QGIS API Documentation  3.16.0-Hannover (43b64b13f3)
qgsmemoryprovider.h
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1 /***************************************************************************
2  memoryprovider.h - provider with storage in memory
3  ------------------
4  begin : June 2008
5  copyright : (C) 2008 by Martin Dobias
6  email : wonder dot sk at gmail dot com
7  ***************************************************************************
8  * *
9  * This program is free software; you can redistribute it and/or modify *
10  * it under the terms of the GNU General Public License as published by *
11  * the Free Software Foundation; either version 2 of the License, or *
12  * (at your option) any later version. *
13  * *
14  ***************************************************************************/
15 
16 #define SIP_NO_FILE
17 
18 #include "qgsvectordataprovider.h"
20 #include "qgsfields.h"
21 
23 typedef QMap<QgsFeatureId, QgsFeature> QgsFeatureMap;
24 
25 class QgsSpatialIndex;
26 
27 class QgsMemoryFeatureIterator;
28 
29 class QgsMemoryProvider final: public QgsVectorDataProvider
30 {
31  Q_OBJECT
32 
33  public:
34  explicit QgsMemoryProvider( const QString &uri, const QgsVectorDataProvider::ProviderOptions &coordinateTransformContext,
35  QgsDataProvider::ReadFlags flags = QgsDataProvider::ReadFlags() );
36 
37  ~QgsMemoryProvider() override;
38 
40  static QString providerKey();
42  static QString providerDescription();
43 
48  static QgsMemoryProvider *createProvider( const QString &uri, const QgsVectorDataProvider::ProviderOptions &coordinateTransformContext,
49  QgsDataProvider::ReadFlags flags = QgsDataProvider::ReadFlags() );
50 
51  /* Implementation of functions from QgsVectorDataProvider */
52 
53  QgsAbstractFeatureSource *featureSource() const override;
54 
55  QString dataSourceUri( bool expandAuthConfig = true ) const override;
56  QString storageType() const override;
57  QgsFeatureIterator getFeatures( const QgsFeatureRequest &request ) const override;
58  QgsWkbTypes::Type wkbType() const override;
59  long featureCount() const override;
60  QgsFields fields() const override;
61  bool addFeatures( QgsFeatureList &flist, QgsFeatureSink::Flags flags = QgsFeatureSink::Flags() ) override;
62  bool deleteFeatures( const QgsFeatureIds &id ) override;
63  bool addAttributes( const QList<QgsField> &attributes ) override;
64  bool renameAttributes( const QgsFieldNameMap &renamedAttributes ) override;
65  bool deleteAttributes( const QgsAttributeIds &attributes ) override;
66  bool changeAttributeValues( const QgsChangedAttributesMap &attr_map ) override;
67  bool changeGeometryValues( const QgsGeometryMap &geometry_map ) override;
68  QString subsetString() const override;
69  bool setSubsetString( const QString &theSQL, bool updateFeatureCount = true ) override;
70  bool supportsSubsetString() const override { return true; }
71  bool createSpatialIndex() override;
73  QgsVectorDataProvider::Capabilities capabilities() const override;
74  bool truncate() override;
75 
76  /* Implementation of functions from QgsDataProvider */
77 
78  QString name() const override;
79  QString description() const override;
80  QgsRectangle extent() const override;
81  void updateExtents() override;
82  bool isValid() const override;
83  QgsCoordinateReferenceSystem crs() const override;
84  void handlePostCloneOperations( QgsVectorDataProvider *source ) override;
85 
86  private:
87  // Coordinate reference system
89 
90  // fields
91  QgsFields mFields;
92  QgsWkbTypes::Type mWkbType;
93  mutable QgsRectangle mExtent;
94 
95  // features
96  QgsFeatureMap mFeatures;
97  QgsFeatureId mNextFeatureId;
98 
99  // indexing
100  QgsSpatialIndex *mSpatialIndex = nullptr;
101 
102  QString mSubsetString;
103 
104  friend class QgsMemoryFeatureSource;
105 };
106 
qgsfields.h
QgsAttributeIds
QSet< int > QgsAttributeIds
Definition: qgsvectordataprovider.h:39
QgsFeatureSource::hasSpatialIndex
virtual SpatialIndexPresence hasSpatialIndex() const
Returns an enum value representing the presence of a valid spatial index on the source,...
Definition: qgsfeaturesource.cpp:190
QgsVectorDataProvider::deleteFeatures
virtual bool deleteFeatures(const QgsFeatureIds &id)
Deletes one or more features from the provider.
Definition: qgsvectordataprovider.cpp:99
QgsVectorDataProvider::createSpatialIndex
virtual bool createSpatialIndex()
Creates a spatial index on the datasource (if supported by the provider type).
Definition: qgsvectordataprovider.cpp:187
QgsDataProvider::supportsSubsetString
virtual bool supportsSubsetString() const
Returns true if the provider supports setting of subset strings.
Definition: qgsdataprovider.h:261
QgsDataProvider::ProviderOptions
Setting options for creating vector data providers.
Definition: qgsdataprovider.h:105
QgsVectorDataProvider::handlePostCloneOperations
virtual void handlePostCloneOperations(QgsVectorDataProvider *source)
Handles any post-clone operations required after this vector data provider was cloned from the source...
Definition: qgsvectordataprovider.cpp:885
QgsVectorDataProvider::fields
QgsFields fields() const override=0
Returns the fields associated with this data provider.
QgsDataProvider::setSubsetString
virtual bool setSubsetString(const QString &subset, bool updateFeatureCount=true)
Set the subset string used to create a subset of features in the layer.
Definition: qgsdataprovider.h:249
QgsVectorDataProvider::changeAttributeValues
virtual bool changeAttributeValues(const QgsChangedAttributesMap &attr_map)
Changes attribute values of existing features.
Definition: qgsvectordataprovider.cpp:137
QgsFields
Container of fields for a vector layer.
Definition: qgsfields.h:45
QgsWkbTypes::Type
Type
The WKB type describes the number of dimensions a geometry has.
Definition: qgswkbtypes.h:70
QgsChangedAttributesMap
QMap< QgsFeatureId, QgsAttributeMap > QgsChangedAttributesMap
Definition: qgsfeature.h:569
QgsDataProvider::dataSourceUri
virtual QString dataSourceUri(bool expandAuthConfig=false) const
Gets the data source specification.
Definition: qgsdataprovider.h:159
QgsRectangle
A rectangle specified with double values.
Definition: qgsrectangle.h:42
QgsDataProvider::description
virtual QString description() const =0
Returns description.
QgsFeatureRequest
This class wraps a request for features to a vector layer (or directly its vector data provider).
Definition: qgsfeaturerequest.h:76
QgsVectorDataProvider::capabilities
virtual QgsVectorDataProvider::Capabilities capabilities() const
Returns flags containing the supported capabilities.
Definition: qgsvectordataprovider.cpp:198
QgsVectorDataProvider::featureCount
long featureCount() const override=0
Number of features in the layer.
QgsVectorDataProvider::changeGeometryValues
virtual bool changeGeometryValues(const QgsGeometryMap &geometry_map)
Changes geometries of existing features.
Definition: qgsvectordataprovider.cpp:169
QgsVectorDataProvider::truncate
virtual bool truncate()
Removes all features from the layer.
Definition: qgsvectordataprovider.cpp:105
QgsVectorDataProvider::featureSource
virtual QgsAbstractFeatureSource * featureSource() const =0
Returns feature source object that can be used for querying provider's data.
QgsFeatureSource::SpatialIndexPresence
SpatialIndexPresence
Enumeration of spatial index presence states.
Definition: qgsfeaturesource.h:188
QgsAbstractFeatureSource
Base class that can be used for any class that is capable of returning features.
Definition: qgsfeaturerequest.h:743
QgsVectorDataProvider::renameAttributes
virtual bool renameAttributes(const QgsFieldNameMap &renamedAttributes)
Renames existing attributes.
Definition: qgsvectordataprovider.cpp:131
qgsvectordataprovider.h
QgsFeatureList
QList< QgsFeature > QgsFeatureList
Definition: qgsfeature.h:583
QgsVectorDataProvider::storageType
virtual QString storageType() const
Returns the permanent storage type for this layer as a friendly name.
Definition: qgsvectordataprovider.cpp:46
QgsSpatialIndex
A spatial index for QgsFeature objects.
Definition: qgsspatialindex.h:68
QgsFeatureMap
QMap< QgsFeatureId, QgsFeature > QgsFeatureMap
Definition: qgsvectorlayereditbuffer.h:30
QgsVectorDataProvider::getFeatures
QgsFeatureIterator getFeatures(const QgsFeatureRequest &request=QgsFeatureRequest()) const override=0
Query the provider for features specified in request.
QgsFeatureIds
QSet< QgsFeatureId > QgsFeatureIds
Definition: qgsfeatureid.h:37
QgsCoordinateReferenceSystem
This class represents a coordinate reference system (CRS).
Definition: qgscoordinatereferencesystem.h:206
QgsVectorDataProvider::deleteAttributes
virtual bool deleteAttributes(const QgsAttributeIds &attributes)
Deletes existing attributes from the provider.
Definition: qgsvectordataprovider.cpp:125
QgsVectorDataProvider::addFeatures
bool addFeatures(QgsFeatureList &flist, QgsFeatureSink::Flags flags=QgsFeatureSink::Flags()) override
Adds a list of features to the sink.
Definition: qgsvectordataprovider.cpp:87
QgsDataProvider::extent
virtual QgsRectangle extent() const =0
Returns the extent of the layer.
QgsFieldNameMap
QMap< int, QString > QgsFieldNameMap
Definition: qgsattributes.h:44
QgsVectorDataProvider::addAttributes
virtual bool addAttributes(const QList< QgsField > &attributes)
Adds new attributes to the provider.
Definition: qgsvectordataprovider.cpp:119
QgsGeometryMap
QMap< QgsFeatureId, QgsGeometry > QgsGeometryMap
Definition: qgsfeature.h:578
QgsVectorDataProvider
This is the base class for vector data providers.
Definition: qgsvectordataprovider.h:59
QgsDataProvider::subsetString
virtual QString subsetString() const
Returns the subset definition string (typically sql) currently in use by the layer and used by the pr...
Definition: qgsdataprovider.h:269
QgsDataProvider::name
virtual QString name() const =0
Returns a provider name.
QgsFeatureIterator
Wrapper for iterator of features from vector data provider or vector layer.
Definition: qgsfeatureiterator.h:265
qgscoordinatereferencesystem.h
QgsVectorDataProvider::wkbType
QgsWkbTypes::Type wkbType() const override=0
Returns the geometry type which is returned by this layer.
QgsDataProvider::isValid
virtual bool isValid() const =0
Returns true if this is a valid layer.
QgsDataProvider::updateExtents
virtual void updateExtents()
Update the extents of the layer.
Definition: qgsdataprovider.h:237
QgsFeatureId
qint64 QgsFeatureId
64 bit feature ids negative numbers are used for uncommitted/newly added features
Definition: qgsfeatureid.h:28
QgsDataProvider::crs
virtual QgsCoordinateReferenceSystem crs() const =0
Returns the coordinate system for the data source.