[rac] Temporarily copy libaddressinput to Chrome.

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

+// Copyright (C) 2013 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.
+//
+// Functions for working with lookup keys. The lookup keys are strings that
+// identify serialized validation rules.
+
+#ifndef I18N_ADDRESSINPUT_LOOKUP_KEY_UTIL_H_
+#define I18N_ADDRESSINPUT_LOOKUP_KEY_UTIL_H_
+
+#include <string>
+
+namespace i18n {
+namespace addressinput {
+
+// Utility functions for lookup keys. Sample usage:
+//    LookupKeyUtil lookup_keys("https://i18napis.appspot.com/ssl-address/");
+//    Download(lookup_keys.GetUrlForKey("data/US"));
+class LookupKeyUtil {
+ public:
+  // Builds a lookup key utility for the |validation_data_url| parameter. The
+  // parameter must end with a '/'.
+  explicit LookupKeyUtil(const std::string& validation_data_url);
+  ~LookupKeyUtil();
+
+  // Returns the URL where the |key| can be retrieved. For example, returns
+  // "https://i18napis.appspot.com/ssl-address/data/US" for input "data/US".
+  // Assumes that the input string is a valid URL segment.
+  std::string GetUrlForKey(const std::string& key) const;
+
+  // Returns the key for the |url|. For example, returns "data/US" for
+  // "https://i18napis.appspot.com/ssl-address/data/US". If the |url| does not
+  // start with |validation_data_url| that was passed to the constructor, then
+  // returns an empty string. (This can happen if the user of the library
+  // returns a bad URL in their Downloader implementation.)
+  std::string GetKeyForUrl(const std::string& url) const;
+
+  // Returns true if the |url| starts with |validation_data_url| that was passed
+  // to the constructor.
+  bool IsValidationDataUrl(const std::string& url) const;
+
+ private:
+  const std::string validation_data_url_;
+};
+
+}  // namespace addressinput
+}  // namespace i18n
+
+#endif  // I18N_ADDRESSINPUT_LOOKUP_KEY_UTIL_H_