Add support for open options in OGR input plugin

plugins/input/ogr/build.py

@@ -31,6 +31,7 @@ plugin_sources = Split(
   """
   %(PLUGIN_NAME)s_converter.cpp
   %(PLUGIN_NAME)s_datasource.cpp
+  %(PLUGIN_NAME)s_utils.cpp
   %(PLUGIN_NAME)s_featureset.cpp
   %(PLUGIN_NAME)s_index_featureset.cpp
   """ % locals()

plugins/input/ogr/ogr_datasource.cpp

@@ -127,16 +127,23 @@ void ogr_datasource::init(mapnik::parameters const& params)
     }
 
     std::string driver = *params.get<std::string>("driver", "");
+    std::vector<ogr_utils::option_ptr> open_options_map = ogr_utils::split_open_options(*params.get<std::string>("open_options", ""));
+    char** open_options = ogr_utils::open_options_for_ogr(open_options_map);
 
     if (!driver.empty())
     {
         unsigned int nOpenFlags = GDAL_OF_READONLY | GDAL_OF_VECTOR;
         const char* papszAllowedDrivers[] = {driver.c_str(), nullptr};
+
         dataset_ = reinterpret_cast<gdal_dataset_type>(
-          GDALOpenEx(dataset_name_.c_str(), nOpenFlags, papszAllowedDrivers, nullptr, nullptr));
+          GDALOpenEx(dataset_name_.c_str(), nOpenFlags, papszAllowedDrivers, open_options, nullptr));
     }
     else
     {
+        if (open_options[0] != nullptr)
+        {
+            throw datasource_exception("<open_options> parameter provided but <driver> is missing");
+        }
         // open ogr driver
         dataset_ = reinterpret_cast<gdal_dataset_type>(OGROpen(dataset_name_.c_str(), false, nullptr));
     }

plugins/input/ogr/ogr_datasource.hpp

@@ -47,6 +47,7 @@ MAPNIK_DISABLE_WARNING_PUSH
 #include <ogrsf_frmts.h>
 MAPNIK_DISABLE_WARNING_POP
 #include "ogr_layer_ptr.hpp"
+#include "ogr_utils.hpp"
 
 DATASOURCE_PLUGIN_DEF(ogr_datasource_plugin, ogr);
 

plugins/input/ogr/ogr_utils.cpp

@@ -0,0 +1,85 @@
+/*****************************************************************************
+ *
+ * This file is part of Mapnik (c++ mapping toolkit)
+ *
+ * Copyright (C) 2023 Artem Pavlenko
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ *****************************************************************************/
+
+#include "ogr_utils.hpp"
+#include <mapnik/datasource.hpp>
+
+std::vector<ogr_utils::option_ptr> ogr_utils::split_open_options(const std::string& options)
+{
+    size_t i;
+    bool escaped = false; // if previous character was a backslash to escape a backslash or space
+    std::vector<ogr_utils::option_ptr> opts;
+    std::string unescaped_str; // copy of input string but unescaped
+    for (i = 0; i < options.size(); ++i)
+    {
+        char current = options.at(i);
+        if (current == '\\')
+        {
+            if (escaped)
+            {
+                unescaped_str.push_back(current);
+            }
+            escaped = !escaped;
+        }
+        else if (current != ' ') {
+            unescaped_str.push_back(current);
+        }
+        if (current == ' ' || i + 1 == options.size())
+        {
+            if (!escaped) {
+                size_t count = unescaped_str.size();
+                if (count > 0)
+                {
+                    option_ptr opt (new char[count + 1], [](char* arr) { delete[] arr; });
+                    unescaped_str.copy(opt.get(), count);
+                    opt[count] = '\0';
+                    opts.push_back(std::move(opt));
+                }
+                unescaped_str = "";
+            }
+            else
+            {
+                escaped = false;
+                unescaped_str.push_back(current);
+            }
+        }
+    }
+    if (escaped)
+    {
+        throw mapnik::datasource_exception("<open_options> parameter ends with single backslash");
+    }
+    opts.emplace_back(nullptr);
+    return opts;
+}
+
+
+char** ogr_utils::open_options_for_ogr(std::vector<ogr_utils::option_ptr>& options)
+{
+    char** for_ogr = new char*[options.size() + 1];
+    for (size_t i = 0; i < options.size(); ++i)
+    {
+        for_ogr[i] = options.at(i).get();
+    }
+    for_ogr[options.size()] = nullptr;
+    return for_ogr;
+}
+

plugins/input/ogr/ogr_utils.hpp

@@ -0,0 +1,43 @@
+/*****************************************************************************
+ *
+ * This file is part of Mapnik (c++ mapping toolkit)
+ *
+ * Copyright (C) 2023 Artem Pavlenko
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ *****************************************************************************/
+
+#ifndef PLUGINS_INPUT_OGR_OGR_UTILS_HPP_
+#define PLUGINS_INPUT_OGR_OGR_UTILS_HPP_
+
+#include <functional>
+#include <memory>
+#include <string>
+#include <vector>
+
+namespace ogr_utils {
+
+using option_ptr = std::unique_ptr<char[], std::function<void(char*)>>;
+
+std::vector<option_ptr> split_open_options(const std::string& options);
+
+char** open_options_for_ogr(std::vector<ogr_utils::option_ptr>& options);
+
+}  // namespace ogr_utils
+
+
+
+#endif /* PLUGINS_INPUT_OGR_OGR_UTILS_HPP_ */

test/build.py

@@ -35,6 +35,7 @@ else:
     # unit tests
     sources = glob.glob('./unit/*/*.cpp')
     sources.extend(glob.glob('./unit/*.cpp'))
+    sources.append('../plugins/input/ogr/ogr_utils.cpp')
     test_program = test_env_local.Program("./unit/run", source=sources)
     Depends(test_program, env.subst('../src/%s' % env['MAPNIK_LIB_NAME']))
     Depends(test_program, env.subst('../src/json/libmapnik-json${LIBSUFFIX}'))

test/unit/datasource/ogr.cpp

@@ -29,6 +29,19 @@
 #include <mapnik/image_reader.hpp>
 #include <mapnik/image_util.hpp>
 #include <mapnik/datasource_cache.hpp>
+#include "../../../plugins/input/ogr/ogr_utils.hpp"
+
+inline std::vector<ogr_utils::option_ptr> split_options(std::string const& options)
+{
+    return ogr_utils::split_open_options(options);
+}
+
+void assert_option(std::vector<ogr_utils::option_ptr> const& options, size_t const& index, std::string const expected)
+{
+    auto const* opt = options.at(index).get();
+    REQUIRE(opt != nullptr);
+    REQUIRE_FALSE(strcmp(opt, expected.c_str()));
+}
 
 TEST_CASE("ogr")
 {
@@ -57,3 +70,59 @@ TEST_CASE("ogr")
         }
     }
 }
+
+TEST_CASE("ogr open_options")
+{
+    const bool have_ogr_plugin = mapnik::datasource_cache::instance().plugin_registered("ogr");
+    if (have_ogr_plugin)
+    {
+        SECTION("splitting open_options string")
+        {
+            std::string opts = "ZOOM=5";
+            std::vector<ogr_utils::option_ptr> v = split_options(opts);
+            assert_option(v, 0, opts);
+        }
+        SECTION("splitting open_options string with multiple components")
+        {
+            std::string opts = "ZOOM=8 USE_BOUNDS=YES";
+            std::vector<ogr_utils::option_ptr> v = split_options(opts);
+            assert_option(v, 0, "ZOOM=8");
+            assert_option(v, 1, "USE_BOUNDS=YES");
+        }
+        SECTION("open_options string with escaped character")
+        {
+            std::string opts = "MY_KEY=THIS\\ VALUE OTHER_KEY=SOMETHING";
+            std::vector<ogr_utils::option_ptr> v = split_options(opts);
+            assert_option(v, 0, "MY_KEY=THIS VALUE");
+            assert_option(v, 1, "OTHER_KEY=SOMETHING");
+        }
+        SECTION("splitting open_options string with escaping")
+        {
+            std::string opts = "ZOOM=14 FANCY_OPTION=WITH\\ SPACE_VALUE";
+            std::vector<ogr_utils::option_ptr> v = split_options(opts);
+            assert_option(v, 0, "ZOOM=14");
+            assert_option(v, 1, "FANCY_OPTION=WITH SPACE_VALUE");
+        }
+        SECTION("splitting open_options string, starts with space")
+        {
+            std::string opts = " ZOOM=14 K23=V45";
+            std::vector<ogr_utils::option_ptr> v = split_options(opts);
+            assert_option(v, 0, "ZOOM=14");
+            assert_option(v, 1, "K23=V45");
+        }
+        SECTION("splitting open_options string, ends with space")
+        {
+            std::string opts = "ZOOM=14 K23=V46 ";
+            std::vector<ogr_utils::option_ptr> v = split_options(opts);
+            assert_option(v, 0, "ZOOM=14");
+            assert_option(v, 1, "K23=V46");
+        }
+        SECTION("splitting open_options string, doubled space")
+        {
+            std::string opts = "ZOOM=14  K23=V47";
+            std::vector<ogr_utils::option_ptr> v = split_options(opts);
+            assert_option(v, 0, "ZOOM=14");
+            assert_option(v, 1, "K23=V47");
+        }
+    }
+}