1 /* 2 * Copyright (C) 2013 Google Inc. All rights reserved. 3 * 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 31 #ifndef WTF_StringView_h 32 #define WTF_StringView_h 33 34 #include "wtf/text/StringImpl.h" 35 36 namespace WTF { 37 38 class WTF_EXPORT StringView { 39 public: StringView()40 StringView() 41 : m_offset(0) 42 , m_length(0) 43 { 44 } 45 StringView(PassRefPtr<StringImpl> impl)46 explicit StringView(PassRefPtr<StringImpl> impl) 47 : m_impl(impl) 48 , m_offset(0) 49 , m_length(m_impl->length()) 50 { 51 } 52 StringView(PassRefPtr<StringImpl> impl,unsigned offset,unsigned length)53 StringView(PassRefPtr<StringImpl> impl, unsigned offset, unsigned length) 54 : m_impl(impl) 55 , m_offset(offset) 56 , m_length(length) 57 { 58 ASSERT_WITH_SECURITY_IMPLICATION(offset + length <= m_impl->length()); 59 } 60 narrow(unsigned offset,unsigned length)61 void narrow(unsigned offset, unsigned length) 62 { 63 ASSERT_WITH_SECURITY_IMPLICATION(offset + length <= m_length); 64 m_offset += offset; 65 m_length = length; 66 } 67 isEmpty()68 bool isEmpty() const { return !m_length; } length()69 unsigned length() const { return m_length; } 70 is8Bit()71 bool is8Bit() const { return m_impl->is8Bit(); } 72 characters8()73 const LChar* characters8() const 74 { 75 if (!m_impl) 76 return 0; 77 ASSERT(is8Bit()); 78 return m_impl->characters8() + m_offset; 79 } 80 characters16()81 const UChar* characters16() const 82 { 83 if (!m_impl) 84 return 0; 85 ASSERT(!is8Bit()); 86 return m_impl->characters16() + m_offset; 87 } 88 toString()89 PassRefPtr<StringImpl> toString() const 90 { 91 if (!m_impl) 92 return m_impl; 93 if (m_impl->is8Bit()) 94 return StringImpl::create(characters8(), m_length); 95 return StringImpl::create(characters16(), m_length); 96 } 97 98 private: 99 RefPtr<StringImpl> m_impl; 100 unsigned m_offset; 101 unsigned m_length; 102 }; 103 104 } 105 106 using WTF::StringView; 107 108 #endif 109