Cleanup: Move InstantRestrictedIDCache from chrome/common to chrome/renderer.

chrome/common/instant_restricted_id_cache.h

-// Copyright 2013 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef CHROME_COMMON_INSTANT_RESTRICTED_ID_CACHE_H_
-#define CHROME_COMMON_INSTANT_RESTRICTED_ID_CACHE_H_
-
-#include <set>
-#include <utility>
-#include <vector>
-
-#include "base/containers/mru_cache.h"
-#include "base/gtest_prod_util.h"
-#include "base/logging.h"
-#include "chrome/common/instant_types.h"
-
-// In InstantExtended, iframes are used to display objects which can only be
-// referenced by the Instant page using an ID (restricted ID). These IDs need to
-// be unique and cached for a while so that the SearchBox API can fetch the
-// object info based on the ID when required by the Instant page. The reason to
-// use a cache of N items as against just the last set of results is that there
-// may be race conditions - e.g. the user clicks on a result being shown but the
-// result set has internally changed but not yet been displayed.
-//
-// The cache can be used in two modes:
-//
-// 1. To store items and assign restricted IDs to them. The cache will store
-//    a max of |max_cache_size_| items and assign them unique IDs.
-//
-// 2. To store items that already have restricted IDs assigned to them (e.g.
-//    from another instance of the cache). The cache will then not generate IDs
-//    and does not make any guarantees of the uniqueness of the IDs. If multiple
-//    items are inserted with the same ID, the cache will return the last
-//    inserted item in GetItemWithRestrictedID() call.
-
-// T needs to be copyable.
-template <typename T>
-class InstantRestrictedIDCache {
- public:
-  typedef std::pair<InstantRestrictedID, T> ItemIDPair;
-  typedef std::vector<T> ItemVector;
-  typedef std::vector<ItemIDPair> ItemIDVector;
-
-  explicit InstantRestrictedIDCache(size_t max_cache_size);
-  ~InstantRestrictedIDCache();
-
-  // Adds items to the cache, assigning restricted IDs in the process. May
-  // delete older items from the cache. |items.size()| has to be less than max
-  // cache size.
-  void AddItems(const ItemVector& items);
-
-  // Adds items to the cache using the supplied restricted IDs. May delete
-  // older items from the cache. No two entries in |items| should have the same
-  // InstantRestrictedID. |items.size()| has to be less than max cache size.
-  void AddItemsWithRestrictedID(const ItemIDVector& items);
-
-  // Returns the last set of items added to the cache either via AddItems() or
-  // AddItemsWithRestrictedID().
-  void GetCurrentItems(ItemIDVector* items) const;
-
-  // Returns true if the |restricted_id| is present in the cache and if so,
-  // returns a copy of the item.
-  bool GetItemWithRestrictedID(InstantRestrictedID restricted_id,
-                               T* item) const;
-
- private:
-  FRIEND_TEST_ALL_PREFIXES(InstantRestrictedIDCacheTest, AutoIDGeneration);
-  FRIEND_TEST_ALL_PREFIXES(InstantRestrictedIDCacheTest, CrazyIDGeneration);
-  FRIEND_TEST_ALL_PREFIXES(InstantRestrictedIDCacheTest, ManualIDGeneration);
-  FRIEND_TEST_ALL_PREFIXES(InstantRestrictedIDCacheTest, MixIDGeneration);
-  FRIEND_TEST_ALL_PREFIXES(InstantRestrictedIDCacheTest, AddEmptySet);
-  FRIEND_TEST_ALL_PREFIXES(InstantRestrictedIDCacheTest,
-                           AddItemsWithRestrictedID);
-
-  typedef base::MRUCache<InstantRestrictedID, T> CacheImpl;
-
-  mutable CacheImpl cache_;
-  typename CacheImpl::reverse_iterator last_add_start_;
-  InstantRestrictedID last_restricted_id_;
-
-  DISALLOW_COPY_AND_ASSIGN(InstantRestrictedIDCache);
-};
-
-template <typename T>
-InstantRestrictedIDCache<T>::InstantRestrictedIDCache(size_t max_cache_size)
-    : cache_(max_cache_size),
-      last_add_start_(cache_.rend()),
-      last_restricted_id_(0) {
-  DCHECK(max_cache_size);
-}
-
-template <typename T>
-InstantRestrictedIDCache<T>::~InstantRestrictedIDCache() {
-}
-
-template <typename T>
-void InstantRestrictedIDCache<T>::AddItems(const ItemVector& items) {
-  DCHECK_LE(items.size(), cache_.max_size());
-
-  if (items.empty()) {
-    last_add_start_ = cache_.rend();
-    return;
-  }
-
-  for (size_t i = 0; i < items.size(); ++i) {
-    InstantRestrictedID id = ++last_restricted_id_;
-    cache_.Put(id, items[i]);
-    if (i == 0)
-      last_add_start_ = --cache_.rend();
-  }
-}
-
-template <typename T>
-void InstantRestrictedIDCache<T>::AddItemsWithRestrictedID(
-    const ItemIDVector& items) {
-  DCHECK_LE(items.size(), cache_.max_size());
-
-  if (items.empty()) {
-    last_add_start_ = cache_.rend();
-    return;
-  }
-
-  std::set<InstantRestrictedID> ids_added;
-  for (size_t i = 0; i < items.size(); ++i) {
-    const ItemIDPair& item_id = items[i];
-
-    DCHECK(ids_added.find(item_id.first) == ids_added.end());
-    ids_added.insert(item_id.first);
-
-    cache_.Put(item_id.first, item_id.second);
-    last_restricted_id_ = std::max(item_id.first, last_restricted_id_);
-  }
-
-  // cache_.Put() can invalidate the iterator |last_add_start_| is pointing to.
-  // Therefore, update |last_add_start_| after adding all the items to the
-  // |cache_|.
-  last_add_start_ = cache_.rend();
-  for (size_t i = 0; i < items.size(); ++i)
-    --last_add_start_;
-}
-
-template <typename T>
-void InstantRestrictedIDCache<T>::GetCurrentItems(ItemIDVector* items) const {
-  items->clear();
-
-  for (typename CacheImpl::reverse_iterator it = last_add_start_;
-       it != cache_.rend(); ++it) {
-    items->push_back(std::make_pair(it->first, it->second));
-  }
-}
-
-template <typename T>
-bool InstantRestrictedIDCache<T>::GetItemWithRestrictedID(
-    InstantRestrictedID restricted_id,
-    T* item) const {
-  DCHECK(item);
-
-  typename CacheImpl::const_iterator cache_it = cache_.Peek(restricted_id);
-  if (cache_it == cache_.end())
-    return false;
-  *item = cache_it->second;
-  return true;
-}
-
-#endif  // CHROME_COMMON_INSTANT_RESTRICTED_ID_CACHE_H_