net/http/http_stream.h

   1 // Copyright (c) 2012 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 // HttpStream provides an abstraction for a basic http streams, SPDY, and QUIC.
   6 // The HttpStream subtype is expected to manage the underlying transport
   7 // appropriately.  For example, a basic http stream will return the transport
   8 // socket to the pool for reuse.  SPDY streams on the other hand leave the
   9 // transport socket management to the SpdySession.
  10
  11 #ifndef NET_HTTP_HTTP_STREAM_H_
  12 #define NET_HTTP_HTTP_STREAM_H_
  13
  14 #include "base/basictypes.h"
  15 #include "base/memory/scoped_ptr.h"
  16 #include "net/base/completion_callback.h"
  17 #include "net/base/net_export.h"
  18 #include "net/base/request_priority.h"
  19 #include "net/base/upload_progress.h"
  20
  21 namespace net {
  22
  23 class BoundNetLog;
  24 class HttpNetworkSession;
  25 class HttpRequestHeaders;
  26 struct HttpRequestInfo;
  27 class HttpResponseInfo;
  28 class IOBuffer;
  29 struct LoadTimingInfo;
  30 class SSLCertRequestInfo;
  31 class SSLInfo;
  32
  33 class NET_EXPORT_PRIVATE HttpStream {
  34  public:
  35   HttpStream() {}
  36   virtual ~HttpStream() {}
  37
  38   // Initialize stream.  Must be called before calling SendRequest().
  39   // |request_info| must outlive the HttpStream.
  40   // Returns a net error code, possibly ERR_IO_PENDING.
  41   virtual int InitializeStream(const HttpRequestInfo* request_info,
  42                                RequestPriority priority,
  43                                const BoundNetLog& net_log,
  44                                const CompletionCallback& callback) = 0;
  45
  46   // Writes the headers and uploads body data to the underlying socket.
  47   // ERR_IO_PENDING is returned if the operation could not be completed
  48   // synchronously, in which case the result will be passed to the callback
  49   // when available. Returns OK on success.
  50   //
  51   // The callback will only be invoked once the first full set of headers have
  52   // been received, at which point |response| will have been populated with that
  53   // set of headers, and is safe to read, until/unless ReadResponseHeaders is
  54   // called.
  55   //
  56   // |response| must remain valid until all sets of headers has been read, or
  57   // the HttpStream is destroyed. There's typically only one set of
  58   // headers, except in the case of 1xx responses (See ReadResponseHeaders).
  59   virtual int SendRequest(const HttpRequestHeaders& request_headers,
  60                           HttpResponseInfo* response,
  61                           const CompletionCallback& callback) = 0;
  62
  63   // Reads from the underlying socket until the next set of response headers
  64   // have been completely received.  This may only be called on 1xx responses
  65   // after SendRequest has completed successfully, to read the next set of
  66   // headers.
  67   //
  68   // ERR_IO_PENDING is returned if the operation could not be completed
  69   // synchronously, in which case the result will be passed to the callback when
  70   // available. Returns OK on success. The response headers are available in
  71   // the HttpResponseInfo passed in to original call to SendRequest.
  72   virtual int ReadResponseHeaders(const CompletionCallback& callback) = 0;
  73
  74   // Reads response body data, up to |buf_len| bytes. |buf_len| should be a
  75   // reasonable size (<2MB). The number of bytes read is returned, or an
  76   // error is returned upon failure.  0 indicates that the request has been
  77   // fully satisfied and there is no more data to read.
  78   // ERR_CONNECTION_CLOSED is returned when the connection has been closed
  79   // prematurely.  ERR_IO_PENDING is returned if the operation could not be
  80   // completed synchronously, in which case the result will be passed to the
  81   // callback when available. If the operation is not completed immediately,
  82   // the socket acquires a reference to the provided buffer until the callback
  83   // is invoked or the socket is destroyed.
  84   virtual int ReadResponseBody(IOBuffer* buf, int buf_len,
  85                                const CompletionCallback& callback) = 0;
  86
  87   // Closes the stream.
  88   // |not_reusable| indicates if the stream can be used for further requests.
  89   // In the case of HTTP, where we re-use the byte-stream (e.g. the connection)
  90   // this means we need to close the connection; in the case of SPDY, where the
  91   // underlying stream is never reused, it has no effect.
  92   // TODO(mbelshe): We should figure out how to fold the not_reusable flag
  93   //                into the stream implementation itself so that the caller
  94   //                does not need to pass it at all.  We might also be able to
  95   //                eliminate the SetConnectionReused() below.
  96   virtual void Close(bool not_reusable) = 0;
  97
  98   // Indicates if the response body has been completely read.
  99   virtual bool IsResponseBodyComplete() const = 0;
 100
 101   // Indicates that the end of the response is detectable. This means that
 102   // the response headers indicate either chunked encoding or content length.
 103   // If neither is sent, the server must close the connection for us to detect
 104   // the end of the response.
 105   // TODO(rch): Rename this method, so that it is clear why it exists
 106   // particularly as it applies to QUIC and SPDY for which the end of the
 107   // response is always findable.
 108   virtual bool CanFindEndOfResponse() const = 0;
 109
 110   // A stream exists on top of a connection.  If the connection has been used
 111   // to successfully exchange data in the past, error handling for the
 112   // stream is done differently.  This method returns true if the underlying
 113   // connection is reused or has been connected and idle for some time.
 114   virtual bool IsConnectionReused() const = 0;
 115   virtual void SetConnectionReused() = 0;
 116
 117   // Checks whether the current state of the underlying connection
 118   // allows it to be reused.
 119   virtual bool IsConnectionReusable() const = 0;
 120
 121   // Get the total number of bytes received from network for this stream.
 122   virtual int64 GetTotalReceivedBytes() const = 0;
 123
 124   // Populates the connection establishment part of |load_timing_info|, and
 125   // socket ID.  |load_timing_info| must have all null times when called.
 126   // Returns false and does nothing if there is no underlying connection, either
 127   // because one has yet to be assigned to the stream, or because the underlying
 128   // socket has been closed.
 129   //
 130   // In practice, this means that this function will always succeed any time
 131   // between when the full headers have been received and the stream has been
 132   // closed.
 133   virtual bool GetLoadTimingInfo(LoadTimingInfo* load_timing_info) const = 0;
 134
 135   // Get the SSLInfo associated with this stream's connection.  This should
 136   // only be called for streams over SSL sockets, otherwise the behavior is
 137   // undefined.
 138   virtual void GetSSLInfo(SSLInfo* ssl_info) = 0;
 139
 140   // Get the SSLCertRequestInfo associated with this stream's connection.
 141   // This should only be called for streams over SSL sockets, otherwise the
 142   // behavior is undefined.
 143   virtual void GetSSLCertRequestInfo(SSLCertRequestInfo* cert_request_info) = 0;
 144
 145   // HACK(willchan): Really, we should move the HttpResponseDrainer logic into
 146   // the HttpStream implementation. This is just a quick hack.
 147   virtual bool IsSpdyHttpStream() const = 0;
 148
 149   // In the case of an HTTP error or redirect, flush the response body (usually
 150   // a simple error or "this page has moved") so that we can re-use the
 151   // underlying connection. This stream is responsible for deleting itself when
 152   // draining is complete.
 153   virtual void Drain(HttpNetworkSession* session) = 0;
 154
 155   // Called when the priority of the parent transaction changes.
 156   virtual void SetPriority(RequestPriority priority) = 0;
 157
 158   // Queries the UploadDataStream for its progress (bytes sent).
 159   virtual UploadProgress GetUploadProgress() const = 0;
 160
 161   // Returns a new (not initialized) stream using the same underlying
 162   // connection and invalidates the old stream - no further methods should be
 163   // called on the old stream.  The caller should ensure that the response body
 164   // from the previous request is drained before calling this method.  If the
 165   // subclass does not support renewing the stream, NULL is returned.
 166   virtual HttpStream* RenewStreamForAuth() = 0;
 167
 168  private:
 169   DISALLOW_COPY_AND_ASSIGN(HttpStream);
 170 };
 171
 172 }  // namespace net
 173
 174 #endif  // NET_HTTP_HTTP_STREAM_H_