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>
46 template<typename NodeTy, typename Traits> class iplist;
47 template<typename NodeTy> class ilist_iterator;
49 // Template traits for intrusive list. By specializing this template class, you
50 // can change what next/prev fields are used to store the links...
51 template<typename NodeTy>
53 static NodeTy *getPrev(NodeTy *N) { return N->getPrev(); }
54 static NodeTy *getNext(NodeTy *N) { return N->getNext(); }
55 static const NodeTy *getPrev(const NodeTy *N) { return N->getPrev(); }
56 static const NodeTy *getNext(const NodeTy *N) { return N->getNext(); }
58 static void setPrev(NodeTy *N, NodeTy *Prev) { N->setPrev(Prev); }
59 static void setNext(NodeTy *N, NodeTy *Next) { N->setNext(Next); }
61 static NodeTy *createNode() { return new NodeTy(); }
62 static NodeTy *createNode(const NodeTy &V) { return new NodeTy(V); }
65 void addNodeToList(NodeTy *NTy) {}
66 void removeNodeFromList(NodeTy *NTy) {}
67 void transferNodesFromList(iplist<NodeTy, ilist_traits> &L2,
68 ilist_iterator<NodeTy> first,
69 ilist_iterator<NodeTy> last) {}
72 // Const traits are the same as nonconst traits...
74 struct ilist_traits<const Ty> : public ilist_traits<Ty> {};
77 //===----------------------------------------------------------------------===//
78 // ilist_iterator<Node> - Iterator for intrusive list.
80 template<typename NodeTy>
82 : public bidirectional_iterator<NodeTy, ptrdiff_t> {
83 typedef ilist_traits<NodeTy> Traits;
84 typedef bidirectional_iterator<NodeTy, ptrdiff_t> super;
87 typedef size_t size_type;
88 typedef typename super::pointer pointer;
89 typedef typename super::reference reference;
94 ilist_iterator(pointer NP) : NodePtr(NP) {}
95 ilist_iterator(reference NR) : NodePtr(&NR) {}
96 ilist_iterator() : NodePtr(0) {}
98 // This is templated so that we can allow constructing a const iterator from
99 // a nonconst iterator...
100 template<class node_ty>
101 ilist_iterator(const ilist_iterator<node_ty> &RHS)
102 : NodePtr(RHS.getNodePtrUnchecked()) {}
104 // This is templated so that we can allow assigning to a const iterator from
105 // a nonconst iterator...
106 template<class node_ty>
107 const ilist_iterator &operator=(const ilist_iterator<node_ty> &RHS) {
108 NodePtr = RHS.getNodePtrUnchecked();
113 operator pointer() const {
114 assert(Traits::getNext(NodePtr) != 0 && "Dereferencing end()!");
118 reference operator*() const {
119 assert(Traits::getNext(NodePtr) != 0 && "Dereferencing end()!");
122 pointer operator->() { return &operator*(); }
123 const pointer operator->() const { return &operator*(); }
125 // Comparison operators
126 bool operator==(const ilist_iterator &RHS) const {
127 return NodePtr == RHS.NodePtr;
129 bool operator!=(const ilist_iterator &RHS) const {
130 return NodePtr != RHS.NodePtr;
133 // Increment and decrement operators...
134 ilist_iterator &operator--() { // predecrement - Back up
135 NodePtr = Traits::getPrev(NodePtr);
136 assert(NodePtr && "--'d off the beginning of an ilist!");
139 ilist_iterator &operator++() { // preincrement - Advance
140 NodePtr = Traits::getNext(NodePtr);
141 assert(NodePtr && "++'d off the end of an ilist!");
144 ilist_iterator operator--(int) { // postdecrement operators...
145 ilist_iterator tmp = *this;
149 ilist_iterator operator++(int) { // postincrement operators...
150 ilist_iterator tmp = *this;
156 // Dummy operators to make errors apparent...
157 template<class X> void operator+(X Val) {}
158 template<class X> void operator-(X Val) {}
160 // Internal interface, do not use...
161 pointer getNodePtrUnchecked() const { return NodePtr; }
164 // Allow ilist_iterators to convert into pointers to a node automatically when
165 // used by the dyn_cast, cast, isa mechanisms...
167 template<typename From> struct simplify_type;
169 template<typename NodeTy> struct simplify_type<ilist_iterator<NodeTy> > {
170 typedef NodeTy* SimpleType;
172 static SimpleType getSimplifiedValue(const ilist_iterator<NodeTy> &Node) {
176 template<typename NodeTy> struct simplify_type<const ilist_iterator<NodeTy> > {
177 typedef NodeTy* SimpleType;
179 static SimpleType getSimplifiedValue(const ilist_iterator<NodeTy> &Node) {
185 //===----------------------------------------------------------------------===//
187 // iplist - The subset of list functionality that can safely be used on nodes of
188 // polymorphic types, ie a heterogeneus list with a common base class that holds
189 // the next/prev pointers...
191 template<typename NodeTy, typename Traits=ilist_traits<NodeTy> >
192 class iplist : public Traits {
195 static bool op_less(NodeTy &L, NodeTy &R) { return L < R; }
196 static bool op_equal(NodeTy &L, NodeTy &R) { return L == R; }
198 typedef NodeTy *pointer;
199 typedef const NodeTy *const_pointer;
200 typedef NodeTy &reference;
201 typedef const NodeTy &const_reference;
202 typedef NodeTy value_type;
203 typedef ilist_iterator<NodeTy> iterator;
204 typedef ilist_iterator<const NodeTy> const_iterator;
205 typedef size_t size_type;
206 typedef ptrdiff_t difference_type;
207 typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
208 typedef std::reverse_iterator<iterator> reverse_iterator;
210 iplist() : Head(this->createNode()), Tail(Head) {
214 ~iplist() { clear(); delete Tail; }
216 // Iterator creation methods...
217 iterator begin() { return iterator(Head); }
218 const_iterator begin() const { return const_iterator(Head); }
219 iterator end() { return iterator(Tail); }
220 const_iterator end() const { return const_iterator(Tail); }
222 // reverse iterator creation methods...
223 reverse_iterator rbegin() { return reverse_iterator(end()); }
224 const_reverse_iterator rbegin() const{ return const_reverse_iterator(end()); }
225 reverse_iterator rend() { return reverse_iterator(begin()); }
226 const_reverse_iterator rend() const {return const_reverse_iterator(begin());}
228 // Miscellaneous inspection routines...
229 size_type max_size() const { return size_type(-1); }
230 bool empty() const { return Head == Tail; }
232 // Front and back accessor functions...
234 assert(!empty() && "Called front() on empty list!");
237 const_reference front() const {
238 assert(!empty() && "Called front() on empty list!");
242 assert(!empty() && "Called back() on empty list!");
243 return *getPrev(Tail);
245 const_reference back() const {
246 assert(!empty() && "Called back() on empty list!");
247 return *getPrev(Tail);
250 void swap(iplist &RHS) {
251 abort(); // Swap does not use list traits callback correctly yet!
252 std::swap(Head, RHS.Head);
253 std::swap(Tail, RHS.Tail);
256 iterator insert(iterator where, NodeTy *New) {
257 NodeTy *CurNode = where.getNodePtrUnchecked(), *PrevNode = getPrev(CurNode);
258 setNext(New, CurNode);
259 setPrev(New, PrevNode);
262 setNext(PrevNode, New);
265 setPrev(CurNode, New);
267 addNodeToList(New); // Notify traits that we added a node...
271 NodeTy *remove(iterator &IT) {
272 assert(IT != end() && "Cannot remove end of list!");
274 NodeTy *NextNode = getNext(Node);
275 NodeTy *PrevNode = getPrev(Node);
278 setNext(PrevNode, NextNode);
281 setPrev(NextNode, PrevNode);
283 removeNodeFromList(Node); // Notify traits that we removed a node...
287 NodeTy *remove(const iterator &IT) {
289 return remove(MutIt);
292 // erase - remove a node from the controlled sequence... and delete it.
293 iterator erase(iterator where) {
294 delete remove(where);
300 // transfer - The heart of the splice function. Move linked list nodes from
301 // [first, last) into position.
303 void transfer(iterator position, iplist &L2, iterator first, iterator last) {
304 assert(first != last && "Should be checked by callers");
305 if (position != last) {
306 // Remove [first, last) from its old position.
307 NodeTy *First = &*first, *Prev = getPrev(First);
308 NodeTy *Next = last.getNodePtrUnchecked(), *Last = getPrev(Next);
315 // Splice [first, last) into its new position.
316 NodeTy *PosNext = position.getNodePtrUnchecked();
317 NodeTy *PosPrev = getPrev(PosNext);
319 // Fix head of list...
321 setNext(PosPrev, First);
324 setPrev(First, PosPrev);
326 // Fix end of list...
327 setNext(Last, PosNext);
328 setPrev(PosNext, Last);
330 transferNodesFromList(L2, First, PosNext);
336 //===----------------------------------------------------------------------===
337 // Functionality derived from other functions defined above...
340 size_type size() const {
342 size_type Result = std::distance(begin(), end());
344 size_type Result = 0;
345 std::distance(begin(), end(), Result);
350 iterator erase(iterator first, iterator last) {
351 while (first != last)
352 first = erase(first);
356 void clear() { erase(begin(), end()); }
358 // Front and back inserters...
359 void push_front(NodeTy *val) { insert(begin(), val); }
360 void push_back(NodeTy *val) { insert(end(), val); }
362 assert(!empty() && "pop_front() on empty list!");
366 assert(!empty() && "pop_back() on empty list!");
367 iterator t = end(); erase(--t);
370 // Special forms of insert...
371 template<class InIt> void insert(iterator where, InIt first, InIt last) {
372 for (; first != last; ++first) insert(where, *first);
375 // Splice members - defined in terms of transfer...
376 void splice(iterator where, iplist &L2) {
378 transfer(where, L2, L2.begin(), L2.end());
380 void splice(iterator where, iplist &L2, iterator first) {
381 iterator last = first; ++last;
382 if (where == first || where == last) return; // No change
383 transfer(where, L2, first, last);
385 void splice(iterator where, iplist &L2, iterator first, iterator last) {
386 if (first != last) transfer(where, L2, first, last);
391 //===----------------------------------------------------------------------===
392 // High-Level Functionality that shouldn't really be here, but is part of list
395 // These two functions are actually called remove/remove_if in list<>, but
396 // they actually do the job of erase, rename them accordingly.
398 void erase(const NodeTy &val) {
399 for (iterator I = begin(), E = end(); I != E; ) {
400 iterator next = I; ++next;
401 if (*I == val) erase(I);
405 template<class Pr1> void erase_if(Pr1 pred) {
406 for (iterator I = begin(), E = end(); I != E; ) {
407 iterator next = I; ++next;
408 if (pred(*I)) erase(I);
413 template<class Pr2> void unique(Pr2 pred) {
415 for (iterator I = begin(), E = end(), Next = begin(); ++Next != E;) {
423 void unique() { unique(op_equal); }
425 template<class Pr3> void merge(iplist &right, Pr3 pred) {
426 iterator first1 = begin(), last1 = end();
427 iterator first2 = right.begin(), last2 = right.end();
428 while (first1 != last1 && first2 != last2)
429 if (pred(*first2, *first1)) {
430 iterator next = first2;
431 transfer(first1, right, first2, ++next);
436 if (first2 != last2) transfer(last1, right, first2, last2);
438 void merge(iplist &right) { return merge(right, op_less); }
440 template<class Pr3> void sort(Pr3 pred);
441 void sort() { sort(op_less); }
446 template<typename NodeTy>
447 struct ilist : public iplist<NodeTy> {
448 typedef typename iplist<NodeTy>::size_type size_type;
449 typedef typename iplist<NodeTy>::iterator iterator;
452 ilist(const ilist &right) {
453 insert(this->begin(), right.begin(), right.end());
455 explicit ilist(size_type count) {
456 insert(this->begin(), count, NodeTy());
458 ilist(size_type count, const NodeTy &val) {
459 insert(this->begin(), count, val);
461 template<class InIt> ilist(InIt first, InIt last) {
462 insert(this->begin(), first, last);
466 // Forwarding functions: A workaround for GCC 2.95 which does not correctly
467 // support 'using' declarations to bring a hidden member into scope.
469 iterator insert(iterator a, NodeTy *b){ return iplist<NodeTy>::insert(a, b); }
470 void push_front(NodeTy *a) { iplist<NodeTy>::push_front(a); }
471 void push_back(NodeTy *a) { iplist<NodeTy>::push_back(a); }
474 // Main implementation here - Insert for a node passed by value...
475 iterator insert(iterator where, const NodeTy &val) {
476 return insert(where, createNode(val));
480 // Front and back inserters...
481 void push_front(const NodeTy &val) { insert(this->begin(), val); }
482 void push_back(const NodeTy &val) { insert(this->end(), val); }
484 // Special forms of insert...
485 template<class InIt> void insert(iterator where, InIt first, InIt last) {
486 for (; first != last; ++first) insert(where, *first);
488 void insert(iterator where, size_type count, const NodeTy &val) {
489 for (; count != 0; --count) insert(where, val);
492 // Assign special forms...
493 void assign(size_type count, const NodeTy &val) {
494 iterator I = this->begin();
495 for (; I != this->end() && count != 0; ++I, --count)
498 insert(this->end(), val, val);
500 erase(I, this->end());
502 template<class InIt> void assign(InIt first1, InIt last1) {
503 iterator first2 = this->begin(), last2 = this->end();
504 for ( ; first1 != last1 && first2 != last2; ++first1, ++first2)
507 erase(first1, last1);
509 insert(last1, first2, last2);
514 void resize(size_type newsize, NodeTy val) {
515 iterator i = this->begin();
517 for ( ; i != this->end() && len < newsize; ++i, ++len) /* empty*/ ;
520 erase(i, this->end());
522 insert(this->end(), newsize - len, val);
524 void resize(size_type newsize) { resize(newsize, NodeTy()); }
527 } // End llvm namespace
530 // Ensure that swap uses the fast list swap...
532 void swap(llvm::iplist<Ty> &Left, llvm::iplist<Ty> &Right) {
535 } // End 'std' extensions...