eckit::geo iterator

CMakeLists.txt

@@ -112,6 +112,14 @@ ecbuild_add_option( FEATURE GEOGRAPHY
     DESCRIPTION "Support for Geoiterator and nearest neighbour"
     DEFAULT ON )
 
+ecbuild_add_option( FEATURE ECKIT_GEO
+    DESCRIPTION "Support for Geoiterator and nearest neighbour (additional backend)"
+    CONDITION ENABLE_GEOGRAPHY
+    DEFAULT OFF )
+if( ECKIT_GEO AND NOT TARGET eckit_geo )
+    find_library(ECKIT_GEO_LIB NAMES eckit_geo REQUIRED)
+endif()
+
 ecbuild_add_option( FEATURE JPG
     DESCRIPTION "Support for JPG decoding/encoding"
     DEFAULT ON )
@@ -485,7 +493,7 @@ ecbuild_pkgconfig(
   IGNORE_INCLUDE_DIRS ${PYTHON_INCLUDE_DIRS} ${NUMPY_INCLUDE_DIRS} ${NETCDF_INCLUDE_DIRS}
   VARIABLES      HAVE_MEMFS HAVE_GEOGRAPHY HAVE_JPEG HAVE_LIBJASPER HAVE_LIBOPENJPEG
                  HAVE_ECCODES_THREADS HAVE_ECCODES_OMP_THREADS
-                 HAVE_NETCDF HAVE_FORTRAN HAVE_PNG HAVE_AEC
+                 HAVE_NETCDF HAVE_FORTRAN HAVE_PNG HAVE_AEC HAVE_ECKIT_GEO
 )
 if( HAVE_FORTRAN )
   ecbuild_pkgconfig(
@@ -497,7 +505,7 @@ if( HAVE_FORTRAN )
                         ${PYTHON_INCLUDE_DIRS} ${NUMPY_INCLUDE_DIRS} ${NETCDF_INCLUDE_DIRS}
     VARIABLES           HAVE_MEMFS HAVE_GEOGRAPHY HAVE_JPEG HAVE_LIBJASPER HAVE_LIBOPENJPEG
                         HAVE_ECCODES_THREADS HAVE_ECCODES_OMP_THREADS
-                        HAVE_NETCDF HAVE_PNG HAVE_AEC
+                        HAVE_NETCDF HAVE_PNG HAVE_AEC HAVE_ECKIT_GEO
   )
 endif()
 

eccodes_config.h.in

@@ -114,6 +114,7 @@
 #cmakedefine HAVE_NETCDF
 
 #cmakedefine HAVE_GEOGRAPHY
+#cmakedefine HAVE_ECKIT_GEO
 #cmakedefine HAVE_MEMFS
 #cmakedefine HAVE_FORTRAN
 

src/CMakeLists.txt

@@ -411,6 +411,15 @@ if( HAVE_MEMFS )
     list(APPEND ECCODES_EXTRA_LIBRARIES eccodes_memfs)
 endif()
 
+if( eccodes_HAVE_GEOGRAPHY AND eccodes_HAVE_ECKIT_GEO )
+    list( APPEND eccodes_src_files
+        eccodes/geo/GeoIterator.cc
+        eccodes/geo/GeoIterator.h
+        eccodes/geo/GribSpec.cc
+        eccodes/geo/GribSpec.h )
+    list( APPEND ECCODES_EXTRA_LIBRARIES eckit_geo )
+endif()
+
 ecbuild_add_library( TARGET    eccodes
                      SOURCES   ${CMAKE_CURRENT_BINARY_DIR}/grib_api_version.cc
                               # griby.cc gribl.cc

src/eccodes/geo/GeoIterator.cc

@@ -0,0 +1,104 @@
+/*
+ * (C) Copyright 2024- ECMWF.
+ *
+ * This software is licensed under the terms of the Apache Licence Version 2.0
+ * which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * In applying this licence, ECMWF does not waive the privileges and immunities granted to it by
+ * virtue of its status as an intergovernmental organisation nor does it submit to any jurisdiction.
+ */
+
+
+#include "eccodes/geo/GeoIterator.h"
+
+#include "eckit/exception/Exceptions.h"
+
+#include "eccodes/geo/GribSpec.h"
+
+
+namespace eccodes::geo
+{
+
+
+GeoIterator::GeoIterator(grib_handle* h, unsigned long flags) :
+    spec_(new GribSpec(h)), grid_(eckit::geo::GridFactory::build(*spec_)), iter_(grid_->cbegin().release()), end_(grid_->cend().release())
+{
+    h_          = h;
+    class_name_ = "geo_iterator";
+    flags_      = flags;
+    Assert(h_ != nullptr);
+
+    CODES_CHECK(codes_get_size(h_, "values", &nv_), "");
+    Assert(nv_ > 0);
+
+    data_ = (flags_ & GRIB_GEOITERATOR_NO_VALUES) ? nullptr : static_cast<double*>(grib_context_malloc(h_->context, nv_ * sizeof(double)));
+    Assert(data_ != nullptr);
+
+    auto size = nv_;
+    CODES_CHECK(codes_get_double_array(h_, "values", data_, &size), "");
+    Assert(nv_ == size);
+}
+
+
+int GeoIterator::init(grib_handle*, grib_arguments*)
+{
+    NOTIMP;
+}
+
+
+int GeoIterator::next(double* lat, double* lon, double* val) const
+{
+    if (iter_ == end_) {
+        return 0;  // (false)
+    }
+
+    const auto p  = *iter_;
+    const auto& q = std::get<eckit::geo::PointLonLat>(p);
+
+    *lat = q.lat;
+    *lon = q.lon;
+    if (val != nullptr && data_ != nullptr) {
+        *val = data_[iter_->index()];
+    }
+
+    ++iter_;
+    return 1;  // (true)
+}
+
+
+int GeoIterator::previous(double*, double*, double*) const
+{
+    return GRIB_NOT_IMPLEMENTED;
+}
+
+
+int GeoIterator::reset()
+{
+    iter_.reset(grid_->cbegin().release());
+    return GRIB_SUCCESS;
+}
+
+
+int GeoIterator::destroy()
+{
+    if (data_ != nullptr) {
+        grib_context_free(h_->context, data_);
+    }
+    return Iterator::destroy();
+}
+
+
+bool GeoIterator::has_next() const
+{
+    return iter_ != end_;
+}
+
+
+geo_iterator::Iterator*
+GeoIterator::create() const
+{
+    return new GeoIterator{ h_, flags_ };
+}
+
+
+}  // namespace eccodes::geo

src/eccodes/geo/GeoIterator.h

@@ -0,0 +1,51 @@
+/*
+ * (C) Copyright 2024- ECMWF.
+ *
+ * This software is licensed under the terms of the Apache Licence Version 2.0
+ * which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * In applying this licence, ECMWF does not waive the privileges and immunities granted to it by
+ * virtue of its status as an intergovernmental organisation nor does it submit to any jurisdiction.
+ */
+
+
+#pragma once
+
+#include <memory>
+
+#include "eckit/geo/Grid.h"
+
+// eccodes macros conflict with eckit
+#ifdef Assert
+    #undef Assert
+#endif
+
+#include "geo_iterator/grib_iterator.h"
+
+
+namespace eccodes::geo
+{
+
+
+class GeoIterator : public geo_iterator::Iterator
+{
+public:
+    explicit GeoIterator(grib_handle*, unsigned long flags);
+
+private:
+    std::unique_ptr<const eckit::geo::Spec> spec_;
+    std::unique_ptr<const eckit::geo::Grid> grid_;
+    mutable eckit::geo::Grid::Iterator iter_;
+    eckit::geo::Grid::Iterator end_;
+
+    int init(grib_handle*, grib_arguments*) override;
+    int next(double* lat, double* lon, double* val) const override;
+    int previous(double* lat, double* lon, double* val) const override;
+    int reset() override;
+    int destroy() override;
+    bool has_next() const override;
+    geo_iterator::Iterator* create() const override;
+};
+
+
+}  // namespace eccodes::geo