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>
37 template<typename NodeTy, typename Traits> class iplist;
38 template<typename NodeTy> class ilist_iterator;
40 // Template traits for intrusive list. By specializing this template class, you
41 // can change what next/prev fields are used to store the links...
42 template<typename NodeTy>
44 static NodeTy *getPrev(NodeTy *N) { return N->getPrev(); }
45 static NodeTy *getNext(NodeTy *N) { return N->getNext(); }
46 static const NodeTy *getPrev(const NodeTy *N) { return N->getPrev(); }
47 static const NodeTy *getNext(const NodeTy *N) { return N->getNext(); }
49 static void setPrev(NodeTy *N, NodeTy *Prev) { N->setPrev(Prev); }
50 static void setNext(NodeTy *N, NodeTy *Next) { N->setNext(Next); }
52 static NodeTy *createNode() { return new NodeTy(); }
53 static NodeTy *createNode(const NodeTy &V) { return new NodeTy(V); }
56 void addNodeToList(NodeTy *NTy) {}
57 void removeNodeFromList(NodeTy *NTy) {}
58 void transferNodesFromList(iplist<NodeTy, ilist_traits> &L2,
59 ilist_iterator<NodeTy> first,
60 ilist_iterator<NodeTy> last) {}
63 // Const traits are the same as nonconst traits...
65 struct ilist_traits<const Ty> : public ilist_traits<Ty> {};
68 //===----------------------------------------------------------------------===//
69 // ilist_iterator<Node> - Iterator for intrusive list.
71 template<typename NodeTy>
73 : public bidirectional_iterator<NodeTy, ptrdiff_t> {
74 typedef ilist_traits<NodeTy> Traits;
75 typedef bidirectional_iterator<NodeTy, ptrdiff_t> super;
78 typedef size_t size_type;
79 typedef typename super::pointer pointer;
80 typedef typename super::reference reference;
85 ilist_iterator(pointer NP) : NodePtr(NP) {}
86 ilist_iterator(reference NR) : NodePtr(&NR) {}
87 ilist_iterator() : NodePtr(0) {}
89 // This is templated so that we can allow constructing a const iterator from
90 // a nonconst iterator...
91 template<class node_ty>
92 ilist_iterator(const ilist_iterator<node_ty> &RHS)
93 : NodePtr(RHS.getNodePtrUnchecked()) {}
95 // This is templated so that we can allow assigning to a const iterator from
96 // a nonconst iterator...
97 template<class node_ty>
98 const ilist_iterator &operator=(const ilist_iterator<node_ty> &RHS) {
99 NodePtr = RHS.getNodePtrUnchecked();
104 operator pointer() const {
105 assert(Traits::getNext(NodePtr) != 0 && "Dereferencing end()!");
109 reference operator*() const {
110 assert(Traits::getNext(NodePtr) != 0 && "Dereferencing end()!");
113 pointer operator->() { return &operator*(); }
114 const pointer operator->() const { return &operator*(); }
116 // Comparison operators
117 bool operator==(const ilist_iterator &RHS) const {
118 return NodePtr == RHS.NodePtr;
120 bool operator!=(const ilist_iterator &RHS) const {
121 return NodePtr != RHS.NodePtr;
124 // Increment and decrement operators...
125 ilist_iterator &operator--() { // predecrement - Back up
126 NodePtr = Traits::getPrev(NodePtr);
127 assert(NodePtr && "--'d off the beginning of an ilist!");
130 ilist_iterator &operator++() { // preincrement - Advance
131 NodePtr = Traits::getNext(NodePtr);
132 assert(NodePtr && "++'d off the end of an ilist!");
135 ilist_iterator operator--(int) { // postdecrement operators...
136 ilist_iterator tmp = *this;
140 ilist_iterator operator++(int) { // postincrement operators...
141 ilist_iterator tmp = *this;
147 // Dummy operators to make errors apparent...
148 template<class X> void operator+(X Val) {}
149 template<class X> void operator-(X Val) {}
151 // Internal interface, do not use...
152 pointer getNodePtrUnchecked() const { return NodePtr; }
155 // Allow ilist_iterators to convert into pointers to a node automatically when
156 // used by the dyn_cast, cast, isa mechanisms...
158 template<typename From> struct simplify_type;
160 template<typename NodeTy> struct simplify_type<ilist_iterator<NodeTy> > {
161 typedef NodeTy* SimpleType;
163 static SimpleType getSimplifiedValue(const ilist_iterator<NodeTy> &Node) {
167 template<typename NodeTy> struct simplify_type<const ilist_iterator<NodeTy> > {
168 typedef NodeTy* SimpleType;
170 static SimpleType getSimplifiedValue(const ilist_iterator<NodeTy> &Node) {
176 //===----------------------------------------------------------------------===//
178 // iplist - The subset of list functionality that can safely be used on nodes of
179 // polymorphic types, ie a heterogeneus list with a common base class that holds
180 // the next/prev pointers...
182 template<typename NodeTy, typename Traits=ilist_traits<NodeTy> >
183 class iplist : public Traits {
186 static bool op_less(NodeTy &L, NodeTy &R) { return L < R; }
187 static bool op_equal(NodeTy &L, NodeTy &R) { return L == R; }
189 typedef NodeTy *pointer;
190 typedef const NodeTy *const_pointer;
191 typedef NodeTy &reference;
192 typedef const NodeTy &const_reference;
193 typedef NodeTy value_type;
194 typedef ilist_iterator<NodeTy> iterator;
195 typedef ilist_iterator<const NodeTy> const_iterator;
196 typedef size_t size_type;
197 typedef ptrdiff_t difference_type;
198 typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
199 typedef std::reverse_iterator<iterator> reverse_iterator;
201 iplist() : Head(createNode()), Tail(Head) {
205 ~iplist() { clear(); delete Tail; }
207 // Iterator creation methods...
208 iterator begin() { return iterator(Head); }
209 const_iterator begin() const { return const_iterator(Head); }
210 iterator end() { return iterator(Tail); }
211 const_iterator end() const { return const_iterator(Tail); }
213 // reverse iterator creation methods...
214 reverse_iterator rbegin() { return reverse_iterator(end()); }
215 const_reverse_iterator rbegin() const{ return const_reverse_iterator(end()); }
216 reverse_iterator rend() { return reverse_iterator(begin()); }
217 const_reverse_iterator rend() const {return const_reverse_iterator(begin());}
219 // Miscellaneous inspection routines...
220 size_type max_size() const { return size_type(-1); }
221 bool empty() const { return Head == Tail; }
223 // Front and back accessor functions...
225 assert(!empty() && "Called front() on empty list!");
228 const_reference front() const {
229 assert(!empty() && "Called front() on empty list!");
233 assert(!empty() && "Called back() on empty list!");
234 return *getPrev(Tail);
236 const_reference back() const {
237 assert(!empty() && "Called back() on empty list!");
238 return *getPrev(Tail);
241 void swap(iplist &RHS) {
242 abort(); // Swap does not use list traits callback correctly yet!
243 std::swap(Head, RHS.Head);
244 std::swap(Tail, RHS.Tail);
247 iterator insert(iterator where, NodeTy *New) {
248 NodeTy *CurNode = where.getNodePtrUnchecked(), *PrevNode = getPrev(CurNode);
249 setNext(New, CurNode);
250 setPrev(New, PrevNode);
253 setNext(PrevNode, New);
256 setPrev(CurNode, New);
258 addNodeToList(New); // Notify traits that we added a node...
262 NodeTy *remove(iterator &IT) {
263 assert(IT != end() && "Cannot remove end of list!");
265 NodeTy *NextNode = getNext(Node);
266 NodeTy *PrevNode = getPrev(Node);
269 setNext(PrevNode, NextNode);
272 setPrev(NextNode, PrevNode);
274 removeNodeFromList(Node); // Notify traits that we added a node...
278 NodeTy *remove(const iterator &IT) {
280 return remove(MutIt);
283 // erase - remove a node from the controlled sequence... and delete it.
284 iterator erase(iterator where) {
285 delete remove(where);
291 // transfer - The heart of the splice function. Move linked list nodes from
292 // [first, last) into position.
294 void transfer(iterator position, iplist &L2, iterator first, iterator last) {
295 assert(first != last && "Should be checked by callers");
296 if (position != last) {
297 // Remove [first, last) from its old position.
298 NodeTy *First = &*first, *Prev = getPrev(First);
299 NodeTy *Next = last.getNodePtrUnchecked(), *Last = getPrev(Next);
306 // Splice [first, last) into its new position.
307 NodeTy *PosNext = position.getNodePtrUnchecked();
308 NodeTy *PosPrev = getPrev(PosNext);
310 // Fix head of list...
312 setNext(PosPrev, First);
315 setPrev(First, PosPrev);
317 // Fix end of list...
318 setNext(Last, PosNext);
319 setPrev(PosNext, Last);
321 transferNodesFromList(L2, First, PosNext);
327 //===----------------------------------------------------------------------===
328 // Functionality derived from other functions defined above...
331 size_type size() const {
333 size_type Result = std::distance(begin(), end());
335 size_type Result = 0;
336 std::distance(begin(), end(), Result);
341 iterator erase(iterator first, iterator last) {
342 while (first != last)
343 first = erase(first);
347 void clear() { erase(begin(), end()); }
349 // Front and back inserters...
350 void push_front(NodeTy *val) { insert(begin(), val); }
351 void push_back(NodeTy *val) { insert(end(), val); }
353 assert(!empty() && "pop_front() on empty list!");
357 assert(!empty() && "pop_back() on empty list!");
358 iterator t = end(); erase(--t);
361 // Special forms of insert...
362 template<class InIt> void insert(iterator where, InIt first, InIt last) {
363 for (; first != last; ++first) insert(where, *first);
366 // Splice members - defined in terms of transfer...
367 void splice(iterator where, iplist &L2) {
369 transfer(where, L2, L2.begin(), L2.end());
371 void splice(iterator where, iplist &L2, iterator first) {
372 iterator last = first; ++last;
373 if (where == first || where == last) return; // No change
374 transfer(where, L2, first, last);
376 void splice(iterator where, iplist &L2, iterator first, iterator last) {
377 if (first != last) transfer(where, L2, first, last);
382 //===----------------------------------------------------------------------===
383 // High-Level Functionality that shouldn't really be here, but is part of list
386 // These two functions are actually called remove/remove_if in list<>, but
387 // they actually do the job of erase, rename them accordingly.
389 void erase(const NodeTy &val) {
390 for (iterator I = begin(), E = end(); I != E; ) {
391 iterator next = I; ++next;
392 if (*I == val) erase(I);
396 template<class Pr1> void erase_if(Pr1 pred) {
397 for (iterator I = begin(), E = end(); I != E; ) {
398 iterator next = I; ++next;
399 if (pred(*I)) erase(I);
404 template<class Pr2> void unique(Pr2 pred) {
406 for (iterator I = begin(), E = end(), Next = begin(); ++Next != E;) {
414 void unique() { unique(op_equal); }
416 template<class Pr3> void merge(iplist &right, Pr3 pred) {
417 iterator first1 = begin(), last1 = end();
418 iterator first2 = right.begin(), last2 = right.end();
419 while (first1 != last1 && first2 != last2)
420 if (pred(*first2, *first1)) {
421 iterator next = first2;
422 transfer(first1, right, first2, ++next);
427 if (first2 != last2) transfer(last1, right, first2, last2);
429 void merge(iplist &right) { return merge(right, op_less); }
431 template<class Pr3> void sort(Pr3 pred);
432 void sort() { sort(op_less); }
437 template<typename NodeTy>
438 struct ilist : public iplist<NodeTy> {
439 typedef typename iplist<NodeTy>::size_type size_type;
440 typedef typename iplist<NodeTy>::iterator iterator;
443 ilist(const ilist &right) {
444 insert(begin(), right.begin(), right.end());
446 explicit ilist(size_type count) {
447 insert(begin(), count, NodeTy());
449 ilist(size_type count, const NodeTy &val) {
450 insert(begin(), count, val);
452 template<class InIt> ilist(InIt first, InIt last) {
453 insert(begin(), first, last);
457 // Forwarding functions: A workaround for GCC 2.95 which does not correctly
458 // support 'using' declarations to bring a hidden member into scope.
460 iterator insert(iterator a, NodeTy *b){ return iplist<NodeTy>::insert(a, b); }
461 void push_front(NodeTy *a) { iplist<NodeTy>::push_front(a); }
462 void push_back(NodeTy *a) { iplist<NodeTy>::push_back(a); }
465 // Main implementation here - Insert for a node passed by value...
466 iterator insert(iterator where, const NodeTy &val) {
467 return insert(where, createNode(val));
471 // Front and back inserters...
472 void push_front(const NodeTy &val) { insert(begin(), val); }
473 void push_back(const NodeTy &val) { insert(end(), val); }
475 // Special forms of insert...
476 template<class InIt> void insert(iterator where, InIt first, InIt last) {
477 for (; first != last; ++first) insert(where, *first);
479 void insert(iterator where, size_type count, const NodeTy &val) {
480 for (; count != 0; --count) insert(where, val);
483 // Assign special forms...
484 void assign(size_type count, const NodeTy &val) {
485 iterator I = begin();
486 for (; I != end() && count != 0; ++I, --count)
489 insert(end(), n, val);
493 template<class InIt> void assign(InIt first, InIt last) {
494 iterator first1 = begin(), last1 = end();
495 for ( ; first1 != last1 && first2 != last2; ++first1, ++first2)
498 erase(first1, last1);
500 insert(last1, first2, last2);
505 void resize(size_type newsize, NodeTy val) {
506 iterator i = begin();
508 for ( ; i != end() && len < newsize; ++i, ++len) /* empty*/ ;
513 insert(end(), newsize - len, val);
515 void resize(size_type newsize) { resize(newsize, NodeTy()); }
519 // Ensure that swap uses the fast list swap...
521 void swap(iplist<Ty> &Left, iplist<Ty> &Right) {
524 } // End 'std' extensions...