Add a static QCache to QgsPointCloudIndex for storing decoded data blocks

python/PyQt6/core/auto_generated/pointcloud/qgspointcloudblock.sip.in

@@ -34,6 +34,12 @@ Ctor
 %End
     virtual ~QgsPointCloudBlock();
 
+    QgsPointCloudBlock *clone() const;
+%Docstring
+Clones the QgsPointCloudBlock returning a new copy.
+Caller takes ownership of the returned object.
+%End
+
     const char *data() const;
 %Docstring
 Returns raw pointer to data

python/core/auto_generated/pointcloud/qgspointcloudblock.sip.in

@@ -34,6 +34,12 @@ Ctor
 %End
     virtual ~QgsPointCloudBlock();
 
+    QgsPointCloudBlock *clone() const;
+%Docstring
+Clones the QgsPointCloudBlock returning a new copy.
+Caller takes ownership of the returned object.
+%End
+
     const char *data() const;
 %Docstring
 Returns raw pointer to data

src/core/pointcloud/qgscopcpointcloudindex.cpp

@@ -138,6 +138,11 @@ bool QgsCopcPointCloudIndex::loadSchema( QgsLazInfo &lazInfo )
 
 std::unique_ptr<QgsPointCloudBlock> QgsCopcPointCloudIndex::nodeData( const IndexedPointCloudNode &n, const QgsPointCloudRequest &request )
 {
+  if ( QgsPointCloudBlock *cached = getNodeDataFromCache( n, request ) )
+  {
+    return std::unique_ptr<QgsPointCloudBlock>( cached );
+  }
+
   const bool found = fetchNodeHierarchy( n );
   if ( !found )
     return nullptr;
@@ -164,7 +169,9 @@ std::unique_ptr<QgsPointCloudBlock> QgsCopcPointCloudIndex::nodeData( const Inde
   }
   QgsRectangle filterRect = request.filterRect();
 
-  return QgsLazDecoder::decompressCopc( rawBlockData, *mLazInfo.get(), pointCount, requestAttributes, filterExpression, filterRect );
+  std::unique_ptr<QgsPointCloudBlock> decoded = QgsLazDecoder::decompressCopc( rawBlockData, *mLazInfo.get(), pointCount, requestAttributes, filterExpression, filterRect );
+  storeNodeDataToCache( decoded.get(), n, request );
+  return decoded;
 }
 
 QgsPointCloudBlockRequest *QgsCopcPointCloudIndex::asyncNodeData( const IndexedPointCloudNode &n, const QgsPointCloudRequest &request )

src/core/pointcloud/qgseptpointcloudindex.cpp

@@ -309,6 +309,11 @@ bool QgsEptPointCloudIndex::loadSchema( const QByteArray &dataJson )
 
 std::unique_ptr<QgsPointCloudBlock> QgsEptPointCloudIndex::nodeData( const IndexedPointCloudNode &n, const QgsPointCloudRequest &request )
 {
+  if ( QgsPointCloudBlock *cached = getNodeDataFromCache( n, request ) )
+  {
+    return std::unique_ptr<QgsPointCloudBlock>( cached );
+  }
+
   mHierarchyMutex.lock();
   const bool found = mHierarchy.contains( n );
   mHierarchyMutex.unlock();
@@ -323,25 +328,25 @@ std::unique_ptr<QgsPointCloudBlock> QgsEptPointCloudIndex::nodeData( const Index
   requestAttributes.extend( attributes(), filterExpression.referencedAttributes() );
   QgsRectangle filterRect = request.filterRect();
 
+  std::unique_ptr<QgsPointCloudBlock> decoded;
   if ( mDataType == QLatin1String( "binary" ) )
   {
     const QString filename = QStringLiteral( "%1/ept-data/%2.bin" ).arg( mDirectory, n.toString() );
-    return QgsEptDecoder::decompressBinary( filename, attributes(), requestAttributes, scale(), offset(), filterExpression, filterRect );
+    decoded = QgsEptDecoder::decompressBinary( filename, attributes(), requestAttributes, scale(), offset(), filterExpression, filterRect );
   }
   else if ( mDataType == QLatin1String( "zstandard" ) )
   {
     const QString filename = QStringLiteral( "%1/ept-data/%2.zst" ).arg( mDirectory, n.toString() );
-    return QgsEptDecoder::decompressZStandard( filename, attributes(), request.attributes(), scale(), offset(), filterExpression, filterRect );
+    decoded = QgsEptDecoder::decompressZStandard( filename, attributes(), request.attributes(), scale(), offset(), filterExpression, filterRect );
   }
   else if ( mDataType == QLatin1String( "laszip" ) )
   {
     const QString filename = QStringLiteral( "%1/ept-data/%2.laz" ).arg( mDirectory, n.toString() );
-    return QgsLazDecoder::decompressLaz( filename, requestAttributes, filterExpression, filterRect );
+    decoded = QgsLazDecoder::decompressLaz( filename, requestAttributes, filterExpression, filterRect );
-  }
-  else
-  {
-    return nullptr;  // unsupported
   }
+
+  storeNodeDataToCache( decoded.get(), n, request );
+  return decoded;
 }
 
 QgsPointCloudBlockRequest *QgsEptPointCloudIndex::asyncNodeData( const IndexedPointCloudNode &n, const QgsPointCloudRequest &request )

src/core/pointcloud/qgspointcloudblock.cpp

@@ -34,6 +34,11 @@ QgsPointCloudBlock::QgsPointCloudBlock(
 {
 }
 
+QgsPointCloudBlock *QgsPointCloudBlock::clone() const
+{
+  return new QgsPointCloudBlock( *this );
+}
+
 const char *QgsPointCloudBlock::data() const
 {
   return mStorage.data();

src/core/pointcloud/qgspointcloudblock.h

@@ -45,6 +45,12 @@ class CORE_EXPORT QgsPointCloudBlock
     //! Dtor
     virtual ~QgsPointCloudBlock() = default;
 
+    /**
+     * Clones the QgsPointCloudBlock returning a new copy.
+     * Caller takes ownership of the returned object.
+     */
+    QgsPointCloudBlock *clone() const;
+
     //! Returns raw pointer to data
     const char *data() const;
 

src/core/pointcloud/qgspointcloudindex.cpp

@@ -27,6 +27,7 @@
 
 #include "qgstiledownloadmanager.h"
 #include "qgspointcloudstatistics.h"
+#include "qgslogger.h"
 
 IndexedPointCloudNode::IndexedPointCloudNode():
   mD( -1 ),
@@ -87,6 +88,31 @@ uint qHash( IndexedPointCloudNode id )
 
 ///@cond PRIVATE
 
+//
+// QgsPointCloudCacheKey
+//
+
+QgsPointCloudCacheKey::QgsPointCloudCacheKey( const IndexedPointCloudNode &n, const QgsPointCloudRequest &request, const QgsPointCloudExpression &expression, const QString &uri )
+  : mNode( n )
+  , mUri( uri )
+  , mRequest( request )
+  , mFilterExpression( expression )
+{
+}
+
+bool QgsPointCloudCacheKey::operator==( const QgsPointCloudCacheKey &other ) const
+{
+  return mNode == other.mNode &&
+         mUri == other.mUri &&
+         mRequest == other.mRequest &&
+         mFilterExpression == other.mFilterExpression;
+}
+
+uint qHash( const QgsPointCloudCacheKey &key )
+{
+  return qHash( key.node() ) ^ qHash( key.request() ) ^ qHash( key.uri() ) ^ qHash( key.filterExpression() );
+}
+
 //
 // QgsPointCloudDataBounds
 //
@@ -153,6 +179,9 @@ QgsDoubleRange QgsPointCloudDataBounds::zRange( const QgsVector3D &offset, const
 // QgsPointCloudIndex
 //
 
+QMutex QgsPointCloudIndex::sBlockCacheMutex;
+QCache<QgsPointCloudCacheKey, QgsPointCloudBlock> QgsPointCloudIndex::sBlockCache( 200'000'000 ); // 200MB of cached points
+
 QgsPointCloudIndex::QgsPointCloudIndex() = default;
 
 QgsPointCloudIndex::~QgsPointCloudIndex() = default;
@@ -364,3 +393,28 @@ void QgsPointCloudIndex::copyCommonProperties( QgsPointCloudIndex *destination )
   destination->mSpan = mSpan;
   destination->mFilterExpression = mFilterExpression;
 }
+
+QgsPointCloudBlock *QgsPointCloudIndex::getNodeDataFromCache( const IndexedPointCloudNode &node, const QgsPointCloudRequest &request )
+{
+  QgsPointCloudCacheKey key( node, request, mFilterExpression, mUri );
+
+  QMutexLocker l( &sBlockCacheMutex );
+  QgsPointCloudBlock *cached = sBlockCache.object( key );
+  return cached ? cached->clone() : nullptr;
+}
+
+void QgsPointCloudIndex::storeNodeDataToCache( QgsPointCloudBlock *data, const IndexedPointCloudNode &node, const QgsPointCloudRequest &request )
+{
+  storeNodeDataToCacheStatic( data, node, request, mFilterExpression, mUri );
+}
+
+void QgsPointCloudIndex::storeNodeDataToCacheStatic( QgsPointCloudBlock *data, const IndexedPointCloudNode &node, const QgsPointCloudRequest &request, const QgsPointCloudExpression &expression, const QString &uri )
+{
+  QgsPointCloudCacheKey key( node, request, expression, uri );
+
+  const int cost = data->pointCount() * data->pointRecordSize();
+
+  QMutexLocker l( &sBlockCacheMutex );
+  QgsDebugMsgLevel( QStringLiteral( "(%1/%2): Caching node %3 of %4" ).arg( sBlockCache.totalCost() ).arg( sBlockCache.maxCost() ).arg( key.node().toString() ).arg( key.uri() ), 4 );
+  sBlockCache.insert( key, data->clone(), cost );
+}

src/core/pointcloud/qgspointcloudindex.h

@@ -25,6 +25,7 @@
 #include <QVector>
 #include <QList>
 #include <QMutex>
+#include <QCache>
 
 #include "qgis_core.h"
 #include "qgsrectangle.h"
@@ -34,6 +35,7 @@
 #include "qgsrange.h"
 #include "qgspointcloudattribute.h"
 #include "qgspointcloudexpression.h"
+#include "qgspointcloudrequest.h"
 
 #define SIP_NO_FILE
 
@@ -105,6 +107,46 @@ Q_DECLARE_TYPEINFO( IndexedPointCloudNode, Q_PRIMITIVE_TYPE );
 //! Hash function for indexed nodes
 CORE_EXPORT uint qHash( IndexedPointCloudNode id );
 
+/**
+ * \ingroup core
+ *
+ * \brief Container class for QgsPointCloudBlock cache keys
+ *
+ * \note The API is considered EXPERIMENTAL and can be changed without a notice
+ *
+ * \since QGIS 3.36
+ */
+class CORE_EXPORT QgsPointCloudCacheKey
+{
+  public:
+    //! Ctor
+    QgsPointCloudCacheKey( const IndexedPointCloudNode &n, const QgsPointCloudRequest &request, const QgsPointCloudExpression &expression, const QString &uri );
+
+    //! Compares keys
+    bool operator==( const QgsPointCloudCacheKey &other ) const;
+
+    //! Returns the key's IndexedPointCloudNode
+    IndexedPointCloudNode node() const { return mNode; }
+
+    //! Returns the key's uri
+    QString uri() const { return mUri; }
+
+    //! Returns the key's QgsPointCloudRequest
+    QgsPointCloudRequest request() const { return mRequest; }
+
+    //! Returns the key's QgsPointCloudExpression
+    QgsPointCloudExpression filterExpression() const { return mFilterExpression; }
+
+  private:
+    IndexedPointCloudNode mNode;
+    QString mUri;
+    QgsPointCloudRequest mRequest;
+    QgsPointCloudExpression mFilterExpression;
+};
+
+//! Hash function for QgsPointCloudCacheKey
+uint qHash( const QgsPointCloudCacheKey &key );
+
 /**
  * \ingroup core
  *
@@ -330,6 +372,24 @@ class CORE_EXPORT QgsPointCloudIndex: public QObject
      */
     void copyCommonProperties( QgsPointCloudIndex *destination ) const;
 
+    /**
+     * Fetches the requested node data from the cache for the specified \a node and \a request.
+     * If not found in the cache, nullptr is returned.
+     * Caller takes ownership of the returned object.
+     */
+    QgsPointCloudBlock *getNodeDataFromCache( const IndexedPointCloudNode &node, const QgsPointCloudRequest &request );
+
+    /**
+     * Stores existing \a data to the cache for the specified \a node and \a request. Ownership is not transferred, block gets cloned in the cache.
+     */
+    void storeNodeDataToCache( QgsPointCloudBlock *data, const IndexedPointCloudNode &node, const QgsPointCloudRequest &request );
+
+    /**
+     * Stores existing \a data to the cache for the specified \a node, \a request, \a expression and \a uri. Ownership is not transferred, block gets cloned in the cache.
+     */
+    static void storeNodeDataToCacheStatic( QgsPointCloudBlock *data, const IndexedPointCloudNode &node, const QgsPointCloudRequest &request,
+                                            const QgsPointCloudExpression &expression, const QString &uri );
+
   protected: //TODO private
     //! Sets native attributes of the data
     void setAttributes( const QgsPointCloudAttributeCollection &attributes );
@@ -348,6 +408,8 @@ class CORE_EXPORT QgsPointCloudIndex: public QObject
 
     QString mError;
     QString mUri;
+    static QMutex sBlockCacheMutex;
+    static QCache<QgsPointCloudCacheKey, QgsPointCloudBlock> sBlockCache;
 };
 
 #endif // QGSPOINTCLOUDINDEX_H

src/core/pointcloud/qgspointcloudrequest.cpp

@@ -21,6 +21,12 @@
 
 QgsPointCloudRequest::QgsPointCloudRequest() = default;
 
+bool QgsPointCloudRequest::operator==( const QgsPointCloudRequest &other ) const
+{
+  return mFilterRect == other.filterRect() &&
+         mAttributes.toFields() == other.attributes().toFields(); //todo: QgsPointCloudAttributeCollection::operator==
+}
+
 QgsPointCloudAttributeCollection QgsPointCloudRequest::attributes() const
 {
   return mAttributes;
@@ -30,3 +36,8 @@ void QgsPointCloudRequest::setAttributes( const QgsPointCloudAttributeCollection
 {
   mAttributes = attributes;
 }
+
+uint qHash( const QgsPointCloudRequest &request )
+{
+  return qHash( request.filterRect() ) ^ qHash( request.attributes().toFields() );
+}

src/core/pointcloud/qgspointcloudrequest.h

@@ -44,6 +44,9 @@ class CORE_EXPORT QgsPointCloudRequest
     //! Ctor
     QgsPointCloudRequest();
 
+    //! Equality operator
+    bool operator==( const QgsPointCloudRequest &other ) const;
+
     //! Returns attributes
     QgsPointCloudAttributeCollection attributes() const;
 
@@ -66,4 +69,7 @@ class CORE_EXPORT QgsPointCloudRequest
     QgsRectangle mFilterRect;
 };
 
+//! Hash function for QgsPointCloudRequest
+uint qHash( const QgsPointCloudRequest &request );
+
 #endif // QGSPOINTCLOUDREQUEST_H