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 }
INLINE(~List ())39 INLINE(~List()) { DeleteData(data_); }
40
41 // Deallocates memory used by the list and leaves the list in a consistent
42 // empty state.
Free()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 }
INLINE(void operator delete (void * p))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.
INLINE(void operator delete (void * p,AllocationPolicy allocator))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 }
at(int i)69 inline T& at(int i) const { return operator[](i); }
last()70 inline T& last() const { return at(length_ - 1); }
first()71 inline T& first() const { return at(0); }
72
73 typedef T* iterator;
begin()74 inline iterator begin() const { return &data_[0]; }
end()75 inline iterator end() const { return &data_[length_]; }
76
INLINE(bool is_empty ()const)77 INLINE(bool is_empty() const) { return length_ == 0; }
INLINE(int length ()const)78 INLINE(int length() const) { return length_; }
INLINE(int capacity ()const)79 INLINE(int capacity() const) { return capacity_; }
80
ToVector()81 Vector<T> ToVector() const { return Vector<T>(data_, length_); }
82
ToConstVector()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.
INLINE(T RemoveLast ())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.
INLINE(void RewindBy (int count))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
INLINE(T * NewData (int n,AllocationPolicy allocator))161 INLINE(T* NewData(int n, AllocationPolicy allocator)) {
162 return static_cast<T*>(allocator.New(n * sizeof(T)));
163 }
INLINE(void DeleteData (T * data))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>
GetMemoryUsedByList(const List<T,P> & list)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