HTTPServer.h

/*
 * 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 Street, Fifth Floor, Boston, MA 02110-1301 USA
 *
 * HTTPServer.h
 * The Base HTTP Server class.
 * Copyright (C) 2005 Simon Newton
 */


#ifndef INCLUDE_OLA_HTTP_HTTPSERVER_H_
#define INCLUDE_OLA_HTTP_HTTPSERVER_H_

#include <ola/Callback.h>
#include <ola/base/Macro.h>
#include <ola/io/Descriptor.h>
#include <ola/io/SelectServer.h>
#include <ola/thread/Thread.h>
#include <ola/web/Json.h>
// 0.4.6 of microhttp doesn't include stdarg so we do it here.
#include <stdarg.h>
#include <stdint.h>
#include <stdlib.h>
#ifdef _WIN32
#define WIN32_LEAN_AND_MEAN
#include <Winsock2.h>
#else
#include <sys/select.h>
#include <sys/socket.h>
#endif
#include <microhttpd.h>
#include <map>
#include <set>
#include <string>
#include <vector>

namespace ola {
namespace http {

/*
 * Represents the HTTP request
 */
class HTTPRequest {
 public:
 HTTPRequest(const std::string &url,
 const std::string &method,
 const std::string &version,
 struct MHD_Connection *connection);
 ~HTTPRequest();
 bool Init();

 // accessors
 const std::string Url() const { return m_url; }
 const std::string Method() const { return m_method; }
 const std::string Version() const { return m_version; }

 void AddHeader(const std::string &key, const std::string &value);
 void AddPostParameter(const std::string &key, const std::string &value);
 void ProcessPostData(const char *data, size_t *data_size);
 const std::string GetHeader(const std::string &key) const;
 bool CheckParameterExists(const std::string &key) const;
 const std::string GetParameter(const std::string &key) const;
 const std::string GetPostParameter(const std::string &key) const;

 bool InFlight() const { return m_in_flight; }
 void SetInFlight() { m_in_flight = true; }

 private:
 std::string m_url;
 std::string m_method;
 std::string m_version;
 struct MHD_Connection *m_connection;
 std::map<std::string, std::string> m_headers;
 std::map<std::string, std::string> m_post_params;
 struct MHD_PostProcessor *m_processor;
 bool m_in_flight;

 static const unsigned int K_POST_BUFFER_SIZE = 1024;

 DISALLOW_COPY_AND_ASSIGN(HTTPRequest);
};


/*
 * Represents the HTTP Response
 */
class HTTPResponse {
 public:
 explicit HTTPResponse(struct MHD_Connection *connection):
 m_connection(connection),
 m_status_code(MHD_HTTP_OK) {}

 void Append(const std::string &data) { m_data.append(data); }
 void SetContentType(const std::string &type);
 void SetHeader(const std::string &key, const std::string &value);
 void SetStatus(unsigned int status) { m_status_code = status; }
 void SetNoCache();
 int SendJson(const ola::web::JsonValue &json);
 int Send();
 struct MHD_Connection *Connection() const { return m_connection; }
 private:
 std::string m_data;
 struct MHD_Connection *m_connection;
 typedef std::multimap<std::string, std::string> HeadersMultiMap;
 HeadersMultiMap m_headers;
 unsigned int m_status_code;

 DISALLOW_COPY_AND_ASSIGN(HTTPResponse);
};


class HTTPServer: public ola::thread::Thread {
 public:
 typedef ola::Callback2<int, const HTTPRequest*, HTTPResponse*>
 BaseHTTPCallback;

 struct HTTPServerOptions {
 public:
 // The port to listen on
 uint16_t port;
 // The root for content served with ServeStaticContent();
 std::string data_dir;

 HTTPServerOptions()
 : port(0),
 data_dir("") {
 }
 };

 explicit HTTPServer(const HTTPServerOptions &options);
 virtual ~HTTPServer();
 bool Init();
 void *Run();
 void Stop();
 void UpdateSockets();

 void HandleHTTPIO() {}

 int DispatchRequest(const HTTPRequest *request, HTTPResponse *response);

 // Register a callback handler.
 bool RegisterHandler(const std::string &path, BaseHTTPCallback *handler);

 // Register a file handler.
 bool RegisterFile(const std::string &path,
 const std::string &content_type);
 bool RegisterFile(const std::string &path,
 const std::string &file,
 const std::string &content_type);
 // Set the default handler.
 void RegisterDefaultHandler(BaseHTTPCallback *handler);

 void Handlers(std::vector<std::string> *handlers) const;
 const std::string DataDir() const { return m_data_dir; }

 // Return an error
 int ServeError(HTTPResponse *response, const std::string &details="");
 int ServeNotFound(HTTPResponse *response);
 static int ServeRedirect(HTTPResponse *response, const std::string &location);

 // Return the contents of a file.
 int ServeStaticContent(const std::string &path,
 const std::string &content_type,
 HTTPResponse *response);

 static const char CONTENT_TYPE_PLAIN[];
 static const char CONTENT_TYPE_HTML[];
 static const char CONTENT_TYPE_GIF[];
 static const char CONTENT_TYPE_PNG[];
 static const char CONTENT_TYPE_CSS[];
 static const char CONTENT_TYPE_JS[];

 // Expose the SelectServer
 ola::io::SelectServer *SelectServer() { return &m_select_server; }

 private :
 typedef struct {
 std::string file_path;
 std::string content_type;
 } static_file_info;

 struct DescriptorState {
 public:
 explicit DescriptorState(ola::io::UnmanagedFileDescriptor *descriptor)
 : descriptor(descriptor), read(0), write(0) {}

 ola::io::UnmanagedFileDescriptor *descriptor;
 uint8_t read : 1;
 uint8_t write : 1;
 uint8_t : 6;
 };

 struct Descriptor_lt {
 bool operator()(const DescriptorState *d1,
 const DescriptorState *d2) const {
 return d1->descriptor->ReadDescriptor() <
 d2->descriptor->ReadDescriptor();
 }
 };

 typedef std::set<DescriptorState*, Descriptor_lt> SocketSet;

 struct MHD_Daemon *m_httpd;
 ola::io::SelectServer m_select_server;
 SocketSet m_sockets;

 std::map<std::string, BaseHTTPCallback*> m_handlers;
 std::map<std::string, static_file_info> m_static_content;
 BaseHTTPCallback *m_default_handler;
 unsigned int m_port;
 std::string m_data_dir;

 int ServeStaticContent(static_file_info *file_info,
 HTTPResponse *response);

 void InsertSocket(bool is_readable, bool is_writeable, int fd);
 void FreeSocket(DescriptorState *state);

 DISALLOW_COPY_AND_ASSIGN(HTTPServer);
};
} // namespace http
} // namespace ola
#endif // INCLUDE_OLA_HTTP_HTTPSERVER_H_