[rac] Use stale libaddressinput data if download fails

third_party/libaddressinput/chromium/cpp/src/wrapper.h

+// Copyright (C) 2014 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// An object to wrap data with a checksum and a timestamp. These fields are used
+// to verify that the data is not stale or corrupted.
+
+#ifndef I18N_ADDRESSINPUT_WRAPPER_H_
+#define I18N_ADDRESSINPUT_WRAPPER_H_
+
+#include <string>
+
+namespace i18n {
+namespace addressinput {
+
+// Wraps data with a checksum and a timestamp. Sample usage:
+//    std::string data = ...
+//    std::string wrapped = Wrapper::Wrap(data);
+//    Process(wrapped);
+//
+//    std::string unwrapped = wrapped;
+//    double age_in_seconds = 0.0;
+//    if (Wrapper::Unwrap(&unwrapped, &age_in_seconds) &&
+//        IsRecent(age_in_seconds)) {
+//      Process(unwrapped);
+//    }
+class Wrapper {

[Evan Stade, 2014/01/23 00:07:23]

Wrapper is far too generic a name to be useful. You might as well call it class
Foo.

Why not put this in an anonymous namespace in retriever.cc[1]? If the only
answer is "testing", I think you could still test it effectively, and the tests
you wrote would even be superior in that they'd be testing behavior rather than
implementation.

[1]I know that before I said this wasn't necessary, but being unable to come up
with a decent name for the class is perhaps an indication it's not generically
useful, so should be folded into Retriever.

[please use gerrit instead, 2014/01/23 01:03:14]

Done.

+ public:
+  // Returns |data| with attached checksum and current timestamp.
+  static std::string Wrap(const std::string& data);
+
+  // Strips out the timestamp and checksum from |data|. Validates the checksum.
+  // Compares the parsed timestamp with current time and saves the difference
+  // into |age_in_seconds|.
+  //
+  // The parameters should not be NULL. Does not take ownership of its
+  // parameters.
+  //
+  // Returns |true| if |data| is correctly formatted and has the correct
+  // checksum.
+  static bool Unwrap(std::string* data, double* age_in_seconds);
+};
+
+}  // namespace addressinput
+}  // namespace i18n
+
+#endif  // I18N_ADDRESSINPUT_WRAPPER_H_