[rac] Download all rules for a country code in libaddressinput.

third_party/libaddressinput/chromium/cpp/src/country_rules_retriever.cc

+// 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.
+
+#include "country_rules_retriever.h"
+
+#include <libaddressinput/address_field.h>
+#include <libaddressinput/callback.h>
+#include <libaddressinput/util/basictypes.h>
+#include <libaddressinput/util/scoped_ptr.h>
+
+#include <cassert>
+#include <cstddef>
+#include <map>
+#include <string>
+#include <utility>
+
+#include "retriever.h"
+#include "rule.h"
+#include "ruleset.h"
+#include "util/stl_util.h"
+
+namespace i18n {
+namespace addressinput {
+
+// Information about data requests sent to Retriever. This data is not returned
+// as part of the ruleset, but is useful in constructing the ruleset
+// asynchronously.
+struct CountryRulesRetriever::RequestData {
+  // Does not take ownership of |parent|.
+  RequestData(RulesetData* ruleset_data,
+              Ruleset* parent,
+              AddressField level,
+              bool is_language_code,
+              const std::string& id)
+      : ruleset_data(ruleset_data),
+        parent(parent),
+        level(level),
+        is_language_code(is_language_code),
+        id(id) {}
+
+  ~RequestData() {}
+
+  // Information about the ruleset being downloaded.
+  RulesetData* ruleset_data;
+
+  // The parent ruleset of the data being downloaded. If NULL, then this is the
+  // root ruleset at the COUNTRY level. The language-specific and sub-region
+  // rules are added to this ruleset. Owned by |RulesetData|.
+  Ruleset* parent;
+
+  // The level of the data being requested. Ranges from COUNTRY to
+  // DEPENDENT_LOCALITY. If COUNTRY, then the rule should use default rules from
+  // Rule::GetDefault().
+  AddressField level;
+
+  // If true, then |id| is a language. The data received for this request should
+  // be placed into a language-specific rule.
+  bool is_language_code;
+
+  // Can be a region name (e.g. "CA") or a language (e.g. "fr"). Used to add a
+  // sub-region or a language-specific rule to |parent|.
+  std::string id;
+};
+
+// Stores information about a ruleset that is being retrieved for a country
+// code.
+class CountryRulesRetriever::RulesetData {
+ public:
+  RulesetData(const std::string& country_code,
+              scoped_ptr<CountryRulesRetriever::Callback> rules_ready)
+      : country_code_(country_code),
+        rules_ready_(rules_ready.Pass()),
+        root_(),
+        num_requested_(0),
+        num_received_(0),
+        success_(true),
+        default_language_(),
+        languages_() {}
+
+  ~RulesetData() {}
+
+  // Sends the |root_| ruleset to |rules_ready_| callback.
+  void InvokeRulesReadyCallback() {
+    (*rules_ready_)(success_, country_code_, root_.Pass());
+  }
+
+  // The country code for which to retrieve the ruleset. Passed to the callback
+  // method to identify the ruleset. Examples: "US", "CA", "CH", etc.
+  const std::string country_code_;
+
+  // The callback to invoke when the ruleset has been retrieved.
+  scoped_ptr<CountryRulesRetriever::Callback> rules_ready_;
+
+  // The top-level ruleset for the country code. Passed to the callback method
+  // as the result of the query.
+  scoped_ptr<Ruleset> root_;
+
+  // The number of requests sent to Retriever. Used to keep track of pending
+  // requests.
+  int num_requested_;
+
+  // The number of responses received from Retriever. Used to determine when the
+  // ruleset construction is finished, by comparing this number to
+  // |num_requested_|.
+  int num_received_;
+
+  // True if all requests to Retriever succeeded. Passed to the callback method
+  // as an indication of whether ruleset retrieval succeeded.
+  bool success_;
+
+  // The default language for the country code. This value is parsed from the
+  // country-level rule for the country code and is used to filter out the
+  // default language from the list of all supported languages for a country.
+  // For example, the list of supported languages for Canada is ["en", "fr"],
+  // but the default language is "en". Data requests for "data/CA/AB--fr" will
+  // succeed, but "data/CA/AB--en" will not return data.
+  std::string default_language_;
+
+  // The list of all supported languages for the country code. This value is
+  // parsed from the country-level rule for the country and is used to download
+  // language-specific rules.
+  std::vector<std::string> languages_;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(RulesetData);
+};
+
+CountryRulesRetriever::CountryRulesRetriever(scoped_ptr<Retriever> retriever)
+    : retriever_(retriever.Pass()) {
+  assert(retriever_ != NULL);
+}
+
+CountryRulesRetriever::~CountryRulesRetriever() {
+  STLDeleteContainerPointers(rulesets_.begin(), rulesets_.end());
+}
+
+void CountryRulesRetriever::RetrieveRules(
+    const std::string& country_code,
+    scoped_ptr<Callback> rules_ready) {
+  RulesetData* ruleset_data = new RulesetData(country_code, rules_ready.Pass());
+  rulesets_.push_back(ruleset_data);

[Evan Stade, 2014/01/07 20:09:58]

why would you need to retrieve rules for more than one country at a time?

[please use gerrit instead, 2014/01/07 22:11:08]

The user might rapidly switch the country combobox in the UI (faster than all
Downloader requests have finished).

[Evan Stade, 2014/01/07 22:13:13]

in which case you could/should probably abandon the old request, no? Like if I
hold the down arrow key and it runs through all the countries, I don't really
want to have it download all rules known to mankind.

[please use gerrit instead, 2014/01/07 22:57:09]

Done.

+
+  // Key construction:
+  // https://code.google.com/p/libaddressinput/wiki/AddressValidationMetadata
+  // Example of a country-level key: "data/CA".
+  std::string key = "data/" + ruleset_data->country_code_;
+  requests_.insert(std::make_pair(
+      key, RequestData(ruleset_data, NULL, COUNTRY, false, std::string())));
+
+  ++ruleset_data->num_requested_;
+  retriever_->Retrieve(
+      key, BuildCallback(this, &CountryRulesRetriever::OnDataReady));
+}
+
+void CountryRulesRetriever::OnDataReady(bool success,
+                                        const std::string& key,
+                                        const std::string& data) {
+  std::map<std::string, RequestData>::iterator request_it =
+      requests_.find(key);

[Evan Stade, 2014/01/07 20:09:58]

remove request_it now that you're done with it after this fn?

[please use gerrit instead, 2014/01/07 22:11:08]

Done.

+  assert(request_it != requests_.end());
+  RequestData& request = request_it->second;
+
+  RulesetData* ruleset_data = request.ruleset_data;
+  assert(ruleset_data != NULL);
+
+  ruleset_data->success_ &= success;
+  ++ruleset_data->num_received_;
+
+  // All country-level rules are based on the default rule.
+  scoped_ptr<Rule> rule(new Rule);
+  if (request.level == COUNTRY) {
+    rule->CopyFrom(Rule::GetDefault());
+  }
+
+  ruleset_data->success_ &= rule->ParseSerializedRule(data);
+
+  // Place the rule in the correct location in the ruleset.
+  Ruleset* ruleset = NULL;
+  if (request.is_language_code) {
+    assert(request.parent != NULL);
+    request.parent->AddLanguageCode(request.id, rule.Pass());
+    ruleset = request.parent;
+  } else if (request.level == COUNTRY) {
+    // The default language and all supported languages for the country code are
+    // in the country-level rule without a language code identifier. For
+    // example: "data/CA".
+    ruleset_data->default_language_ = rule->GetLanguage();
+    ruleset_data->languages_ = rule->GetLanguages();
+
+    ruleset_data->root_.reset(new Ruleset(rule.Pass()));
+    ruleset = ruleset_data->root_.get();
+  } else {
+    assert(request.parent != NULL);
+    ruleset = request.parent->AddSubRegion(request.id, rule.Pass());
+  }
+
+  if (!request.is_language_code) {
+    // Retrieve the language-specific rules for this region.
+    for (std::vector<std::string>::const_iterator
+         lang_it = ruleset_data->languages_.begin();
+         lang_it != ruleset_data->languages_.end();
+         ++lang_it) {
+      if (*lang_it == ruleset_data->default_language_) {
+        continue;
+      }
+      // Example of a language-specific key: "data/CA--fr".
+      std::string language_code_key = key + "--" + *lang_it;
+      requests_.insert(std::make_pair(
+          key,
+          RequestData(ruleset_data, ruleset, request.level, true, *lang_it)));
+      ++ruleset_data->num_requested_;
+      retriever_->Retrieve(
+          language_code_key,
+          BuildCallback(this, &CountryRulesRetriever::OnDataReady));
+    }
+
+    if (request.level < DEPENDENT_LOCALITY) {
+      // Retrieve the sub-region rules for this region.
+      for (std::vector<std::string>::const_iterator
+           subkey_it = ruleset->rule().GetSubKeys().begin();
+           subkey_it != ruleset->rule().GetSubKeys().end();
+           ++subkey_it) {
+        // Example of a sub-region key: "data/CA/AB".
+        std::string sub_region_key = key + "/" + *subkey_it;
+        requests_.insert(std::make_pair(
+            key,
+            RequestData(ruleset_data,
+                        ruleset,
+                        static_cast<AddressField>(request.level + 1),
+                        false,
+                        *subkey_it)));
+        ++ruleset_data->num_requested_;
+        retriever_->Retrieve(
+            sub_region_key,
+            BuildCallback(this, &CountryRulesRetriever::OnDataReady));
+      }
+    }
+  }
+
+  if (ruleset_data->num_received_ == ruleset_data->num_requested_) {
+    ruleset_data->InvokeRulesReadyCallback();
+    std::vector<RulesetData*>::iterator ruleset_it =
+        std::find(rulesets_.begin(), rulesets_.end(), ruleset_data);
+    assert(ruleset_it != rulesets_.end());
+    rulesets_.erase(ruleset_it);
+    delete ruleset_data;
+  }
+}
+
+}  // namespace addressinput
+}  // namespace i18n