| Index: net/url_request/url_request_simple_job.cc
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| diff --git a/net/url_request/url_request_simple_job.cc b/net/url_request/url_request_simple_job.cc
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| index ebc2b5dfe44800f50f2489466f5145eebceaa3be..b50bbc8173b0c76bbc1503f2151ef439ff4aea55 100644
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| --- a/net/url_request/url_request_simple_job.cc
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| +++ b/net/url_request/url_request_simple_job.cc
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| @@ -11,6 +11,7 @@
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|  #include "base/memory/ref_counted_memory.h"
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|  #include "base/message_loop/message_loop.h"
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|  #include "base/profiler/scoped_tracker.h"
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| +#include "base/threading/worker_pool.h"
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|  #include "net/base/io_buffer.h"
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|  #include "net/base/net_errors.h"
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|  #include "net/http/http_request_headers.h"
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| @@ -19,11 +20,28 @@
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|  
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|  namespace net {
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|  
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| -URLRequestSimpleJob::URLRequestSimpleJob(
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| -    URLRequest* request, NetworkDelegate* network_delegate)
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| +namespace {
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| +
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| +void CopyData(const scoped_refptr<IOBuffer>& buf,
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| +              int buf_size,
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| +              const scoped_refptr<base::RefCountedMemory>& data,
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| +              int64 data_offset) {
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| +  // TODO(vadimt): Remove ScopedTracker below once crbug.com/422489 is fixed.
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| +  tracked_objects::ScopedTracker tracking_profile(
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| +      FROM_HERE_WITH_EXPLICIT_FUNCTION("422489 CopyData"));
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| +
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| +  memcpy(buf->data(), data->front() + data_offset, buf_size);
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| +}
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| +
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| +}  // namespace
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| +
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| +URLRequestSimpleJob::URLRequestSimpleJob(URLRequest* request,
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| +                                         NetworkDelegate* network_delegate)
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|      : URLRangeRequestJob(request, network_delegate),
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| -      data_offset_(0),
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| -      weak_factory_(this) {}
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| +      next_data_offset_(0),
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| +      task_runner_(base::WorkerPool::GetTaskRunner(false)),
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| +      weak_factory_(this) {
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| +}
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|  
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|  void URLRequestSimpleJob::Start() {
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|    // Start reading asynchronously so that all error reporting and data
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| @@ -53,13 +71,33 @@ bool URLRequestSimpleJob::ReadRawData(IOBuffer* buf, int buf_size,
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|            "422489 URLRequestSimpleJob::ReadRawData"));
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|  
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|    DCHECK(bytes_read);
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| -  buf_size = static_cast<int>(std::min(
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| -      static_cast<int64>(buf_size),
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| -      byte_range_.last_byte_position() - data_offset_ + 1));
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| -  memcpy(buf->data(), data_->front() + data_offset_, buf_size);
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| -  data_offset_ += buf_size;
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| -  *bytes_read = buf_size;
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| -  return true;
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| +  buf_size = static_cast<int>(
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| +      std::min(static_cast<int64>(buf_size),
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| +               byte_range_.last_byte_position() - next_data_offset_ + 1));
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| +  DCHECK_GE(buf_size, 0);
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| +  if (buf_size == 0) {
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| +    *bytes_read = 0;
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| +    return true;
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| +  }
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| +
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| +  // Do memory copy on a background thread. See crbug.com/422489.
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| +  GetTaskRunner()->PostTaskAndReply(
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| +      FROM_HERE, base::Bind(&CopyData, make_scoped_refptr(buf), buf_size, data_,
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| +                            next_data_offset_),
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| +      base::Bind(&URLRequestSimpleJob::OnReadCompleted,
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| +                 weak_factory_.GetWeakPtr(), buf_size));
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| +  next_data_offset_ += buf_size;
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| +  SetStatus(net::URLRequestStatus(net::URLRequestStatus::IO_PENDING, 0));
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| +  return false;
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| +}
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| +
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| +void URLRequestSimpleJob::OnReadCompleted(int bytes_read) {
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| +  SetStatus(net::URLRequestStatus());
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| +  NotifyReadComplete(bytes_read);
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| +}
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| +
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| +base::TaskRunner* URLRequestSimpleJob::GetTaskRunner() const {
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| +  return task_runner_.get();
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|  }
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|  
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|  int URLRequestSimpleJob::GetData(std::string* mime_type,
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| @@ -137,9 +175,9 @@ void URLRequestSimpleJob::OnGetDataCompleted(int result) {
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|        return;
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|      }
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|  
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| -    data_offset_ = byte_range_.first_byte_position();
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| -    set_expected_content_size(
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| -        byte_range_.last_byte_position() - data_offset_ + 1);
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| +    next_data_offset_ = byte_range_.first_byte_position();
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| +    set_expected_content_size(byte_range_.last_byte_position() -
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| +                              next_data_offset_ + 1);
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|      NotifyHeadersComplete();
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|    } else {
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|      NotifyStartError(URLRequestStatus(URLRequestStatus::FAILED, result));
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| 
 |