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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 #ifndef TALK_BASE_HTTPCLIENT_H__
     29 #define TALK_BASE_HTTPCLIENT_H__
     30 
     31 #include "talk/base/common.h"
     32 #include "talk/base/httpbase.h"
     33 #include "talk/base/nethelpers.h"
     34 #include "talk/base/proxyinfo.h"
     35 #include "talk/base/scoped_ptr.h"
     36 #include "talk/base/sigslot.h"
     37 #include "talk/base/socketaddress.h"
     38 #include "talk/base/socketpool.h"
     39 
     40 namespace talk_base {
     41 
     42 //////////////////////////////////////////////////////////////////////
     43 // Client-specific http utilities
     44 //////////////////////////////////////////////////////////////////////
     45 
     46 // Write cache-relevant response headers to output stream.  If size is non-null,
     47 // it contains the length of the output in bytes.  output may be null if only
     48 // the length is desired.
     49 bool HttpWriteCacheHeaders(const HttpResponseData* response,
     50                            StreamInterface* output, size_t* size);
     51 // Read cached headers from a stream, and them merge them into the response
     52 // object using the specified combine operation.
     53 bool HttpReadCacheHeaders(StreamInterface* input,
     54                           HttpResponseData* response,
     55                           HttpData::HeaderCombine combine);
     56 
     57 //////////////////////////////////////////////////////////////////////
     58 // HttpClient
     59 // Implements an HTTP 1.1 client.
     60 //////////////////////////////////////////////////////////////////////
     61 
     62 class DiskCache;
     63 class HttpClient;
     64 class IPNetPool;
     65 
     66 class SignalThread;
     67 // What to do:  Define STRICT_HTTP_ERROR=1 in your makefile.  Use HttpError in
     68 // your code (HttpErrorType should only be used for code that is shared
     69 // with groups which have not yet migrated).
     70 #if STRICT_HTTP_ERROR
     71 typedef HttpError HttpErrorType;
     72 #else  // !STRICT_HTTP_ERROR
     73 typedef int HttpErrorType;
     74 #endif  // !STRICT_HTTP_ERROR
     75 
     76 class HttpClient : private IHttpNotify, public sigslot::has_slots<> {
     77 public:
     78   // If HttpRequestData and HttpResponseData objects are provided, they must
     79   // be freed by the caller.  Otherwise, an internal object is allocated.
     80   HttpClient(const std::string& agent, StreamPool* pool,
     81              HttpTransaction* transaction = NULL);
     82   virtual ~HttpClient();
     83 
     84   void set_pool(StreamPool* pool) { pool_ = pool; }
     85 
     86   void set_agent(const std::string& agent) { agent_ = agent; }
     87   const std::string& agent() const { return agent_; }
     88 
     89   void set_proxy(const ProxyInfo& proxy) { proxy_ = proxy; }
     90   const ProxyInfo& proxy() const { return proxy_; }
     91 
     92   // Request retries occur when the connection closes before the beginning of
     93   // an http response is received.  In these cases, the http server may have
     94   // timed out the keepalive connection before it received our request.  Note
     95   // that if a request document cannot be rewound, no retry is made.  The
     96   // default is 1.
     97   void set_request_retries(size_t retries) { retries_ = retries; }
     98   size_t request_retries() const { return retries_; }
     99 
    100   enum RedirectAction { REDIRECT_DEFAULT, REDIRECT_ALWAYS, REDIRECT_NEVER };
    101   void set_redirect_action(RedirectAction action) { redirect_action_ = action; }
    102   RedirectAction redirect_action() const { return redirect_action_; }
    103   // Deprecated
    104   void set_fail_redirect(bool fail_redirect) {
    105     redirect_action_ = REDIRECT_NEVER;
    106   }
    107   bool fail_redirect() const { return (REDIRECT_NEVER == redirect_action_); }
    108 
    109   enum UriForm { URI_DEFAULT, URI_ABSOLUTE, URI_RELATIVE };
    110   void set_uri_form(UriForm form) { uri_form_ = form; }
    111   UriForm uri_form() const { return uri_form_; }
    112 
    113   void set_cache(DiskCache* cache) { ASSERT(!IsCacheActive()); cache_ = cache; }
    114   bool cache_enabled() const { return (NULL != cache_); }
    115 
    116   // reset clears the server, request, and response structures.  It will also
    117   // abort an active request.
    118   void reset();
    119 
    120   void set_server(const SocketAddress& address);
    121   const SocketAddress& server() const { return server_; }
    122 
    123   // Note: in order for HttpClient to retry a POST in response to
    124   // an authentication challenge, a redirect response, or socket disconnection,
    125   // the request document must support 'replaying' by calling Rewind() on it.
    126   // In the case where just a subset of a stream should be used as the request
    127   // document, the stream may be wrapped with the StreamSegment adapter.
    128   HttpTransaction* transaction() { return transaction_; }
    129   const HttpTransaction* transaction() const { return transaction_; }
    130   HttpRequestData& request() { return transaction_->request; }
    131   const HttpRequestData& request() const { return transaction_->request; }
    132   HttpResponseData& response() { return transaction_->response; }
    133   const HttpResponseData& response() const { return transaction_->response; }
    134 
    135   // convenience methods
    136   void prepare_get(const std::string& url);
    137   void prepare_post(const std::string& url, const std::string& content_type,
    138                     StreamInterface* request_doc);
    139 
    140   // Convert HttpClient to a pull-based I/O model.
    141   StreamInterface* GetDocumentStream();
    142 
    143   // After you finish setting up your request, call start.
    144   void start();
    145 
    146   // Signalled when the header has finished downloading, before the document
    147   // content is processed.  You may change the response document in response
    148   // to this signal.  The second parameter indicates whether this is an
    149   // intermediate (false) or final (true) header.  An intermediate header is
    150   // one that generates another request, such as a redirect or authentication
    151   // challenge.  The third parameter indicates the length of the response
    152   // document, or else SIZE_UNKNOWN.  Note: Do NOT abort the request in response
    153   // to this signal.
    154   sigslot::signal3<HttpClient*,bool,size_t> SignalHeaderAvailable;
    155   // Signalled when the current request finishes.  On success, err is 0.
    156   sigslot::signal2<HttpClient*,HttpErrorType> SignalHttpClientComplete;
    157 
    158 protected:
    159   void connect();
    160   void release();
    161 
    162   bool ShouldRedirect(std::string* location) const;
    163 
    164   bool BeginCacheFile();
    165   HttpError WriteCacheHeaders(const std::string& id);
    166   void CompleteCacheFile();
    167 
    168   bool CheckCache();
    169   HttpError ReadCacheHeaders(const std::string& id, bool override);
    170   HttpError ReadCacheBody(const std::string& id);
    171 
    172   bool PrepareValidate();
    173   HttpError CompleteValidate();
    174 
    175   HttpError OnHeaderAvailable(bool ignore_data, bool chunked, size_t data_size);
    176 
    177   void StartDNSLookup();
    178   void OnResolveResult(AsyncResolverInterface* resolver);
    179 
    180   // IHttpNotify Interface
    181   virtual HttpError onHttpHeaderComplete(bool chunked, size_t& data_size);
    182   virtual void onHttpComplete(HttpMode mode, HttpError err);
    183   virtual void onHttpClosed(HttpError err);
    184 
    185 private:
    186   enum CacheState { CS_READY, CS_WRITING, CS_READING, CS_VALIDATING };
    187   bool IsCacheActive() const { return (cache_state_ > CS_READY); }
    188 
    189   std::string agent_;
    190   StreamPool* pool_;
    191   HttpBase base_;
    192   SocketAddress server_;
    193   ProxyInfo proxy_;
    194   HttpTransaction* transaction_;
    195   bool free_transaction_;
    196   size_t retries_, attempt_, redirects_;
    197   RedirectAction redirect_action_;
    198   UriForm uri_form_;
    199   scoped_ptr<HttpAuthContext> context_;
    200   DiskCache* cache_;
    201   CacheState cache_state_;
    202   AsyncResolverInterface* resolver_;
    203 };
    204 
    205 //////////////////////////////////////////////////////////////////////
    206 // HttpClientDefault - Default implementation of HttpClient
    207 //////////////////////////////////////////////////////////////////////
    208 
    209 class HttpClientDefault : public ReuseSocketPool, public HttpClient {
    210 public:
    211   HttpClientDefault(SocketFactory* factory, const std::string& agent,
    212                     HttpTransaction* transaction = NULL);
    213 };
    214 
    215 //////////////////////////////////////////////////////////////////////
    216 
    217 }  // namespace talk_base
    218 
    219 #endif // TALK_BASE_HTTPCLIENT_H__
    220