Added "memory" provider. It stores all data in heap, offering 3rd par…

…ty developers fast provider for temporary data. git-svn-id: http://svn.osgeo.org/qgis/trunk@8626 c8812cc2-4d05-0410-92ff-de0c093fc19c
qgis · Jun 8, 2008 · 4886170 · 4886170
1 parent fa9d34e
commit 4886170
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diff --git a/src/providers/CMakeLists.txt b/src/providers/CMakeLists.txt
@@ -1,5 +1,5 @@
 
-SUBDIRS (ogr wms delimitedtext)
+SUBDIRS (memory ogr wms delimitedtext)
 
 IF (POSTGRES_FOUND)
   SUBDIRS (postgres)

diff --git a/src/providers/memory/CMakeLists.txt b/src/providers/memory/CMakeLists.txt
@@ -0,0 +1,22 @@
+
+SET (MEMORY_SRCS memoryprovider.cpp)
+
+INCLUDE_DIRECTORIES(
+  .
+  ../../core
+#  ${GEOS_INCLUDE_DIR}
+)
+
+ADD_LIBRARY(memoryprovider MODULE ${MEMORY_SRCS})
+
+TARGET_LINK_LIBRARIES(memoryprovider
+  ${QT_QTCORE_LIBRARY} 
+# ${GDAL_LIBRARY}
+#  ${GEOS_LIBRARY}
+  qgis_core
+)
+
+
+INSTALL (TARGETS memoryprovider
+  RUNTIME DESTINATION ${QGIS_PLUGIN_DIR}
+  LIBRARY DESTINATION ${QGIS_PLUGIN_DIR})
diff --git a/src/providers/memory/memoryprovider.cpp b/src/providers/memory/memoryprovider.cpp
@@ -0,0 +1,308 @@
+/***************************************************************************
+    memoryprovider.cpp - provider with storage in memory
+    ------------------
+    begin                : June 2008
+    copyright            : (C) 2008 by Martin Dobias
+    email                : wonder.sk at gmail.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 "memoryprovider.h"
+
+#include "qgsfeature.h"
+#include "qgsfield.h"
+#include "qgsgeometry.h"
+#include "qgslogger.h"
+#include "qgsspatialrefsys.h"
+
+
+static const QString TEXT_PROVIDER_KEY = "memory";
+static const QString TEXT_PROVIDER_DESCRIPTION = "Memory provider";
+
+QgsMemoryProvider::QgsMemoryProvider(QString uri)
+  : QgsVectorDataProvider(uri)
+{
+  if (uri == "Point")
+    mWkbType = QGis::WKBPoint;
+  else if (uri == "LineString")
+    mWkbType = QGis::WKBLineString;
+  else if (uri == "Polygon")
+    mWkbType = QGis::WKBPolygon;
+  else if (uri == "WKBMultiPoint")
+    mWkbType = QGis::WKBMultiPoint;
+  else if (uri == "WKBMultiLineString")
+    mWkbType = QGis::WKBMultiLineString;
+  else if (uri == "WKBMultiPolygon")
+    mWkbType = QGis::WKBMultiPolygon;
+  else
+    mWkbType = QGis::WKBUnknown;
+
+  mNextFeatureId = 1;
+}
+
+QgsMemoryProvider::~QgsMemoryProvider()
+{
+}
+
+QString QgsMemoryProvider::storageType() const
+{
+  return "Memory storage";
+}
+
+bool QgsMemoryProvider::getNextFeature(QgsFeature& feature)
+{
+  bool hasFeature = FALSE;
+  while (mSelectIterator != mFeatures.end())
+  {
+    if (mSelectRect.isEmpty())
+    {
+      hasFeature = TRUE;
+      break;
+    }
+    else
+    {
+      // TODO: could use some less accurate test when not using mSelectUseIntersect (e.g. spatial index)
+      if (feature.geometry()->intersects(mSelectRect))
+      {
+        hasFeature = TRUE;
+        break;
+      }
+    }
+
+    mSelectIterator++;
+  }
+
+  // copy feature
+  if (hasFeature)
+  {
+    feature = mSelectIterator.value();
+    mSelectIterator++;
+  }
+
+  return hasFeature;
+}
+
+bool QgsMemoryProvider::getFeatureAtId(int featureId,
+                              QgsFeature& feature,
+                              bool fetchGeometry,
+                              QgsAttributeList fetchAttributes)
+{
+  QgsFeatureMap::iterator it = mFeatures.find(featureId);
+
+  if (it == mFeatures.end())
+    return FALSE;
+
+  feature = *it;
+  return TRUE;
+}
+
+
+void QgsMemoryProvider::select(QgsAttributeList fetchAttributes,
+                                      QgsRect rect,
+                                      bool fetchGeometry,
+                                      bool useIntersect)
+{
+  mSelectAttrs = fetchAttributes;
+  mSelectRect = rect;
+  mSelectGeometry = fetchGeometry;
+  mSelectUseIntersect = useIntersect;
+
+  reset();
+}
+
+void QgsMemoryProvider::reset()
+{
+  mSelectIterator = mFeatures.begin();
+}
+
+
+QgsRect QgsMemoryProvider::extent()
+{
+  return mExtent;
+}
+
+QGis::WKBTYPE QgsMemoryProvider::geometryType() const
+{
+  return mWkbType;
+}
+
+long QgsMemoryProvider::featureCount() const
+{
+  return mFeatures.count();
+}
+
+uint QgsMemoryProvider::fieldCount() const
+{
+  return mFields.count();
+}
+
+
+const QgsFieldMap & QgsMemoryProvider::fields() const
+{
+  return mFields;
+}
+
+bool QgsMemoryProvider::isValid()
+{
+  return (mWkbType != QGis::WKBUnknown);
+}
+
+QgsSpatialRefSys QgsMemoryProvider::getSRS()
+{
+  // TODO: make provider projection-aware
+  return QgsSpatialRefSys(); // return default SRS
+}
+
+
+bool QgsMemoryProvider::addFeatures(QgsFeatureList & flist)
+{
+  // TODO: sanity checks of fields and geometries
+  for (QgsFeatureList::iterator it = flist.begin(); it != flist.end(); ++it)
+  {
+    mFeatures[mNextFeatureId] = *it;
+    mFeatures[mNextFeatureId].setFeatureId(mNextFeatureId);
+    mNextFeatureId++;
+  }
+
+  updateExtent();
+
+  return TRUE;
+}
+
+bool QgsMemoryProvider::deleteFeatures(const QgsFeatureIds & id)
+{
+  for (QgsFeatureIds::const_iterator it = id.begin(); it != id.end(); ++it)
+    mFeatures.remove(*it);
+
+  updateExtent();
+
+  return TRUE;
+}
+
+bool QgsMemoryProvider::addAttributes(const QgsNewAttributesMap & attributes)
+{
+  for (QgsNewAttributesMap::const_iterator it = attributes.begin(); it != attributes.end(); ++it)
+  {
+    QString name = it.key();
+    QString typeName = it.value();
+    QVariant::Type type;
+    if (typeName == "int")
+      type = QVariant::Int;
+    else if (typeName == "double")
+      type = QVariant::Double;
+    else if (typeName == "string")
+      type = QVariant::String;
+    else
+    {
+      QgsDebugMsg("Field type not supported: "+type);
+      continue;
+    }
+
+    // add new field as a last one
+    int nextId = -1;
+    for (QgsFieldMap::iterator it2 = mFields.begin(); it2 != mFields.end(); ++it2)
+      if (it2.key() > nextId) nextId = it2.key();
+    mFields[nextId+1] = QgsField(name, type, typeName);
+  }
+  return TRUE;
+}
+
+bool QgsMemoryProvider::deleteAttributes(const QgsAttributeIds& attributes)
+{
+  for (QgsAttributeIds::const_iterator it = attributes.begin(); it != attributes.end(); ++it)
+    mFields.remove(*it);
+  return TRUE;
+}
+
+bool QgsMemoryProvider::changeAttributeValues(const QgsChangedAttributesMap & attr_map)
+{
+  // TODO: change attribute values
+  return FALSE;
+}
+
+bool QgsMemoryProvider::changeGeometryValues(QgsGeometryMap & geometry_map)
+{
+  // TODO: change geometries
+
+  updateExtent();
+
+  return FALSE;
+}
+
+int QgsMemoryProvider::capabilities() const
+{
+  return AddFeatures | DeleteFeatures | ChangeGeometries |
+      ChangeAttributeValues | AddAttributes | DeleteAttributes |
+      SelectAtId | SelectGeometryAtId | RandomSelectGeometryAtId | SequentialSelectGeometryAtId;
+}
+
+
+void QgsMemoryProvider::updateExtent()
+{
+  if (mFeatures.count() == 0)
+  {
+    mExtent = QgsRect();
+  }
+  else
+  {
+    mExtent = mFeatures.begin().value().geometry()->boundingBox();
+    for (QgsFeatureMap::iterator it = mFeatures.begin(); it != mFeatures.end(); ++it)
+      mExtent.unionRect(it.value().geometry()->boundingBox());
+  }
+}
+
+
+
+// --------------------------------
+
+QString  QgsMemoryProvider::name() const
+{
+  return TEXT_PROVIDER_KEY;
+}
+
+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;
+}