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// HttpStream is an interface for reading and writing data to an HttpStream that
6// keeps the client agnostic of the actual underlying transport layer.  This
7// provides an abstraction for both a basic http stream as well as http
8// pipelining implementations.  The HttpStream subtype is expected to manage the
9// underlying transport appropriately.  For example, a non-pipelined HttpStream
10// would return the transport socket to the pool for reuse.  SPDY streams on the
11// other hand leave the transport socket management to the SpdySession.
12
13#ifndef NET_HTTP_HTTP_STREAM_H_
14#define NET_HTTP_HTTP_STREAM_H_
15#pragma once
16
17#include <string>
18
19#include "base/basictypes.h"
20#include "net/base/completion_callback.h"
21
22namespace net {
23
24class BoundNetLog;
25class HttpRequestHeaders;
26struct HttpRequestInfo;
27class HttpResponseInfo;
28class IOBuffer;
29class SSLCertRequestInfo;
30class SSLInfo;
31class UploadDataStream;
32
33class HttpStream {
34 public:
35  HttpStream() {}
36  virtual ~HttpStream() {}
37
38  // Initialize stream.  Must be called before calling SendRequest().
39  // Returns a net error code, possibly ERR_IO_PENDING.
40  virtual int InitializeStream(const HttpRequestInfo* request_info,
41                               const BoundNetLog& net_log,
42                               CompletionCallback* callback) = 0;
43
44  // Writes the headers and uploads body data to the underlying socket.
45  // ERR_IO_PENDING is returned if the operation could not be completed
46  // synchronously, in which case the result will be passed to the callback
47  // when available. Returns OK on success. The HttpStream takes ownership
48  // of the request_body.
49  virtual int SendRequest(const HttpRequestHeaders& request_headers,
50                          UploadDataStream* request_body,
51                          HttpResponseInfo* response,
52                          CompletionCallback* callback) = 0;
53
54  // Queries the UploadDataStream for its progress (bytes sent).
55  virtual uint64 GetUploadProgress() const = 0;
56
57  // Reads from the underlying socket until the response headers have been
58  // completely received. ERR_IO_PENDING is returned if the operation could
59  // not be completed synchronously, in which case the result will be passed
60  // to the callback when available. Returns OK on success.  The response
61  // headers are available in the HttpResponseInfo returned by GetResponseInfo
62  virtual int ReadResponseHeaders(CompletionCallback* callback) = 0;
63
64  // Provides access to HttpResponseInfo (owned by HttpStream).
65  virtual const HttpResponseInfo* GetResponseInfo() const = 0;
66
67  // Reads response body data, up to |buf_len| bytes. |buf_len| should be a
68  // reasonable size (<2MB). The number of bytes read is returned, or an
69  // error is returned upon failure.  0 indicates that the request has been
70  // fully satisfied and there is no more data to read.
71  // ERR_CONNECTION_CLOSED is returned when the connection has been closed
72  // prematurely.  ERR_IO_PENDING is returned if the operation could not be
73  // completed synchronously, in which case the result will be passed to the
74  // callback when available. If the operation is not completed immediately,
75  // the socket acquires a reference to the provided buffer until the callback
76  // is invoked or the socket is destroyed.
77  virtual int ReadResponseBody(IOBuffer* buf, int buf_len,
78                               CompletionCallback* callback) = 0;
79
80  // Closes the stream.
81  // |not_reusable| indicates if the stream can be used for further requests.
82  // In the case of HTTP, where we re-use the byte-stream (e.g. the connection)
83  // this means we need to close the connection; in the case of SPDY, where the
84  // underlying stream is never reused, it has no effect.
85  // TODO(mbelshe): We should figure out how to fold the not_reusable flag
86  //                into the stream implementation itself so that the caller
87  //                does not need to pass it at all.  We might also be able to
88  //                eliminate the SetConnectionReused() below.
89  virtual void Close(bool not_reusable) = 0;
90
91  // Returns a new (not initialized) stream using the same underlying
92  // connection and invalidates the old stream - no further methods should be
93  // called on the old stream.  The caller should ensure that the response body
94  // from the previous request is drained before calling this method.  If the
95  // subclass does not support renewing the stream, NULL is returned.
96  virtual HttpStream* RenewStreamForAuth() = 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  virtual bool CanFindEndOfResponse() const = 0;
106
107  // After the response headers have been read and after the response body
108  // is complete, this function indicates if more data (either erroneous or
109  // as part of the next pipelined response) has been read from the socket.
110  virtual bool IsMoreDataBuffered() const = 0;
111
112  // A stream exists on top of a connection.  If the connection has been used
113  // to successfully exchange data in the past, error handling for the
114  // stream is done differently.  This method returns true if the underlying
115  // connection is reused or has been connected and idle for some time.
116  virtual bool IsConnectionReused() const = 0;
117  virtual void SetConnectionReused() = 0;
118
119  // Checks whether the current state of the underlying connection
120  // allows it to be reused.
121  virtual bool IsConnectionReusable() const = 0;
122
123  // Get the SSLInfo associated with this stream's connection.  This should
124  // only be called for streams over SSL sockets, otherwise the behavior is
125  // undefined.
126  virtual void GetSSLInfo(SSLInfo* ssl_info) = 0;
127
128  // Get the SSLCertRequestInfo associated with this stream's connection.
129  // This should only be called for streams over SSL sockets, otherwise the
130  // behavior is undefined.
131  virtual void GetSSLCertRequestInfo(SSLCertRequestInfo* cert_request_info) = 0;
132
133  // HACK(willchan): Really, we should move the HttpResponseDrainer logic into
134  // the HttpStream implementation. This is just a quick hack.
135  virtual bool IsSpdyHttpStream() const = 0;
136
137 private:
138  DISALLOW_COPY_AND_ASSIGN(HttpStream);
139};
140
141}  // namespace net
142
143#endif  // NET_HTTP_HTTP_STREAM_H_
144