android_webview/browser/net/input_stream_reader.cc

   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 "android_webview/browser/net/input_stream_reader.h"
   6
   7 #include "android_webview/browser/input_stream.h"
   8 #include "base/message_loop/message_loop.h"
   9 #include "content/public/browser/browser_thread.h"
  10 #include "net/base/net_errors.h"
  11 #include "net/http/http_byte_range.h"
  12
  13 using content::BrowserThread;
  14
  15 namespace android_webview {
  16
  17 InputStreamReader::InputStreamReader(android_webview::InputStream* stream)
  18     : stream_(stream) {
  19   DCHECK(stream);
  20 }
  21
  22 InputStreamReader::~InputStreamReader() {
  23 }
  24
  25 int InputStreamReader::Seek(const net::HttpByteRange& byte_range) {
  26   int content_size = 0;
  27   net::HttpByteRange verified_byte_range(byte_range);
  28
  29   int error_code = VerifyRequestedRange(&verified_byte_range, &content_size);
  30   if (error_code != net::OK)
  31     return error_code;
  32
  33   error_code = SkipToRequestedRange(verified_byte_range);
  34   if (error_code != net::OK)
  35     return error_code;
  36
  37   DCHECK_GE(content_size, 0);
  38   return content_size;
  39 }
  40
  41 int InputStreamReader::ReadRawData(net::IOBuffer* dest, int dest_size) {
  42   if (!dest_size)
  43     return 0;
  44
  45   DCHECK_GT(dest_size, 0);
  46
  47   int bytes_read = 0;
  48   if (!stream_->Read(dest, dest_size, &bytes_read))
  49     return net::ERR_FAILED;
  50   else
  51     return bytes_read;
  52 }
  53
  54 int InputStreamReader::VerifyRequestedRange(net::HttpByteRange* byte_range,
  55                                             int* content_size) {
  56   DCHECK(content_size);
  57   int32_t size = 0;
  58   if (!stream_->BytesAvailable(&size))
  59     return net::ERR_FAILED;
  60
  61   if (size <= 0)
  62     return net::OK;
  63
  64   // Check that the requested range was valid.
  65   if (!byte_range->ComputeBounds(size))
  66     return net::ERR_REQUEST_RANGE_NOT_SATISFIABLE;
  67
  68   size = byte_range->last_byte_position() -
  69          byte_range->first_byte_position() + 1;
  70   DCHECK_GE(size, 0);
  71   *content_size = size;
  72
  73   return net::OK;
  74 }
  75
  76 int InputStreamReader::SkipToRequestedRange(
  77     const net::HttpByteRange& byte_range) {
  78   // Skip to the start of the requested data. This has to be done in a loop
  79   // because the underlying InputStream is not guaranteed to skip the requested
  80   // number of bytes.
  81   if (byte_range.IsValid() && byte_range.first_byte_position() > 0) {
  82     int64_t bytes_to_skip = byte_range.first_byte_position();
  83     do {
  84       int64_t skipped = 0;
  85       if (!stream_->Skip(bytes_to_skip, &skipped))
  86         return net::ERR_FAILED;
  87
  88       if (skipped <= 0)
  89         return net::ERR_REQUEST_RANGE_NOT_SATISFIABLE;
  90       DCHECK_LE(skipped, bytes_to_skip);
  91
  92       bytes_to_skip -= skipped;
  93     } while (bytes_to_skip > 0);
  94   }
  95   return net::OK;
  96 }
  97
  98 } // namespace android_webview