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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 PPAPI_CPP_URL_LOADER_H_
6 #define PPAPI_CPP_URL_LOADER_H_
7 
8 #include "ppapi/c/pp_stdint.h"
9 #include "ppapi/cpp/resource.h"
10 
11 /// @file
12 /// This file defines the API for loading URLs.
13 namespace pp {
14 
15 class CompletionCallback;
16 class InstanceHandle;
17 class URLRequestInfo;
18 class URLResponseInfo;
19 
20 /// URLLoader provides an API for loading URLs.
21 /// Refer to <code>ppapi/examples/url_loader/streaming.cc</code>
22 /// for an example of how to use this class.
23 class URLLoader : public Resource {
24  public:
25   /// Default constructor for creating an is_null()
26   /// <code>URLLoader</code> object.
URLLoader()27   URLLoader() {}
28 
29   /// A constructor used when a <code>PP_Resource</code> is provided as a
30   /// return value whose reference count we need to increment.
31   ///
32   /// @param[in] resource A <code>PP_Resource</code> corresponding to a
33   /// <code>URLLoader</code> resource.
34   explicit URLLoader(PP_Resource resource);
35 
36   /// A constructor used to allocate a new URLLoader in the browser. The
37   /// resulting object will be <code>is_null</code> if the allocation failed.
38   ///
39   /// @param[in] instance The instance with which this resource will be
40   /// associated.
41   explicit URLLoader(const InstanceHandle& instance);
42 
43   /// The copy constructor for <code>URLLoader</code>.
44   ///
45   /// @param other A <code>URLLoader</code> to be copied.
46   URLLoader(const URLLoader& other);
47 
48   /// This function begins loading the <code>URLRequestInfo</code>.
49   /// The operation completes when response headers are received or when an
50   /// error occurs.  Use GetResponseInfo() to access the response
51   /// headers.
52   ///
53   /// @param[in] request_info A <code>URLRequestInfo</code> corresponding to a
54   /// URLRequestInfo.
55   /// @param[in] cc A <code>CompletionCallback</code> to run on asynchronous
56   /// completion of Open(). This callback will run when response
57   /// headers for the url are received or error occurred. This callback
58   /// will only run if Open() returns <code>PP_OK_COMPLETIONPENDING</code>.
59   ///
60   /// @return An int32_t containing an error code from
61   /// <code>pp_errors.h</code>.
62   int32_t Open(const URLRequestInfo& request_info,
63                const CompletionCallback& cc);
64 
65   /// This function can be invoked to follow a
66   /// redirect after Open() completed on receiving redirect headers.
67   ///
68   /// @param[in] cc A <code>CompletionCallback</code> to run on asynchronous
69   /// completion of FollowRedirect(). This callback will run when response
70   /// headers for the redirect url are received or error occurred. This callback
71   /// will only run if FollowRedirect() returns
72   /// <code>PP_OK_COMPLETIONPENDING</code>.
73   ///
74   /// @return An int32_t containing an error code from
75   /// <code>pp_errors.h</code>.
76   int32_t FollowRedirect(const CompletionCallback& cc);
77 
78   /// This function returns the current upload progress (which is only
79   /// meaningful after Open() has been called). Progress only refers to the
80   /// request body and does not include the headers.
81   ///
82   /// This data is only available if the <code>URLRequestInfo</code> passed to
83   /// Open() had the
84   /// <code>PP_URLREQUESTPROPERTY_REPORTUPLOADPROGRESS</code> property set to
85   /// <code>PP_TRUE</code>.
86   ///
87   /// @param[in] bytes_sent The number of bytes sent thus far.
88   /// @param[in] total_bytes_to_be_sent The total number of bytes to be sent.
89   ///
90   /// @return true if the upload progress is available, false if it is not
91   /// available.
92   bool GetUploadProgress(int64_t* bytes_sent,
93                          int64_t* total_bytes_to_be_sent) const;
94 
95   /// This function returns the current download progress, which is meaningful
96   /// after Open() has been called. Progress only refers to the response body
97   /// and does not include the headers.
98   ///
99   /// This data is only available if the <code>URLRequestInfo</code> passed to
100   /// Open() had the
101   /// <code>PP_URLREQUESTPROPERTY_REPORTDOWNLOADPROGRESS</code> property set to
102   /// PP_TRUE.
103   ///
104   /// @param[in] bytes_received The number of bytes received thus far.
105   /// @param[in] total_bytes_to_be_received The total number of bytes to be
106   /// received. The total bytes to be received may be unknown, in which case
107   /// <code>total_bytes_to_be_received</code> will be set to -1.
108   ///
109   /// @return true if the download progress is available, false if it is
110   /// not available.
111   bool GetDownloadProgress(int64_t* bytes_received,
112                            int64_t* total_bytes_to_be_received) const;
113 
114   /// This is a function that returns the current
115   /// <code>URLResponseInfo</code> object.
116   ///
117   /// @return A <code>URLResponseInfo</code> corresponding to the
118   /// <code>URLResponseInfo</code> if successful, an <code>is_null</code>
119   /// object if the loader is not a valid resource or if Open() has not been
120   /// called.
121   URLResponseInfo GetResponseInfo() const;
122 
123   /// This function is used to read the response body. The size of the buffer
124   /// must be large enough to hold the specified number of bytes to read.
125   /// This function might perform a partial read.
126   ///
127   /// @param[in,out] buffer A pointer to the buffer for the response body.
128   /// @param[in] bytes_to_read The number of bytes to read.
129   /// @param[in] cc A <code>CompletionCallback</code> to run on asynchronous
130   /// completion. The callback will run if the bytes (full or partial) are
131   /// read or an error occurs asynchronously. This callback will run only if
132   /// this function returns <code>PP_OK_COMPLETIONPENDING</code>.
133   ///
134   /// @return An int32_t containing the number of bytes read or an error code
135   /// from <code>pp_errors.h</code>.
136   int32_t ReadResponseBody(void* buffer,
137                            int32_t bytes_to_read,
138                            const CompletionCallback& cc);
139 
140   /// This function is used to wait for the response body to be completely
141   /// downloaded to the file provided by the GetBodyAsFileRef() in the current
142   /// <code>URLResponseInfo</code>. This function is only used if
143   /// <code>PP_URLREQUESTPROPERTY_STREAMTOFILE</code> was set on the
144   /// <code>URLRequestInfo</code> passed to Open().
145   ///
146   /// @param[in] cc A <code>CompletionCallback</code> to run on asynchronous
147   /// completion. This callback will run when body is downloaded or an error
148   /// occurs after FinishStreamingToFile() returns
149   /// <code>PP_OK_COMPLETIONPENDING</code>.
150   ///
151   /// @return An int32_t containing the number of bytes read or an error code
152   /// from <code>pp_errors.h</code>.
153   int32_t FinishStreamingToFile(const CompletionCallback& cc);
154 
155   /// This function is used to cancel any pending IO and close the URLLoader
156   /// object. Any pending callbacks will still run, reporting
157   /// <code>PP_ERROR_ABORTED</code> if pending IO was interrupted.  It is NOT
158   /// valid to call Open() again after a call to this function.
159   ///
160   /// <strong>Note:</strong> If the <code>URLLoader</code> object is destroyed
161   /// while it is still open, then it will be implicitly closed so you are not
162   /// required to call Close().
163   void Close();
164 };
165 
166 }  // namespace pp
167 
168 #endif  // PPAPI_CPP_URL_LOADER_H_
169