1 //===-- Support/ilist - Intrusive Linked List Template ----------*- C++ -*-===//
3 // This file defines classes to implement an intrusive doubly linked list class
4 // (ie each node of the list must contain a next and previous field for the
7 // The ilist_traits trait class is used to gain access to the next and previous
8 // fields of the node type that the list is instantiated with. If it is not
9 // specialized, the list defaults to using the getPrev(), getNext() method calls
10 // to get the next and previous pointers.
12 // The ilist class itself, should be a plug in replacement for list, assuming
13 // that the nodes contain next/prev pointers. This list replacement does not
14 // provides a constant time size() method, so be careful to use empty() when you
15 // really want to know if it's empty.
17 // The ilist class is implemented by allocating a 'tail' node when the list is
18 // created (using ilist_traits<>::createEndMarker()). This tail node is
19 // absolutely required because the user must be able to compute end()-1. Because
20 // of this, users of the direct next/prev links will see an extra link on the
21 // end of the list, which should be ignored.
23 // Requirements for a user of this list:
25 // 1. The user must provide {g|s}et{Next|Prev} methods, or specialize
26 // ilist_traits to provide an alternate way of getting and setting next and
29 //===----------------------------------------------------------------------===//
35 #include <Support/iterator>
38 template<typename NodeTy, typename Traits> class iplist;
39 template<typename NodeTy> class ilist_iterator;
41 // Template traits for intrusive list. By specializing this template class, you
42 // can change what next/prev fields are used to store the links...
43 template<typename NodeTy>
45 static NodeTy *getPrev(NodeTy *N) { return N->getPrev(); }
46 static NodeTy *getNext(NodeTy *N) { return N->getNext(); }
47 static const NodeTy *getPrev(const NodeTy *N) { return N->getPrev(); }
48 static const NodeTy *getNext(const NodeTy *N) { return N->getNext(); }
50 static void setPrev(NodeTy *N, NodeTy *Prev) { N->setPrev(Prev); }
51 static void setNext(NodeTy *N, NodeTy *Next) { N->setNext(Next); }
53 static NodeTy *createNode() { return new NodeTy(); }
54 static NodeTy *createNode(const NodeTy &V) { return new NodeTy(V); }
57 void addNodeToList(NodeTy *NTy) {}
58 void removeNodeFromList(NodeTy *NTy) {}
59 void transferNodesFromList(iplist<NodeTy, ilist_traits> &L2,
60 ilist_iterator<NodeTy> first,
61 ilist_iterator<NodeTy> last) {}
64 // Const traits are the same as nonconst traits...
66 struct ilist_traits<const Ty> : public ilist_traits<Ty> {};
69 //===----------------------------------------------------------------------===//
70 // ilist_iterator<Node> - Iterator for intrusive list.
72 template<typename NodeTy>
74 : public bidirectional_iterator<NodeTy, ptrdiff_t> {
75 typedef ilist_traits<NodeTy> Traits;
76 typedef bidirectional_iterator<NodeTy, ptrdiff_t> super;
79 typedef size_t size_type;
80 typedef typename super::pointer pointer;
81 typedef typename super::reference reference;
86 ilist_iterator(pointer NP) : NodePtr(NP) {}
87 ilist_iterator(reference NR) : NodePtr(&NR) {}
88 ilist_iterator() : NodePtr(0) {}
90 // This is templated so that we can allow constructing a const iterator from
91 // a nonconst iterator...
92 template<class node_ty>
93 ilist_iterator(const ilist_iterator<node_ty> &RHS)
94 : NodePtr(RHS.getNodePtrUnchecked()) {}
96 // This is templated so that we can allow assigning to a const iterator from
97 // a nonconst iterator...
98 template<class node_ty>
99 const ilist_iterator &operator=(const ilist_iterator<node_ty> &RHS) {
100 NodePtr = RHS.getNodePtrUnchecked();
105 operator pointer() const {
106 assert(Traits::getNext(NodePtr) != 0 && "Dereferencing end()!");
110 reference operator*() const {
111 assert(Traits::getNext(NodePtr) != 0 && "Dereferencing end()!");
114 pointer operator->() { return &operator*(); }
115 const pointer operator->() const { return &operator*(); }
117 // Comparison operators
118 bool operator==(const ilist_iterator &RHS) const {
119 return NodePtr == RHS.NodePtr;
121 bool operator!=(const ilist_iterator &RHS) const {
122 return NodePtr != RHS.NodePtr;
125 // Increment and decrement operators...
126 ilist_iterator &operator--() { // predecrement - Back up
127 NodePtr = Traits::getPrev(NodePtr);
128 assert(NodePtr && "--'d off the beginning of an ilist!");
131 ilist_iterator &operator++() { // preincrement - Advance
132 NodePtr = Traits::getNext(NodePtr);
133 assert(NodePtr && "++'d off the end of an ilist!");
136 ilist_iterator operator--(int) { // postdecrement operators...
137 ilist_iterator tmp = *this;
141 ilist_iterator operator++(int) { // postincrement operators...
142 ilist_iterator tmp = *this;
148 // Dummy operators to make errors apparent...
149 template<class X> void operator+(X Val) {}
150 template<class X> void operator-(X Val) {}
152 // Internal interface, do not use...
153 pointer getNodePtrUnchecked() const { return NodePtr; }
156 // Allow ilist_iterators to convert into pointers to a node automatically when
157 // used by the dyn_cast, cast, isa mechanisms...
159 template<typename From> struct simplify_type;
161 template<typename NodeTy> struct simplify_type<ilist_iterator<NodeTy> > {
162 typedef NodeTy* SimpleType;
164 static SimpleType getSimplifiedValue(const ilist_iterator<NodeTy> &Node) {
168 template<typename NodeTy> struct simplify_type<const ilist_iterator<NodeTy> > {
169 typedef NodeTy* SimpleType;
171 static SimpleType getSimplifiedValue(const ilist_iterator<NodeTy> &Node) {
177 //===----------------------------------------------------------------------===//
179 // iplist - The subset of list functionality that can safely be used on nodes of
180 // polymorphic types, ie a heterogeneus list with a common base class that holds
181 // the next/prev pointers...
183 template<typename NodeTy, typename Traits=ilist_traits<NodeTy> >
184 class iplist : public Traits {
187 static bool op_less(NodeTy &L, NodeTy &R) { return L < R; }
188 static bool op_equal(NodeTy &L, NodeTy &R) { return L == R; }
190 typedef NodeTy *pointer;
191 typedef const NodeTy *const_pointer;
192 typedef NodeTy &reference;
193 typedef const NodeTy &const_reference;
194 typedef NodeTy value_type;
195 typedef ilist_iterator<NodeTy> iterator;
196 typedef ilist_iterator<const NodeTy> const_iterator;
197 typedef size_t size_type;
198 typedef ptrdiff_t difference_type;
199 typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
200 typedef std::reverse_iterator<iterator> reverse_iterator;
202 iplist() : Head(this->createNode()), Tail(Head) {
206 ~iplist() { clear(); delete Tail; }
208 // Iterator creation methods...
209 iterator begin() { return iterator(Head); }
210 const_iterator begin() const { return const_iterator(Head); }
211 iterator end() { return iterator(Tail); }
212 const_iterator end() const { return const_iterator(Tail); }
214 // reverse iterator creation methods...
215 reverse_iterator rbegin() { return reverse_iterator(end()); }
216 const_reverse_iterator rbegin() const{ return const_reverse_iterator(end()); }
217 reverse_iterator rend() { return reverse_iterator(begin()); }
218 const_reverse_iterator rend() const {return const_reverse_iterator(begin());}
220 // Miscellaneous inspection routines...
221 size_type max_size() const { return size_type(-1); }
222 bool empty() const { return Head == Tail; }
224 // Front and back accessor functions...
226 assert(!empty() && "Called front() on empty list!");
229 const_reference front() const {
230 assert(!empty() && "Called front() on empty list!");
234 assert(!empty() && "Called back() on empty list!");
235 return *getPrev(Tail);
237 const_reference back() const {
238 assert(!empty() && "Called back() on empty list!");
239 return *getPrev(Tail);
242 void swap(iplist &RHS) {
243 abort(); // Swap does not use list traits callback correctly yet!
244 std::swap(Head, RHS.Head);
245 std::swap(Tail, RHS.Tail);
248 iterator insert(iterator where, NodeTy *New) {
249 NodeTy *CurNode = where.getNodePtrUnchecked(), *PrevNode = getPrev(CurNode);
250 setNext(New, CurNode);
251 setPrev(New, PrevNode);
254 setNext(PrevNode, New);
257 setPrev(CurNode, New);
259 addNodeToList(New); // Notify traits that we added a node...
263 NodeTy *remove(iterator &IT) {
264 assert(IT != end() && "Cannot remove end of list!");
266 NodeTy *NextNode = getNext(Node);
267 NodeTy *PrevNode = getPrev(Node);
270 setNext(PrevNode, NextNode);
273 setPrev(NextNode, PrevNode);
275 removeNodeFromList(Node); // Notify traits that we added a node...
279 NodeTy *remove(const iterator &IT) {
281 return remove(MutIt);
284 // erase - remove a node from the controlled sequence... and delete it.
285 iterator erase(iterator where) {
286 delete remove(where);
292 // transfer - The heart of the splice function. Move linked list nodes from
293 // [first, last) into position.
295 void transfer(iterator position, iplist &L2, iterator first, iterator last) {
296 assert(first != last && "Should be checked by callers");
297 if (position != last) {
298 // Remove [first, last) from its old position.
299 NodeTy *First = &*first, *Prev = getPrev(First);
300 NodeTy *Next = last.getNodePtrUnchecked(), *Last = getPrev(Next);
307 // Splice [first, last) into its new position.
308 NodeTy *PosNext = position.getNodePtrUnchecked();
309 NodeTy *PosPrev = getPrev(PosNext);
311 // Fix head of list...
313 setNext(PosPrev, First);
316 setPrev(First, PosPrev);
318 // Fix end of list...
319 setNext(Last, PosNext);
320 setPrev(PosNext, Last);
322 transferNodesFromList(L2, First, PosNext);
328 //===----------------------------------------------------------------------===
329 // Functionality derived from other functions defined above...
332 size_type size() const {
334 size_type Result = std::distance(begin(), end());
336 size_type Result = 0;
337 std::distance(begin(), end(), Result);
342 iterator erase(iterator first, iterator last) {
343 while (first != last)
344 first = erase(first);
348 void clear() { erase(begin(), end()); }
350 // Front and back inserters...
351 void push_front(NodeTy *val) { insert(begin(), val); }
352 void push_back(NodeTy *val) { insert(end(), val); }
354 assert(!empty() && "pop_front() on empty list!");
358 assert(!empty() && "pop_back() on empty list!");
359 iterator t = end(); erase(--t);
362 // Special forms of insert...
363 template<class InIt> void insert(iterator where, InIt first, InIt last) {
364 for (; first != last; ++first) insert(where, *first);
367 // Splice members - defined in terms of transfer...
368 void splice(iterator where, iplist &L2) {
370 transfer(where, L2, L2.begin(), L2.end());
372 void splice(iterator where, iplist &L2, iterator first) {
373 iterator last = first; ++last;
374 if (where == first || where == last) return; // No change
375 transfer(where, L2, first, last);
377 void splice(iterator where, iplist &L2, iterator first, iterator last) {
378 if (first != last) transfer(where, L2, first, last);
383 //===----------------------------------------------------------------------===
384 // High-Level Functionality that shouldn't really be here, but is part of list
387 // These two functions are actually called remove/remove_if in list<>, but
388 // they actually do the job of erase, rename them accordingly.
390 void erase(const NodeTy &val) {
391 for (iterator I = begin(), E = end(); I != E; ) {
392 iterator next = I; ++next;
393 if (*I == val) erase(I);
397 template<class Pr1> void erase_if(Pr1 pred) {
398 for (iterator I = begin(), E = end(); I != E; ) {
399 iterator next = I; ++next;
400 if (pred(*I)) erase(I);
405 template<class Pr2> void unique(Pr2 pred) {
407 for (iterator I = begin(), E = end(), Next = begin(); ++Next != E;) {
415 void unique() { unique(op_equal); }
417 template<class Pr3> void merge(iplist &right, Pr3 pred) {
418 iterator first1 = begin(), last1 = end();
419 iterator first2 = right.begin(), last2 = right.end();
420 while (first1 != last1 && first2 != last2)
421 if (pred(*first2, *first1)) {
422 iterator next = first2;
423 transfer(first1, right, first2, ++next);
428 if (first2 != last2) transfer(last1, right, first2, last2);
430 void merge(iplist &right) { return merge(right, op_less); }
432 template<class Pr3> void sort(Pr3 pred);
433 void sort() { sort(op_less); }
438 template<typename NodeTy>
439 struct ilist : public iplist<NodeTy> {
440 typedef typename iplist<NodeTy>::size_type size_type;
441 typedef typename iplist<NodeTy>::iterator iterator;
444 ilist(const ilist &right) {
445 insert(this->begin(), right.begin(), right.end());
447 explicit ilist(size_type count) {
448 insert(this->begin(), count, NodeTy());
450 ilist(size_type count, const NodeTy &val) {
451 insert(this->begin(), count, val);
453 template<class InIt> ilist(InIt first, InIt last) {
454 insert(this->begin(), first, last);
458 // Forwarding functions: A workaround for GCC 2.95 which does not correctly
459 // support 'using' declarations to bring a hidden member into scope.
461 iterator insert(iterator a, NodeTy *b){ return iplist<NodeTy>::insert(a, b); }
462 void push_front(NodeTy *a) { iplist<NodeTy>::push_front(a); }
463 void push_back(NodeTy *a) { iplist<NodeTy>::push_back(a); }
466 // Main implementation here - Insert for a node passed by value...
467 iterator insert(iterator where, const NodeTy &val) {
468 return insert(where, createNode(val));
472 // Front and back inserters...
473 void push_front(const NodeTy &val) { insert(this->begin(), val); }
474 void push_back(const NodeTy &val) { insert(this->end(), val); }
476 // Special forms of insert...
477 template<class InIt> void insert(iterator where, InIt first, InIt last) {
478 for (; first != last; ++first) insert(where, *first);
480 void insert(iterator where, size_type count, const NodeTy &val) {
481 for (; count != 0; --count) insert(where, val);
484 // Assign special forms...
485 void assign(size_type count, const NodeTy &val) {
486 iterator I = this->begin();
487 for (; I != this->end() && count != 0; ++I, --count)
490 insert(this->end(), val, val);
492 erase(I, this->end());
494 template<class InIt> void assign(InIt first1, InIt last1) {
495 iterator first2 = this->begin(), last2 = this->end();
496 for ( ; first1 != last1 && first2 != last2; ++first1, ++first2)
499 erase(first1, last1);
501 insert(last1, first2, last2);
506 void resize(size_type newsize, NodeTy val) {
507 iterator i = this->begin();
509 for ( ; i != this->end() && len < newsize; ++i, ++len) /* empty*/ ;
512 erase(i, this->end());
514 insert(this->end(), newsize - len, val);
516 void resize(size_type newsize) { resize(newsize, NodeTy()); }
520 // Ensure that swap uses the fast list swap...
522 void swap(iplist<Ty> &Left, iplist<Ty> &Right) {
525 } // End 'std' extensions...