Add 'gdal vector select' (extracting --fields functionality from 'gdal vector filter')

Author: rouault

apps/CMakeLists.txt

@@ -31,6 +31,7 @@ add_library(
   gdalalg_vector_read.cpp
   gdalalg_vector_filter.cpp
   gdalalg_vector_reproject.cpp
+  gdalalg_vector_select.cpp
   gdalalg_vector_sql.cpp
   gdalalg_vector_write.cpp
   gdalinfo_lib.cpp

apps/gdalalg_vector.cpp

@@ -18,6 +18,7 @@
 #include "gdalalg_vector_pipeline.h"
 #include "gdalalg_vector_filter.h"
 #include "gdalalg_vector_reproject.h"
+#include "gdalalg_vector_select.h"
 #include "gdalalg_vector_sql.h"
 
 /************************************************************************/
@@ -44,6 +45,7 @@ class GDALVectorAlgorithm final : public GDALAlgorithm
         RegisterSubAlgorithm<GDALVectorPipelineAlgorithm>();
         RegisterSubAlgorithm<GDALVectorFilterAlgorithmStandalone>();
         RegisterSubAlgorithm<GDALVectorReprojectAlgorithmStandalone>();
+        RegisterSubAlgorithm<GDALVectorSelectAlgorithmStandalone>();
         RegisterSubAlgorithm<GDALVectorSQLAlgorithmStandalone>();
     }
 

apps/gdalalg_vector_filter.cpp

@@ -40,209 +40,8 @@ GDALVectorFilterAlgorithm::GDALVectorFilterAlgorithm(bool standaloneStep)
         .SetReadFromFileAtSyntaxAllowed()
         .SetMetaVar("<WHERE>|@<filename>")
         .SetRemoveSQLCommentsEnabled();
-    AddArg("fields", 0, _("Selected fields"), &m_selectedFields);
 }
 
-namespace
-{
-
-/************************************************************************/
-/*                   GDALVectorFilterAlgorithmLayer                     */
-/************************************************************************/
-
-class GDALVectorFilterAlgorithmLayer final
-    : public OGRLayer,
-      public OGRGetNextFeatureThroughRaw<GDALVectorFilterAlgorithmLayer>
-{
-  private:
-    bool m_bIsOK = true;
-    OGRLayer *const m_poSrcLayer;
-    OGRFeatureDefn *const m_poFeatureDefn = nullptr;
-    std::vector<int> m_anMapSrcFieldsToDstFields{};
-    std::vector<int> m_anMapDstGeomFieldsToSrcGeomFields{};
-
-    CPL_DISALLOW_COPY_ASSIGN(GDALVectorFilterAlgorithmLayer)
-
-    std::unique_ptr<OGRFeature> TranslateFeature(OGRFeature *poSrcFeature) const
-    {
-        auto poFeature = std::make_unique<OGRFeature>(m_poFeatureDefn);
-        poFeature->SetFID(poSrcFeature->GetFID());
-        const auto styleString = poSrcFeature->GetStyleString();
-        if (styleString)
-            poFeature->SetStyleString(styleString);
-        poFeature->SetFieldsFrom(
-            poSrcFeature, m_anMapSrcFieldsToDstFields.data(), false, false);
-        int iDstGeomField = 0;
-        for (int nSrcGeomField : m_anMapDstGeomFieldsToSrcGeomFields)
-        {
-            poFeature->SetGeomFieldDirectly(
-                iDstGeomField, poSrcFeature->StealGeometry(nSrcGeomField));
-            ++iDstGeomField;
-        }
-        return poFeature;
-    }
-
-    DEFINE_GET_NEXT_FEATURE_THROUGH_RAW(GDALVectorFilterAlgorithmLayer)
-
-  public:
-    GDALVectorFilterAlgorithmLayer(
-        OGRLayer *poSrcLayer, const std::vector<std::string> &selectedFields,
-        bool bStrict)
-        : m_poSrcLayer(poSrcLayer),
-          m_poFeatureDefn(new OGRFeatureDefn(poSrcLayer->GetName()))
-    {
-        SetDescription(poSrcLayer->GetDescription());
-        m_poFeatureDefn->SetGeomType(wkbNone);
-        m_poFeatureDefn->Reference();
-
-        std::set<std::string> oSetSelFields;
-        std::set<std::string> oSetSelFieldsUC;
-        for (const std::string &osFieldName : selectedFields)
-        {
-            oSetSelFields.insert(osFieldName);
-            oSetSelFieldsUC.insert(CPLString(osFieldName).toupper());
-        }
-
-        std::set<std::string> oSetUsedSetFieldsUC;
-
-        const auto poSrcLayerDefn = poSrcLayer->GetLayerDefn();
-        for (int i = 0; i < poSrcLayerDefn->GetFieldCount(); ++i)
-        {
-            const auto poSrcFieldDefn = poSrcLayerDefn->GetFieldDefn(i);
-            auto oIter = oSetSelFieldsUC.find(
-                CPLString(poSrcFieldDefn->GetNameRef()).toupper());
-            if (oIter != oSetSelFieldsUC.end())
-            {
-                m_anMapSrcFieldsToDstFields.push_back(
-                    m_poFeatureDefn->GetFieldCount());
-                OGRFieldDefn oDstFieldDefn(*poSrcFieldDefn);
-                m_poFeatureDefn->AddFieldDefn(&oDstFieldDefn);
-                oSetUsedSetFieldsUC.insert(*oIter);
-            }
-            else
-            {
-                m_anMapSrcFieldsToDstFields.push_back(-1);
-            }
-        }
-
-        for (int i = 0; i < poSrcLayerDefn->GetGeomFieldCount(); ++i)
-        {
-            const auto poSrcFieldDefn = poSrcLayerDefn->GetGeomFieldDefn(i);
-            auto oIter = oSetSelFieldsUC.find(
-                CPLString(poSrcFieldDefn->GetNameRef()).toupper());
-            if (oIter != oSetSelFieldsUC.end())
-            {
-                m_anMapDstGeomFieldsToSrcGeomFields.push_back(i);
-                OGRGeomFieldDefn oDstFieldDefn(*poSrcFieldDefn);
-                m_poFeatureDefn->AddGeomFieldDefn(&oDstFieldDefn);
-                oSetUsedSetFieldsUC.insert(*oIter);
-            }
-        }
-
-        auto oIter = oSetSelFieldsUC.find(
-            CPLString(OGR_GEOMETRY_DEFAULT_NON_EMPTY_NAME).toupper());
-        if (m_poFeatureDefn->GetGeomFieldCount() == 0 &&
-            oIter != oSetSelFieldsUC.end() &&
-            poSrcLayerDefn->GetGeomFieldCount() == 1)
-        {
-            const auto poSrcFieldDefn = poSrcLayerDefn->GetGeomFieldDefn(0);
-            m_anMapDstGeomFieldsToSrcGeomFields.push_back(0);
-            OGRGeomFieldDefn oDstFieldDefn(*poSrcFieldDefn);
-            m_poFeatureDefn->AddGeomFieldDefn(&oDstFieldDefn);
-            oSetUsedSetFieldsUC.insert(*oIter);
-        }
-
-        if (oSetUsedSetFieldsUC.size() != oSetSelFields.size())
-        {
-            for (const std::string &osName : oSetSelFields)
-            {
-                if (!cpl::contains(oSetUsedSetFieldsUC,
-                                   CPLString(osName).toupper()))
-                {
-                    CPLError(bStrict ? CE_Failure : CE_Warning, CPLE_AppDefined,
-                             "Field '%s' does not exist in layer '%s'.%s",
-                             osName.c_str(), poSrcLayer->GetDescription(),
-                             bStrict ? "" : " It will be ignored");
-                    if (bStrict)
-                        m_bIsOK = false;
-                }
-            }
-        }
-    }
-
-    ~GDALVectorFilterAlgorithmLayer() override
-    {
-        if (m_poFeatureDefn)
-            m_poFeatureDefn->Dereference();
-    }
-
-    bool IsOK() const
-    {
-        return m_bIsOK;
-    }
-
-    OGRFeatureDefn *GetLayerDefn() override
-    {
-        return m_poFeatureDefn;
-    }
-
-    GIntBig GetFeatureCount(int bForce) override
-    {
-        if (!m_poAttrQuery && !m_poFilterGeom)
-            return m_poSrcLayer->GetFeatureCount(bForce);
-        return OGRLayer::GetFeatureCount(bForce);
-    }
-
-    OGRErr GetExtent(OGREnvelope *psExtent, int bForce) override
-    {
-        return m_poSrcLayer->GetExtent(psExtent, bForce);
-    }
-
-    OGRErr GetExtent(int iGeomField, OGREnvelope *psExtent, int bForce) override
-    {
-        return m_poSrcLayer->GetExtent(iGeomField, psExtent, bForce);
-    }
-
-    void ResetReading() override
-    {
-        m_poSrcLayer->ResetReading();
-    }
-
-    OGRFeature *GetNextRawFeature()
-    {
-        auto poSrcFeature =
-            std::unique_ptr<OGRFeature>(m_poSrcLayer->GetNextFeature());
-        if (!poSrcFeature)
-            return nullptr;
-        return TranslateFeature(poSrcFeature.get()).release();
-    }
-
-    OGRFeature *GetFeature(GIntBig nFID) override
-    {
-        auto poSrcFeature =
-            std::unique_ptr<OGRFeature>(m_poSrcLayer->GetFeature(nFID));
-        if (!poSrcFeature)
-            return nullptr;
-        return TranslateFeature(poSrcFeature.get()).release();
-    }
-
-    int TestCapability(const char *pszCap) override
-    {
-        if (EQUAL(pszCap, OLCRandomRead) || EQUAL(pszCap, OLCCurveGeometries) ||
-            EQUAL(pszCap, OLCMeasuredGeometries) ||
-            EQUAL(pszCap, OLCZGeometries) ||
-            (EQUAL(pszCap, OLCFastFeatureCount) && !m_poAttrQuery &&
-             !m_poFilterGeom) ||
-            EQUAL(pszCap, OLCFastGetExtent) || EQUAL(pszCap, OLCStringsAsUTF8))
-        {
-            return m_poSrcLayer->TestCapability(pszCap);
-        }
-        return false;
-    }
-};
-
-}  // namespace
-
 /************************************************************************/
 /*               GDALVectorFilterAlgorithm::RunStep()                   */
 /************************************************************************/
@@ -284,30 +83,7 @@ bool GDALVectorFilterAlgorithm::RunStep(GDALProgressFunc, void *)
         }
     }
 
-    if (ret && !m_selectedFields.empty())
-    {
-        auto outDS = std::make_unique<GDALVectorPipelineOutputDataset>();
-        outDS->SetDescription(poSrcDS->GetDescription());
-
-        for (int i = 0; i < nLayerCount; ++i)
-        {
-            auto poSrcLayer = poSrcDS->GetLayer(i);
-            ret = ret && (poSrcLayer != nullptr);
-            if (ret)
-            {
-                auto poLayer = std::make_unique<GDALVectorFilterAlgorithmLayer>(
-                    poSrcLayer, m_selectedFields, /* bStrict = */ true);
-                ret = poLayer->IsOK();
-                if (ret)
-                {
-                    outDS->AddLayer(std::move(poLayer));
-                }
-            }
-        }
-
-        m_outputDataset.Set(std::move(outDS));
-    }
-    else if (ret)
+    if (ret)
     {
         m_outputDataset.Set(m_inputDataset.GetDatasetRef());
     }

apps/gdalalg_vector_filter.h

@@ -27,8 +27,7 @@ class GDALVectorFilterAlgorithm /* non final */
   public:
     static constexpr const char *NAME = "filter";
     static constexpr const char *DESCRIPTION = "Filter a vector dataset.";
-    static constexpr const char *HELP_URL =
-        "/programs/gdal_vector_pipeline.html";
+    static constexpr const char *HELP_URL = "/programs/gdal_vector_filter.html";
 
     static std::vector<std::string> GetAliases()
     {
@@ -42,7 +41,6 @@ class GDALVectorFilterAlgorithm /* non final */
 
     std::vector<double> m_bbox{};
     std::string m_where{};
-    std::vector<std::string> m_selectedFields{};
 };
 
 /************************************************************************/

apps/gdalalg_vector_pipeline.cpp

@@ -15,6 +15,7 @@
 #include "gdalalg_vector_clip.h"
 #include "gdalalg_vector_filter.h"
 #include "gdalalg_vector_reproject.h"
+#include "gdalalg_vector_select.h"
 #include "gdalalg_vector_sql.h"
 #include "gdalalg_vector_write.h"
 
@@ -193,6 +194,7 @@ GDALVectorPipelineAlgorithm::GDALVectorPipelineAlgorithm()
     m_stepRegistry.Register<GDALVectorClipAlgorithm>();
     m_stepRegistry.Register<GDALVectorReprojectAlgorithm>();
     m_stepRegistry.Register<GDALVectorFilterAlgorithm>();
+    m_stepRegistry.Register<GDALVectorSelectAlgorithm>();
     m_stepRegistry.Register<GDALVectorSQLAlgorithm>();
 }