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 //===----------------------------------------------------------------------===//
36 #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;
78 typedef typename super::pointer pointer;
79 typedef typename super::reference reference;
82 typedef size_t size_type;
84 ilist_iterator(pointer NP) : NodePtr(NP) {}
85 ilist_iterator(reference NR) : NodePtr(&NR) {}
86 ilist_iterator() : NodePtr(0) {}
88 // This is templated so that we can allow constructing a const iterator from
89 // a nonconst iterator...
90 template<class node_ty>
91 ilist_iterator(const ilist_iterator<node_ty> &RHS)
92 : NodePtr(RHS.getNodePtrUnchecked()) {}
94 // This is templated so that we can allow assigning to a const iterator from
95 // a nonconst iterator...
96 template<class node_ty>
97 const ilist_iterator &operator=(const ilist_iterator<node_ty> &RHS) {
98 NodePtr = RHS.getNodePtrUnchecked();
103 operator pointer() const {
104 assert(Traits::getNext(NodePtr) != 0 && "Dereferencing end()!");
108 reference operator*() const {
109 assert(Traits::getNext(NodePtr) != 0 && "Dereferencing end()!");
112 pointer operator->() { return &operator*(); }
113 const pointer operator->() const { return &operator*(); }
115 // Comparison operators
116 bool operator==(const ilist_iterator &RHS) const {
117 return NodePtr == RHS.NodePtr;
119 bool operator!=(const ilist_iterator &RHS) const {
120 return NodePtr != RHS.NodePtr;
123 // Increment and decrement operators...
124 ilist_iterator &operator--() { // predecrement - Back up
125 NodePtr = Traits::getPrev(NodePtr);
126 assert(NodePtr && "--'d off the beginning of an ilist!");
129 ilist_iterator &operator++() { // preincrement - Advance
130 NodePtr = Traits::getNext(NodePtr);
131 assert(NodePtr && "++'d off the end of an ilist!");
134 ilist_iterator operator--(int) { // postdecrement operators...
135 ilist_iterator tmp = *this;
139 ilist_iterator operator++(int) { // postincrement operators...
140 ilist_iterator tmp = *this;
146 // Dummy operators to make errors apparent...
147 template<class X> void operator+(X Val) {}
148 template<class X> void operator-(X Val) {}
150 // Internal interface, do not use...
151 pointer getNodePtrUnchecked() const { return NodePtr; }
154 // Allow ilist_iterators to convert into pointers to a node automatically when
155 // used by the dyn_cast, cast, isa mechanisms...
157 template<typename From> struct simplify_type;
159 template<typename NodeTy> struct simplify_type<ilist_iterator<NodeTy> > {
160 typedef NodeTy* SimpleType;
162 static SimpleType getSimplifiedValue(const ilist_iterator<NodeTy> &Node) {
166 template<typename NodeTy> struct simplify_type<const ilist_iterator<NodeTy> > {
167 typedef NodeTy* SimpleType;
169 static SimpleType getSimplifiedValue(const ilist_iterator<NodeTy> &Node) {
175 //===----------------------------------------------------------------------===//
177 // iplist - The subset of list functionality that can safely be used on nodes of
178 // polymorphic types, ie a heterogeneus list with a common base class that holds
179 // the next/prev pointers...
181 template<typename NodeTy, typename Traits=ilist_traits<NodeTy> >
182 class iplist : public Traits {
185 static bool op_less(NodeTy &L, NodeTy &R) { return L < R; }
186 static bool op_equal(NodeTy &L, NodeTy &R) { return L == R; }
188 typedef NodeTy *pointer;
189 typedef const NodeTy *const_pointer;
190 typedef NodeTy &reference;
191 typedef const NodeTy &const_reference;
192 typedef NodeTy value_type;
193 typedef ilist_iterator<NodeTy> iterator;
194 typedef ilist_iterator<const NodeTy> const_iterator;
195 typedef size_t size_type;
196 typedef ptrdiff_t difference_type;
197 typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
198 typedef std::reverse_iterator<iterator> reverse_iterator;
200 iplist() : Head(createNode()), Tail(Head) {
204 ~iplist() { clear(); delete Tail; }
206 // Iterator creation methods...
207 iterator begin() { return iterator(Head); }
208 const_iterator begin() const { return const_iterator(Head); }
209 iterator end() { return iterator(Tail); }
210 const_iterator end() const { return const_iterator(Tail); }
212 // reverse iterator creation methods...
213 reverse_iterator rbegin() { return reverse_iterator(end()); }
214 const_reverse_iterator rbegin() const{ return const_reverse_iterator(end()); }
215 reverse_iterator rend() { return reverse_iterator(begin()); }
216 const_reverse_iterator rend() const {return const_reverse_iterator(begin());}
218 // Miscellaneous inspection routines...
219 size_type max_size() const { return size_type(-1); }
220 bool empty() const { return Head == Tail; }
222 // Front and back accessor functions...
224 assert(!empty() && "Called front() on empty list!");
227 const_reference front() const {
228 assert(!empty() && "Called front() on empty list!");
232 assert(!empty() && "Called back() on empty list!");
233 return *getPrev(Tail);
235 const_reference back() const {
236 assert(!empty() && "Called back() on empty list!");
237 return *getPrev(Tail);
240 void swap(iplist &RHS) {
241 abort(); // Swap does not use list traits callback correctly yet!
242 std::swap(Head, RHS.Head);
243 std::swap(Tail, RHS.Tail);
246 iterator insert(iterator where, NodeTy *New) {
247 NodeTy *CurNode = where.getNodePtrUnchecked(), *PrevNode = getPrev(CurNode);
248 setNext(New, CurNode);
249 setPrev(New, PrevNode);
252 setNext(PrevNode, New);
255 setPrev(CurNode, New);
257 addNodeToList(New); // Notify traits that we added a node...
261 NodeTy *remove(iterator &IT) {
262 assert(IT != end() && "Cannot remove end of list!");
264 NodeTy *NextNode = getNext(Node);
265 NodeTy *PrevNode = getPrev(Node);
268 setNext(PrevNode, NextNode);
271 setPrev(NextNode, PrevNode);
273 removeNodeFromList(Node); // Notify traits that we added a node...
277 NodeTy *remove(const iterator &IT) {
279 return remove(MutIt);
282 // erase - remove a node from the controlled sequence... and delete it.
283 iterator erase(iterator where) {
284 delete remove(where);
290 // transfer - The heart of the splice function. Move linked list nodes from
291 // [first, last) into position.
293 void transfer(iterator position, iplist &L2, iterator first, iterator last) {
294 assert(first != last && "Should be checked by callers");
295 if (position != last) {
296 // Remove [first, last) from its old position.
297 NodeTy *First = &*first, *Prev = getPrev(First);
298 NodeTy *Next = last.getNodePtrUnchecked(), *Last = getPrev(Next);
305 // Splice [first, last) into its new position.
306 NodeTy *PosNext = position.getNodePtrUnchecked();
307 NodeTy *PosPrev = getPrev(PosNext);
309 // Fix head of list...
311 setNext(PosPrev, First);
314 setPrev(First, PosPrev);
316 // Fix end of list...
317 setNext(Last, PosNext);
318 setPrev(PosNext, Last);
320 transferNodesFromList(L2, First, PosNext);
326 //===----------------------------------------------------------------------===
327 // Functionality derived from other functions defined above...
330 size_type size() const {
332 size_type Result = std::distance(begin(), end());
334 size_type Result = 0;
335 std::distance(begin(), end(), Result);
340 iterator erase(iterator first, iterator last) {
341 while (first != last)
342 first = erase(first);
346 void clear() { erase(begin(), end()); }
348 // Front and back inserters...
349 void push_front(NodeTy *val) { insert(begin(), val); }
350 void push_back(NodeTy *val) { insert(end(), val); }
352 assert(!empty() && "pop_front() on empty list!");
356 assert(!empty() && "pop_back() on empty list!");
357 iterator t = end(); erase(--t);
360 // Special forms of insert...
361 template<class InIt> void insert(iterator where, InIt first, InIt last) {
362 for (; first != last; ++first) insert(where, *first);
365 // Splice members - defined in terms of transfer...
366 void splice(iterator where, iplist &L2) {
368 transfer(where, L2, L2.begin(), L2.end());
370 void splice(iterator where, iplist &L2, iterator first) {
371 iterator last = first; ++last;
372 if (where == first || where == last) return; // No change
373 transfer(where, L2, first, last);
375 void splice(iterator where, iplist &L2, iterator first, iterator last) {
376 if (first != last) transfer(where, L2, first, last);
381 //===----------------------------------------------------------------------===
382 // High-Level Functionality that shouldn't really be here, but is part of list
385 // These two functions are actually called remove/remove_if in list<>, but
386 // they actually do the job of erase, rename them accordingly.
388 void erase(const NodeTy &val) {
389 for (iterator I = begin(), E = end(); I != E; ) {
390 iterator next = I; ++next;
391 if (*I == val) erase(I);
395 template<class Pr1> void erase_if(Pr1 pred) {
396 for (iterator I = begin(), E = end(); I != E; ) {
397 iterator next = I; ++next;
398 if (pred(*I)) erase(I);
403 template<class Pr2> void unique(Pr2 pred) {
405 for (iterator I = begin(), E = end(), Next = begin(); ++Next != E;) {
413 void unique() { unique(op_equal); }
415 template<class Pr3> void merge(iplist &right, Pr3 pred) {
416 iterator first1 = begin(), last1 = end();
417 iterator first2 = right.begin(), last2 = right.end();
418 while (first1 != last1 && first2 != last2)
419 if (pred(*first2, *first1)) {
420 iterator next = first2;
421 transfer(first1, right, first2, ++next);
426 if (first2 != last2) transfer(last1, right, first2, last2);
428 void merge(iplist &right) { return merge(right, op_less); }
430 template<class Pr3> void sort(Pr3 pred);
431 void sort() { sort(op_less); }
436 template<typename NodeTy>
437 struct ilist : public iplist<NodeTy> {
438 typedef typename iplist<NodeTy>::size_type size_type;
439 typedef typename iplist<NodeTy>::iterator iterator;
442 ilist(const ilist &right) {
443 insert(begin(), right.begin(), right.end());
445 explicit ilist(size_type count) {
446 insert(begin(), count, NodeTy());
448 ilist(size_type count, const NodeTy &val) {
449 insert(begin(), count, val);
451 template<class InIt> ilist(InIt first, InIt last) {
452 insert(begin(), first, last);
456 // Forwarding functions: A workaround for GCC 2.95 which does not correctly
457 // support 'using' declarations to bring a hidden member into scope.
459 iterator insert(iterator a, NodeTy *b){ return iplist<NodeTy>::insert(a, b); }
460 void push_front(NodeTy *a) { iplist<NodeTy>::push_front(a); }
461 void push_back(NodeTy *a) { iplist<NodeTy>::push_back(a); }
464 // Main implementation here - Insert for a node passed by value...
465 iterator insert(iterator where, const NodeTy &val) {
466 return insert(where, createNode(val));
470 // Front and back inserters...
471 void push_front(const NodeTy &val) { insert(begin(), val); }
472 void push_back(const NodeTy &val) { insert(end(), val); }
474 // Special forms of insert...
475 template<class InIt> void insert(iterator where, InIt first, InIt last) {
476 for (; first != last; ++first) insert(where, *first);
478 void insert(iterator where, size_type count, const NodeTy &val) {
479 for (; count != 0; --count) insert(where, val);
482 // Assign special forms...
483 void assign(size_type count, const NodeTy &val) {
484 iterator I = begin();
485 for (; I != end() && count != 0; ++I, --count)
488 insert(end(), n, val);
492 template<class InIt> void assign(InIt first, InIt last) {
493 iterator first1 = begin(), last1 = end();
494 for ( ; first1 != last1 && first2 != last2; ++first1, ++first2)
497 erase(first1, last1);
499 insert(last1, first2, last2);
504 void resize(size_type newsize, NodeTy val) {
505 iterator i = begin();
507 for ( ; i != end() && len < newsize; ++i, ++len) /* empty*/ ;
512 insert(end(), newsize - len, val);
514 void resize(size_type newsize) { resize(newsize, NodeTy()); }
518 // Ensure that swap uses the fast list swap...
520 void swap(iplist<Ty> &Left, iplist<Ty> &Right) {
523 } // End 'std' extensions...