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