net/http/http_transaction.h

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef NET_HTTP_HTTP_TRANSACTION_H_
   6 #define NET_HTTP_HTTP_TRANSACTION_H_
   7
   8 #include "net/base/completion_callback.h"
   9 #include "net/base/load_states.h"
  10 #include "net/base/net_export.h"
  11 #include "net/base/request_priority.h"
  12 #include "net/base/upload_progress.h"
  13 #include "net/websockets/websocket_handshake_stream_base.h"
  14
  15 namespace net {
  16
  17 class AuthCredentials;
  18 class BoundNetLog;
  19 class HttpRequestHeaders;
  20 struct HttpRequestInfo;
  21 class HttpResponseInfo;
  22 class IOBuffer;
  23 struct LoadTimingInfo;
  24 class X509Certificate;
  25
  26 // Represents a single HTTP transaction (i.e., a single request/response pair).
  27 // HTTP redirects are not followed and authentication challenges are not
  28 // answered.  Cookies are assumed to be managed by the caller.
  29 class NET_EXPORT_PRIVATE HttpTransaction {
  30  public:
  31   // If |*defer| is set to true, the transaction will wait until
  32   // ResumeNetworkStart is called before establishing a connection.
  33   typedef base::Callback<void(bool* defer)> BeforeNetworkStartCallback;
  34
  35   // Stops any pending IO and destroys the transaction object.
  36   virtual ~HttpTransaction() {}
  37
  38   // Starts the HTTP transaction (i.e., sends the HTTP request).
  39   //
  40   // Returns OK if the transaction could be started synchronously, which means
  41   // that the request was served from the cache.  ERR_IO_PENDING is returned to
  42   // indicate that the CompletionCallback will be notified once response info is
  43   // available or if an IO error occurs.  Any other return value indicates that
  44   // the transaction could not be started.
  45   //
  46   // Regardless of the return value, the caller is expected to keep the
  47   // request_info object alive until Destroy is called on the transaction.
  48   //
  49   // NOTE: The transaction is not responsible for deleting the callback object.
  50   //
  51   // Profiling information for the request is saved to |net_log| if non-NULL.
  52   virtual int Start(const HttpRequestInfo* request_info,
  53                     const CompletionCallback& callback,
  54                     const BoundNetLog& net_log) = 0;
  55
  56   // Restarts the HTTP transaction, ignoring the last error.  This call can
  57   // only be made after a call to Start (or RestartIgnoringLastError) failed.
  58   // Once Read has been called, this method cannot be called.  This method is
  59   // used, for example, to continue past various SSL related errors.
  60   //
  61   // Not all errors can be ignored using this method.  See error code
  62   // descriptions for details about errors that can be ignored.
  63   //
  64   // NOTE: The transaction is not responsible for deleting the callback object.
  65   //
  66   virtual int RestartIgnoringLastError(const CompletionCallback& callback) = 0;
  67
  68   // Restarts the HTTP transaction with a client certificate.
  69   virtual int RestartWithCertificate(X509Certificate* client_cert,
  70                                      const CompletionCallback& callback) = 0;
  71
  72   // Restarts the HTTP transaction with authentication credentials.
  73   virtual int RestartWithAuth(const AuthCredentials& credentials,
  74                               const CompletionCallback& callback) = 0;
  75
  76   // Returns true if auth is ready to be continued. Callers should check
  77   // this value anytime Start() completes: if it is true, the transaction
  78   // can be resumed with RestartWithAuth(L"", L"", callback) to resume
  79   // the automatic auth exchange. This notification gives the caller a
  80   // chance to process the response headers from all of the intermediate
  81   // restarts needed for authentication.
  82   virtual bool IsReadyToRestartForAuth() = 0;
  83
  84   // Once response info is available for the transaction, response data may be
  85   // read by calling this method.
  86   //
  87   // Response data is copied into the given buffer and the number of bytes
  88   // copied is returned.  ERR_IO_PENDING is returned if response data is not
  89   // yet available.  The CompletionCallback is notified when the data copy
  90   // completes, and it is passed the number of bytes that were successfully
  91   // copied.  Or, if a read error occurs, the CompletionCallback is notified of
  92   // the error.  Any other negative return value indicates that the transaction
  93   // could not be read.
  94   //
  95   // NOTE: The transaction is not responsible for deleting the callback object.
  96   // If the operation is not completed immediately, the transaction must acquire
  97   // a reference to the provided buffer.
  98   //
  99   virtual int Read(IOBuffer* buf, int buf_len,
 100                    const CompletionCallback& callback) = 0;
 101
 102   // Stops further caching of this request by the HTTP cache, if there is any.
 103   virtual void StopCaching() = 0;
 104
 105   // Gets the full request headers sent to the server.  This is guaranteed to
 106   // work only if Start returns success and the underlying transaction supports
 107   // it.  (Right now, this is only network transactions, not cache ones.)
 108   //
 109   // Returns true and overwrites headers if it can get the request headers;
 110   // otherwise, returns false and does not modify headers.
 111   virtual bool GetFullRequestHeaders(HttpRequestHeaders* headers) const = 0;
 112
 113   // Get the number of bytes received from network.
 114   virtual int64 GetTotalReceivedBytes() const = 0;
 115
 116   // Called to tell the transaction that we have successfully reached the end
 117   // of the stream. This is equivalent to performing an extra Read() at the end
 118   // that should return 0 bytes. This method should not be called if the
 119   // transaction is busy processing a previous operation (like a pending Read).
 120   //
 121   // DoneReading may also be called before the first Read() to notify that the
 122   // entire response body is to be ignored (e.g., in a redirect).
 123   virtual void DoneReading() = 0;
 124
 125   // Returns the response info for this transaction or NULL if the response
 126   // info is not available.
 127   virtual const HttpResponseInfo* GetResponseInfo() const = 0;
 128
 129   // Returns the load state for this transaction.
 130   virtual LoadState GetLoadState() const = 0;
 131
 132   // Returns the upload progress in bytes.  If there is no upload data,
 133   // zero will be returned.  This does not include the request headers.
 134   virtual UploadProgress GetUploadProgress() const = 0;
 135
 136   // Populates all of load timing, except for request start times and receive
 137   // headers time.
 138   // |load_timing_info| must have all null times when called.  Returns false and
 139   // does not modify |load_timing_info| if there's no timing information to
 140   // provide.
 141   virtual bool GetLoadTimingInfo(LoadTimingInfo* load_timing_info) const = 0;
 142
 143   // Called when the priority of the parent job changes.
 144   virtual void SetPriority(RequestPriority priority) = 0;
 145
 146   // Set the WebSocketHandshakeStreamBase::CreateHelper to be used for the
 147   // request.  Only relevant to WebSocket transactions. Must be called before
 148   // Start(). Ownership of |create_helper| remains with the caller.
 149   virtual void SetWebSocketHandshakeStreamCreateHelper(
 150       WebSocketHandshakeStreamBase::CreateHelper* create_helper) = 0;
 151
 152   // Set the callback to receive notification just before network use.
 153   virtual void SetBeforeNetworkStartCallback(
 154       const BeforeNetworkStartCallback& callback) = 0;
 155
 156   // Resumes the transaction after being deferred.
 157   virtual int ResumeNetworkStart() = 0;
 158 };
 159
 160 }  // namespace net
 161
 162 #endif  // NET_HTTP_HTTP_TRANSACTION_H_