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// 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 CONTENT_COMMON_DOM_STORAGE_DOM_STORAGE_MAP_H_
#define CONTENT_COMMON_DOM_STORAGE_DOM_STORAGE_MAP_H_
#include <stddef.h>
#include <map>
#include "base/gtest_prod_util.h"
#include "base/memory/ref_counted.h"
#include "base/strings/nullable_string16.h"
#include "base/strings/string16.h"
#include "content/common/content_export.h"
#include "content/common/dom_storage/dom_storage_types.h"
namespace content {
// A wrapper around a std::map that adds refcounting and
// tracks the size in bytes of the keys/values, enforcing a quota.
// See class comments for DOMStorageContextImpl for a larger overview.
class CONTENT_EXPORT DOMStorageMap
: public base::RefCountedThreadSafe<DOMStorageMap> {
public:
DOMStorageMap(size_t quota, bool only_keys);
explicit DOMStorageMap(size_t quota);
unsigned Length() const;
base::NullableString16 Key(unsigned index);
// Sets and removes items from the storage. Old value is wriiten into
// |old_value| if it's not null and |has_only_keys| is false. |old_value| is
// not accessed or modified when |has_only_keys|.
bool SetItem(const base::string16& key, const base::string16& value,
base::NullableString16* old_value);
bool RemoveItem(const base::string16& key, base::string16* old_value);
// Returns value for the given |key|. Use only when |has_only_keys| is false.
base::NullableString16 GetItem(const base::string16& key) const;
// Writes a copy of the current set of map_ to the |map|. Use only when
// |has_only_keys| is false.
void ExtractValues(DOMStorageValuesMap* map) const;
// Swaps the values from |map| to |keys_values_| in this instances,
// Note: to grandfather in pre-existing files that are overbudget,
// this method does not do quota checking. Use only when |has_only_keys| is
// false.
void SwapValues(DOMStorageValuesMap* map);
// Stores the keys and sizes of values from |map| to |keys_only_|. Use only
// when |has_only_keys| is true. This method does not do quota checking.
void TakeKeysFrom(const DOMStorageValuesMap& map);
// Creates a new instance of DOMStorageMap containing
// a deep copy of the map.
DOMStorageMap* DeepCopy() const;
const DOMStorageValuesMap& keys_values() const { return keys_values_; }
size_t storage_used() const { return storage_used_; }
size_t memory_used() const { return memory_used_; }
size_t quota() const { return quota_; }
void set_quota(size_t quota) { quota_ = quota; }
bool has_only_keys() const { return has_only_keys_; }
static size_t CountBytes(const DOMStorageValuesMap& values);
private:
friend class base::RefCountedThreadSafe<DOMStorageMap>;
FRIEND_TEST_ALL_PREFIXES(DOMStorageMapParamTest, EnforcesQuota);
using KeysMap = std::map<base::string16, size_t>;
~DOMStorageMap();
template <typename MapType>
bool SetItemInternal(MapType* map_type,
const base::string16& key,
const typename MapType::mapped_type& value,
typename MapType::mapped_type* old_value);
template <typename MapType>
bool RemoveItemInternal(MapType* map_type,
const base::string16& key,
typename MapType::mapped_type* old_value);
void ResetKeyIterator();
// Used when |has_only_keys_| is false.
DOMStorageValuesMap keys_values_;
// Used when |has_only_keys_| is true.
KeysMap keys_only_;
DOMStorageValuesMap::const_iterator keys_values_iterator_;
KeysMap::const_iterator keys_only_iterator_;
unsigned last_key_index_;
size_t storage_used_;
size_t memory_used_;
size_t quota_;
const bool has_only_keys_;
};
} // namespace content
#endif // CONTENT_COMMON_DOM_STORAGE_DOM_STORAGE_MAP_H_