chrome/browser/extensions/blob_reader.cc

   1 // Copyright 2013 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 "chrome/browser/extensions/blob_reader.h"
   6
   7 #include "base/format_macros.h"
   8 #include "base/strings/string_util.h"
   9 #include "base/strings/stringprintf.h"
  10 #include "chrome/browser/profiles/profile.h"
  11 #include "content/public/browser/browser_thread.h"
  12 #include "net/http/http_request_headers.h"
  13 #include "net/http/http_response_headers.h"
  14 #include "net/url_request/url_fetcher.h"
  15 #include "net/url_request/url_request_context.h"
  16 #include "net/url_request/url_request_context_getter.h"
  17
  18 BlobReader::BlobReader(Profile* profile,
  19                        const std::string& blob_uuid,
  20                        BlobReadCallback callback)
  21     : callback_(callback) {
  22   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
  23   GURL blob_url;
  24   if (StartsWithASCII(blob_uuid, "blob:blobinternal", true)) {
  25     // TODO(michaeln): remove support for deprecated blob urls
  26     blob_url = GURL(blob_uuid);
  27   } else {
  28     blob_url = GURL(std::string("blob:uuid/") + blob_uuid);
  29   }
  30   DCHECK(blob_url.is_valid());
  31   fetcher_.reset(net::URLFetcher::Create(
  32       blob_url, net::URLFetcher::GET,
  33       this));
  34   fetcher_->SetRequestContext(profile->GetRequestContext());
  35 }
  36
  37 BlobReader::~BlobReader() { DCHECK_CURRENTLY_ON(content::BrowserThread::UI); }
  38
  39 void BlobReader::SetByteRange(int64 offset, int64 length) {
  40   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
  41   CHECK_GE(offset, 0);
  42   CHECK_GT(length, 0);
  43   CHECK_LE(offset, kint64max - length);
  44
  45   net::HttpRequestHeaders headers;
  46   headers.SetHeader(
  47       net::HttpRequestHeaders::kRange,
  48       base::StringPrintf("bytes=%" PRId64 "-%" PRId64, offset,
  49                          offset + length - 1));
  50   fetcher_->SetExtraRequestHeaders(headers.ToString());
  51 }
  52
  53 void BlobReader::Start() {
  54   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
  55   fetcher_->Start();
  56 }
  57
  58 // Overridden from net::URLFetcherDelegate.
  59 void BlobReader::OnURLFetchComplete(const net::URLFetcher* source) {
  60   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
  61   scoped_ptr<std::string> response(new std::string);
  62   int64 first = 0, last = 0, length = 0;
  63   source->GetResponseAsString(response.get());
  64   source->GetResponseHeaders()->GetContentRange(&first, &last, &length);
  65   callback_.Run(response.Pass(), length);
  66
  67   delete this;
  68 }