Retrieved Hostlist information from Directory service.

remoting/test/chromoting_host_list_fetcher.h

+// Copyright 2015 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.
+
+#ifndef REMOTING_TEST_CHROMOTING_HOST_LIST_FETCHER_H_
+#define REMOTING_TEST_CHROMOTING_HOST_LIST_FETCHER_H_
+
+#include <string>
+#include <vector>
+
+#include "base/callback.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "net/url_request/url_fetcher_delegate.h"
+#include "remoting/test/chromoting_host_info.h"
+
+namespace net {
+class UrlFetcher;
+}
+namespace remoting {
+class URLRequestContextGetter;
+}
+
+namespace remoting {
+namespace test {
+
+// Used by the HostlistFetcher to make HTTP requests and also by the
+// unittests for this class to set fake response data for these URLs.
+const char kChromotingHostListProdRequestUrl[] = "https://www.googleapis.com/"
+    "chromoting/v1/@me/hosts";
+
+// Requests a host list from the Directory service for an access token.
+// Destroying the RemoteHostInfoFetcher while a request is outstanding
+// will cancel the request. It is safe to delete the fetcher from within a
+// completion callback.  Must be used from a thread running an IO message loop.
+// The public method is virtual to allow for mocking and fakes.
+class ChromotingHostListFetcher : public net::URLFetcherDelegate {
+ public:
+  ChromotingHostListFetcher();
+  ~ChromotingHostListFetcher() override;
+
+  // Supplied by the client for each hostlist request and returns a valid,
+  // initialized Hostlist object on success.
+  typedef base::Callback<void(const std::vector<ChromotingHostInfo>& hostlist,
+                              bool request_success)>

[Sergey Ulanov, 2015/07/08 19:57:34]

nit: it's better to reverse the order of the parameters. hostlist is
meaniningful only if request_success=true;

[tonychun, 2015/07/08 22:38:16]

I've decided to take this out for two reasons:

1) Not knowing whether or not there was a parsing error or if the response was
empty is not critical to know at the callback. There is already logging for when
an parsing error occurs and neither case will have any hosts in their hostlist
to connect to.
2) If in the future this needs to be added, it is very simple to do. However, as
of now, it does not serve a meaningful purpose for my driver.

+    HostlistCallback;
+
+  // Makes a service call to retrieve a hostlist. The
+  // callback will be called once the HTTP request has completed.
+  virtual void RetrieveHostlist(const std::string& access_token,
+                                const HostlistCallback& callback);
+
+ private:
+  // Provides the callback a way to distinguish between an empty list from a
+  // a failed request.

[joedow, 2015/07/08 17:19:07]

I think this comment is a little off, this function processes the reponse from
the directory service.  It could be used w/o a callback if the internal
implementation changed.

[tonychun, 2015/07/08 22:38:16]

Done.

+  bool ProcessResponse(std::vector<ChromotingHostInfo>* hostlist);
+
+  // net::URLFetcherDelegate interface.
+  void OnURLFetchComplete(const net::URLFetcher* source) override;
+
+  // Holds the URLFetcher for the Chromoting Host List request.
+  scoped_ptr<net::URLFetcher> request_;
+
+  // Provides application-specific context for the network request.
+  scoped_refptr<remoting::URLRequestContextGetter> request_context_getter_;
+
+  // Caller-supplied callback used to return hostlist on success.
+  HostlistCallback hostlist_callback_;
+
+  DISALLOW_COPY_AND_ASSIGN(ChromotingHostListFetcher);
+};
+
+}  // namespace test
+}  // namespace remoting
+
+#endif  // REMOTING_TEST_CHROMOTING_HOST_LIST_FETCHER_H_