third_party/WebKit/public/platform/WebVector.h

   1 /*
   2  * Copyright (C) 2009 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 WebVector_h
  32 #define WebVector_h
  33
  34 #include "WebCommon.h"
  35
  36 #include <algorithm>
  37 #include <limits>
  38 #include <stdlib.h>
  39
  40 namespace blink {
  41
  42 // A simple vector class.
  43 //
  44 // Sample usage:
  45 //
  46 //   void Foo(WebVector<int>& result)
  47 //   {
  48 //       WebVector<int> data(10);
  49 //       for (size_t i = 0; i < data.size(); ++i)
  50 //           data[i] = ...
  51 //       result.swap(data);
  52 //   }
  53 //
  54 // It is also possible to assign from other types of random access
  55 // containers:
  56 //
  57 //   void Foo(const std::vector<std::string>& input)
  58 //   {
  59 //       WebVector<WebCString> cstrings = input;
  60 //       ...
  61 //   }
  62 //
  63 template <typename T>
  64 class WebVector {
  65 public:
  66     using ValueType = T;
  67     using iterator = T*;
  68     using const_iterator = const T*;
  69
  70     ~WebVector()
  71     {
  72         destroy();
  73     }
  74
  75     explicit WebVector(size_t size = 0)
  76     {
  77         initialize(size);
  78     }
  79
  80     template <typename U>
  81     WebVector(const U* values, size_t size)
  82     {
  83         initializeFrom(values, size);
  84     }
  85
  86     WebVector(const WebVector<T>& other)
  87     {
  88         initializeFrom(other.m_ptr, other.m_size);
  89     }
  90
  91     template <typename C>
  92     WebVector(const C& other)
  93     {
  94         initializeFrom(other.size() ? &other[0] : 0, other.size());
  95     }
  96
  97     WebVector& operator=(const WebVector& other)
  98     {
  99         if (this != &other)
 100             assign(other);
 101         return *this;
 102     }
 103
 104     template <typename C>
 105     WebVector<T>& operator=(const C& other)
 106     {
 107         if (this != reinterpret_cast<const WebVector<T>*>(&other))
 108             assign(other);
 109         return *this;
 110     }
 111
 112     template <typename C>
 113     void assign(const C& other)
 114     {
 115         assign(other.size() ? &other[0] : 0, other.size());
 116     }
 117
 118     template <typename U>
 119     void assign(const U* values, size_t size)
 120     {
 121         destroy();
 122         initializeFrom(values, size);
 123     }
 124
 125     size_t size() const { return m_size; }
 126     bool isEmpty() const { return !m_size; }
 127
 128     T& operator[](size_t i)
 129     {
 130         BLINK_ASSERT(i < m_size);
 131         return m_ptr[i];
 132     }
 133     const T& operator[](size_t i) const
 134     {
 135         BLINK_ASSERT(i < m_size);
 136         return m_ptr[i];
 137     }
 138
 139     bool contains(const T& value) const
 140     {
 141         for (size_t i = 0; i < m_size; i++) {
 142             if (m_ptr[i] == value)
 143                 return true;
 144         }
 145         return false;
 146     }
 147
 148     T* data() { return m_ptr; }
 149     const T* data() const { return m_ptr; }
 150
 151     iterator begin() { return data(); }
 152     iterator end() { return begin() + m_size; }
 153     const_iterator begin() const { return data(); }
 154     const_iterator end() const { return begin() + m_size; }
 155
 156     void swap(WebVector<T>& other)
 157     {
 158         std::swap(m_ptr, other.m_ptr);
 159         std::swap(m_size, other.m_size);
 160     }
 161
 162 private:
 163     void initialize(size_t size)
 164     {
 165         validateSize(size);
 166         m_size = size;
 167         if (!m_size)
 168             m_ptr = 0;
 169         else {
 170             char* cptr = static_cast<char*>(::operator new(sizeof(T) * m_size));
 171             for (size_t i = 0; i < m_size; ++i)
 172                 new (&cptr[sizeof(T) * i]) T();
 173             m_ptr = reinterpret_cast<T*>(cptr);
 174         }
 175     }
 176
 177     template <typename U>
 178     void initializeFrom(const U* values, size_t size)
 179     {
 180         validateSize(size);
 181         m_size = size;
 182         if (!m_size)
 183             m_ptr = 0;
 184         else {
 185             char* cptr = static_cast<char*>(::operator new(sizeof(T) * m_size));
 186             for (size_t i = 0; i < m_size; ++i)
 187                 new (&cptr[sizeof(T) * i]) T(values[i]);
 188             m_ptr = reinterpret_cast<T*>(cptr);
 189         }
 190     }
 191
 192     void validateSize(size_t size)
 193     {
 194         if (std::numeric_limits<size_t>::max() / sizeof(T) < size)
 195             abort();
 196     }
 197
 198     void destroy()
 199     {
 200         for (size_t i = 0; i < m_size; ++i)
 201             m_ptr[i].~T();
 202         ::operator delete(m_ptr);
 203     }
 204
 205     T* m_ptr;
 206     size_t m_size;
 207 };
 208
 209 } // namespace blink
 210
 211 #endif