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 #include "components/embedder_support/android/util/input_stream_reader.h"
6
7 #include "components/embedder_support/android/util/input_stream.h"
8 #include "net/base/net_errors.h"
9 #include "net/http/http_byte_range.h"
10
11 namespace embedder_support {
12
InputStreamReader(InputStream * stream)13 InputStreamReader::InputStreamReader(InputStream* stream) : stream_(stream) {
14 DCHECK(stream);
15 }
16
~InputStreamReader()17 InputStreamReader::~InputStreamReader() {}
18
Seek(const net::HttpByteRange & byte_range)19 int InputStreamReader::Seek(const net::HttpByteRange& byte_range) {
20 int content_size = 0;
21 net::HttpByteRange verified_byte_range(byte_range);
22
23 int error_code = VerifyRequestedRange(&verified_byte_range, &content_size);
24 if (error_code != net::OK)
25 return error_code;
26
27 error_code = SkipToRequestedRange(verified_byte_range);
28 if (error_code != net::OK)
29 return error_code;
30
31 DCHECK_GE(content_size, 0);
32 return content_size;
33 }
34
ReadRawData(net::IOBuffer * dest,int dest_size)35 int InputStreamReader::ReadRawData(net::IOBuffer* dest, int dest_size) {
36 if (!dest_size)
37 return 0;
38
39 DCHECK_GT(dest_size, 0);
40
41 int bytes_read = 0;
42 if (!stream_->Read(dest, dest_size, &bytes_read))
43 return net::ERR_FAILED;
44 else
45 return bytes_read;
46 }
47
VerifyRequestedRange(net::HttpByteRange * byte_range,int * content_size)48 int InputStreamReader::VerifyRequestedRange(net::HttpByteRange* byte_range,
49 int* content_size) {
50 DCHECK(content_size);
51 int32_t size = 0;
52 if (!stream_->BytesAvailable(&size))
53 return net::ERR_FAILED;
54
55 if (size <= 0)
56 return net::OK;
57
58 // Check that the requested range was valid.
59 if (!byte_range->ComputeBounds(size))
60 return net::ERR_REQUEST_RANGE_NOT_SATISFIABLE;
61
62 size =
63 byte_range->last_byte_position() - byte_range->first_byte_position() + 1;
64 DCHECK_GE(size, 0);
65 *content_size = size;
66
67 return net::OK;
68 }
69
SkipToRequestedRange(const net::HttpByteRange & byte_range)70 int InputStreamReader::SkipToRequestedRange(
71 const net::HttpByteRange& byte_range) {
72 // Skip to the start of the requested data. This has to be done in a loop
73 // because the underlying InputStream is not guaranteed to skip the requested
74 // number of bytes.
75 if (byte_range.IsValid() && byte_range.first_byte_position() > 0) {
76 int64_t bytes_to_skip = byte_range.first_byte_position();
77 do {
78 int64_t skipped = 0;
79 if (!stream_->Skip(bytes_to_skip, &skipped))
80 return net::ERR_FAILED;
81
82 if (skipped <= 0)
83 return net::ERR_REQUEST_RANGE_NOT_SATISFIABLE;
84 DCHECK_LE(skipped, bytes_to_skip);
85
86 bytes_to_skip -= skipped;
87 } while (bytes_to_skip > 0);
88 }
89 return net::OK;
90 }
91
92 } // namespace embedder_support
93