QgsSpatialIndexKDBush is implicitly shared for fast copies

python/core/auto_generated/qgsspatialindexkdbush.sip.in

@@ -0,0 +1,85 @@
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/core/qgsspatialindexkdbush.h                                     *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/
+
+
+
+
+
+class QgsSpatialIndexKDBush
+{
+%Docstring
+
+A very fast static spatial index for 2D points based on a flat KD-tree.
+
+Compared to QgsSpatialIndex, this index:
+- supports single point features only (no multipoints)
+- is static (features cannot be added or removed from the index after construction)
+- is much faster!
+- supports true "distance based" searches, i.e. return all points within a radius
+from a search point
+
+.. seealso:: :py:class:`QgsSpatialIndex`
+
+.. versionadded:: 3.4
+%End
+
+%TypeHeaderCode
+#include "qgsspatialindexkdbush.h"
+%End
+  public:
+
+    explicit QgsSpatialIndexKDBush( QgsFeatureIterator &fi, QgsFeedback *feedback = 0 );
+%Docstring
+Constructor - creates KDBush index and bulk loads it with features from the iterator.
+
+The optional ``feedback`` object can be used to allow cancelation of bulk feature loading. Ownership
+of ``feedback`` is not transferred, and callers must take care that the lifetime of feedback exceeds
+that of the spatial index construction.
+
+Any non-single point features encountered during iteration will be ignored and not included in the index.
+%End
+
+    explicit QgsSpatialIndexKDBush( const QgsFeatureSource &source, QgsFeedback *feedback = 0 );
+%Docstring
+Constructor - creates KDBush index and bulk loads it with features from the source.
+
+The optional ``feedback`` object can be used to allow cancelation of bulk feature loading. Ownership
+of ``feedback`` is not transferred, and callers must take care that the lifetime of feedback exceeds
+that of the spatial index construction.
+
+Any non-single point features encountered during iteration will be ignored and not included in the index.
+%End
+
+    QgsSpatialIndexKDBush( const QgsSpatialIndexKDBush &other );
+%Docstring
+Copy constructor
+%End
+
+
+    ~QgsSpatialIndexKDBush();
+
+    QList<QgsFeatureId> intersect( const QgsRectangle &rectangle ) const;
+%Docstring
+Returns a list of features which fall within the specified ``rectangle``.
+%End
+
+    QList<QgsFeatureId> within( const QgsPointXY &point, double radius ) const;
+%Docstring
+Returns a list of features which are within the given search ``radius``
+of ``point``.
+%End
+
+};
+
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/core/qgsspatialindexkdbush.h                                     *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/

src/core/CMakeLists.txt

@@ -914,6 +914,7 @@ SET(QGIS_CORE_HDRS
   qgssnappingutils.h
   qgsspatialindex.h
   qgsspatialindexkdbush.h
+  qgsspatialindexkdbush_p.h
   qgsspatialiteutils.h
   qgssqlstatement.h
   qgssqliteutils.h

src/core/qgsspatialindexkdbush.cpp

@@ -16,91 +16,59 @@
  ***************************************************************************/
 
 #include "qgsspatialindexkdbush.h"
-#include "kdbush.hpp"
+#include "qgsspatialindexkdbush_p.h"
 #include "qgsfeatureiterator.h"
 #include "qgsfeedback.h"
 #include "qgsfeaturesource.h"
 
-class PointXYKDBush : public kdbush::KDBush< std::pair<double, double>, QgsFeatureId >
+QgsSpatialIndexKDBush::QgsSpatialIndexKDBush( QgsFeatureIterator &fi, QgsFeedback *feedback )
+  : d( new QgsSpatialIndexKDBushPrivate( fi, feedback ) )
 {
-  public:
-
-    explicit PointXYKDBush( QgsFeatureIterator &fi, QgsFeedback *feedback = nullptr )
-    {
-      fillFromIterator( fi, feedback );
-    }
-
-    explicit PointXYKDBush( const QgsFeatureSource &source, QgsFeedback *feedback )
-    {
-      points.reserve( source.featureCount() );
-      ids.reserve( source.featureCount() );
-      QgsFeatureIterator it = source.getFeatures( QgsFeatureRequest().setSubsetOfAttributes( QgsAttributeList() ) );
-      fillFromIterator( it, feedback );
-    }
-
-    void fillFromIterator( QgsFeatureIterator &fi, QgsFeedback *feedback = nullptr )
-    {
-      QgsFeatureId size = 0;
-
-      QgsFeature f;
-      while ( fi.nextFeature( f ) )
-      {
-        if ( feedback && feedback->isCanceled() )
-          return;
-
-        if ( !f.hasGeometry() )
-          continue;
-
-        if ( QgsWkbTypes::flatType( f.geometry().wkbType() ) == QgsWkbTypes::Point )
-        {
-          const QgsPoint *point = qgsgeometry_cast< const QgsPoint * >( f.geometry().constGet() );
-          points.emplace_back( point->x(), point->y() );
-        }
-        else
-        {
-          // not a point
-          continue;
-        }
-
-        ids.push_back( f.id() );
-        size++;
-      }
-
-      sortKD( 0, size - 1, 0 );
-    }
 
-};
-
-//
-// QgsSpatialIndexKDBush
-//
+}
 
-QgsSpatialIndexKDBush::QgsSpatialIndexKDBush( QgsFeatureIterator &fi, QgsFeedback *feedback )
-  : mIndex( qgis::make_unique < PointXYKDBush >( fi, feedback ) )
+QgsSpatialIndexKDBush::QgsSpatialIndexKDBush( const QgsFeatureSource &source, QgsFeedback *feedback )
+  : d( new QgsSpatialIndexKDBushPrivate( source, feedback ) )
 {
+}
 
+QgsSpatialIndexKDBush::QgsSpatialIndexKDBush( const QgsSpatialIndexKDBush &other )
+{
+  d = other.d;
+  d->ref.ref();
 }
 
-QgsSpatialIndexKDBush::QgsSpatialIndexKDBush( const QgsFeatureSource &source, QgsFeedback *feedback )
-  : mIndex( qgis::make_unique < PointXYKDBush >( source, feedback ) )
+QgsSpatialIndexKDBush &QgsSpatialIndexKDBush::operator=( const QgsSpatialIndexKDBush &other )
 {
+  if ( !d->ref.deref() )
+  {
+    delete d;
+  }
+
+  d = other.d;
+  d->ref.ref();
+  return *this;
 }
 
-QgsSpatialIndexKDBush::~QgsSpatialIndexKDBush() = default;
+QgsSpatialIndexKDBush::~QgsSpatialIndexKDBush()
+{
+  if ( !d->ref.deref() )
+    delete d;
+}
 
 QList<QgsFeatureId> QgsSpatialIndexKDBush::within( const QgsPointXY &point, double radius ) const
 {
   QList<QgsFeatureId> result;
-  mIndex->within( point.x(), point.y(), radius, [&result]( const QgsFeatureId id ) { result << id; } );
+  d->index->within( point.x(), point.y(), radius, [&result]( const QgsFeatureId id ) { result << id; } );
   return result;
 }
 
 QList<QgsFeatureId> QgsSpatialIndexKDBush::intersect( const QgsRectangle &rectangle ) const
 {
   QList<QgsFeatureId> result;
-  mIndex->range( rectangle.xMinimum(),
-                 rectangle.yMinimum(),
-                 rectangle.xMaximum(),
+  d->index->range( rectangle.xMinimum(),
+                   rectangle.yMinimum(),
+                   rectangle.xMaximum(),
   rectangle.yMaximum(), [&result]( const QgsFeatureId id ) { result << id; } );
   return result;
 }

src/core/qgsspatialindexkdbush.h

@@ -22,7 +22,7 @@ class QgsPointXY;
 class QgsFeatureIterator;
 class QgsFeedback;
 class QgsFeatureSource;
-class PointXYKDBush;
+class QgsSpatialIndexKDBushPrivate;
 class QgsRectangle;
 
 #include "qgis_core.h"
@@ -43,6 +43,8 @@ class QgsRectangle;
  * - supports true "distance based" searches, i.e. return all points within a radius
  * from a search point
  *
+ * QgsSpatialIndexKDBush objects are implicitly shared and can be inexpensively copied.
+ *
  * \see QgsSpatialIndex, which is an general, mutable index for geometry bounding boxes.
  * \since QGIS 3.4
 */
@@ -72,6 +74,12 @@ class CORE_EXPORT QgsSpatialIndexKDBush
      */
     explicit QgsSpatialIndexKDBush( const QgsFeatureSource &source, QgsFeedback *feedback = nullptr );
 
+    //! Copy constructor
+    QgsSpatialIndexKDBush( const QgsSpatialIndexKDBush &other );
+
+    //! Assignment operator
+    QgsSpatialIndexKDBush &operator=( const QgsSpatialIndexKDBush &other );
+
     ~QgsSpatialIndexKDBush();
 
     /**
@@ -87,7 +95,8 @@ class CORE_EXPORT QgsSpatialIndexKDBush
 
   private:
 
-    std::unique_ptr< PointXYKDBush > mIndex;
+    //! Implicitly shared data pointer
+    QgsSpatialIndexKDBushPrivate *d = nullptr;
 };
 
 #endif // QGSSPATIALINDEXKDBUSH_H

src/core/qgsspatialindexkdbush_p.h

@@ -0,0 +1,109 @@
+/***************************************************************************
+                             qgsspatialindexkdbush_p.h
+                             -----------------
+    begin                : July 2018
+    copyright            : (C) 2018 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 QGSSPATIALINDEXKDBUSH_PRIVATE_H
+#define QGSSPATIALINDEXKDBUSH_PRIVATE_H
+
+/// @cond PRIVATE
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the QGIS API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+
+#include "qgsfeature.h"
+
+#include "qgsfeatureiterator.h"
+#include "qgsfeedback.h"
+#include "qgsfeaturesource.h"
+#include <memory>
+#include <QList>
+#include "kdbush.hpp"
+
+class PointXYKDBush : public kdbush::KDBush< std::pair<double, double>, QgsFeatureId >
+{
+  public:
+
+    explicit PointXYKDBush( QgsFeatureIterator &fi, QgsFeedback *feedback = nullptr )
+    {
+      fillFromIterator( fi, feedback );
+    }
+
+    explicit PointXYKDBush( const QgsFeatureSource &source, QgsFeedback *feedback )
+    {
+      points.reserve( source.featureCount() );
+      ids.reserve( source.featureCount() );
+      QgsFeatureIterator it = source.getFeatures( QgsFeatureRequest().setSubsetOfAttributes( QgsAttributeList() ) );
+      fillFromIterator( it, feedback );
+    }
+
+    void fillFromIterator( QgsFeatureIterator &fi, QgsFeedback *feedback = nullptr )
+    {
+      QgsFeatureId size = 0;
+
+      QgsFeature f;
+      while ( fi.nextFeature( f ) )
+      {
+        if ( feedback && feedback->isCanceled() )
+          return;
+
+        if ( !f.hasGeometry() )
+          continue;
+
+        if ( QgsWkbTypes::flatType( f.geometry().wkbType() ) == QgsWkbTypes::Point )
+        {
+          const QgsPoint *point = qgsgeometry_cast< const QgsPoint * >( f.geometry().constGet() );
+          points.emplace_back( point->x(), point->y() );
+        }
+        else
+        {
+          // not a point
+          continue;
+        }
+
+        ids.push_back( f.id() );
+        size++;
+      }
+
+      sortKD( 0, size - 1, 0 );
+    }
+
+};
+
+class QgsSpatialIndexKDBushPrivate
+{
+  public:
+
+    explicit QgsSpatialIndexKDBushPrivate( QgsFeatureIterator &fi, QgsFeedback *feedback = nullptr )
+      : index( qgis::make_unique < PointXYKDBush >( fi, feedback ) )
+    {}
+
+    explicit QgsSpatialIndexKDBushPrivate( const QgsFeatureSource &source, QgsFeedback *feedback = nullptr )
+      : index( qgis::make_unique < PointXYKDBush >( source, feedback ) )
+    {}
+
+    QAtomicInt ref = 1;
+    std::unique_ptr< PointXYKDBush > index;
+};
+
+/// @endcond
+
+#endif // QGSSPATIALINDEXKDBUSH_PRIVATE_H