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 <algorithm>
9
10 #include "src/checks.h"
11 #include "src/vector.h"
12
13 namespace v8 {
14 namespace internal {
15
16 template<typename T> class Vector;
17
18 // ----------------------------------------------------------------------------
19 // The list is a template for very light-weight lists. We are not
20 // using the STL because we want full control over space and speed of
21 // the code. This implementation is based on code by Robert Griesemer
22 // and Rob Pike.
23 //
24 // The list is parameterized by the type of its elements (T) and by an
25 // allocation policy (P). The policy is used for allocating lists in
26 // the C free store or the zone; see zone.h.
27
28 // Forward defined as
29 // template <typename T,
30 // class AllocationPolicy = FreeStoreAllocationPolicy> class List;
31 template <typename T, class AllocationPolicy>
32 class List {
33 public:
34 explicit List(AllocationPolicy allocator = AllocationPolicy()) {
35 Initialize(0, allocator);
36 }
37 INLINE(explicit List(int capacity,
38 AllocationPolicy allocator = AllocationPolicy())) {
39 Initialize(capacity, allocator);
40 }
INLINE(~List ())41 INLINE(~List()) { DeleteData(data_); }
42
43 // Deallocates memory used by the list and leaves the list in a consistent
44 // empty state.
Free()45 void Free() {
46 DeleteData(data_);
47 Initialize(0);
48 }
49
50 INLINE(void* operator new(size_t size,
51 AllocationPolicy allocator = AllocationPolicy())) {
52 return allocator.New(static_cast<int>(size));
53 }
INLINE(void operator delete (void * p))54 INLINE(void operator delete(void* p)) {
55 AllocationPolicy::Delete(p);
56 }
57
58 // Please the MSVC compiler. We should never have to execute this.
INLINE(void operator delete (void * p,AllocationPolicy allocator))59 INLINE(void operator delete(void* p, AllocationPolicy allocator)) {
60 UNREACHABLE();
61 }
62
63 // Returns a reference to the element at index i. This reference is
64 // not safe to use after operations that can change the list's
65 // backing store (e.g. Add).
66 inline T& operator[](int i) const {
67 DCHECK_LE(0, i);
68 DCHECK_GT(static_cast<unsigned>(length_), static_cast<unsigned>(i));
69 return data_[i];
70 }
at(int i)71 inline T& at(int i) const { return operator[](i); }
last()72 inline T& last() const { return at(length_ - 1); }
first()73 inline T& first() const { return at(0); }
74
75 typedef T* iterator;
begin()76 inline iterator begin() const { return &data_[0]; }
end()77 inline iterator end() const { return &data_[length_]; }
78
INLINE(bool is_empty ()const)79 INLINE(bool is_empty() const) { return length_ == 0; }
INLINE(int length ()const)80 INLINE(int length() const) { return length_; }
INLINE(int capacity ()const)81 INLINE(int capacity() const) { return capacity_; }
82
ToVector()83 Vector<T> ToVector() const { return Vector<T>(data_, length_); }
84
ToConstVector()85 Vector<const T> ToConstVector() const {
86 return Vector<const T>(data_, length_);
87 }
88
89 // Adds a copy of the given 'element' to the end of the list,
90 // expanding the list if necessary.
91 void Add(const T& element, AllocationPolicy allocator = AllocationPolicy());
92
93 // Add all the elements from the argument list to this list.
94 void AddAll(const List<T, AllocationPolicy>& other,
95 AllocationPolicy allocator = AllocationPolicy());
96
97 // Add all the elements from the vector to this list.
98 void AddAll(const Vector<T>& other,
99 AllocationPolicy allocator = AllocationPolicy());
100
101 // Inserts the element at the specific index.
102 void InsertAt(int index, const T& element,
103 AllocationPolicy allocator = AllocationPolicy());
104
105 // Overwrites the element at the specific index.
106 void Set(int index, const T& element);
107
108 // Added 'count' elements with the value 'value' and returns a
109 // vector that allows access to the elements. The vector is valid
110 // until the next change is made to this list.
111 Vector<T> AddBlock(T value, int count,
112 AllocationPolicy allocator = AllocationPolicy());
113
114 // Removes the i'th element without deleting it even if T is a
115 // pointer type; moves all elements above i "down". Returns the
116 // removed element. This function's complexity is linear in the
117 // size of the list.
118 T Remove(int i);
119
120 // Remove the given element from the list. Returns whether or not
121 // the input is included in the list in the first place.
122 bool RemoveElement(const T& elm);
123
124 // Removes the last element without deleting it even if T is a
125 // pointer type. Returns the removed element.
INLINE(T RemoveLast ())126 INLINE(T RemoveLast()) { return Remove(length_ - 1); }
127
128 // Deletes current list contents and allocates space for 'length' elements.
129 INLINE(void Allocate(int length,
130 AllocationPolicy allocator = AllocationPolicy()));
131
132 // Clears the list by freeing the storage memory. If you want to keep the
133 // memory, use Rewind(0) instead. Be aware, that even if T is a
134 // pointer type, clearing the list doesn't delete the entries.
135 INLINE(void Clear());
136
137 // Drops all but the first 'pos' elements from the list.
138 INLINE(void Rewind(int pos));
139
140 // Drop the last 'count' elements from the list.
INLINE(void RewindBy (int count))141 INLINE(void RewindBy(int count)) { Rewind(length_ - count); }
142
143 // Swaps the contents of the two lists.
144 INLINE(void Swap(List<T, AllocationPolicy>* list));
145
146 // Halve the capacity if fill level is less than a quarter.
147 INLINE(void Trim(AllocationPolicy allocator = AllocationPolicy()));
148
149 bool Contains(const T& elm) const;
150 int CountOccurrences(const T& elm, int start, int end) const;
151
152 // Iterate through all list entries, starting at index 0.
153 void Iterate(void (*callback)(T* x));
154 template<class Visitor>
155 void Iterate(Visitor* visitor);
156
157 // Sort all list entries (using QuickSort)
158 template <typename CompareFunction>
159 void Sort(CompareFunction cmp, size_t start, size_t length);
160 template <typename CompareFunction>
161 void Sort(CompareFunction cmp);
162 void Sort();
163 template <typename CompareFunction>
164 void StableSort(CompareFunction cmp, size_t start, size_t length);
165 template <typename CompareFunction>
166 void StableSort(CompareFunction cmp);
167 void StableSort();
168
169 INLINE(void Initialize(int capacity,
170 AllocationPolicy allocator = AllocationPolicy())) {
171 DCHECK(capacity >= 0);
172 data_ = (capacity > 0) ? NewData(capacity, allocator) : NULL;
173 capacity_ = capacity;
174 length_ = 0;
175 }
176
177 private:
178 T* data_;
179 int capacity_;
180 int length_;
181
INLINE(T * NewData (int n,AllocationPolicy allocator))182 INLINE(T* NewData(int n, AllocationPolicy allocator)) {
183 return static_cast<T*>(allocator.New(n * sizeof(T)));
184 }
INLINE(void DeleteData (T * data))185 INLINE(void DeleteData(T* data)) {
186 AllocationPolicy::Delete(data);
187 }
188
189 // Increase the capacity of a full list, and add an element.
190 // List must be full already.
191 void ResizeAdd(const T& element, AllocationPolicy allocator);
192
193 // Inlined implementation of ResizeAdd, shared by inlined and
194 // non-inlined versions of ResizeAdd.
195 void ResizeAddInternal(const T& element, AllocationPolicy allocator);
196
197 // Resize the list.
198 void Resize(int new_capacity, AllocationPolicy allocator);
199
200 DISALLOW_COPY_AND_ASSIGN(List);
201 };
202
203
204 template<typename T, class P>
GetMemoryUsedByList(const List<T,P> & list)205 size_t GetMemoryUsedByList(const List<T, P>& list) {
206 return list.length() * sizeof(T) + sizeof(list);
207 }
208
209
210 class Map;
211 class FieldType;
212 class Code;
213 template<typename T> class Handle;
214 typedef List<Map*> MapList;
215 typedef List<Code*> CodeList;
216 typedef List<Handle<Map> > MapHandleList;
217 typedef List<Handle<FieldType> > TypeHandleList;
218 typedef List<Handle<Code> > CodeHandleList;
219
220 // Perform binary search for an element in an already sorted
221 // list. Returns the index of the element of -1 if it was not found.
222 // |cmp| is a predicate that takes a pointer to an element of the List
223 // and returns +1 if it is greater, -1 if it is less than the element
224 // being searched.
225 template <typename T, class P>
226 int SortedListBSearch(const List<T>& list, P cmp);
227 template <typename T>
228 int SortedListBSearch(const List<T>& list, T elem);
229
230
231 } // namespace internal
232 } // namespace v8
233
234
235 #endif // V8_LIST_H_
236