1 //===-- Support/ilist - Intrusive Linked List Template ----------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines classes to implement an intrusive doubly linked list class
11 // (ie each node of the list must contain a next and previous field for the
14 // The ilist_traits trait class is used to gain access to the next and previous
15 // fields of the node type that the list is instantiated with. If it is not
16 // specialized, the list defaults to using the getPrev(), getNext() method calls
17 // to get the next and previous pointers.
19 // The ilist class itself, should be a plug in replacement for list, assuming
20 // that the nodes contain next/prev pointers. This list replacement does not
21 // provides a constant time size() method, so be careful to use empty() when you
22 // really want to know if it's empty.
24 // The ilist class is implemented by allocating a 'tail' node when the list is
25 // created (using ilist_traits<>::createEndMarker()). This tail node is
26 // absolutely required because the user must be able to compute end()-1. Because
27 // of this, users of the direct next/prev links will see an extra link on the
28 // end of the list, which should be ignored.
30 // Requirements for a user of this list:
32 // 1. The user must provide {g|s}et{Next|Prev} methods, or specialize
33 // ilist_traits to provide an alternate way of getting and setting next and
36 //===----------------------------------------------------------------------===//
41 #include <Support/iterator>
44 template<typename NodeTy, typename Traits> class iplist;
45 template<typename NodeTy> class ilist_iterator;
47 // Template traits for intrusive list. By specializing this template class, you
48 // can change what next/prev fields are used to store the links...
49 template<typename NodeTy>
51 static NodeTy *getPrev(NodeTy *N) { return N->getPrev(); }
52 static NodeTy *getNext(NodeTy *N) { return N->getNext(); }
53 static const NodeTy *getPrev(const NodeTy *N) { return N->getPrev(); }
54 static const NodeTy *getNext(const NodeTy *N) { return N->getNext(); }
56 static void setPrev(NodeTy *N, NodeTy *Prev) { N->setPrev(Prev); }
57 static void setNext(NodeTy *N, NodeTy *Next) { N->setNext(Next); }
59 static NodeTy *createNode() { return new NodeTy(); }
60 static NodeTy *createNode(const NodeTy &V) { return new NodeTy(V); }
63 void addNodeToList(NodeTy *NTy) {}
64 void removeNodeFromList(NodeTy *NTy) {}
65 void transferNodesFromList(iplist<NodeTy, ilist_traits> &L2,
66 ilist_iterator<NodeTy> first,
67 ilist_iterator<NodeTy> last) {}
70 // Const traits are the same as nonconst traits...
72 struct ilist_traits<const Ty> : public ilist_traits<Ty> {};
75 //===----------------------------------------------------------------------===//
76 // ilist_iterator<Node> - Iterator for intrusive list.
78 template<typename NodeTy>
80 : public bidirectional_iterator<NodeTy, ptrdiff_t> {
81 typedef ilist_traits<NodeTy> Traits;
82 typedef bidirectional_iterator<NodeTy, ptrdiff_t> super;
85 typedef size_t size_type;
86 typedef typename super::pointer pointer;
87 typedef typename super::reference reference;
92 ilist_iterator(pointer NP) : NodePtr(NP) {}
93 ilist_iterator(reference NR) : NodePtr(&NR) {}
94 ilist_iterator() : NodePtr(0) {}
96 // This is templated so that we can allow constructing a const iterator from
97 // a nonconst iterator...
98 template<class node_ty>
99 ilist_iterator(const ilist_iterator<node_ty> &RHS)
100 : NodePtr(RHS.getNodePtrUnchecked()) {}
102 // This is templated so that we can allow assigning to a const iterator from
103 // a nonconst iterator...
104 template<class node_ty>
105 const ilist_iterator &operator=(const ilist_iterator<node_ty> &RHS) {
106 NodePtr = RHS.getNodePtrUnchecked();
111 operator pointer() const {
112 assert(Traits::getNext(NodePtr) != 0 && "Dereferencing end()!");
116 reference operator*() const {
117 assert(Traits::getNext(NodePtr) != 0 && "Dereferencing end()!");
120 pointer operator->() { return &operator*(); }
121 const pointer operator->() const { return &operator*(); }
123 // Comparison operators
124 bool operator==(const ilist_iterator &RHS) const {
125 return NodePtr == RHS.NodePtr;
127 bool operator!=(const ilist_iterator &RHS) const {
128 return NodePtr != RHS.NodePtr;
131 // Increment and decrement operators...
132 ilist_iterator &operator--() { // predecrement - Back up
133 NodePtr = Traits::getPrev(NodePtr);
134 assert(NodePtr && "--'d off the beginning of an ilist!");
137 ilist_iterator &operator++() { // preincrement - Advance
138 NodePtr = Traits::getNext(NodePtr);
139 assert(NodePtr && "++'d off the end of an ilist!");
142 ilist_iterator operator--(int) { // postdecrement operators...
143 ilist_iterator tmp = *this;
147 ilist_iterator operator++(int) { // postincrement operators...
148 ilist_iterator tmp = *this;
154 // Dummy operators to make errors apparent...
155 template<class X> void operator+(X Val) {}
156 template<class X> void operator-(X Val) {}
158 // Internal interface, do not use...
159 pointer getNodePtrUnchecked() const { return NodePtr; }
162 // Allow ilist_iterators to convert into pointers to a node automatically when
163 // used by the dyn_cast, cast, isa mechanisms...
165 template<typename From> struct simplify_type;
167 template<typename NodeTy> struct simplify_type<ilist_iterator<NodeTy> > {
168 typedef NodeTy* SimpleType;
170 static SimpleType getSimplifiedValue(const ilist_iterator<NodeTy> &Node) {
174 template<typename NodeTy> struct simplify_type<const ilist_iterator<NodeTy> > {
175 typedef NodeTy* SimpleType;
177 static SimpleType getSimplifiedValue(const ilist_iterator<NodeTy> &Node) {
183 //===----------------------------------------------------------------------===//
185 // iplist - The subset of list functionality that can safely be used on nodes of
186 // polymorphic types, ie a heterogeneus list with a common base class that holds
187 // the next/prev pointers...
189 template<typename NodeTy, typename Traits=ilist_traits<NodeTy> >
190 class iplist : public Traits {
193 static bool op_less(NodeTy &L, NodeTy &R) { return L < R; }
194 static bool op_equal(NodeTy &L, NodeTy &R) { return L == R; }
196 typedef NodeTy *pointer;
197 typedef const NodeTy *const_pointer;
198 typedef NodeTy &reference;
199 typedef const NodeTy &const_reference;
200 typedef NodeTy value_type;
201 typedef ilist_iterator<NodeTy> iterator;
202 typedef ilist_iterator<const NodeTy> const_iterator;
203 typedef size_t size_type;
204 typedef ptrdiff_t difference_type;
205 typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
206 typedef std::reverse_iterator<iterator> reverse_iterator;
208 iplist() : Head(this->createNode()), Tail(Head) {
212 ~iplist() { clear(); delete Tail; }
214 // Iterator creation methods...
215 iterator begin() { return iterator(Head); }
216 const_iterator begin() const { return const_iterator(Head); }
217 iterator end() { return iterator(Tail); }
218 const_iterator end() const { return const_iterator(Tail); }
220 // reverse iterator creation methods...
221 reverse_iterator rbegin() { return reverse_iterator(end()); }
222 const_reverse_iterator rbegin() const{ return const_reverse_iterator(end()); }
223 reverse_iterator rend() { return reverse_iterator(begin()); }
224 const_reverse_iterator rend() const {return const_reverse_iterator(begin());}
226 // Miscellaneous inspection routines...
227 size_type max_size() const { return size_type(-1); }
228 bool empty() const { return Head == Tail; }
230 // Front and back accessor functions...
232 assert(!empty() && "Called front() on empty list!");
235 const_reference front() const {
236 assert(!empty() && "Called front() on empty list!");
240 assert(!empty() && "Called back() on empty list!");
241 return *getPrev(Tail);
243 const_reference back() const {
244 assert(!empty() && "Called back() on empty list!");
245 return *getPrev(Tail);
248 void swap(iplist &RHS) {
249 abort(); // Swap does not use list traits callback correctly yet!
250 std::swap(Head, RHS.Head);
251 std::swap(Tail, RHS.Tail);
254 iterator insert(iterator where, NodeTy *New) {
255 NodeTy *CurNode = where.getNodePtrUnchecked(), *PrevNode = getPrev(CurNode);
256 setNext(New, CurNode);
257 setPrev(New, PrevNode);
260 setNext(PrevNode, New);
263 setPrev(CurNode, New);
265 addNodeToList(New); // Notify traits that we added a node...
269 NodeTy *remove(iterator &IT) {
270 assert(IT != end() && "Cannot remove end of list!");
272 NodeTy *NextNode = getNext(Node);
273 NodeTy *PrevNode = getPrev(Node);
276 setNext(PrevNode, NextNode);
279 setPrev(NextNode, PrevNode);
281 removeNodeFromList(Node); // Notify traits that we added a node...
285 NodeTy *remove(const iterator &IT) {
287 return remove(MutIt);
290 // erase - remove a node from the controlled sequence... and delete it.
291 iterator erase(iterator where) {
292 delete remove(where);
298 // transfer - The heart of the splice function. Move linked list nodes from
299 // [first, last) into position.
301 void transfer(iterator position, iplist &L2, iterator first, iterator last) {
302 assert(first != last && "Should be checked by callers");
303 if (position != last) {
304 // Remove [first, last) from its old position.
305 NodeTy *First = &*first, *Prev = getPrev(First);
306 NodeTy *Next = last.getNodePtrUnchecked(), *Last = getPrev(Next);
313 // Splice [first, last) into its new position.
314 NodeTy *PosNext = position.getNodePtrUnchecked();
315 NodeTy *PosPrev = getPrev(PosNext);
317 // Fix head of list...
319 setNext(PosPrev, First);
322 setPrev(First, PosPrev);
324 // Fix end of list...
325 setNext(Last, PosNext);
326 setPrev(PosNext, Last);
328 transferNodesFromList(L2, First, PosNext);
334 //===----------------------------------------------------------------------===
335 // Functionality derived from other functions defined above...
338 size_type size() const {
340 size_type Result = std::distance(begin(), end());
342 size_type Result = 0;
343 std::distance(begin(), end(), Result);
348 iterator erase(iterator first, iterator last) {
349 while (first != last)
350 first = erase(first);
354 void clear() { erase(begin(), end()); }
356 // Front and back inserters...
357 void push_front(NodeTy *val) { insert(begin(), val); }
358 void push_back(NodeTy *val) { insert(end(), val); }
360 assert(!empty() && "pop_front() on empty list!");
364 assert(!empty() && "pop_back() on empty list!");
365 iterator t = end(); erase(--t);
368 // Special forms of insert...
369 template<class InIt> void insert(iterator where, InIt first, InIt last) {
370 for (; first != last; ++first) insert(where, *first);
373 // Splice members - defined in terms of transfer...
374 void splice(iterator where, iplist &L2) {
376 transfer(where, L2, L2.begin(), L2.end());
378 void splice(iterator where, iplist &L2, iterator first) {
379 iterator last = first; ++last;
380 if (where == first || where == last) return; // No change
381 transfer(where, L2, first, last);
383 void splice(iterator where, iplist &L2, iterator first, iterator last) {
384 if (first != last) transfer(where, L2, first, last);
389 //===----------------------------------------------------------------------===
390 // High-Level Functionality that shouldn't really be here, but is part of list
393 // These two functions are actually called remove/remove_if in list<>, but
394 // they actually do the job of erase, rename them accordingly.
396 void erase(const NodeTy &val) {
397 for (iterator I = begin(), E = end(); I != E; ) {
398 iterator next = I; ++next;
399 if (*I == val) erase(I);
403 template<class Pr1> void erase_if(Pr1 pred) {
404 for (iterator I = begin(), E = end(); I != E; ) {
405 iterator next = I; ++next;
406 if (pred(*I)) erase(I);
411 template<class Pr2> void unique(Pr2 pred) {
413 for (iterator I = begin(), E = end(), Next = begin(); ++Next != E;) {
421 void unique() { unique(op_equal); }
423 template<class Pr3> void merge(iplist &right, Pr3 pred) {
424 iterator first1 = begin(), last1 = end();
425 iterator first2 = right.begin(), last2 = right.end();
426 while (first1 != last1 && first2 != last2)
427 if (pred(*first2, *first1)) {
428 iterator next = first2;
429 transfer(first1, right, first2, ++next);
434 if (first2 != last2) transfer(last1, right, first2, last2);
436 void merge(iplist &right) { return merge(right, op_less); }
438 template<class Pr3> void sort(Pr3 pred);
439 void sort() { sort(op_less); }
444 template<typename NodeTy>
445 struct ilist : public iplist<NodeTy> {
446 typedef typename iplist<NodeTy>::size_type size_type;
447 typedef typename iplist<NodeTy>::iterator iterator;
450 ilist(const ilist &right) {
451 insert(this->begin(), right.begin(), right.end());
453 explicit ilist(size_type count) {
454 insert(this->begin(), count, NodeTy());
456 ilist(size_type count, const NodeTy &val) {
457 insert(this->begin(), count, val);
459 template<class InIt> ilist(InIt first, InIt last) {
460 insert(this->begin(), first, last);
464 // Forwarding functions: A workaround for GCC 2.95 which does not correctly
465 // support 'using' declarations to bring a hidden member into scope.
467 iterator insert(iterator a, NodeTy *b){ return iplist<NodeTy>::insert(a, b); }
468 void push_front(NodeTy *a) { iplist<NodeTy>::push_front(a); }
469 void push_back(NodeTy *a) { iplist<NodeTy>::push_back(a); }
472 // Main implementation here - Insert for a node passed by value...
473 iterator insert(iterator where, const NodeTy &val) {
474 return insert(where, createNode(val));
478 // Front and back inserters...
479 void push_front(const NodeTy &val) { insert(this->begin(), val); }
480 void push_back(const NodeTy &val) { insert(this->end(), val); }
482 // Special forms of insert...
483 template<class InIt> void insert(iterator where, InIt first, InIt last) {
484 for (; first != last; ++first) insert(where, *first);
486 void insert(iterator where, size_type count, const NodeTy &val) {
487 for (; count != 0; --count) insert(where, val);
490 // Assign special forms...
491 void assign(size_type count, const NodeTy &val) {
492 iterator I = this->begin();
493 for (; I != this->end() && count != 0; ++I, --count)
496 insert(this->end(), val, val);
498 erase(I, this->end());
500 template<class InIt> void assign(InIt first1, InIt last1) {
501 iterator first2 = this->begin(), last2 = this->end();
502 for ( ; first1 != last1 && first2 != last2; ++first1, ++first2)
505 erase(first1, last1);
507 insert(last1, first2, last2);
512 void resize(size_type newsize, NodeTy val) {
513 iterator i = this->begin();
515 for ( ; i != this->end() && len < newsize; ++i, ++len) /* empty*/ ;
518 erase(i, this->end());
520 insert(this->end(), newsize - len, val);
522 void resize(size_type newsize) { resize(newsize, NodeTy()); }
526 // Ensure that swap uses the fast list swap...
528 void swap(iplist<Ty> &Left, iplist<Ty> &Right) {
531 } // End 'std' extensions...