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1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. | |
2 // Use of this source code is governed by a BSD-style license that can be | |
3 // found in the LICENSE file. | |
4 | |
5 #include "webkit/common/dom_storage/dom_storage_map.h" | |
6 | |
7 #include "base/logging.h" | |
8 | |
9 namespace { | |
10 | |
11 size_t size_of_item(const base::string16& key, const base::string16& value) { | |
12 return (key.length() + value.length()) * sizeof(char16); | |
13 } | |
14 | |
15 size_t CountBytes(const dom_storage::ValuesMap& values) { | |
16 if (values.size() == 0) | |
17 return 0; | |
18 | |
19 size_t count = 0; | |
20 dom_storage::ValuesMap::const_iterator it = values.begin(); | |
21 for (; it != values.end(); ++it) | |
22 count += size_of_item(it->first, it->second.string()); | |
23 return count; | |
24 } | |
25 | |
26 } // namespace | |
27 | |
28 namespace dom_storage { | |
29 | |
30 DomStorageMap::DomStorageMap(size_t quota) | |
31 : bytes_used_(0), | |
32 quota_(quota) { | |
33 ResetKeyIterator(); | |
34 } | |
35 | |
36 DomStorageMap::~DomStorageMap() {} | |
37 | |
38 unsigned DomStorageMap::Length() const { | |
39 return values_.size(); | |
40 } | |
41 | |
42 base::NullableString16 DomStorageMap::Key(unsigned index) { | |
43 if (index >= values_.size()) | |
44 return base::NullableString16(); | |
45 while (last_key_index_ != index) { | |
46 if (last_key_index_ > index) { | |
47 --key_iterator_; | |
48 --last_key_index_; | |
49 } else { | |
50 ++key_iterator_; | |
51 ++last_key_index_; | |
52 } | |
53 } | |
54 return base::NullableString16(key_iterator_->first, false); | |
55 } | |
56 | |
57 base::NullableString16 DomStorageMap::GetItem(const base::string16& key) const { | |
58 ValuesMap::const_iterator found = values_.find(key); | |
59 if (found == values_.end()) | |
60 return base::NullableString16(); | |
61 return found->second; | |
62 } | |
63 | |
64 bool DomStorageMap::SetItem( | |
65 const base::string16& key, const base::string16& value, | |
66 base::NullableString16* old_value) { | |
67 ValuesMap::const_iterator found = values_.find(key); | |
68 if (found == values_.end()) | |
69 *old_value = base::NullableString16(); | |
70 else | |
71 *old_value = found->second; | |
72 | |
73 size_t old_item_size = old_value->is_null() ? | |
74 0 : size_of_item(key, old_value->string()); | |
75 size_t new_item_size = size_of_item(key, value); | |
76 size_t new_bytes_used = bytes_used_ - old_item_size + new_item_size; | |
77 | |
78 // Only check quota if the size is increasing, this allows | |
79 // shrinking changes to pre-existing files that are over budget. | |
80 if (new_item_size > old_item_size && new_bytes_used > quota_) | |
81 return false; | |
82 | |
83 values_[key] = base::NullableString16(value, false); | |
84 ResetKeyIterator(); | |
85 bytes_used_ = new_bytes_used; | |
86 return true; | |
87 } | |
88 | |
89 bool DomStorageMap::RemoveItem( | |
90 const base::string16& key, | |
91 base::string16* old_value) { | |
92 ValuesMap::iterator found = values_.find(key); | |
93 if (found == values_.end()) | |
94 return false; | |
95 *old_value = found->second.string(); | |
96 values_.erase(found); | |
97 ResetKeyIterator(); | |
98 bytes_used_ -= size_of_item(key, *old_value); | |
99 return true; | |
100 } | |
101 | |
102 void DomStorageMap::SwapValues(ValuesMap* values) { | |
103 // Note: A pre-existing file may be over the quota budget. | |
104 values_.swap(*values); | |
105 bytes_used_ = CountBytes(values_); | |
106 ResetKeyIterator(); | |
107 } | |
108 | |
109 DomStorageMap* DomStorageMap::DeepCopy() const { | |
110 DomStorageMap* copy = new DomStorageMap(quota_); | |
111 copy->values_ = values_; | |
112 copy->bytes_used_ = bytes_used_; | |
113 copy->ResetKeyIterator(); | |
114 return copy; | |
115 } | |
116 | |
117 void DomStorageMap::ResetKeyIterator() { | |
118 key_iterator_ = values_.begin(); | |
119 last_key_index_ = 0; | |
120 } | |
121 | |
122 } // namespace dom_storage | |
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