/*
 * Copyright 2010 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.
 */

// Author: jmarantz@google.com (Joshua Marantz)

#include "pagespeed/kernel/cache/lru_cache.h"

#include <cstddef>
#include "pagespeed/kernel/base/cache_interface.h"
#include "pagespeed/kernel/base/shared_string.h"
#include "pagespeed/kernel/base/string.h"

namespace net_instaweb {

LRUCache::LRUCache(size_t max_size)
    : base_(max_size, &value_helper_),
      is_healthy_(true) {
  ClearStats();
}

LRUCache::~LRUCache() {
  Clear();
}

void LRUCache::Get(const GoogleString& key, Callback* callback) {
  if (!is_healthy_) {
    ValidateAndReportResult(key, kNotFound, callback);
    return;
  }
  KeyState key_state = kNotFound;
  SharedString* value = base_.GetFreshen(key);
  if (value != NULL) {
    key_state = kAvailable;
    *callback->value() = *value;
  }
  ValidateAndReportResult(key, key_state, callback);
}

void LRUCache::Put(const GoogleString& key, SharedString* new_value) {
  if (!is_healthy_) {
    return;
  }

  base_.Put(key, new_value);
}

void LRUCache::Delete(const GoogleString& key) {
  if (!is_healthy_) {
    return;
  }

  base_.Delete(key);
}

void LRUCache::DeleteWithPrefixForTesting(StringPiece prefix) {
  if (!is_healthy_) {
    return;
  }

  base_.DeleteWithPrefixForTesting(prefix);
}

}  // namespace net_instaweb