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