1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
|
// Copyright 2018 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef THIRD_PARTY_BLINK_RENDERER_MODULES_STORAGE_STORAGE_AREA_MAP_H_
#define THIRD_PARTY_BLINK_RENDERER_MODULES_STORAGE_STORAGE_AREA_MAP_H_
#include "third_party/blink/renderer/modules/modules_export.h"
#include "third_party/blink/renderer/platform/wtf/allocator/allocator.h"
#include "third_party/blink/renderer/platform/wtf/text/string_hash.h"
#include "third_party/blink/renderer/platform/wtf/text/wtf_string.h"
namespace blink {
// This class is used to represent the in-memory version of the data in a
// StorageArea. This class is responsible for enforcing a quota, and for
// providing somewhat efficient iteration over all the items in the map via
// GetLength/GetKey/GetItem.
// Any modifications to the data in the map can cause all items to be reordered.
// Nothing is guaranteed about the order of items in the map.
// For the purpose of quota each character in the key and value strings is
// counted as two bytes, even if the actual in-memory representation of the
// string only uses one byte per character.
class MODULES_EXPORT StorageAreaMap {
USING_FAST_MALLOC(StorageAreaMap);
public:
explicit StorageAreaMap(size_t quota);
unsigned GetLength() const;
String GetKey(unsigned index) const;
String GetItem(const String& key) const;
// Returns false iff quota would be exceeded.
bool SetItem(const String& key, const String& value, String* old_value);
void SetItemIgnoringQuota(const String& key, const String& value);
// Returns fals iff item wasn't found.
bool RemoveItem(const String& key, String* old_value);
size_t quota_used() const { return quota_used_; }
size_t memory_used() const { return memory_used_; }
size_t quota() const { return quota_; }
private:
void ResetKeyIterator() const;
bool SetItemInternal(const String& key,
const String& value,
String* old_value,
bool check_quota);
HashMap<String, String> keys_values_;
// To make iterating over all keys somewhat less inefficient, we keep track of
// an iterator to and index of the last key returned by GetKey().
mutable HashMap<String, String>::const_iterator key_iterator_;
mutable unsigned last_key_index_;
size_t quota_used_ = 0;
size_t memory_used_ = 0;
const size_t quota_;
};
} // namespace blink
#endif // THIRD_PARTY_BLINK_RENDERER_MODULES_STORAGE_STORAGE_AREA_MAP_H_
|
