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      1 /*
      2  * libjingle
      3  * Copyright 2004--2005, Google Inc.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions are met:
      7  *
      8  *  1. Redistributions of source code must retain the above copyright notice,
      9  *     this list of conditions and the following disclaimer.
     10  *  2. Redistributions in binary form must reproduce the above copyright notice,
     11  *     this list of conditions and the following disclaimer in the documentation
     12  *     and/or other materials provided with the distribution.
     13  *  3. The name of the author may not be used to endorse or promote products
     14  *     derived from this software without specific prior written permission.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
     17  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
     18  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
     19  * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     20  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     21  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
     22  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
     23  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
     24  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
     25  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     26  */
     27 
     28 // Copyright 2005 Google Inc.  All Rights Reserved.
     29 //
     30 
     31 
     32 #ifndef TALK_BASE_HTTPBASE_H__
     33 #define TALK_BASE_HTTPBASE_H__
     34 
     35 #include "talk/base/httpcommon.h"
     36 
     37 namespace talk_base {
     38 
     39 class StreamInterface;
     40 
     41 ///////////////////////////////////////////////////////////////////////////////
     42 // HttpParser - Parses an HTTP stream provided via Process and end_of_input, and
     43 // generates events for:
     44 //  Structural Elements: Leader, Headers, Document Data
     45 //  Events: End of Headers, End of Document, Errors
     46 ///////////////////////////////////////////////////////////////////////////////
     47 
     48 class HttpParser {
     49 public:
     50   enum ProcessResult { PR_CONTINUE, PR_BLOCK, PR_COMPLETE };
     51   HttpParser();
     52   virtual ~HttpParser();
     53 
     54   void reset();
     55   ProcessResult Process(const char* buffer, size_t len, size_t* processed,
     56                         HttpError* error);
     57   bool is_valid_end_of_input() const;
     58   void complete(HttpError err);
     59 
     60   size_t GetDataRemaining() const { return data_size_; }
     61 
     62 protected:
     63   ProcessResult ProcessLine(const char* line, size_t len, HttpError* error);
     64 
     65   // HttpParser Interface
     66   virtual ProcessResult ProcessLeader(const char* line, size_t len,
     67                                       HttpError* error) = 0;
     68   virtual ProcessResult ProcessHeader(const char* name, size_t nlen,
     69                                       const char* value, size_t vlen,
     70                                       HttpError* error) = 0;
     71   virtual ProcessResult ProcessHeaderComplete(bool chunked, size_t& data_size,
     72                                               HttpError* error) = 0;
     73   virtual ProcessResult ProcessData(const char* data, size_t len, size_t& read,
     74                                     HttpError* error) = 0;
     75   virtual void OnComplete(HttpError err) = 0;
     76 
     77 private:
     78   enum State {
     79     ST_LEADER, ST_HEADERS,
     80     ST_CHUNKSIZE, ST_CHUNKTERM, ST_TRAILERS,
     81     ST_DATA, ST_COMPLETE
     82   } state_;
     83   bool chunked_;
     84   size_t data_size_;
     85 };
     86 
     87 ///////////////////////////////////////////////////////////////////////////////
     88 // IHttpNotify
     89 ///////////////////////////////////////////////////////////////////////////////
     90 
     91 enum HttpMode { HM_NONE, HM_CONNECT, HM_RECV, HM_SEND };
     92 
     93 class IHttpNotify {
     94 public:
     95   virtual ~IHttpNotify() {}
     96   virtual HttpError onHttpHeaderComplete(bool chunked, size_t& data_size) = 0;
     97   virtual void onHttpComplete(HttpMode mode, HttpError err) = 0;
     98   virtual void onHttpClosed(HttpError err) = 0;
     99 };
    100 
    101 ///////////////////////////////////////////////////////////////////////////////
    102 // HttpBase - Provides a state machine for implementing HTTP-based components.
    103 // Attach HttpBase to a StreamInterface which represents a bidirectional HTTP
    104 // stream, and then call send() or recv() to initiate sending or receiving one
    105 // side of an HTTP transaction.  By default, HttpBase operates as an I/O pump,
    106 // moving data from the HTTP stream to the HttpData object and vice versa.
    107 // However, it can also operate in stream mode, in which case the user of the
    108 // stream interface drives I/O via calls to Read().
    109 ///////////////////////////////////////////////////////////////////////////////
    110 
    111 class HttpBase
    112 : private HttpParser,
    113   public sigslot::has_slots<>
    114 {
    115 public:
    116   HttpBase();
    117   virtual ~HttpBase();
    118 
    119   void notify(IHttpNotify* notify) { notify_ = notify; }
    120   bool attach(StreamInterface* stream);
    121   StreamInterface* stream() { return http_stream_; }
    122   StreamInterface* detach();
    123   bool isConnected() const;
    124 
    125   void send(HttpData* data);
    126   void recv(HttpData* data);
    127   void abort(HttpError err);
    128 
    129   HttpMode mode() const { return mode_; }
    130 
    131   void set_ignore_data(bool ignore) { ignore_data_ = ignore; }
    132   bool ignore_data() const { return ignore_data_; }
    133 
    134   // Obtaining this stream puts HttpBase into stream mode until the stream
    135   // is closed.  HttpBase can only expose one open stream interface at a time.
    136   // Further calls will return NULL.
    137   StreamInterface* GetDocumentStream();
    138 
    139 protected:
    140   // Do cleanup when the http stream closes (error may be 0 for a clean
    141   // shutdown), and return the error code to signal.
    142   HttpError HandleStreamClose(int error);
    143 
    144   // DoReceiveLoop acts as a data pump, pulling data from the http stream,
    145   // pushing it through the HttpParser, and then populating the HttpData object
    146   // based on the callbacks from the parser.  One of the most interesting
    147   // callbacks is ProcessData, which provides the actual http document body.
    148   // This data is then written to the HttpData::document.  As a result, data
    149   // flows from the network to the document, with some incidental protocol
    150   // parsing in between.
    151   // Ideally, we would pass in the document* to DoReceiveLoop, to more easily
    152   // support GetDocumentStream().  However, since the HttpParser is callback
    153   // driven, we are forced to store the pointer somewhere until the callback
    154   // is triggered.
    155   // Returns true if the received document has finished, and
    156   // HttpParser::complete should be called.
    157   bool DoReceiveLoop(HttpError* err);
    158 
    159   void read_and_process_data();
    160   void flush_data();
    161   bool queue_headers();
    162   void do_complete(HttpError err = HE_NONE);
    163 
    164   void OnHttpStreamEvent(StreamInterface* stream, int events, int error);
    165   void OnDocumentEvent(StreamInterface* stream, int events, int error);
    166 
    167   // HttpParser Interface
    168   virtual ProcessResult ProcessLeader(const char* line, size_t len,
    169                                       HttpError* error);
    170   virtual ProcessResult ProcessHeader(const char* name, size_t nlen,
    171                                       const char* value, size_t vlen,
    172                                       HttpError* error);
    173   virtual ProcessResult ProcessHeaderComplete(bool chunked, size_t& data_size,
    174                                               HttpError* error);
    175   virtual ProcessResult ProcessData(const char* data, size_t len, size_t& read,
    176                                     HttpError* error);
    177   virtual void OnComplete(HttpError err);
    178 
    179 private:
    180   class DocumentStream;
    181   friend class DocumentStream;
    182 
    183   enum { kBufferSize = 32 * 1024 };
    184 
    185   HttpMode mode_;
    186   HttpData* data_;
    187   IHttpNotify* notify_;
    188   StreamInterface* http_stream_;
    189   DocumentStream* doc_stream_;
    190   char buffer_[kBufferSize];
    191   size_t len_;
    192 
    193   bool ignore_data_, chunk_data_;
    194   HttpData::const_iterator header_;
    195 };
    196 
    197 ///////////////////////////////////////////////////////////////////////////////
    198 
    199 } // namespace talk_base
    200 
    201 #endif // TALK_BASE_HTTPBASE_H__
    202