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1 /* | 1 // Copyright 2016 The Chromium Authors. All rights reserved. |
2 * Copyright (C) 2013 Google Inc. All rights reserved. | 2 // Use of this source code is governed by a BSD-style license that can be |
3 * | 3 // found in the LICENSE file. |
4 * Redistribution and use in source and binary forms, with or without | |
5 * modification, are permitted provided that the following conditions are | |
6 * met: | |
7 * | |
8 * * Redistributions of source code must retain the above copyright | |
9 * notice, this list of conditions and the following disclaimer. | |
10 * * Redistributions in binary form must reproduce the above | |
11 * copyright notice, this list of conditions and the following disclaimer | |
12 * in the documentation and/or other materials provided with the | |
13 * distribution. | |
14 * * Neither the name of Google Inc. nor the names of its | |
15 * contributors may be used to endorse or promote products derived from | |
16 * this software without specific prior written permission. | |
17 * | |
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | |
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | |
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | |
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT | |
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | |
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT | |
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | |
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
29 */ | |
30 | 4 |
31 #ifndef WTF_StringView_h | 5 #ifndef WTF_StringView_h |
32 #define WTF_StringView_h | 6 #define WTF_StringView_h |
33 | 7 |
34 #include "wtf/Allocator.h" | 8 #include "wtf/Allocator.h" |
35 #include "wtf/text/StringImpl.h" | 9 #if DCHECK_IS_ON() |
| 10 #include "wtf/RefPtr.h" |
| 11 #endif |
| 12 #include "wtf/text/Unicode.h" |
| 13 #include <cstring> |
36 | 14 |
37 namespace WTF { | 15 namespace WTF { |
38 | 16 |
| 17 class AtomicString; |
| 18 class String; |
| 19 class StringImpl; |
| 20 |
39 class WTF_EXPORT StringView { | 21 class WTF_EXPORT StringView { |
40 DISALLOW_NEW(); | 22 DISALLOW_NEW_EXCEPT_PLACEMENT_NEW(); |
41 public: | 23 public: |
42 StringView() | 24 // Null string. |
43 : m_offset(0) | 25 StringView() { clear(); } |
44 , m_length(0) | |
45 { | |
46 } | |
47 | 26 |
48 explicit StringView(PassRefPtr<StringImpl> impl) | 27 // From a StringImpl (implemented in StringImpl.h) |
49 : m_impl(impl) | 28 StringView(StringImpl*); |
50 , m_offset(0) | 29 StringView(StringImpl*, unsigned offset); |
51 , m_length(m_impl->length()) | 30 StringView(StringImpl*, unsigned offset, unsigned length); |
52 { | |
53 } | |
54 | 31 |
55 StringView(PassRefPtr<StringImpl> impl, unsigned offset, unsigned length) | 32 // From a String (implemented in WTFString.h) |
56 : m_impl(impl) | 33 StringView(const String&); |
57 , m_offset(offset) | 34 StringView(const String&, unsigned offset); |
58 , m_length(length) | 35 StringView(const String&, unsigned offset, unsigned length); |
59 { | |
60 ASSERT_WITH_SECURITY_IMPLICATION(offset + length <= m_impl->length()); | |
61 } | |
62 | 36 |
63 void narrow(unsigned offset, unsigned length) | 37 // From an AtomicString (implemented in in AtomicString.h) |
64 { | 38 StringView(const AtomicString&); |
65 ASSERT_WITH_SECURITY_IMPLICATION(offset + length <= m_length); | 39 StringView(const AtomicString&, unsigned offset); |
66 m_offset += offset; | 40 StringView(const AtomicString&, unsigned offset, unsigned length); |
67 m_length = length; | |
68 } | |
69 | 41 |
| 42 // From a StringView. |
| 43 StringView(const StringView&, unsigned offset); |
| 44 StringView(const StringView&, unsigned offset, unsigned length); |
| 45 |
| 46 // From a literal string or LChar buffer. |
| 47 StringView(const LChar* chars); |
| 48 StringView(const char* chars); |
| 49 StringView(const LChar* chars, unsigned length); |
| 50 StringView(const char* chars, unsigned length); |
| 51 |
| 52 // From a UChar buffer. |
| 53 StringView(const UChar* chars); |
| 54 StringView(const UChar* chars, unsigned length); |
| 55 |
| 56 #if DCHECK_IS_ON() |
| 57 ~StringView(); |
| 58 #endif |
| 59 |
| 60 bool isNull() const { return !m_data.bytes; } |
70 bool isEmpty() const { return !m_length; } | 61 bool isEmpty() const { return !m_length; } |
| 62 |
71 unsigned length() const { return m_length; } | 63 unsigned length() const { return m_length; } |
72 | 64 |
73 bool is8Bit() const { return m_impl->is8Bit(); } | 65 bool is8Bit() const { return m_is8Bit; } |
| 66 |
| 67 void clear() |
| 68 { |
| 69 m_length = 0; |
| 70 m_is8Bit = true; |
| 71 m_data.bytes = nullptr; |
| 72 #if DCHECK_IS_ON() |
| 73 m_impl = nullptr; |
| 74 #endif |
| 75 } |
74 | 76 |
75 const LChar* characters8() const | 77 const LChar* characters8() const |
76 { | 78 { |
77 if (!m_impl) | |
78 return 0; | |
79 ASSERT(is8Bit()); | 79 ASSERT(is8Bit()); |
80 return m_impl->characters8() + m_offset; | 80 return m_data.characters8; |
81 } | 81 } |
82 | 82 |
83 const UChar* characters16() const | 83 const UChar* characters16() const |
84 { | 84 { |
85 if (!m_impl) | |
86 return 0; | |
87 ASSERT(!is8Bit()); | 85 ASSERT(!is8Bit()); |
88 return m_impl->characters16() + m_offset; | 86 return m_data.characters16; |
89 } | 87 } |
90 | 88 |
91 PassRefPtr<StringImpl> toString() const | 89 String toString() const; |
92 { | |
93 if (!m_impl) | |
94 return m_impl; | |
95 if (m_impl->is8Bit()) | |
96 return StringImpl::create(characters8(), m_length); | |
97 return StringImpl::create(characters16(), m_length); | |
98 } | |
99 | 90 |
100 private: | 91 private: |
| 92 // Implemented in StringImpl.h |
| 93 void set(StringImpl&, unsigned offset, unsigned length); |
| 94 |
| 95 #if DCHECK_IS_ON() |
101 RefPtr<StringImpl> m_impl; | 96 RefPtr<StringImpl> m_impl; |
102 unsigned m_offset; | 97 #endif |
| 98 union DataUnion { |
| 99 const LChar* characters8; |
| 100 const UChar* characters16; |
| 101 const void* bytes; |
| 102 } m_data; |
103 unsigned m_length; | 103 unsigned m_length; |
| 104 unsigned m_is8Bit : 1; |
104 }; | 105 }; |
105 | 106 |
| 107 inline StringView::StringView(const StringView& view, unsigned offset, unsigned
length) |
| 108 : m_length(length) |
| 109 , m_is8Bit(view.is8Bit()) |
| 110 { |
| 111 SECURITY_DCHECK(offset + length <= view.length()); |
| 112 if (is8Bit()) |
| 113 m_data.characters8 = view.characters8() + offset; |
| 114 else |
| 115 m_data.characters16 = view.characters16() + offset; |
| 116 } |
| 117 |
| 118 inline StringView::StringView(const StringView& view, unsigned offset) |
| 119 : StringView(view, offset, view.m_length - offset) {} |
| 120 |
| 121 inline StringView::StringView(const LChar* chars, unsigned length) |
| 122 : m_length(length) |
| 123 , m_is8Bit(true) |
| 124 { |
| 125 m_data.characters8 = chars; |
| 126 } |
| 127 |
| 128 inline StringView::StringView(const char* chars, unsigned length) |
| 129 : StringView(reinterpret_cast<const LChar*>(chars), length) {} |
| 130 inline StringView::StringView(const LChar* chars) |
| 131 : StringView(chars, chars ? strlen(reinterpret_cast<const char*>(chars)) : 0
) {} |
| 132 inline StringView::StringView(const char* chars) |
| 133 : StringView(reinterpret_cast<const LChar*>(chars)) {} |
| 134 |
| 135 // TODO(esprehn): Can't make this an overload of WTF::equal since that makes |
| 136 // calls to equal() that pass literal strings ambiguous. Figure out if we can |
| 137 // replace all the callers with equalStringView and then rename it to equal(). |
| 138 WTF_EXPORT bool equalStringView(const StringView&, const StringView&); |
| 139 |
| 140 inline bool operator==(const StringView& a, const StringView& b) |
| 141 { |
| 142 return equalStringView(a, b); |
| 143 } |
| 144 |
| 145 inline bool operator!=(const StringView& a, const StringView& b) |
| 146 { |
| 147 return !(a == b); |
| 148 } |
| 149 |
106 } // namespace WTF | 150 } // namespace WTF |
107 | 151 |
108 using WTF::StringView; | 152 using WTF::StringView; |
109 | 153 |
110 #endif | 154 #endif |
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