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      1 /*
      2  *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
      3  *
      4  *  Use of this source code is governed by a BSD-style license
      5  *  that can be found in the LICENSE file in the root of the source
      6  *  tree. An additional intellectual property rights grant can be found
      7  *  in the file PATENTS.  All contributing project authors may
      8  *  be found in the AUTHORS file in the root of the source tree.
      9  */
     10 
     11 #ifndef WEBRTC_BASE_HTTPCLIENT_H__
     12 #define WEBRTC_BASE_HTTPCLIENT_H__
     13 
     14 #include "webrtc/base/common.h"
     15 #include "webrtc/base/httpbase.h"
     16 #include "webrtc/base/nethelpers.h"
     17 #include "webrtc/base/proxyinfo.h"
     18 #include "webrtc/base/scoped_ptr.h"
     19 #include "webrtc/base/sigslot.h"
     20 #include "webrtc/base/socketaddress.h"
     21 #include "webrtc/base/socketpool.h"
     22 
     23 namespace rtc {
     24 
     25 //////////////////////////////////////////////////////////////////////
     26 // Client-specific http utilities
     27 //////////////////////////////////////////////////////////////////////
     28 
     29 // Write cache-relevant response headers to output stream.  If size is non-null,
     30 // it contains the length of the output in bytes.  output may be null if only
     31 // the length is desired.
     32 bool HttpWriteCacheHeaders(const HttpResponseData* response,
     33                            StreamInterface* output, size_t* size);
     34 // Read cached headers from a stream, and them merge them into the response
     35 // object using the specified combine operation.
     36 bool HttpReadCacheHeaders(StreamInterface* input,
     37                           HttpResponseData* response,
     38                           HttpData::HeaderCombine combine);
     39 
     40 //////////////////////////////////////////////////////////////////////
     41 // HttpClient
     42 // Implements an HTTP 1.1 client.
     43 //////////////////////////////////////////////////////////////////////
     44 
     45 class DiskCache;
     46 class HttpClient;
     47 class IPNetPool;
     48 
     49 class SignalThread;
     50 // What to do:  Define STRICT_HTTP_ERROR=1 in your makefile.  Use HttpError in
     51 // your code (HttpErrorType should only be used for code that is shared
     52 // with groups which have not yet migrated).
     53 #if STRICT_HTTP_ERROR
     54 typedef HttpError HttpErrorType;
     55 #else  // !STRICT_HTTP_ERROR
     56 typedef int HttpErrorType;
     57 #endif  // !STRICT_HTTP_ERROR
     58 
     59 class HttpClient : private IHttpNotify, public sigslot::has_slots<> {
     60 public:
     61   // If HttpRequestData and HttpResponseData objects are provided, they must
     62   // be freed by the caller.  Otherwise, an internal object is allocated.
     63   HttpClient(const std::string& agent, StreamPool* pool,
     64              HttpTransaction* transaction = NULL);
     65   ~HttpClient() override;
     66 
     67   void set_pool(StreamPool* pool) { pool_ = pool; }
     68 
     69   void set_agent(const std::string& agent) { agent_ = agent; }
     70   const std::string& agent() const { return agent_; }
     71 
     72   void set_proxy(const ProxyInfo& proxy) { proxy_ = proxy; }
     73   const ProxyInfo& proxy() const { return proxy_; }
     74 
     75   // Request retries occur when the connection closes before the beginning of
     76   // an http response is received.  In these cases, the http server may have
     77   // timed out the keepalive connection before it received our request.  Note
     78   // that if a request document cannot be rewound, no retry is made.  The
     79   // default is 1.
     80   void set_request_retries(size_t retries) { retries_ = retries; }
     81   size_t request_retries() const { return retries_; }
     82 
     83   enum RedirectAction { REDIRECT_DEFAULT, REDIRECT_ALWAYS, REDIRECT_NEVER };
     84   void set_redirect_action(RedirectAction action) { redirect_action_ = action; }
     85   RedirectAction redirect_action() const { return redirect_action_; }
     86 
     87   enum UriForm { URI_DEFAULT, URI_ABSOLUTE, URI_RELATIVE };
     88   void set_uri_form(UriForm form) { uri_form_ = form; }
     89   UriForm uri_form() const { return uri_form_; }
     90 
     91   void set_cache(DiskCache* cache) { ASSERT(!IsCacheActive()); cache_ = cache; }
     92   bool cache_enabled() const { return (NULL != cache_); }
     93 
     94   // reset clears the server, request, and response structures.  It will also
     95   // abort an active request.
     96   void reset();
     97 
     98   void set_server(const SocketAddress& address);
     99   const SocketAddress& server() const { return server_; }
    100 
    101   // Note: in order for HttpClient to retry a POST in response to
    102   // an authentication challenge, a redirect response, or socket disconnection,
    103   // the request document must support 'replaying' by calling Rewind() on it.
    104   HttpTransaction* transaction() { return transaction_; }
    105   const HttpTransaction* transaction() const { return transaction_; }
    106   HttpRequestData& request() { return transaction_->request; }
    107   const HttpRequestData& request() const { return transaction_->request; }
    108   HttpResponseData& response() { return transaction_->response; }
    109   const HttpResponseData& response() const { return transaction_->response; }
    110 
    111   // convenience methods
    112   void prepare_get(const std::string& url);
    113   void prepare_post(const std::string& url, const std::string& content_type,
    114                     StreamInterface* request_doc);
    115 
    116   // Convert HttpClient to a pull-based I/O model.
    117   StreamInterface* GetDocumentStream();
    118 
    119   // After you finish setting up your request, call start.
    120   void start();
    121 
    122   // Signalled when the header has finished downloading, before the document
    123   // content is processed.  You may change the response document in response
    124   // to this signal.  The second parameter indicates whether this is an
    125   // intermediate (false) or final (true) header.  An intermediate header is
    126   // one that generates another request, such as a redirect or authentication
    127   // challenge.  The third parameter indicates the length of the response
    128   // document, or else SIZE_UNKNOWN.  Note: Do NOT abort the request in response
    129   // to this signal.
    130   sigslot::signal3<HttpClient*,bool,size_t> SignalHeaderAvailable;
    131   // Signalled when the current request finishes.  On success, err is 0.
    132   sigslot::signal2<HttpClient*,HttpErrorType> SignalHttpClientComplete;
    133 
    134 protected:
    135   void connect();
    136   void release();
    137 
    138   bool ShouldRedirect(std::string* location) const;
    139 
    140   bool BeginCacheFile();
    141   HttpError WriteCacheHeaders(const std::string& id);
    142   void CompleteCacheFile();
    143 
    144   bool CheckCache();
    145   HttpError ReadCacheHeaders(const std::string& id, bool override);
    146   HttpError ReadCacheBody(const std::string& id);
    147 
    148   bool PrepareValidate();
    149   HttpError CompleteValidate();
    150 
    151   HttpError OnHeaderAvailable(bool ignore_data, bool chunked, size_t data_size);
    152 
    153   void StartDNSLookup();
    154   void OnResolveResult(AsyncResolverInterface* resolver);
    155 
    156   // IHttpNotify Interface
    157   HttpError onHttpHeaderComplete(bool chunked, size_t& data_size) override;
    158   void onHttpComplete(HttpMode mode, HttpError err) override;
    159   void onHttpClosed(HttpError err) override;
    160 
    161 private:
    162   enum CacheState { CS_READY, CS_WRITING, CS_READING, CS_VALIDATING };
    163   bool IsCacheActive() const { return (cache_state_ > CS_READY); }
    164 
    165   std::string agent_;
    166   StreamPool* pool_;
    167   HttpBase base_;
    168   SocketAddress server_;
    169   ProxyInfo proxy_;
    170   HttpTransaction* transaction_;
    171   bool free_transaction_;
    172   size_t retries_, attempt_, redirects_;
    173   RedirectAction redirect_action_;
    174   UriForm uri_form_;
    175   scoped_ptr<HttpAuthContext> context_;
    176   DiskCache* cache_;
    177   CacheState cache_state_;
    178   AsyncResolverInterface* resolver_;
    179 };
    180 
    181 //////////////////////////////////////////////////////////////////////
    182 // HttpClientDefault - Default implementation of HttpClient
    183 //////////////////////////////////////////////////////////////////////
    184 
    185 class HttpClientDefault : public ReuseSocketPool, public HttpClient {
    186 public:
    187   HttpClientDefault(SocketFactory* factory, const std::string& agent,
    188                     HttpTransaction* transaction = NULL);
    189 };
    190 
    191 //////////////////////////////////////////////////////////////////////
    192 
    193 }  // namespace rtc
    194 
    195 #endif // WEBRTC_BASE_HTTPCLIENT_H__
    196