Add a plugin mechanism to resource_retriever

resource_retriever/CMakeLists.txt

@@ -17,8 +17,12 @@ find_package(libcurl_vendor REQUIRED)
 find_package(CURL REQUIRED)
 
 # TODO(wjwwood): split cpp and python apis into separate packages
-
-add_library(${PROJECT_NAME} src/retriever.cpp)
+add_library(${PROJECT_NAME}
+  src/retriever.cpp
+  src/plugins/retriever_plugin.cpp
+  src/plugins/filesystem_retriever.cpp
+  src/plugins/curl_retriever.cpp
+)
 target_include_directories(${PROJECT_NAME}
   PUBLIC
     $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>

resource_retriever/include/resource_retriever/exception.hpp

@@ -0,0 +1,49 @@
+// Copyright 2009, Willow Garage, Inc. All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+//    * Redistributions of source code must retain the above copyright
+//      notice, this list of conditions and the following disclaimer.
+//
+//    * Redistributions in binary form must reproduce the above copyright
+//      notice, this list of conditions and the following disclaimer in the
+//      documentation and/or other materials provided with the distribution.
+//
+//    * Neither the name of the  Willow Garage, Inc. nor the names of its
+//      contributors may be used to endorse or promote products derived from
+//      this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+// POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef RESOURCE_RETRIEVER__EXCEPTION_HPP_
+#define RESOURCE_RETRIEVER__EXCEPTION_HPP_
+
+#include <stdexcept>
+#include <string>
+
+#include "resource_retriever/visibility_control.hpp"
+
+namespace resource_retriever
+{
+class RESOURCE_RETRIEVER_PUBLIC Exception : public std::runtime_error
+{
+public:
+  Exception(const std::string & file, const std::string & error_msg)
+  : std::runtime_error("Error retrieving file [" + file + "]: " + error_msg)
+  {
+  }
+};
+}  // namespace resource_retriever
+
+#endif  // RESOURCE_RETRIEVER__EXCEPTION_HPP_

resource_retriever/include/resource_retriever/memory_resource.hpp

@@ -0,0 +1,64 @@
+// Copyright 2009, Willow Garage, Inc. All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+//    * Redistributions of source code must retain the above copyright
+//      notice, this list of conditions and the following disclaimer.
+//
+//    * Redistributions in binary form must reproduce the above copyright
+//      notice, this list of conditions and the following disclaimer in the
+//      documentation and/or other materials provided with the distribution.
+//
+//    * Neither the name of the  Willow Garage, Inc. nor the names of its
+//      contributors may be used to endorse or promote products derived from
+//      this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+// POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef RESOURCE_RETRIEVER__MEMORY_RESOURCE_HPP_
+#define RESOURCE_RETRIEVER__MEMORY_RESOURCE_HPP_
+
+#include <memory>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "resource_retriever/visibility_control.hpp"
+
+namespace resource_retriever
+{
+/**
+ * \brief A combination of a pointer to data in memory along with the data's size.
+ */
+struct RESOURCE_RETRIEVER_PUBLIC MemoryResource
+{
+  explicit MemoryResource(
+    std::string url_in,
+    std::string expanded_url_in,
+    std::vector<uint8_t> data_in)
+  : url(std::move(url_in)),
+    expanded_url(std::move(expanded_url_in)),
+    data(std::move(data_in))
+  {
+  }
+  const std::string url;
+  const std::string expanded_url;
+  const std::vector<uint8_t> data;
+};
+
+using MemoryResourcePtr = std::shared_ptr<MemoryResource>;
+
+}  //  namespace resource_retriever
+
+#endif  // RESOURCE_RETRIEVER__MEMORY_RESOURCE_HPP_

resource_retriever/include/resource_retriever/plugins/curl_retriever.hpp

@@ -0,0 +1,68 @@
+// Copyright 2009, Willow Garage, Inc. All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+//    * Redistributions of source code must retain the above copyright
+//      notice, this list of conditions and the following disclaimer.
+//
+//    * Redistributions in binary form must reproduce the above copyright
+//      notice, this list of conditions and the following disclaimer in the
+//      documentation and/or other materials provided with the distribution.
+//
+//    * Neither the name of the  Willow Garage, Inc. nor the names of its
+//      contributors may be used to endorse or promote products derived from
+//      this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+// POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef RESOURCE_RETRIEVER__PLUGINS__CURL_RETRIEVER_HPP_
+#define RESOURCE_RETRIEVER__PLUGINS__CURL_RETRIEVER_HPP_
+
+#include <string>
+
+#include "resource_retriever/plugins/retriever_plugin.hpp"
+#include "resource_retriever/visibility_control.hpp"
+
+using CURL = void;
+
+namespace resource_retriever::plugins
+{
+
+class RESOURCE_RETRIEVER_PUBLIC CurlRetriever : public RetrieverPlugin
+{
+public:
+  /// Construct a CurlRetriever plugin and initialize libcurl.
+  /**
+   * \throws std::runtime_error if libcurl fails to initialize
+   */
+  CurlRetriever();
+  ~CurlRetriever() override;
+
+  CurlRetriever(const CurlRetriever & ret) = delete;
+  CurlRetriever & operator=(const CurlRetriever & other) = delete;
+
+  CurlRetriever(CurlRetriever && other) noexcept;
+  CurlRetriever & operator=(CurlRetriever && other) noexcept;
+
+  bool can_handle(const std::string & url) override;
+  std::string name() override;
+  MemoryResourcePtr get(const std::string & url) override;
+
+private:
+  CURL * curl_handle_ {nullptr};
+};
+
+}  //  namespace resource_retriever::plugins
+
+#endif  // RESOURCE_RETRIEVER__PLUGINS__CURL_RETRIEVER_HPP_

resource_retriever/include/resource_retriever/plugins/filesystem_retriever.hpp

@@ -0,0 +1,53 @@
+// Copyright 2009, Willow Garage, Inc. All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+//    * Redistributions of source code must retain the above copyright
+//      notice, this list of conditions and the following disclaimer.
+//
+//    * Redistributions in binary form must reproduce the above copyright
+//      notice, this list of conditions and the following disclaimer in the
+//      documentation and/or other materials provided with the distribution.
+//
+//    * Neither the name of the  Willow Garage, Inc. nor the names of its
+//      contributors may be used to endorse or promote products derived from
+//      this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+// POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef RESOURCE_RETRIEVER__PLUGINS__FILESYSTEM_RETRIEVER_HPP_
+#define RESOURCE_RETRIEVER__PLUGINS__FILESYSTEM_RETRIEVER_HPP_
+
+#include <string>
+
+#include "resource_retriever/plugins/retriever_plugin.hpp"
+#include "resource_retriever/visibility_control.hpp"
+
+namespace resource_retriever::plugins
+{
+
+class RESOURCE_RETRIEVER_PUBLIC FilesystemRetriever : public RetrieverPlugin
+{
+public:
+  FilesystemRetriever();
+  ~FilesystemRetriever() override;
+
+  bool can_handle(const std::string & url) override;
+  std::string name() override;
+  MemoryResourcePtr get(const std::string & url) override;
+};
+
+}  //  namespace resource_retriever::plugins
+
+#endif  // RESOURCE_RETRIEVER__PLUGINS__FILESYSTEM_RETRIEVER_HPP_

resource_retriever/include/resource_retriever/plugins/retriever_plugin.hpp

@@ -0,0 +1,55 @@
+// Copyright 2009, Willow Garage, Inc. All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+//    * Redistributions of source code must retain the above copyright
+//      notice, this list of conditions and the following disclaimer.
+//
+//    * Redistributions in binary form must reproduce the above copyright
+//      notice, this list of conditions and the following disclaimer in the
+//      documentation and/or other materials provided with the distribution.
+//
+//    * Neither the name of the  Willow Garage, Inc. nor the names of its
+//      contributors may be used to endorse or promote products derived from
+//      this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+// POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef RESOURCE_RETRIEVER__PLUGINS__RETRIEVER_PLUGIN_HPP_
+#define RESOURCE_RETRIEVER__PLUGINS__RETRIEVER_PLUGIN_HPP_
+
+#include <string>
+
+#include <resource_retriever/memory_resource.hpp>
+#include "resource_retriever/visibility_control.hpp"
+
+namespace resource_retriever::plugins
+{
+std::string expand_package_url(const std::string & url);
+std::string escape_spaces(const std::string & url);
+
+class RESOURCE_RETRIEVER_PUBLIC RetrieverPlugin
+{
+public:
+  RetrieverPlugin();
+  virtual ~RetrieverPlugin() = 0;
+
+  virtual std::string name() = 0;
+  virtual bool can_handle(const std::string & url) = 0;
+  virtual MemoryResourcePtr get(const std::string & url) = 0;
+};
+
+}  //  namespace resource_retriever::plugins
+
+#endif  // RESOURCE_RETRIEVER__PLUGINS__RETRIEVER_PLUGIN_HPP_

resource_retriever/include/resource_retriever/retriever.hpp

@@ -33,30 +33,18 @@
 #include <memory>
 #include <stdexcept>
 #include <string>
+#include <vector>
 
+#include "resource_retriever/plugins/retriever_plugin.hpp"
 #include "resource_retriever/visibility_control.hpp"
 
-using CURL = void;
-
 namespace resource_retriever
 {
-class Exception : public std::runtime_error
-{
-public:
-  Exception(const std::string & file, const std::string & error_msg)
-  : std::runtime_error("Error retrieving file [" + file + "]: " + error_msg)
-  {
-  }
-};
 
-/**
- * \brief A combination of a pointer to data in memory along with the data's size.
- */
-struct MemoryResource
-{
-  std::shared_ptr<uint8_t> data;
-  size_t size {0};
-};
+using RetrieverPluginPtr = std::shared_ptr<plugins::RetrieverPlugin>;
+using RetrieverVec = std::vector<RetrieverPluginPtr>;
+
+RetrieverVec RESOURCE_RETRIEVER_PUBLIC default_plugins();
 
 /**
  * \brief Retrieves files from from a url.  Caches a CURL handle so multiple accesses to a single url
@@ -65,26 +53,20 @@ struct MemoryResource
 class RESOURCE_RETRIEVER_PUBLIC Retriever
 {
 public:
-  Retriever();
+  explicit Retriever(RetrieverVec plugins = default_plugins());
 
   ~Retriever();
 
-  Retriever(const Retriever & ret) = delete;
-  Retriever & operator=(const Retriever & other) = delete;
-
-  Retriever(Retriever && other) noexcept;
-  Retriever & operator=(Retriever && other) noexcept;
-
   /**
    * \brief Get a file and store it in memory
    * \param url The url to retrieve.  package://package/file will be turned into the correct file:// invocation
    * \return The file, loaded into memory
    * \throws resource_retriever::Exception if anything goes wrong.
    */
-  MemoryResource get(const std::string & url);
+  MemoryResourcePtr get(const std::string & url);
 
 private:
-  CURL * curl_handle_ {nullptr};
+  RetrieverVec plugins;
 };
 
 }  //  namespace resource_retriever