cpp/src/rule_retriever.cc

// 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.

#include "rule_retriever.h"

#include <libaddressinput/callback.h>

#include <cassert>
#include <cstddef>
#include <memory>
#include <string>

#include "retriever.h"
#include "rule.h"

namespace i18n {
namespace addressinput {

namespace {

class Helper {
 public:
  Helper(const Helper&) = delete;
  Helper& operator=(const Helper&) = delete;

  Helper(const std::string& key,
         const RuleRetriever::Callback& rule_ready,
         const Retriever& data_retriever)
      : rule_ready_(rule_ready),
        data_retrieved_(BuildCallback(this, &Helper::OnDataRetrieved)) {
    data_retriever.Retrieve(key, *data_retrieved_);
  }

 private:
  ~Helper() = default;

  void OnDataRetrieved(bool success,
                       const std::string& key,
                       const std::string& data) {
    Rule rule;
    if (!success) {
      rule_ready_(false, key, rule);
    } else {
      success = rule.ParseSerializedRule(data);
      rule_ready_(success, key, rule);
    }
    delete this;
  }

  const RuleRetriever::Callback& rule_ready_;
  const std::unique_ptr<const Retriever::Callback> data_retrieved_;
};

}  // namespace

RuleRetriever::RuleRetriever(const Retriever* retriever)
    : data_retriever_(retriever) {
  assert(data_retriever_ != nullptr);
}

RuleRetriever::~RuleRetriever() = default;

void RuleRetriever::RetrieveRule(const std::string& key,
                                 const Callback& rule_ready) const {
  new Helper(key, rule_ready, *data_retriever_);
}

}  // namespace addressinput
}  // namespace i18n