text: /*
   * Copyright (C) 2009, Willow Garage, Inc.
   *
   * 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 names of Stanford University or 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 OWNER 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_RETRIEVER_H
  #define RESOURCE_RETRIEVER_RETRIEVER_H
  
  #include <stdint.h>
  #include <string>
  #include <boost/shared_array.hpp>
  #include <stdexcept>
  
  typedef void CURL;
  
  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
  {
    MemoryResource()
    : size(0)
    {}
  
    boost::shared_array<uint8_t> data;
    uint32_t size;
  };
  
  /**
   * \brief Retrieves files from from a url.  Caches a CURL handle so multiple accesses to a single url
   * will keep connections open.
   */
  class Retriever
  {
  public:
    Retriever();
    ~Retriever();
  
    /**
     * \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);
  
  private:
    Retriever(const Retriever & ret) = delete;
  
    CURL* curl_handle_;
  };
  
  } // namespace resource_retriever
  
  #endif // RESOURCE_RETRIEVER_RETRIEVER_H
  