1 // Copyright 2011 the V8 project 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 #ifndef V8_LIST_H_ 6 #define V8_LIST_H_ 7 8 #include "src/checks.h" 9 #include "src/utils.h" 10 11 namespace v8 { 12 namespace internal { 13 14 template<typename T> class Vector; 15 16 // ---------------------------------------------------------------------------- 17 // The list is a template for very light-weight lists. We are not 18 // using the STL because we want full control over space and speed of 19 // the code. This implementation is based on code by Robert Griesemer 20 // and Rob Pike. 21 // 22 // The list is parameterized by the type of its elements (T) and by an 23 // allocation policy (P). The policy is used for allocating lists in 24 // the C free store or the zone; see zone.h. 25 26 // Forward defined as 27 // template <typename T, 28 // class AllocationPolicy = FreeStoreAllocationPolicy> class List; 29 template <typename T, class AllocationPolicy> 30 class List { 31 public: 32 explicit List(AllocationPolicy allocator = AllocationPolicy()) { 33 Initialize(0, allocator); 34 } 35 INLINE(explicit List(int capacity, 36 AllocationPolicy allocator = AllocationPolicy())) { 37 Initialize(capacity, allocator); 38 } 39 INLINE(~List()) { DeleteData(data_); } 40 41 // Deallocates memory used by the list and leaves the list in a consistent 42 // empty state. 43 void Free() { 44 DeleteData(data_); 45 Initialize(0); 46 } 47 48 INLINE(void* operator new(size_t size, 49 AllocationPolicy allocator = AllocationPolicy())) { 50 return allocator.New(static_cast<int>(size)); 51 } 52 INLINE(void operator delete(void* p)) { 53 AllocationPolicy::Delete(p); 54 } 55 56 // Please the MSVC compiler. We should never have to execute this. 57 INLINE(void operator delete(void* p, AllocationPolicy allocator)) { 58 UNREACHABLE(); 59 } 60 61 // Returns a reference to the element at index i. This reference is 62 // not safe to use after operations that can change the list's 63 // backing store (e.g. Add). 64 inline T& operator[](int i) const { 65 DCHECK(0 <= i); 66 SLOW_DCHECK(i < length_); 67 return data_[i]; 68 } 69 inline T& at(int i) const { return operator[](i); } 70 inline T& last() const { return at(length_ - 1); } 71 inline T& first() const { return at(0); } 72 73 typedef T* iterator; 74 inline iterator begin() const { return &data_[0]; } 75 inline iterator end() const { return &data_[length_]; } 76 77 INLINE(bool is_empty() const) { return length_ == 0; } 78 INLINE(int length() const) { return length_; } 79 INLINE(int capacity() const) { return capacity_; } 80 81 Vector<T> ToVector() const { return Vector<T>(data_, length_); } 82 83 Vector<const T> ToConstVector() { return Vector<const T>(data_, length_); } 84 85 // Adds a copy of the given 'element' to the end of the list, 86 // expanding the list if necessary. 87 void Add(const T& element, AllocationPolicy allocator = AllocationPolicy()); 88 89 // Add all the elements from the argument list to this list. 90 void AddAll(const List<T, AllocationPolicy>& other, 91 AllocationPolicy allocator = AllocationPolicy()); 92 93 // Add all the elements from the vector to this list. 94 void AddAll(const Vector<T>& other, 95 AllocationPolicy allocator = AllocationPolicy()); 96 97 // Inserts the element at the specific index. 98 void InsertAt(int index, const T& element, 99 AllocationPolicy allocator = AllocationPolicy()); 100 101 // Overwrites the element at the specific index. 102 void Set(int index, const T& element); 103 104 // Added 'count' elements with the value 'value' and returns a 105 // vector that allows access to the elements. The vector is valid 106 // until the next change is made to this list. 107 Vector<T> AddBlock(T value, int count, 108 AllocationPolicy allocator = AllocationPolicy()); 109 110 // Removes the i'th element without deleting it even if T is a 111 // pointer type; moves all elements above i "down". Returns the 112 // removed element. This function's complexity is linear in the 113 // size of the list. 114 T Remove(int i); 115 116 // Remove the given element from the list. Returns whether or not 117 // the input is included in the list in the first place. 118 bool RemoveElement(const T& elm); 119 120 // Removes the last element without deleting it even if T is a 121 // pointer type. Returns the removed element. 122 INLINE(T RemoveLast()) { return Remove(length_ - 1); } 123 124 // Deletes current list contents and allocates space for 'length' elements. 125 INLINE(void Allocate(int length, 126 AllocationPolicy allocator = AllocationPolicy())); 127 128 // Clears the list by setting the length to zero. Even if T is a 129 // pointer type, clearing the list doesn't delete the entries. 130 INLINE(void Clear()); 131 132 // Drops all but the first 'pos' elements from the list. 133 INLINE(void Rewind(int pos)); 134 135 // Drop the last 'count' elements from the list. 136 INLINE(void RewindBy(int count)) { Rewind(length_ - count); } 137 138 // Halve the capacity if fill level is less than a quarter. 139 INLINE(void Trim(AllocationPolicy allocator = AllocationPolicy())); 140 141 bool Contains(const T& elm) const; 142 int CountOccurrences(const T& elm, int start, int end) const; 143 144 // Iterate through all list entries, starting at index 0. 145 void Iterate(void (*callback)(T* x)); 146 template<class Visitor> 147 void Iterate(Visitor* visitor); 148 149 // Sort all list entries (using QuickSort) 150 void Sort(int (*cmp)(const T* x, const T* y)); 151 void Sort(); 152 153 INLINE(void Initialize(int capacity, 154 AllocationPolicy allocator = AllocationPolicy())); 155 156 private: 157 T* data_; 158 int capacity_; 159 int length_; 160 161 INLINE(T* NewData(int n, AllocationPolicy allocator)) { 162 return static_cast<T*>(allocator.New(n * sizeof(T))); 163 } 164 INLINE(void DeleteData(T* data)) { 165 AllocationPolicy::Delete(data); 166 } 167 168 // Increase the capacity of a full list, and add an element. 169 // List must be full already. 170 void ResizeAdd(const T& element, AllocationPolicy allocator); 171 172 // Inlined implementation of ResizeAdd, shared by inlined and 173 // non-inlined versions of ResizeAdd. 174 void ResizeAddInternal(const T& element, AllocationPolicy allocator); 175 176 // Resize the list. 177 void Resize(int new_capacity, AllocationPolicy allocator); 178 179 DISALLOW_COPY_AND_ASSIGN(List); 180 }; 181 182 183 template<typename T, class P> 184 size_t GetMemoryUsedByList(const List<T, P>& list) { 185 return list.length() * sizeof(T) + sizeof(list); 186 } 187 188 189 class Map; 190 template<class> class TypeImpl; 191 struct HeapTypeConfig; 192 typedef TypeImpl<HeapTypeConfig> HeapType; 193 class Code; 194 template<typename T> class Handle; 195 typedef List<Map*> MapList; 196 typedef List<Code*> CodeList; 197 typedef List<Handle<Map> > MapHandleList; 198 typedef List<Handle<HeapType> > TypeHandleList; 199 typedef List<Handle<Code> > CodeHandleList; 200 201 // Perform binary search for an element in an already sorted 202 // list. Returns the index of the element of -1 if it was not found. 203 // |cmp| is a predicate that takes a pointer to an element of the List 204 // and returns +1 if it is greater, -1 if it is less than the element 205 // being searched. 206 template <typename T, class P> 207 int SortedListBSearch(const List<T>& list, P cmp); 208 template <typename T> 209 int SortedListBSearch(const List<T>& list, T elem); 210 211 212 } } // namespace v8::internal 213 214 215 #endif // V8_LIST_H_ 216