(QGIS_CORE_SRCS
   processing/qgsprocessingregistry.cpp
   processing/qgsprocessingutils.cpp
 
+  providers/memory/qgsmemoryfeatureiterator.cpp
+  providers/memory/qgsmemoryprovider.cpp
+
   scalebar/qgsdoubleboxscalebarrenderer.cpp
   scalebar/qgsnumericscalebarrenderer.cpp
   scalebar/qgsscalebarrenderer.cpp
@@ -618,6 +621,8 @@ SET(QGIS_CORE_MOC_HDRS
   processing/qgsprocessingprovider.h
   processing/qgsprocessingregistry.h
 
+  providers/memory/qgsmemoryprovider.h
+
   raster/qgsrasterfilewritertask.h
   raster/qgsrasterlayer.h
   raster/qgsrasterdataprovider.h
@@ -866,6 +871,8 @@ SET(QGIS_CORE_HDRS
   processing/qgsprocessingcontext.h
   processing/qgsprocessingutils.h
 
+  providers/memory/qgsmemoryfeatureiterator.h
+
   raster/qgsbilinearrasterresampler.h
   raster/qgsbrightnesscontrastfilter.h
   raster/qgscliptominmaxenhancement.h
@@ -1001,6 +1008,8 @@ INCLUDE_DIRECTORIES(
   metadata
   pal
   processing
+  providers
+  providers/memory
   raster
   renderer
   scalebar

diff --git a/...iders/memory/qgsmemoryfeatureiterator.cpp → ...iders/memory/qgsmemoryfeatureiterator.cpp b/...iders/memory/qgsmemoryfeatureiterator.cpp → ...iders/memory/qgsmemoryfeatureiterator.cpp
@@ -21,7 +21,7 @@
 #include "qgsmessagelog.h"
 #include "qgsproject.h"
 
-
+///@cond PRIVATE
 
 QgsMemoryFeatureIterator::QgsMemoryFeatureIterator( QgsMemoryFeatureSource *source, bool ownSource, const QgsFeatureRequest &request )
   : QgsAbstractFeatureIteratorFromSource<QgsMemoryFeatureSource>( source, ownSource, request )
@@ -223,3 +223,5 @@ QgsFeatureIterator QgsMemoryFeatureSource::getFeatures( const QgsFeatureRequest
 {
   return QgsFeatureIterator( new QgsMemoryFeatureIterator( this, false, request ) );
 }
+
+///@endcond PRIVATE
diff --git a/...oviders/memory/qgsmemoryfeatureiterator.h → ...oviders/memory/qgsmemoryfeatureiterator.h b/...oviders/memory/qgsmemoryfeatureiterator.h → ...oviders/memory/qgsmemoryfeatureiterator.h
@@ -20,6 +20,8 @@
 #include "qgsfields.h"
 #include "qgsgeometry.h"
 
+///@cond PRIVATE
+
 class QgsMemoryProvider;
 
 typedef QMap<QgsFeatureId, QgsFeature> QgsFeatureMap;
@@ -72,4 +74,6 @@ class QgsMemoryFeatureIterator : public QgsAbstractFeatureIteratorFromSource<Qgs
 
 };
 
+///@endcond PRIVATE
+
 #endif // QGSMEMORYFEATUREITERATOR_H
diff --git a/src/providers/memory/qgsmemoryprovider.cpp → ...re/providers/memory/qgsmemoryprovider.cpp b/src/providers/memory/qgsmemoryprovider.cpp → ...re/providers/memory/qgsmemoryprovider.cpp
@@ -26,6 +26,7 @@
 #include <QUrl>
 #include <QRegExp>
 
+///@cond PRIVATE
 
 static const QString TEXT_PROVIDER_KEY = QStringLiteral( "memory" );
 static const QString TEXT_PROVIDER_DESCRIPTION = QStringLiteral( "Memory provider" );
@@ -190,6 +191,21 @@ QgsMemoryProvider::~QgsMemoryProvider()
   delete mSpatialIndex;
 }
 
+QString QgsMemoryProvider::providerKey()
+{
+  return TEXT_PROVIDER_KEY;
+}
+
+QString QgsMemoryProvider::providerDescription()
+{
+  return TEXT_PROVIDER_DESCRIPTION;
+}
+
+QgsMemoryProvider *QgsMemoryProvider::createProvider( const QString &uri )
+{
+  return new QgsMemoryProvider( uri );
+}
+
 QgsAbstractFeatureSource *QgsMemoryProvider::featureSource() const
 {
   return new QgsMemoryFeatureSource( this );
@@ -523,52 +539,15 @@ void QgsMemoryProvider::updateExtent()
   }
 }
 
-
-
-// --------------------------------
-
-QString  QgsMemoryProvider::name() const
+QString QgsMemoryProvider::name() const
 {
   return TEXT_PROVIDER_KEY;
 }
 
-QString  QgsMemoryProvider::description() const
+QString QgsMemoryProvider::description() const
 {
   return TEXT_PROVIDER_DESCRIPTION;
 }
 
-// --------------------------------
-
 
-/**
- * Class factory to return a pointer to a newly created
- * QgsMemoryProvider object
- */
-QGISEXTERN QgsMemoryProvider *classFactory( const QString *uri )
-{
-  return new QgsMemoryProvider( *uri );
-}
-
-/** Required key function (used to map the plugin to a data store type)
- */
-QGISEXTERN QString providerKey()
-{
-  return TEXT_PROVIDER_KEY;
-}
-
-/**
- * Required description function
- */
-QGISEXTERN QString description()
-{
-  return TEXT_PROVIDER_DESCRIPTION;
-}
-
-/**
- * Required isProvider function. Used to determine if this shared library
- * is a data provider plugin
- */
-QGISEXTERN bool isProvider()
-{
-  return true;
-}
+///@endcond
diff --git a/src/providers/memory/qgsmemoryprovider.h → ...core/providers/memory/qgsmemoryprovider.h b/src/providers/memory/qgsmemoryprovider.h → ...core/providers/memory/qgsmemoryprovider.h
@@ -17,6 +17,7 @@
 #include "qgscoordinatereferencesystem.h"
 #include "qgsfields.h"
 
+///@cond PRIVATE
 typedef QMap<QgsFeatureId, QgsFeature> QgsFeatureMap;
 
 class QgsSpatialIndex;
@@ -32,6 +33,13 @@ class QgsMemoryProvider : public QgsVectorDataProvider
 
     virtual ~QgsMemoryProvider();
 
+    //! Returns the memory provider key
+    static QString providerKey();
+    //! Returns the memory provider description
+    static QString providerDescription();
+
+    static QgsMemoryProvider *createProvider( const QString &uri );
+
     /* Implementation of functions from QgsVectorDataProvider */
 
     virtual QgsAbstractFeatureSource *featureSource() const override;
@@ -88,3 +96,5 @@ class QgsMemoryProvider : public QgsVectorDataProvider
 
     friend class QgsMemoryFeatureSource;
 };
+
+///@endcond
diff --git a/src/core/providers/memory/qgsmemoryproviderutils.cpp b/src/core/providers/memory/qgsmemoryproviderutils.cpp
@@ -0,0 +1,18 @@
+/***************************************************************************
+                         qgsmemoryproviderutils.cpp
+                         --------------------------
+    begin                : May 2017
+    copyright            : (C) 2017 by Nyall Dawson
+    email                : nyall dot dawson at gmail dot com
+ ***************************************************************************/
+
+/***************************************************************************
+ *                                                                         *
+ *   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 "qgsmemoryproviderutils.h"
diff --git a/src/core/providers/memory/qgsmemoryproviderutils.h b/src/core/providers/memory/qgsmemoryproviderutils.h
@@ -0,0 +1,38 @@
+/***************************************************************************
+                         qgsmemoryproviderutils.h
+                         ------------------------
+    begin                : May 2017
+    copyright            : (C) 2017 by Nyall Dawson
+    email                : nyall dot dawson at gmail dot com
+ ***************************************************************************/
+
+/***************************************************************************
+ *                                                                         *
+ *   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 QGSMEMORYPROVIDERUTILS_H
+#define QGSMEMORYPROVIDERUTILS_H
+
+#include "qgis_core.h"
+
+/**
+ * \class QgsMemoryProviderUtils
+ * \ingroup core
+ * Utility functions for use with the memory vector data provider.
+ * \since QGIS 3.0
+ */
+class CORE_EXPORT QgsMemoryProviderUtils
+{
+
+  public:
+
+};
+
+#endif // QGSMEMORYPROVIDERUTILS_H
+
+
diff --git a/src/core/qgsprovidermetadata.cpp b/src/core/qgsprovidermetadata.cpp
@@ -28,6 +28,12 @@ QgsProviderMetadata::QgsProviderMetadata( QString const &_key,
   , library_( _library )
 {}
 
+QgsProviderMetadata::QgsProviderMetadata( const QString &key, const QString &description, QgsProviderMetadata::CreateDataProviderFunction createFunc )
+  : key_( key )
+  , description_( description )
+  , mCreateFunc( createFunc )
+{}
+
 QString QgsProviderMetadata::key() const
 {
   return key_;
@@ -42,3 +48,8 @@ QString QgsProviderMetadata::library() const
 {
   return library_;
 }
+
+QgsProviderMetadata::CreateDataProviderFunction QgsProviderMetadata::createFunction() const
+{
+  return mCreateFunc;
+}
diff --git a/src/core/qgsprovidermetadata.h b/src/core/qgsprovidermetadata.h
@@ -21,27 +21,48 @@
 
 
 #include <QString>
-
+#include "qgis.h"
 #include "qgis_core.h"
+#include <functional>
 
-/** \ingroup core
- * Holds data provider key, description, and associated shared library file information.
-
-   The metadata class is used in a lazy load implementation in
-   QgsProviderRegistry.  To save memory, data providers are only actually
-   loaded via QLibrary calls if they're to be used.  (Though they're all
-   iteratively loaded once to get their metadata information, and then
-   unloaded when the QgsProviderRegistry is created.)  QgsProviderMetadata
-   supplies enough information to be able to later load the associated shared
-   library object.
+class QgsDataProvider;
 
+/** \ingroup core
+ * Holds data provider key, description, and associated shared library file or function pointer information.
+ *
+ * Provider metadata refers either to providers which are loaded via libraries or
+ * which are native providers that are included in the core QGIS installation
+ * and accessed through function pointers.
+ *
+ * For library based providers, the metadata class is used in a lazy load
+ * implementation in QgsProviderRegistry.  To save memory, data providers
+ * are only actually loaded via QLibrary calls if they're to be used.  (Though they're all
+ * iteratively loaded once to get their metadata information, and then
+ * unloaded when the QgsProviderRegistry is created.)  QgsProviderMetadata
+ * supplies enough information to be able to later load the associated shared
+ * library object.
+ *
  */
 class CORE_EXPORT QgsProviderMetadata
 {
   public:
 
+    /**
+     * Typedef for data provider creation function.
+     * \since QGIS 3.0
+     */
+    SIP_SKIP typedef std::function < QgsDataProvider*( const QString & ) > CreateDataProviderFunction;
+
     QgsProviderMetadata( const QString &_key, const QString &_description, const QString &_library );
 
+    /**
+     * Metadata for provider with direct provider creation function pointer, where
+     * no library is involved.
+     * \since QGIS 3.0
+     * \note not available in Python bindings
+     */
+    SIP_SKIP QgsProviderMetadata( const QString &key, const QString &description, QgsProviderMetadata::CreateDataProviderFunction createFunc );
+
     /** This returns the unique key associated with the provider
 
         This key string is used for the associative container in QgsProviderRegistry
@@ -60,6 +81,14 @@ class CORE_EXPORT QgsProviderMetadata
      */
     QString library() const;
 
+    /**
+     * Returns a pointer to the direct provider creation function, if supported
+     * by the provider.
+     * \since QGIS 3.0
+     * \note not available in Python bindings
+     */
+    SIP_SKIP CreateDataProviderFunction createFunction() const;
+
   private:
 
     /// unique key for data provider
@@ -71,7 +100,9 @@ class CORE_EXPORT QgsProviderMetadata
     /// file path
     QString library_;
 
-}; // class QgsProviderMetadata
+    CreateDataProviderFunction mCreateFunc = nullptr;
+
+};
 
 #endif //QGSPROVIDERMETADATA_H