1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
|
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CONTENT_BROWSER_LOADER_MIME_TYPE_RESOURCE_HANDLER_H_
#define CONTENT_BROWSER_LOADER_MIME_TYPE_RESOURCE_HANDLER_H_
#include <string>
#include <vector>
#include "base/memory/weak_ptr.h"
#include "content/browser/loader/layered_resource_handler.h"
#include "content/common/content_export.h"
#include "content/public/browser/resource_controller.h"
namespace net {
class URLRequest;
}
namespace content {
class PluginService;
class ResourceDispatcherHostImpl;
struct WebPluginInfo;
// ResourceHandler that, if necessary, buffers a response body without passing
// it to the next ResourceHandler until it can perform mime sniffing on it.
// Once a response's MIME type is known, initiates special handling of the
// response if needed (starts downloads, sends data to some plugin types via a
// special channel).
//
// Uses the buffer provided by the original event handler for buffering, and
// continues to reuses it until it can determine the MIME type
// subsequent reads until it's done buffering. As a result, the buffer
// returned by the next ResourceHandler must have a capacity of at least
// net::kMaxBytesToSniff * 2.
class CONTENT_EXPORT MimeTypeResourceHandler
: public LayeredResourceHandler,
public ResourceController {
public:
// If ENABLE_PLUGINS is defined, |plugin_service| must not be NULL.
MimeTypeResourceHandler(scoped_ptr<ResourceHandler> next_handler,
ResourceDispatcherHostImpl* host,
PluginService* plugin_service,
net::URLRequest* request);
~MimeTypeResourceHandler() override;
private:
// ResourceHandler implementation:
void SetController(ResourceController* controller) override;
bool OnResponseStarted(ResourceResponse* response, bool* defer) override;
bool OnWillRead(scoped_refptr<net::IOBuffer>* buf,
int* buf_size,
int min_size) override;
bool OnReadCompleted(int bytes_read, bool* defer) override;
void OnResponseCompleted(const net::URLRequestStatus& status,
const std::string& security_info,
bool* defer) override;
// ResourceController implementation:
void Resume() override;
void Cancel() override;
void CancelAndIgnore() override;
void CancelWithError(int error_code) override;
bool ProcessResponse(bool* defer);
bool ShouldSniffContent();
bool DetermineMimeType();
// Determines whether a plugin will handle the current request, and if so,
// sets up the handler to direct the response to that plugin. Returns false
// if there is an error and the request should be cancelled and true
// otherwise. |defer| is set to true if plugin data is stale and needs to be
// refreshed before the request can be handled (in this case the function
// still returns true). If the request is directed to a plugin,
// |handled_by_plugin| is set to true.
bool SelectPluginHandler(bool* defer, bool* handled_by_plugin);
// Returns false if the request should be cancelled.
bool SelectNextHandler(bool* defer);
bool UseAlternateNextHandler(scoped_ptr<ResourceHandler> handler,
const std::string& payload_for_old_handler);
bool ReplayReadCompleted(bool* defer);
void CallReplayReadCompleted();
bool MustDownload();
// Copies data from |read_buffer_| to |next_handler_|.
bool CopyReadBufferToNextHandler();
// Called on the IO thread once the list of plugins has been loaded.
void OnPluginsLoaded(const std::vector<WebPluginInfo>& plugins);
enum State {
STATE_STARTING,
// In this state, we are filling read_buffer_ with data for the purpose
// of sniffing the mime type of the response.
STATE_BUFFERING,
// In this state, we are select an appropriate downstream ResourceHandler
// based on the mime type of the response. We are also potentially waiting
// for plugins to load so that we can determine if a plugin is available to
// handle the mime type.
STATE_PROCESSING,
// In this state, we are replaying buffered events (OnResponseStarted and
// OnReadCompleted) to the downstream ResourceHandler.
STATE_REPLAYING,
// In this state, we are just a blind pass-through ResourceHandler.
STATE_STREAMING
};
State state_;
scoped_refptr<ResourceResponse> response_;
ResourceDispatcherHostImpl* host_;
PluginService* plugin_service_;
scoped_refptr<net::IOBuffer> read_buffer_;
int read_buffer_size_;
int bytes_read_;
bool must_download_;
bool must_download_is_set_;
base::WeakPtrFactory<MimeTypeResourceHandler> weak_ptr_factory_;
DISALLOW_COPY_AND_ASSIGN(MimeTypeResourceHandler);
};
} // namespace content
#endif // CONTENT_BROWSER_LOADER_MIME_TYPE_RESOURCE_HANDLER_H_
|