[FEATURE] Expression compiler for SpatiaLite provider

qgis · Nov 18, 2015 · 35d0dd3 · 35d0dd3
1 parent 5f65f87
commit 35d0dd3
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Showing 10 changed files with 182 additions and 20 deletions.
diff --git a/src/core/qgssqlexpressioncompiler.cpp b/src/core/qgssqlexpressioncompiler.cpp
@@ -30,7 +30,7 @@ QgsSqlExpressionCompiler::~QgsSqlExpressionCompiler()
 QgsSqlExpressionCompiler::Result QgsSqlExpressionCompiler::compile( const QgsExpression* exp )
 {
   if ( exp->rootNode() )
-    return compile( exp->rootNode(), mResult );
+    return compileNode( exp->rootNode(), mResult );
   else
     return Fail;
 }
@@ -69,7 +69,7 @@ QString QgsSqlExpressionCompiler::quotedValue( const QVariant& value )
   }
 }
 
-QgsSqlExpressionCompiler::Result QgsSqlExpressionCompiler::compile( const QgsExpression::Node* node, QString& result )
+QgsSqlExpressionCompiler::Result QgsSqlExpressionCompiler::compileNode( const QgsExpression::Node* node, QString& result )
 {
   switch ( node->nodeType() )
   {
@@ -133,18 +133,26 @@ QgsSqlExpressionCompiler::Result QgsSqlExpressionCompiler::compile( const QgsExp
 
         case QgsExpression::boLike:
           op = "LIKE";
+          partialCompilation = mFlags.testFlag( LikeIsCaseInsensitive );
           break;
 
         case QgsExpression::boILike:
-          op = "ILIKE";
+          if ( mFlags.testFlag( LikeIsCaseInsensitive ) )
+            op = "LIKE";
+          else
+            op = "ILIKE";
           break;
 
         case QgsExpression::boNotLike:
           op = "NOT LIKE";
+          partialCompilation = mFlags.testFlag( LikeIsCaseInsensitive );
           break;
 
         case QgsExpression::boNotILike:
-          op = "NOT ILIKE";
+          if ( mFlags.testFlag( LikeIsCaseInsensitive ) )
+            op = "NOT LIKE";
+          else
+            op = "NOT ILIKE";
           break;
 
         case QgsExpression::boOr:
@@ -198,10 +206,10 @@ QgsSqlExpressionCompiler::Result QgsSqlExpressionCompiler::compile( const QgsExp
         return Fail;
 
       QString left;
-      Result lr( compile( n->opLeft(), left ) );
+      Result lr( compileNode( n->opLeft(), left ) );
 
       QString right;
-      Result rr( compile( n->opRight(), right ) );
+      Result rr( compileNode( n->opRight(), right ) );
 
       result = left + ' ' + op + ' ' + right;
       if ( lr == Complete && rr == Complete )
@@ -251,7 +259,7 @@ QgsSqlExpressionCompiler::Result QgsSqlExpressionCompiler::compile( const QgsExp
       Q_FOREACH ( const QgsExpression::Node* ln, n->list()->list() )
       {
         QString s;
-        Result r = compile( ln, s );
+        Result r = compileNode( ln, s );
         if ( r == Complete || r == Partial )
         {
           list << s;
@@ -263,7 +271,7 @@ QgsSqlExpressionCompiler::Result QgsSqlExpressionCompiler::compile( const QgsExp
       }
 
       QString nd;
-      Result rn = compile( n->node(), nd );
+      Result rn = compileNode( n->node(), nd );
       if ( rn != Complete && rn != Partial )
         return rn;
 

diff --git a/src/core/qgssqlexpressioncompiler.h b/src/core/qgssqlexpressioncompiler.h
@@ -47,7 +47,8 @@ class CORE_EXPORT QgsSqlExpressionCompiler
      */
     enum Flag
     {
-      CaseInsensitiveStringMatch = 0x01,  //!< Provider performs case-insensitive string matching
+      CaseInsensitiveStringMatch = 0x01,  //!< Provider performs case-insensitive string matching for all strings
+      LikeIsCaseInsensitive = 0x02, //!< Provider treats LIKE as case-insensitive
     };
     Q_DECLARE_FLAGS( Flags, Flag )
 
@@ -86,7 +87,7 @@ class CORE_EXPORT QgsSqlExpressionCompiler
      * @param str string representing compiled node should be stored in this parameter
      * @returns result of node compilation
      */
-    virtual Result compile( const QgsExpression::Node* node, QString& str );
+    virtual Result compileNode( const QgsExpression::Node* node, QString& str );
 
     QString mResult;
     QgsFields mFields;

diff --git a/src/providers/ogr/qgsogrexpressioncompiler.cpp b/src/providers/ogr/qgsogrexpressioncompiler.cpp
@@ -23,7 +23,7 @@ QgsOgrExpressionCompiler::QgsOgrExpressionCompiler( QgsOgrFeatureSource* source
 }
 
 
-QgsOgrExpressionCompiler::Result QgsOgrExpressionCompiler::compile( const QgsExpression* exp )
+QgsSqlExpressionCompiler::Result QgsOgrExpressionCompiler::compile( const QgsExpression* exp )
 {
   //for certain driver types, OGR forwards SQL through to the underlying provider. In these cases
   //the syntax may differ from OGR SQL, so we don't support compilation for these drivers
@@ -46,7 +46,7 @@ QgsOgrExpressionCompiler::Result QgsOgrExpressionCompiler::compile( const QgsExp
   return QgsSqlExpressionCompiler::compile( exp );
 }
 
-QgsOgrExpressionCompiler::Result QgsOgrExpressionCompiler::compile( const QgsExpression::Node* node, QString& result )
+QgsSqlExpressionCompiler::Result QgsOgrExpressionCompiler::compileNode( const QgsExpression::Node* node, QString& result )
 {
   switch ( node->nodeType() )
   {
@@ -68,7 +68,7 @@ QgsOgrExpressionCompiler::Result QgsOgrExpressionCompiler::compile( const QgsExp
 
         default:
           //fallback to default handling
-          return QgsSqlExpressionCompiler::compile( node, result );
+          return QgsSqlExpressionCompiler::compileNode( node, result );
       }
     }
 
@@ -78,10 +78,10 @@ QgsOgrExpressionCompiler::Result QgsOgrExpressionCompiler::compile( const QgsExp
       return Fail;
 
     default:
-      return QgsSqlExpressionCompiler::compile( node, result );
+      return QgsSqlExpressionCompiler::compileNode( node, result );
   }
 
-  return QgsSqlExpressionCompiler::compile( node, result );
+  return QgsSqlExpressionCompiler::compileNode( node, result );
 }
 
 QString QgsOgrExpressionCompiler::quotedIdentifier( const QString& identifier )

diff --git a/src/providers/ogr/qgsogrexpressioncompiler.h b/src/providers/ogr/qgsogrexpressioncompiler.h
@@ -26,11 +26,11 @@ class QgsOgrExpressionCompiler : public QgsSqlExpressionCompiler
 
     explicit QgsOgrExpressionCompiler( QgsOgrFeatureSource* source );
 
-    Result compile( const QgsExpression* exp ) override;
+    virtual Result compile( const QgsExpression* exp ) override;
 
   protected:
 
-    Result compile( const QgsExpression::Node* node, QString& str ) override;
+    virtual Result compileNode( const QgsExpression::Node* node, QString& str ) override;
     virtual QString quotedIdentifier( const QString& identifier ) override;
     virtual QString quotedValue( const QVariant& value ) override;
 

diff --git a/src/providers/ogr/qgsogrfeatureiterator.cpp b/src/providers/ogr/qgsogrfeatureiterator.cpp
@@ -88,15 +88,15 @@ QgsOgrFeatureIterator::QgsOgrFeatureIterator( QgsOgrFeatureSource* source, bool
   {
     QgsOgrExpressionCompiler compiler = QgsOgrExpressionCompiler( source );
 
-    QgsOgrExpressionCompiler::Result result = compiler.compile( request.filterExpression() );
+    QgsSqlExpressionCompiler::Result result = compiler.compile( request.filterExpression() );
 
-    if ( result == QgsOgrExpressionCompiler::Complete || result == QgsOgrExpressionCompiler::Partial )
+    if ( result == QgsSqlExpressionCompiler::Complete || result == QgsSqlExpressionCompiler::Partial )
     {
       QString whereClause = compiler.result();
       if ( OGR_L_SetAttributeFilter( ogrLayer, whereClause.toLocal8Bit().data() ) == OGRERR_NONE )
       {
         //if only partial success when compiling expression, we need to double-check results using QGIS' expressions
-        mExpressionCompiled = ( result == QgsOgrExpressionCompiler::Complete );
+        mExpressionCompiled = ( result == QgsSqlExpressionCompiler::Complete );
       }
     }
     else

diff --git a/src/providers/spatialite/CMakeLists.txt b/src/providers/spatialite/CMakeLists.txt
@@ -10,6 +10,7 @@ SET(SPATIALITE_SRCS
   qgsspatialitedataitems.cpp
   qgsspatialiteconnection.cpp
   qgsspatialiteconnpool.cpp
+  qgsspatialiteexpressioncompiler.cpp
   qgsspatialitefeatureiterator.cpp
   qgsspatialitesourceselect.cpp
   qgsspatialitetablemodel.cpp

diff --git a/src/providers/spatialite/qgsspatialiteexpressioncompiler.cpp b/src/providers/spatialite/qgsspatialiteexpressioncompiler.cpp
@@ -0,0 +1,80 @@
+/***************************************************************************
+                             qgsspatialiteexpressioncompiler.cpp
+                             -----------------------------------
+    begin                : November 2015
+    copyright            : (C) 2015 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 "qgsspatialiteexpressioncompiler.h"
+#include "qgssqlexpressioncompiler.h"
+#include "qgsspatialiteprovider.h"
+
+QgsSpatiaLiteExpressionCompiler::QgsSpatiaLiteExpressionCompiler( QgsSpatiaLiteFeatureSource* source )
+    : QgsSqlExpressionCompiler( source->mFields, QgsSqlExpressionCompiler::LikeIsCaseInsensitive )
+{
+}
+
+QgsSqlExpressionCompiler::Result QgsSpatiaLiteExpressionCompiler::compileNode( const QgsExpression::Node* node, QString& result )
+{
+  switch ( node->nodeType() )
+  {
+    case QgsExpression::ntBinaryOperator:
+    {
+      switch ( static_cast<const QgsExpression::NodeBinaryOperator*>( node )->op() )
+      {
+        case QgsExpression::boPow:
+        case QgsExpression::boRegexp:
+          return Fail; //not supported by SQLite
+
+        default:
+          //fallback to default handling
+          return QgsSqlExpressionCompiler::compileNode( node, result );
+      }
+    }
+
+    default:
+      return QgsSqlExpressionCompiler::compileNode( node, result );
+  }
+
+  return QgsSqlExpressionCompiler::compileNode( node, result );
+}
+
+QString QgsSpatiaLiteExpressionCompiler::quotedIdentifier( const QString& identifier )
+{
+  return QgsSpatiaLiteProvider::quotedIdentifier( identifier );
+}
+
+QString QgsSpatiaLiteExpressionCompiler::quotedValue( const QVariant& value )
+{
+  if ( value.isNull() )
+    return "NULL";
+
+  switch ( value.type() )
+  {
+    case QVariant::Int:
+    case QVariant::LongLong:
+    case QVariant::Double:
+      return value.toString();
+
+    case QVariant::Bool:
+      //SQLite has no boolean literals
+      return value.toBool() ? "1" : "0";
+
+    default:
+    case QVariant::String:
+      QString v = value.toString();
+      v.replace( '\'', "''" );
+      if ( v.contains( '\\' ) )
+        return v.replace( '\\', "\\\\" ).prepend( "E'" ).append( '\'' );
+      else
+        return v.prepend( '\'' ).append( '\'' );
+  }
+}
diff --git a/src/providers/spatialite/qgsspatialiteexpressioncompiler.h b/src/providers/spatialite/qgsspatialiteexpressioncompiler.h
@@ -0,0 +1,37 @@
+/***************************************************************************
+                             qgsspatialiteexpressioncompiler.h
+                             ---------------------------------
+    begin                : November 2015
+    copyright            : (C) 2015 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 QGSSPATIALITEEXPRESSIONCOMPILER_H
+#define QGSSPATIALITEEXPRESSIONCOMPILER_H
+
+#include "qgssqlexpressioncompiler.h"
+#include "qgsexpression.h"
+#include "qgsspatialitefeatureiterator.h"
+
+class QgsSpatiaLiteExpressionCompiler : public QgsSqlExpressionCompiler
+{
+  public:
+
+    explicit QgsSpatiaLiteExpressionCompiler( QgsSpatiaLiteFeatureSource* source );
+
+  protected:
+
+    virtual Result compileNode( const QgsExpression::Node* node, QString& str ) override;
+    virtual QString quotedIdentifier( const QString& identifier ) override;
+    virtual QString quotedValue( const QVariant& value ) override;
+
+};
+
+#endif // QGSSPATIALITEEXPRESSIONCOMPILER_H
diff --git a/src/providers/spatialite/qgsspatialitefeatureiterator.cpp b/src/providers/spatialite/qgsspatialitefeatureiterator.cpp
@@ -17,6 +17,7 @@
 #include "qgsspatialiteconnection.h"
 #include "qgsspatialiteconnpool.h"
 #include "qgsspatialiteprovider.h"
+#include "qgsspatialiteexpressioncompiler.h"
 
 #include "qgslogger.h"
 #include "qgsmessagelog.h"
@@ -26,6 +27,7 @@
 QgsSpatiaLiteFeatureIterator::QgsSpatiaLiteFeatureIterator( QgsSpatiaLiteFeatureSource* source, bool ownSource, const QgsFeatureRequest& request )
     : QgsAbstractFeatureIteratorFromSource<QgsSpatiaLiteFeatureSource>( source, ownSource, request )
     , sqliteStatement( NULL )
+    , mExpressionCompiled( false )
 {
 
   mHandle = QgsSpatiaLiteConnPool::instance()->acquireConnection( mSource->mSqlitePath );
@@ -62,6 +64,23 @@ QgsSpatiaLiteFeatureIterator::QgsSpatiaLiteFeatureIterator( QgsSpatiaLiteFeature
       whereClauses.append( whereClause );
     }
   }
+  else if ( request.filterType() == QgsFeatureRequest::FilterExpression )
+  {
+    QgsSpatiaLiteExpressionCompiler compiler = QgsSpatiaLiteExpressionCompiler( source );
+
+    QgsSqlExpressionCompiler::Result result = compiler.compile( request.filterExpression() );
+
+    if ( result == QgsSqlExpressionCompiler::Complete || result == QgsSqlExpressionCompiler::Partial )
+    {
+      whereClause = compiler.result();
+      if ( !whereClause.isEmpty() )
+      {
+        whereClauses.append( whereClause );
+        //if only partial success when compiling expression, we need to double-check results using QGIS' expressions
+        mExpressionCompiled = ( result == QgsSqlExpressionCompiler::Complete );
+      }
+    }
+  }
 
   if ( !mSource->mSubsetString.isEmpty() )
   {
@@ -116,6 +135,14 @@ bool QgsSpatiaLiteFeatureIterator::fetchFeature( QgsFeature& feature )
   return true;
 }
 
+bool QgsSpatiaLiteFeatureIterator::nextFeatureFilterExpression( QgsFeature& f )
+{
+  if ( !mExpressionCompiled )
+    return QgsAbstractFeatureIterator::nextFeatureFilterExpression( f );
+  else
+    return fetchFeature( f );
+}
+
 
 bool QgsSpatiaLiteFeatureIterator::rewind()
 {

diff --git a/src/providers/spatialite/qgsspatialitefeatureiterator.h b/src/providers/spatialite/qgsspatialitefeatureiterator.h
@@ -49,6 +49,7 @@ class QgsSpatiaLiteFeatureSource : public QgsAbstractFeatureSource
     QString mSqlitePath;
 
     friend class QgsSpatiaLiteFeatureIterator;
+    friend class QgsSpatiaLiteExpressionCompiler;
 };
 
 class QgsSpatiaLiteFeatureIterator : public QgsAbstractFeatureIteratorFromSource<QgsSpatiaLiteFeatureSource>
@@ -69,6 +70,9 @@ class QgsSpatiaLiteFeatureIterator : public QgsAbstractFeatureIteratorFromSource
     //! fetch next feature, return true on success
     virtual bool fetchFeature( QgsFeature& feature ) override;
 
+    //! fetch next feature filter expression
+    bool nextFeatureFilterExpression( QgsFeature& f ) override;
+
     QString whereClauseRect();
     QString whereClauseFid();
     QString whereClauseFids();
@@ -96,6 +100,10 @@ class QgsSpatiaLiteFeatureIterator : public QgsAbstractFeatureIteratorFromSource
 
     bool mHasPrimaryKey;
     QgsFeatureId mRowNumber;
+
+  private:
+
+    bool mExpressionCompiled;
 };
 
 #endif // QGSSPATIALITEFEATUREITERATOR_H