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// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "net/dns/single_request_host_resolver.h"
#include "base/bind.h"
#include "base/bind_helpers.h"
#include "base/compiler_specific.h"
#include "base/logging.h"
#include "net/base/net_errors.h"
namespace net {
SingleRequestHostResolver::SingleRequestHostResolver(HostResolver* resolver)
: resolver_(resolver),
cur_request_(NULL),
callback_(
base::Bind(&SingleRequestHostResolver::OnResolveCompletion,
base::Unretained(this))) {
DCHECK(resolver_ != NULL);
}
SingleRequestHostResolver::~SingleRequestHostResolver() {
Cancel();
}
int SingleRequestHostResolver::Resolve(const HostResolver::RequestInfo& info,
RequestPriority priority,
AddressList* addresses,
const CompletionCallback& callback,
const BoundNetLog& net_log) {
DCHECK(addresses);
DCHECK_EQ(false, callback.is_null());
DCHECK(cur_request_callback_.is_null()) << "resolver already in use";
HostResolver::RequestHandle request = NULL;
// We need to be notified of completion before |callback| is called, so that
// we can clear out |cur_request_*|.
CompletionCallback transient_callback =
callback.is_null() ? CompletionCallback() : callback_;
int rv = resolver_->Resolve(
info, priority, addresses, transient_callback, &request, net_log);
if (rv == ERR_IO_PENDING) {
DCHECK_EQ(false, callback.is_null());
// Cleared in OnResolveCompletion().
cur_request_ = request;
cur_request_callback_ = callback;
}
return rv;
}
void SingleRequestHostResolver::Cancel() {
if (!cur_request_callback_.is_null()) {
resolver_->CancelRequest(cur_request_);
cur_request_ = NULL;
cur_request_callback_.Reset();
}
}
void SingleRequestHostResolver::OnResolveCompletion(int result) {
DCHECK(cur_request_);
DCHECK_EQ(false, cur_request_callback_.is_null());
CompletionCallback callback = cur_request_callback_;
// Clear the outstanding request information.
cur_request_ = NULL;
cur_request_callback_.Reset();
// Call the user's original callback.
callback.Run(result);
}
} // namespace net
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