1 //===- llvm/ADT/IntervalMap.h - A sorted interval map -----------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements a coalescing interval map for small objects.
12 // KeyT objects are mapped to ValT objects. Intervals of keys that map to the
13 // same value are represented in a compressed form.
15 // Iterators provide ordered access to the compressed intervals rather than the
16 // individual keys, and insert and erase operations use key intervals as well.
18 // Like SmallVector, IntervalMap will store the first N intervals in the map
19 // object itself without any allocations. When space is exhausted it switches to
20 // a B+-tree representation with very small overhead for small key and value
23 // A Traits class specifies how keys are compared. It also allows IntervalMap to
24 // work with both closed and half-open intervals.
26 // Keys and values are not stored next to each other in a std::pair, so we don't
27 // provide such a value_type. Dereferencing iterators only returns the mapped
28 // value. The interval bounds are accessible through the start() and stop()
31 // IntervalMap is optimized for small key and value objects, 4 or 8 bytes each
32 // is the optimal size. For large objects use std::map instead.
34 //===----------------------------------------------------------------------===//
38 // template <typename KeyT, typename ValT, unsigned N, typename Traits>
39 // class IntervalMap {
41 // typedef KeyT key_type;
42 // typedef ValT mapped_type;
43 // typedef RecyclingAllocator<...> Allocator;
45 // class const_iterator;
47 // explicit IntervalMap(Allocator&);
50 // bool empty() const;
51 // KeyT start() const;
53 // ValT lookup(KeyT x, Value NotFound = Value()) const;
55 // const_iterator begin() const;
56 // const_iterator end() const;
59 // const_iterator find(KeyT x) const;
60 // iterator find(KeyT x);
62 // void insert(KeyT a, KeyT b, ValT y);
66 // template <typename KeyT, typename ValT, unsigned N, typename Traits>
67 // class IntervalMap::const_iterator :
68 // public std::iterator<std::bidirectional_iterator_tag, ValT> {
70 // bool operator==(const const_iterator &) const;
71 // bool operator!=(const const_iterator &) const;
72 // bool valid() const;
74 // const KeyT &start() const;
75 // const KeyT &stop() const;
76 // const ValT &value() const;
77 // const ValT &operator*() const;
78 // const ValT *operator->() const;
80 // const_iterator &operator++();
81 // const_iterator &operator++(int);
82 // const_iterator &operator--();
83 // const_iterator &operator--(int);
87 // void advanceTo(KeyT x);
90 // template <typename KeyT, typename ValT, unsigned N, typename Traits>
91 // class IntervalMap::iterator : public const_iterator {
93 // void insert(KeyT a, KeyT b, Value y);
97 //===----------------------------------------------------------------------===//
99 #ifndef LLVM_ADT_INTERVALMAP_H
100 #define LLVM_ADT_INTERVALMAP_H
102 #include "llvm/ADT/SmallVector.h"
103 #include "llvm/ADT/PointerIntPair.h"
104 #include "llvm/Support/Allocator.h"
105 #include "llvm/Support/RecyclingAllocator.h"
109 // FIXME: Remove debugging code.
110 #include "llvm/Support/raw_ostream.h"
115 //===----------------------------------------------------------------------===//
116 //--- Key traits ---//
117 //===----------------------------------------------------------------------===//
119 // The IntervalMap works with closed or half-open intervals.
120 // Adjacent intervals that map to the same value are coalesced.
122 // The IntervalMapInfo traits class is used to determine if a key is contained
123 // in an interval, and if two intervals are adjacent so they can be coalesced.
124 // The provided implementation works for closed integer intervals, other keys
125 // probably need a specialized version.
127 // The point x is contained in [a;b] when !startLess(x, a) && !stopLess(b, x).
129 // It is assumed that (a;b] half-open intervals are not used, only [a;b) is
130 // allowed. This is so that stopLess(a, b) can be used to determine if two
131 // intervals overlap.
133 //===----------------------------------------------------------------------===//
135 template <typename T>
136 struct IntervalMapInfo {
138 /// startLess - Return true if x is not in [a;b].
139 /// This is x < a both for closed intervals and for [a;b) half-open intervals.
140 static inline bool startLess(const T &x, const T &a) {
144 /// stopLess - Return true if x is not in [a;b].
145 /// This is b < x for a closed interval, b <= x for [a;b) half-open intervals.
146 static inline bool stopLess(const T &b, const T &x) {
150 /// adjacent - Return true when the intervals [x;a] and [b;y] can coalesce.
151 /// This is a+1 == b for closed intervals, a == b for half-open intervals.
152 static inline bool adjacent(const T &a, const T &b) {
158 /// IntervalMapImpl - Namespace used for IntervalMap implementation details.
159 /// It should be considered private to the implementation.
160 namespace IntervalMapImpl {
162 // Forward declarations.
163 template <typename, typename, unsigned, typename> class LeafNode;
164 template <typename, typename, unsigned, typename> class BranchNode;
166 typedef std::pair<unsigned,unsigned> IdxPair;
169 //===----------------------------------------------------------------------===//
170 //--- Node Storage ---//
171 //===----------------------------------------------------------------------===//
173 // Both leaf and branch nodes store vectors of (key,value) pairs.
174 // Leaves store ((KeyT, KeyT), ValT) pairs, branches use (KeyT, NodeRef).
176 // Keys and values are stored in separate arrays to avoid padding caused by
177 // different object alignments. This also helps improve locality of reference
178 // when searching the keys.
180 // The nodes don't know how many elements they contain - that information is
181 // stored elsewhere. Omitting the size field prevents padding and allows a node
182 // to fill the allocated cache lines completely.
184 // These are typical key and value sizes, the node branching factor (N), and
185 // wasted space when nodes are sized to fit in three cache lines (192 bytes):
187 // KT VT N Waste Used by
188 // 4 4 24 0 Branch<4> (32-bit pointers)
189 // 4 8 16 0 Branch<4>
190 // 8 4 16 0 Leaf<4,4>
191 // 8 8 12 0 Leaf<4,8>, Branch<8>
192 // 16 4 9 12 Leaf<8,4>
193 // 16 8 8 0 Leaf<8,8>
195 //===----------------------------------------------------------------------===//
197 template <typename KT, typename VT, unsigned N>
200 enum { Capacity = N };
205 /// copy - Copy elements from another node.
206 /// @param other Node elements are copied from.
207 /// @param i Beginning of the source range in other.
208 /// @param j Beginning of the destination range in this.
209 /// @param count Number of elements to copy.
210 template <unsigned M>
211 void copy(const NodeBase<KT, VT, M> &Other, unsigned i,
212 unsigned j, unsigned Count) {
213 assert(i + Count <= M && "Invalid source range");
214 assert(j + Count <= N && "Invalid dest range");
215 std::copy(Other.key + i, Other.key + i + Count, key + j);
216 std::copy(Other.val + i, Other.val + i + Count, val + j);
219 /// lmove - Move elements to the left.
220 /// @param i Beginning of the source range.
221 /// @param j Beginning of the destination range.
222 /// @param count Number of elements to copy.
223 void lmove(unsigned i, unsigned j, unsigned Count) {
224 assert(j <= i && "Use rmove shift elements right");
225 copy(*this, i, j, Count);
228 /// rmove - Move elements to the right.
229 /// @param i Beginning of the source range.
230 /// @param j Beginning of the destination range.
231 /// @param count Number of elements to copy.
232 void rmove(unsigned i, unsigned j, unsigned Count) {
233 assert(i <= j && "Use lmove shift elements left");
234 assert(j + Count <= N && "Invalid range");
235 std::copy_backward(key + i, key + i + Count, key + j + Count);
236 std::copy_backward(val + i, val + i + Count, val + j + Count);
239 /// erase - Erase elements [i;j).
240 /// @param i Beginning of the range to erase.
241 /// @param j End of the range. (Exclusive).
242 /// @param size Number of elements in node.
243 void erase(unsigned i, unsigned j, unsigned Size) {
244 lmove(j, i, Size - j);
247 /// shift - Shift elements [i;size) 1 position to the right.
248 /// @param i Beginning of the range to move.
249 /// @param size Number of elements in node.
250 void shift(unsigned i, unsigned Size) {
251 rmove(i, i + 1, Size - i);
254 /// xferLeft - Transfer elements to a left sibling node.
255 /// @param size Number of elements in this.
256 /// @param sib Left sibling node.
257 /// @param ssize Number of elements in sib.
258 /// @param count Number of elements to transfer.
259 void xferLeft(unsigned Size, NodeBase &Sib, unsigned SSize, unsigned Count) {
260 Sib.copy(*this, 0, SSize, Count);
261 erase(0, Count, Size);
264 /// xferRight - Transfer elements to a right sibling node.
265 /// @param size Number of elements in this.
266 /// @param sib Right sibling node.
267 /// @param ssize Number of elements in sib.
268 /// @param count Number of elements to transfer.
269 void xferRight(unsigned Size, NodeBase &Sib, unsigned SSize, unsigned Count) {
270 Sib.rmove(0, Count, SSize);
271 Sib.copy(*this, Size-Count, 0, Count);
274 /// adjLeftSib - Adjust the number if elements in this node by moving
275 /// elements to or from a left sibling node.
276 /// @param size Number of elements in this.
277 /// @param sib Right sibling node.
278 /// @param ssize Number of elements in sib.
279 /// @param add The number of elements to add to this node, possibly < 0.
280 /// @return Number of elements added to this node, possibly negative.
281 int adjLeftSib(unsigned Size, NodeBase &Sib, unsigned SSize, int Add) {
283 // We want to grow, copy from sib.
284 unsigned Count = std::min(std::min(unsigned(Add), SSize), N - Size);
285 Sib.xferRight(SSize, *this, Size, Count);
288 // We want to shrink, copy to sib.
289 unsigned Count = std::min(std::min(unsigned(-Add), Size), N - SSize);
290 xferLeft(Size, Sib, SSize, Count);
297 //===----------------------------------------------------------------------===//
298 //--- NodeSizer ---//
299 //===----------------------------------------------------------------------===//
301 // Compute node sizes from key and value types.
303 // The branching factors are chosen to make nodes fit in three cache lines.
304 // This may not be possible if keys or values are very large. Such large objects
305 // are handled correctly, but a std::map would probably give better performance.
307 //===----------------------------------------------------------------------===//
310 // Cache line size. Most architectures have 32 or 64 byte cache lines.
311 // We use 64 bytes here because it provides good branching factors.
313 CacheLineBytes = 1 << Log2CacheLine,
314 DesiredNodeBytes = 3 * CacheLineBytes
317 template <typename KeyT, typename ValT>
320 // Compute the leaf node branching factor that makes a node fit in three
321 // cache lines. The branching factor must be at least 3, or some B+-tree
322 // balancing algorithms won't work.
323 // LeafSize can't be larger than CacheLineBytes. This is required by the
324 // PointerIntPair used by NodeRef.
325 DesiredLeafSize = DesiredNodeBytes /
326 static_cast<unsigned>(2*sizeof(KeyT)+sizeof(ValT)),
328 LeafSize = DesiredLeafSize > MinLeafSize ? DesiredLeafSize : MinLeafSize
331 typedef NodeBase<std::pair<KeyT, KeyT>, ValT, LeafSize> LeafBase;
334 // Now that we have the leaf branching factor, compute the actual allocation
335 // unit size by rounding up to a whole number of cache lines.
336 AllocBytes = (sizeof(LeafBase) + CacheLineBytes-1) & ~(CacheLineBytes-1),
338 // Determine the branching factor for branch nodes.
339 BranchSize = AllocBytes /
340 static_cast<unsigned>(sizeof(KeyT) + sizeof(void*))
343 /// Allocator - The recycling allocator used for both branch and leaf nodes.
344 /// This typedef is very likely to be identical for all IntervalMaps with
345 /// reasonably sized entries, so the same allocator can be shared among
346 /// different kinds of maps.
347 typedef RecyclingAllocator<BumpPtrAllocator, char,
348 AllocBytes, CacheLineBytes> Allocator;
353 //===----------------------------------------------------------------------===//
355 //===----------------------------------------------------------------------===//
357 // B+-tree nodes can be leaves or branches, so we need a polymorphic node
358 // pointer that can point to both kinds.
360 // All nodes are cache line aligned and the low 6 bits of a node pointer are
361 // always 0. These bits are used to store the number of elements in the
362 // referenced node. Besides saving space, placing node sizes in the parents
363 // allow tree balancing algorithms to run without faulting cache lines for nodes
364 // that may not need to be modified.
366 // A NodeRef doesn't know whether it references a leaf node or a branch node.
367 // It is the responsibility of the caller to use the correct types.
369 // Nodes are never supposed to be empty, and it is invalid to store a node size
370 // of 0 in a NodeRef. The valid range of sizes is 1-64.
372 //===----------------------------------------------------------------------===//
374 struct CacheAlignedPointerTraits {
375 static inline void *getAsVoidPointer(void *P) { return P; }
376 static inline void *getFromVoidPointer(void *P) { return P; }
377 enum { NumLowBitsAvailable = Log2CacheLine };
380 template <typename KeyT, typename ValT, typename Traits>
383 typedef LeafNode<KeyT, ValT, NodeSizer<KeyT, ValT>::LeafSize, Traits> Leaf;
384 typedef BranchNode<KeyT, ValT, NodeSizer<KeyT, ValT>::BranchSize,
388 PointerIntPair<void*, Log2CacheLine, unsigned, CacheAlignedPointerTraits> pip;
391 /// NodeRef - Create a null ref.
394 /// operator bool - Detect a null ref.
395 operator bool() const { return pip.getOpaqueValue(); }
397 /// NodeRef - Create a reference to the leaf node p with n elements.
398 NodeRef(Leaf *p, unsigned n) : pip(p, n - 1) {}
400 /// NodeRef - Create a reference to the branch node p with n elements.
401 NodeRef(Branch *p, unsigned n) : pip(p, n - 1) {}
403 /// size - Return the number of elements in the referenced node.
404 unsigned size() const { return pip.getInt() + 1; }
406 /// setSize - Update the node size.
407 void setSize(unsigned n) { pip.setInt(n - 1); }
409 /// leaf - Return the referenced leaf node.
410 /// Note there are no dynamic type checks.
412 return *reinterpret_cast<Leaf*>(pip.getPointer());
415 /// branch - Return the referenced branch node.
416 /// Note there are no dynamic type checks.
417 Branch &branch() const {
418 return *reinterpret_cast<Branch*>(pip.getPointer());
421 bool operator==(const NodeRef &RHS) const {
424 assert(pip.getPointer() != RHS.pip.getPointer() && "Inconsistent NodeRefs");
428 bool operator!=(const NodeRef &RHS) const {
429 return !operator==(RHS);
433 //===----------------------------------------------------------------------===//
434 //--- Leaf nodes ---//
435 //===----------------------------------------------------------------------===//
437 // Leaf nodes store up to N disjoint intervals with corresponding values.
439 // The intervals are kept sorted and fully coalesced so there are no adjacent
440 // intervals mapping to the same value.
442 // These constraints are always satisfied:
444 // - Traits::stopLess(key[i].start, key[i].stop) - Non-empty, sane intervals.
446 // - Traits::stopLess(key[i].stop, key[i + 1].start) - Sorted.
448 // - val[i] != val[i + 1] ||
449 // !Traits::adjacent(key[i].stop, key[i + 1].start) - Fully coalesced.
451 //===----------------------------------------------------------------------===//
453 template <typename KeyT, typename ValT, unsigned N, typename Traits>
454 class LeafNode : public NodeBase<std::pair<KeyT, KeyT>, ValT, N> {
456 const KeyT &start(unsigned i) const { return this->key[i].first; }
457 const KeyT &stop(unsigned i) const { return this->key[i].second; }
458 const ValT &value(unsigned i) const { return this->val[i]; }
460 KeyT &start(unsigned i) { return this->key[i].first; }
461 KeyT &stop(unsigned i) { return this->key[i].second; }
462 ValT &value(unsigned i) { return this->val[i]; }
464 /// findFrom - Find the first interval after i that may contain x.
465 /// @param i Starting index for the search.
466 /// @param size Number of elements in node.
467 /// @param x Key to search for.
468 /// @return First index with !stopLess(key[i].stop, x), or size.
469 /// This is the first interval that can possibly contain x.
470 unsigned findFrom(unsigned i, unsigned Size, KeyT x) const {
471 assert(i <= Size && Size <= N && "Bad indices");
472 assert((i == 0 || Traits::stopLess(stop(i - 1), x)) &&
473 "Index is past the needed point");
474 while (i != Size && Traits::stopLess(stop(i), x)) ++i;
478 /// safeFind - Find an interval that is known to exist. This is the same as
479 /// findFrom except is it assumed that x is at least within range of the last
481 /// @param i Starting index for the search.
482 /// @param x Key to search for.
483 /// @return First index with !stopLess(key[i].stop, x), never size.
484 /// This is the first interval that can possibly contain x.
485 unsigned safeFind(unsigned i, KeyT x) const {
486 assert(i < N && "Bad index");
487 assert((i == 0 || Traits::stopLess(stop(i - 1), x)) &&
488 "Index is past the needed point");
489 while (Traits::stopLess(stop(i), x)) ++i;
490 assert(i < N && "Unsafe intervals");
494 /// safeLookup - Lookup mapped value for a safe key.
495 /// It is assumed that x is within range of the last entry.
496 /// @param x Key to search for.
497 /// @param NotFound Value to return if x is not in any interval.
498 /// @return The mapped value at x or NotFound.
499 ValT safeLookup(KeyT x, ValT NotFound) const {
500 unsigned i = safeFind(0, x);
501 return Traits::startLess(x, start(i)) ? NotFound : value(i);
504 IdxPair insertFrom(unsigned i, unsigned Size, KeyT a, KeyT b, ValT y);
505 unsigned extendStop(unsigned i, unsigned Size, KeyT b);
508 void dump(unsigned Size) {
509 errs() << " N" << this << " [shape=record label=\"{ " << Size << '/' << N;
510 for (unsigned i = 0; i != Size; ++i)
511 errs() << " | {" << start(i) << '-' << stop(i) << "|" << value(i) << '}';
518 /// insertFrom - Add mapping of [a;b] to y if possible, coalescing as much as
519 /// possible. This may cause the node to grow by 1, or it may cause the node
520 /// to shrink because of coalescing.
521 /// @param i Starting index = insertFrom(0, size, a)
522 /// @param size Number of elements in node.
523 /// @param a Interval start.
524 /// @param b Interval stop.
525 /// @param y Value be mapped.
526 /// @return (insert position, new size), or (i, Capacity+1) on overflow.
527 template <typename KeyT, typename ValT, unsigned N, typename Traits>
528 IdxPair LeafNode<KeyT, ValT, N, Traits>::
529 insertFrom(unsigned i, unsigned Size, KeyT a, KeyT b, ValT y) {
530 assert(i <= Size && Size <= N && "Invalid index");
531 assert(!Traits::stopLess(b, a) && "Invalid interval");
533 // Verify the findFrom invariant.
534 assert((i == 0 || Traits::stopLess(stop(i - 1), a)));
535 assert((i == Size || !Traits::stopLess(stop(i), a)));
537 // Coalesce with previous interval.
538 if (i && value(i - 1) == y && Traits::adjacent(stop(i - 1), a))
539 return IdxPair(i - 1, extendStop(i - 1, Size, b));
543 return IdxPair(i, N + 1);
545 // Add new interval at end.
550 return IdxPair(i, Size + 1);
553 // Overlapping intervals?
554 if (!Traits::stopLess(b, start(i))) {
555 assert(value(i) == y && "Inconsistent values in overlapping intervals");
556 if (Traits::startLess(a, start(i)))
558 return IdxPair(i, extendStop(i, Size, b));
561 // Try to coalesce with following interval.
562 if (value(i) == y && Traits::adjacent(b, start(i))) {
564 return IdxPair(i, Size);
567 // We must insert before i. Detect overflow.
569 return IdxPair(i, N + 1);
572 this->shift(i, Size);
576 return IdxPair(i, Size + 1);
579 /// extendStop - Extend stop(i) to b, coalescing with following intervals.
580 /// @param i Interval to extend.
581 /// @param size Number of elements in node.
582 /// @param b New interval end point.
583 /// @return New node size after coalescing.
584 template <typename KeyT, typename ValT, unsigned N, typename Traits>
585 unsigned LeafNode<KeyT, ValT, N, Traits>::
586 extendStop(unsigned i, unsigned Size, KeyT b) {
587 assert(i < Size && Size <= N && "Bad indices");
589 // Are we even extending the interval?
590 if (Traits::startLess(b, stop(i)))
593 // Find the first interval that may be preserved.
594 unsigned j = findFrom(i + 1, Size, b);
596 // Would key[i] overlap key[j] after the extension?
597 if (Traits::stopLess(b, start(j))) {
598 // Not overlapping. Perhaps adjacent and coalescable?
599 if (value(i) == value(j) && Traits::adjacent(b, start(j)))
602 // Overlap. Include key[j] in the new interval.
603 assert(value(i) == value(j) && "Overlapping values");
609 // Entries [i+1;j) were coalesced.
610 if (i + 1 < j && j < Size)
611 this->erase(i + 1, j, Size);
612 return Size - (j - (i + 1));
616 //===----------------------------------------------------------------------===//
617 //--- Branch nodes ---//
618 //===----------------------------------------------------------------------===//
620 // A branch node stores references to 1--N subtrees all of the same height.
622 // The key array in a branch node holds the rightmost stop key of each subtree.
623 // It is redundant to store the last stop key since it can be found in the
624 // parent node, but doing so makes tree balancing a lot simpler.
626 // It is unusual for a branch node to only have one subtree, but it can happen
627 // in the root node if it is smaller than the normal nodes.
629 // When all of the leaf nodes from all the subtrees are concatenated, they must
630 // satisfy the same constraints as a single leaf node. They must be sorted,
631 // sane, and fully coalesced.
633 //===----------------------------------------------------------------------===//
635 template <typename KeyT, typename ValT, unsigned N, typename Traits>
636 class BranchNode : public NodeBase<KeyT, NodeRef<KeyT, ValT, Traits>, N> {
637 typedef NodeRef<KeyT, ValT, Traits> NodeRefT;
639 const KeyT &stop(unsigned i) const { return this->key[i]; }
640 const NodeRefT &subtree(unsigned i) const { return this->val[i]; }
642 KeyT &stop(unsigned i) { return this->key[i]; }
643 NodeRefT &subtree(unsigned i) { return this->val[i]; }
645 /// findFrom - Find the first subtree after i that may contain x.
646 /// @param i Starting index for the search.
647 /// @param size Number of elements in node.
648 /// @param x Key to search for.
649 /// @return First index with !stopLess(key[i], x), or size.
650 /// This is the first subtree that can possibly contain x.
651 unsigned findFrom(unsigned i, unsigned Size, KeyT x) const {
652 assert(i <= Size && Size <= N && "Bad indices");
653 assert((i == 0 || Traits::stopLess(stop(i - 1), x)) &&
654 "Index to findFrom is past the needed point");
655 while (i != Size && Traits::stopLess(stop(i), x)) ++i;
659 /// safeFind - Find a subtree that is known to exist. This is the same as
660 /// findFrom except is it assumed that x is in range.
661 /// @param i Starting index for the search.
662 /// @param x Key to search for.
663 /// @return First index with !stopLess(key[i], x), never size.
664 /// This is the first subtree that can possibly contain x.
665 unsigned safeFind(unsigned i, KeyT x) const {
666 assert(i < N && "Bad index");
667 assert((i == 0 || Traits::stopLess(stop(i - 1), x)) &&
668 "Index is past the needed point");
669 while (Traits::stopLess(stop(i), x)) ++i;
670 assert(i < N && "Unsafe intervals");
674 /// safeLookup - Get the subtree containing x, Assuming that x is in range.
675 /// @param x Key to search for.
676 /// @return Subtree containing x
677 NodeRefT safeLookup(KeyT x) const {
678 return subtree(safeFind(0, x));
681 /// insert - Insert a new (subtree, stop) pair.
682 /// @param i Insert position, following entries will be shifted.
683 /// @param size Number of elements in node.
684 /// @param node Subtree to insert.
685 /// @param stp Last key in subtree.
686 void insert(unsigned i, unsigned Size, NodeRefT Node, KeyT Stop) {
687 assert(Size < N && "branch node overflow");
688 assert(i <= Size && "Bad insert position");
689 this->shift(i, Size);
695 void dump(unsigned Size) {
696 errs() << " N" << this << " [shape=record label=\"" << Size << '/' << N;
697 for (unsigned i = 0; i != Size; ++i)
698 errs() << " | <s" << i << "> " << stop(i);
700 for (unsigned i = 0; i != Size; ++i)
701 errs() << " N" << this << ":s" << i << " -> N"
702 << &subtree(i).branch() << ";\n";
708 } // namespace IntervalMapImpl
711 //===----------------------------------------------------------------------===//
712 //--- IntervalMap ----//
713 //===----------------------------------------------------------------------===//
715 template <typename KeyT, typename ValT,
716 unsigned N = IntervalMapImpl::NodeSizer<KeyT, ValT>::LeafSize,
717 typename Traits = IntervalMapInfo<KeyT> >
719 typedef IntervalMapImpl::NodeRef<KeyT, ValT, Traits> NodeRef;
720 typedef IntervalMapImpl::NodeSizer<KeyT, ValT> NodeSizer;
721 typedef typename NodeRef::Leaf Leaf;
722 typedef typename NodeRef::Branch Branch;
723 typedef IntervalMapImpl::LeafNode<KeyT, ValT, N, Traits> RootLeaf;
724 typedef IntervalMapImpl::IdxPair IdxPair;
726 // The RootLeaf capacity is given as a template parameter. We must compute the
727 // corresponding RootBranch capacity.
729 DesiredRootBranchCap = (sizeof(RootLeaf) - sizeof(KeyT)) /
730 (sizeof(KeyT) + sizeof(NodeRef)),
731 RootBranchCap = DesiredRootBranchCap ? DesiredRootBranchCap : 1
734 typedef IntervalMapImpl::BranchNode<KeyT, ValT, RootBranchCap, Traits> RootBranch;
736 // When branched, we store a global start key as well as the branch node.
737 struct RootBranchData {
743 RootDataSize = sizeof(RootBranchData) > sizeof(RootLeaf) ?
744 sizeof(RootBranchData) : sizeof(RootLeaf)
748 typedef typename NodeSizer::Allocator Allocator;
751 // The root data is either a RootLeaf or a RootBranchData instance.
752 // We can't put them in a union since C++03 doesn't allow non-trivial
753 // constructors in unions.
754 // Instead, we use a char array with pointer alignment. The alignment is
755 // ensured by the allocator member in the class, but still verified in the
756 // constructor. We don't support keys or values that are more aligned than a
758 char data[RootDataSize];
761 // 0: Leaves in root.
762 // 1: Root points to leaf.
763 // 2: root->branch->leaf ...
766 // Number of entries in the root node.
769 // Allocator used for creating external nodes.
770 Allocator &allocator;
772 /// dataAs - Represent data as a node type without breaking aliasing rules.
773 template <typename T>
783 const RootLeaf &rootLeaf() const {
784 assert(!branched() && "Cannot acces leaf data in branched root");
785 return dataAs<RootLeaf>();
787 RootLeaf &rootLeaf() {
788 assert(!branched() && "Cannot acces leaf data in branched root");
789 return dataAs<RootLeaf>();
791 RootBranchData &rootBranchData() const {
792 assert(branched() && "Cannot access branch data in non-branched root");
793 return dataAs<RootBranchData>();
795 RootBranchData &rootBranchData() {
796 assert(branched() && "Cannot access branch data in non-branched root");
797 return dataAs<RootBranchData>();
799 const RootBranch &rootBranch() const { return rootBranchData().node; }
800 RootBranch &rootBranch() { return rootBranchData().node; }
801 KeyT rootBranchStart() const { return rootBranchData().start; }
802 KeyT &rootBranchStart() { return rootBranchData().start; }
805 return new(allocator.template Allocate<Leaf>()) Leaf();
807 void freeLeaf(Leaf *P) {
809 allocator.Deallocate(P);
812 Branch *allocBranch() {
813 return new(allocator.template Allocate<Branch>()) Branch();
815 void freeBranch(Branch *P) {
817 allocator.Deallocate(P);
821 IdxPair branchRoot(unsigned Position);
822 IdxPair splitRoot(unsigned Position);
824 void switchRootToBranch() {
825 rootLeaf().~RootLeaf();
827 new (&rootBranchData()) RootBranchData();
830 void switchRootToLeaf() {
831 rootBranchData().~RootBranchData();
833 new(&rootLeaf()) RootLeaf();
836 bool branched() const { return height > 0; }
838 ValT treeSafeLookup(KeyT x, ValT NotFound) const;
840 void visitNodes(void (IntervalMap::*f)(NodeRef, unsigned Level));
843 explicit IntervalMap(Allocator &a) : height(0), rootSize(0), allocator(a) {
844 assert((uintptr_t(data) & (alignOf<RootLeaf>() - 1)) == 0 &&
845 "Insufficient alignment");
846 new(&rootLeaf()) RootLeaf();
849 /// empty - Return true when no intervals are mapped.
851 return rootSize == 0;
854 /// start - Return the smallest mapped key in a non-empty map.
856 assert(!empty() && "Empty IntervalMap has no start");
857 return !branched() ? rootLeaf().start(0) : rootBranchStart();
860 /// stop - Return the largest mapped key in a non-empty map.
862 assert(!empty() && "Empty IntervalMap has no stop");
863 return !branched() ? rootLeaf().stop(rootSize - 1) :
864 rootBranch().stop(rootSize - 1);
867 /// lookup - Return the mapped value at x or NotFound.
868 ValT lookup(KeyT x, ValT NotFound = ValT()) const {
869 if (empty() || Traits::startLess(x, start()) || Traits::stopLess(stop(), x))
871 return branched() ? treeSafeLookup(x, NotFound) :
872 rootLeaf().safeLookup(x, NotFound);
875 /// insert - Add a mapping of [a;b] to y, coalesce with adjacent intervals.
876 /// It is assumed that no key in the interval is mapped to another value, but
877 /// overlapping intervals already mapped to y will be coalesced.
878 void insert(KeyT a, KeyT b, ValT y) {
879 find(a).insert(a, b, y);
882 class const_iterator;
884 friend class const_iterator;
885 friend class iterator;
887 const_iterator begin() const {
899 const_iterator end() const {
911 /// find - Return an iterator pointing to the first interval ending at or
912 /// after x, or end().
913 const_iterator find(KeyT x) const {
919 iterator find(KeyT x) {
927 void dumpNode(NodeRef Node, unsigned Height);
931 /// treeSafeLookup - Return the mapped value at x or NotFound, assuming a
933 template <typename KeyT, typename ValT, unsigned N, typename Traits>
934 ValT IntervalMap<KeyT, ValT, N, Traits>::
935 treeSafeLookup(KeyT x, ValT NotFound) const {
936 assert(branched() && "treeLookup assumes a branched root");
938 NodeRef NR = rootBranch().safeLookup(x);
939 for (unsigned h = height-1; h; --h)
940 NR = NR.branch().safeLookup(x);
941 return NR.leaf().safeLookup(x, NotFound);
945 // branchRoot - Switch from a leaf root to a branched root.
946 // Return the new (root offset, node offset) corresponding to Position.
947 template <typename KeyT, typename ValT, unsigned N, typename Traits>
948 IntervalMapImpl::IdxPair IntervalMap<KeyT, ValT, N, Traits>::
949 branchRoot(unsigned Position) {
950 // How many external leaf nodes to hold RootLeaf+1?
951 const unsigned Nodes = RootLeaf::Capacity / Leaf::Capacity + 1;
953 // Compute element distribution among new nodes.
954 unsigned size[Nodes];
955 IdxPair NewOffset(0, Position);
957 // Is is very common for the root node to be smaller than external nodes.
961 NewOffset = distribute(Nodes, rootSize, Leaf::Capacity, NULL, size,
964 // Allocate new nodes.
967 for (unsigned n = 0; n != Nodes; ++n) {
968 node[n] = NodeRef(allocLeaf(), size[n]);
969 node[n].leaf().copy(rootLeaf(), pos, 0, size[n]);
973 // Destroy the old leaf node, construct branch node instead.
974 switchRootToBranch();
975 for (unsigned n = 0; n != Nodes; ++n) {
976 rootBranch().stop(n) = node[n].leaf().stop(size[n]-1);
977 rootBranch().subtree(n) = node[n];
979 rootBranchStart() = node[0].leaf().start(0);
984 // splitRoot - Split the current BranchRoot into multiple Branch nodes.
985 // Return the new (root offset, node offset) corresponding to Position.
986 template <typename KeyT, typename ValT, unsigned N, typename Traits>
987 IntervalMapImpl::IdxPair IntervalMap<KeyT, ValT, N, Traits>::
988 splitRoot(unsigned Position) {
989 // How many external leaf nodes to hold RootBranch+1?
990 const unsigned Nodes = RootBranch::Capacity / Branch::Capacity + 1;
992 // Compute element distribution among new nodes.
993 unsigned Size[Nodes];
994 IdxPair NewOffset(0, Position);
996 // Is is very common for the root node to be smaller than external nodes.
1000 NewOffset = distribute(Nodes, rootSize, Leaf::Capacity, NULL, Size,
1003 // Allocate new nodes.
1005 NodeRef Node[Nodes];
1006 for (unsigned n = 0; n != Nodes; ++n) {
1007 Node[n] = NodeRef(allocBranch(), Size[n]);
1008 Node[n].branch().copy(rootBranch(), Pos, 0, Size[n]);
1012 for (unsigned n = 0; n != Nodes; ++n) {
1013 rootBranch().stop(n) = Node[n].branch().stop(Size[n]-1);
1014 rootBranch().subtree(n) = Node[n];
1020 /// visitNodes - Visit each external node.
1021 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1022 void IntervalMap<KeyT, ValT, N, Traits>::
1023 visitNodes(void (IntervalMap::*f)(NodeRef, unsigned Height)) {
1026 SmallVector<NodeRef, 4> Refs, NextRefs;
1028 // Collect level 0 nodes from the root.
1029 for (unsigned i = 0; i != rootSize; ++i)
1030 Refs.push_back(rootBranch().subtree(i));
1032 // Visit all branch nodes.
1033 for (unsigned h = height - 1; h; --h) {
1034 for (unsigned i = 0, e = Refs.size(); i != e; ++i) {
1035 Branch &B = Refs[i].branch();
1036 for (unsigned j = 0, s = Refs[i].size(); j != s; ++j)
1037 NextRefs.push_back(B.subtree(j));
1038 (this->*f)(Refs[i], h);
1041 Refs.swap(NextRefs);
1044 // Visit all leaf nodes.
1045 for (unsigned i = 0, e = Refs.size(); i != e; ++i)
1046 (this->*f)(Refs[i], 0);
1050 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1051 void IntervalMap<KeyT, ValT, N, Traits>::
1052 dumpNode(NodeRef Node, unsigned Height) {
1054 Node.branch().dump(Node.size());
1056 Node.leaf().dump(Node.size());
1059 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1060 void IntervalMap<KeyT, ValT, N, Traits>::
1062 errs() << "digraph {\n";
1064 rootBranch().dump(rootSize);
1066 rootLeaf().dump(rootSize);
1067 visitNodes(&IntervalMap::dumpNode);
1072 //===----------------------------------------------------------------------===//
1073 //--- const_iterator ----//
1074 //===----------------------------------------------------------------------===//
1076 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1077 class IntervalMap<KeyT, ValT, N, Traits>::const_iterator :
1078 public std::iterator<std::bidirectional_iterator_tag, ValT> {
1080 friend class IntervalMap;
1081 typedef std::pair<NodeRef, unsigned> PathEntry;
1082 typedef SmallVector<PathEntry, 4> Path;
1084 // The map referred to.
1087 // The offset into map's root node.
1088 unsigned rootOffset;
1090 // We store a full path from the root to the current position.
1092 // When rootOffset == map->rootSize, we are at end() and path() is empty.
1093 // Otherwise, when branched these conditions hold:
1095 // 1. path.front().first == rootBranch().subtree(rootOffset)
1096 // 2. path[i].first == path[i-1].first.branch().subtree(path[i-1].second)
1097 // 3. path.size() == map->height.
1099 // Thus, path.back() always refers to the current leaf node unless the root is
1102 // The path may be partially filled, but never between iterator calls.
1105 explicit const_iterator(IntervalMap &map)
1106 : map(&map), rootOffset(map.rootSize) {}
1108 bool branched() const {
1109 assert(map && "Invalid iterator");
1110 return map->branched();
1113 NodeRef pathNode(unsigned h) const { return path[h].first; }
1114 NodeRef &pathNode(unsigned h) { return path[h].first; }
1115 unsigned pathOffset(unsigned h) const { return path[h].second; }
1116 unsigned &pathOffset(unsigned h) { return path[h].second; }
1118 Leaf &treeLeaf() const {
1119 assert(branched() && path.size() == map->height);
1120 return path.back().first.leaf();
1122 unsigned treeLeafSize() const {
1123 assert(branched() && path.size() == map->height);
1124 return path.back().first.size();
1126 unsigned &treeLeafOffset() {
1127 assert(branched() && path.size() == map->height);
1128 return path.back().second;
1130 unsigned treeLeafOffset() const {
1131 assert(branched() && path.size() == map->height);
1132 return path.back().second;
1135 // Get the next node ptr for an incomplete path.
1136 NodeRef pathNextDown() {
1137 assert(path.size() < map->height && "Path is already complete");
1140 return map->rootBranch().subtree(rootOffset);
1142 return path.back().first.branch().subtree(path.back().second);
1145 void pathFillLeft();
1146 void pathFillFind(KeyT x);
1147 void pathFillRight();
1149 NodeRef leftSibling(unsigned level) const;
1150 NodeRef rightSibling(unsigned level) const;
1152 void treeIncrement();
1153 void treeDecrement();
1154 void treeFind(KeyT x);
1157 /// valid - Return true if the current position is valid, false for end().
1158 bool valid() const {
1159 assert(map && "Invalid iterator");
1160 return rootOffset < map->rootSize;
1163 /// start - Return the beginning of the current interval.
1164 const KeyT &start() const {
1165 assert(valid() && "Cannot access invalid iterator");
1166 return branched() ? treeLeaf().start(treeLeafOffset()) :
1167 map->rootLeaf().start(rootOffset);
1170 /// stop - Return the end of the current interval.
1171 const KeyT &stop() const {
1172 assert(valid() && "Cannot access invalid iterator");
1173 return branched() ? treeLeaf().stop(treeLeafOffset()) :
1174 map->rootLeaf().stop(rootOffset);
1177 /// value - Return the mapped value at the current interval.
1178 const ValT &value() const {
1179 assert(valid() && "Cannot access invalid iterator");
1180 return branched() ? treeLeaf().value(treeLeafOffset()) :
1181 map->rootLeaf().value(rootOffset);
1184 const ValT &operator*() const {
1188 bool operator==(const const_iterator &RHS) const {
1189 assert(map == RHS.map && "Cannot compare iterators from different maps");
1190 return rootOffset == RHS.rootOffset &&
1191 (!valid() || !branched() || path.back() == RHS.path.back());
1194 bool operator!=(const const_iterator &RHS) const {
1195 return !operator==(RHS);
1198 /// goToBegin - Move to the first interval in map.
1206 /// goToEnd - Move beyond the last interval in map.
1208 rootOffset = map->rootSize;
1212 /// preincrement - move to the next interval.
1213 const_iterator &operator++() {
1214 assert(valid() && "Cannot increment end()");
1217 else if (treeLeafOffset() != treeLeafSize() - 1)
1224 /// postincrement - Dont do that!
1225 const_iterator operator++(int) {
1226 const_iterator tmp = *this;
1231 /// predecrement - move to the previous interval.
1232 const_iterator &operator--() {
1234 assert(rootOffset && "Cannot decrement begin()");
1236 } else if (treeLeafOffset())
1243 /// postdecrement - Dont do that!
1244 const_iterator operator--(int) {
1245 const_iterator tmp = *this;
1250 /// find - Move to the first interval with stop >= x, or end().
1251 /// This is a full search from the root, the current position is ignored.
1256 rootOffset = map->rootLeaf().findFrom(0, map->rootSize, x);
1259 /// advanceTo - Move to the first interval with stop >= x, or end().
1260 /// The search is started from the current position, and no earlier positions
1261 /// can be found. This is much faster than find() for small moves.
1262 void advanceTo(KeyT x) {
1266 rootOffset = map->rootLeaf().findFrom(rootOffset, map->rootSize, x);
1271 // pathFillLeft - Complete path by following left-most branches.
1272 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1273 void IntervalMap<KeyT, ValT, N, Traits>::
1274 const_iterator::pathFillLeft() {
1275 NodeRef NR = pathNextDown();
1276 for (unsigned i = map->height - path.size() - 1; i; --i) {
1277 path.push_back(PathEntry(NR, 0));
1278 NR = NR.branch().subtree(0);
1280 path.push_back(PathEntry(NR, 0));
1283 // pathFillFind - Complete path by searching for x.
1284 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1285 void IntervalMap<KeyT, ValT, N, Traits>::
1286 const_iterator::pathFillFind(KeyT x) {
1287 NodeRef NR = pathNextDown();
1288 for (unsigned i = map->height - path.size() - 1; i; --i) {
1289 unsigned p = NR.branch().safeFind(0, x);
1290 path.push_back(PathEntry(NR, p));
1291 NR = NR.branch().subtree(p);
1293 path.push_back(PathEntry(NR, NR.leaf().safeFind(0, x)));
1296 // pathFillRight - Complete path by adding rightmost entries.
1297 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1298 void IntervalMap<KeyT, ValT, N, Traits>::
1299 const_iterator::pathFillRight() {
1300 NodeRef NR = pathNextDown();
1301 for (unsigned i = map->height - path.size() - 1; i; --i) {
1302 unsigned p = NR.size() - 1;
1303 path.push_back(PathEntry(NR, p));
1304 NR = NR.branch().subtree(p);
1306 path.push_back(PathEntry(NR, NR.size() - 1));
1309 /// leftSibling - find the left sibling node to path[level].
1310 /// @param level 0 is just below the root, map->height - 1 for the leaves.
1311 /// @return The left sibling NodeRef, or NULL.
1312 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1313 typename IntervalMap<KeyT, ValT, N, Traits>::NodeRef
1314 IntervalMap<KeyT, ValT, N, Traits>::
1315 const_iterator::leftSibling(unsigned level) const {
1316 assert(branched() && "Not at a branched node");
1317 assert(level <= path.size() && "Bad level");
1319 // Go up the tree until we can go left.
1321 while (h && pathOffset(h - 1) == 0)
1324 // We are at the first leaf node, no left sibling.
1325 if (!h && rootOffset == 0)
1328 // NR is the subtree containing our left sibling.
1330 pathNode(h - 1).branch().subtree(pathOffset(h - 1) - 1) :
1331 map->rootBranch().subtree(rootOffset - 1);
1333 // Keep right all the way down.
1334 for (; h != level; ++h)
1335 NR = NR.branch().subtree(NR.size() - 1);
1339 /// rightSibling - find the right sibling node to path[level].
1340 /// @param level 0 is just below the root, map->height - 1 for the leaves.
1341 /// @return The right sibling NodeRef, or NULL.
1342 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1343 typename IntervalMap<KeyT, ValT, N, Traits>::NodeRef
1344 IntervalMap<KeyT, ValT, N, Traits>::
1345 const_iterator::rightSibling(unsigned level) const {
1346 assert(branched() && "Not at a branched node");
1347 assert(level <= this->path.size() && "Bad level");
1349 // Go up the tree until we can go right.
1351 while (h && pathOffset(h - 1) == pathNode(h - 1).size() - 1)
1354 // We are at the last leaf node, no right sibling.
1355 if (!h && rootOffset == map->rootSize - 1)
1358 // NR is the subtree containing our right sibling.
1360 pathNode(h - 1).branch().subtree(pathOffset(h - 1) + 1) :
1361 map->rootBranch().subtree(rootOffset + 1);
1363 // Keep left all the way down.
1364 for (; h != level; ++h)
1365 NR = NR.branch().subtree(0);
1369 // treeIncrement - Move to the beginning of the next leaf node.
1370 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1371 void IntervalMap<KeyT, ValT, N, Traits>::
1372 const_iterator::treeIncrement() {
1373 assert(branched() && "treeIncrement is not for small maps");
1374 assert(path.size() == map->height && "inconsistent iterator");
1376 while (!path.empty() && path.back().second == path.back().first.size() - 1);
1382 ++path.back().second;
1386 // treeDecrement - Move to the end of the previous leaf node.
1387 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1388 void IntervalMap<KeyT, ValT, N, Traits>::
1389 const_iterator::treeDecrement() {
1390 assert(branched() && "treeDecrement is not for small maps");
1392 assert(path.size() == map->height && "inconsistent iterator");
1394 while (!path.empty() && path.back().second == 0);
1397 assert(rootOffset && "cannot treeDecrement() on begin()");
1400 --path.back().second;
1404 // treeFind - Find in a branched tree.
1405 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1406 void IntervalMap<KeyT, ValT, N, Traits>::
1407 const_iterator::treeFind(KeyT x) {
1409 rootOffset = map->rootBranch().findFrom(0, map->rootSize, x);
1415 //===----------------------------------------------------------------------===//
1416 //--- iterator ----//
1417 //===----------------------------------------------------------------------===//
1419 namespace IntervalMapImpl {
1421 /// distribute - Compute a new distribution of node elements after an overflow
1422 /// or underflow. Reserve space for a new element at Position, and compute the
1423 /// node that will hold Position after redistributing node elements.
1425 /// It is required that
1427 /// Elements == sum(CurSize), and
1428 /// Elements + Grow <= Nodes * Capacity.
1430 /// NewSize[] will be filled in such that:
1432 /// sum(NewSize) == Elements, and
1433 /// NewSize[i] <= Capacity.
1435 /// The returned index is the node where Position will go, so:
1437 /// sum(NewSize[0..idx-1]) <= Position
1438 /// sum(NewSize[0..idx]) >= Position
1440 /// The last equality, sum(NewSize[0..idx]) == Position, can only happen when
1441 /// Grow is set and NewSize[idx] == Capacity-1. The index points to the node
1442 /// before the one holding the Position'th element where there is room for an
1445 /// @param Nodes The number of nodes.
1446 /// @param Elements Total elements in all nodes.
1447 /// @param Capacity The capacity of each node.
1448 /// @param CurSize Array[Nodes] of current node sizes, or NULL.
1449 /// @param NewSize Array[Nodes] to receive the new node sizes.
1450 /// @param Position Insert position.
1451 /// @param Grow Reserve space for a new element at Position.
1452 /// @return (node, offset) for Position.
1453 IdxPair distribute(unsigned Nodes, unsigned Elements, unsigned Capacity,
1454 const unsigned *CurSize, unsigned NewSize[],
1455 unsigned Position, bool Grow);
1459 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1460 class IntervalMap<KeyT, ValT, N, Traits>::iterator : public const_iterator {
1461 friend class IntervalMap;
1462 typedef IntervalMapImpl::IdxPair IdxPair;
1464 explicit iterator(IntervalMap &map) : const_iterator(map) {}
1466 void setNodeSize(unsigned Level, unsigned Size);
1467 void setNodeStop(unsigned Level, KeyT Stop);
1468 void insertNode(unsigned Level, NodeRef Node, KeyT Stop);
1469 void overflowLeaf();
1470 void treeInsert(KeyT a, KeyT b, ValT y);
1473 /// insert - Insert mapping [a;b] -> y before the current position.
1474 void insert(KeyT a, KeyT b, ValT y);
1478 /// setNodeSize - Set the size of the node at path[level], updating both path
1479 /// and the real tree.
1480 /// @param level 0 is just below the root, map->height - 1 for the leaves.
1481 /// @param size New node size.
1482 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1483 void IntervalMap<KeyT, ValT, N, Traits>::
1484 iterator::setNodeSize(unsigned Level, unsigned Size) {
1485 this->pathNode(Level).setSize(Size);
1487 this->pathNode(Level-1).branch()
1488 .subtree(this->pathOffset(Level-1)).setSize(Size);
1490 this->map->rootBranch().subtree(this->rootOffset).setSize(Size);
1493 /// setNodeStop - Update the stop key of the current node at level and above.
1494 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1495 void IntervalMap<KeyT, ValT, N, Traits>::
1496 iterator::setNodeStop(unsigned Level, KeyT Stop) {
1498 this->pathNode(Level).branch().stop(this->pathOffset(Level)) = Stop;
1499 if (this->pathOffset(Level) != this->pathNode(Level).size() - 1)
1502 this->map->rootBranch().stop(this->rootOffset) = Stop;
1505 /// insertNode - insert a node before the current path at level.
1506 /// Leave the current path pointing at the new node.
1507 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1508 void IntervalMap<KeyT, ValT, N, Traits>::
1509 iterator::insertNode(unsigned Level, NodeRef Node, KeyT Stop) {
1511 // Insert into the root branch node.
1512 IntervalMap &IM = *this->map;
1513 if (IM.rootSize < RootBranch::Capacity) {
1514 IM.rootBranch().insert(this->rootOffset, IM.rootSize, Node, Stop);
1519 // We need to split the root while keeping our position.
1520 IdxPair Offset = IM.splitRoot(this->rootOffset);
1521 this->rootOffset = Offset.first;
1522 this->path.insert(this->path.begin(),std::make_pair(
1523 this->map->rootBranch().subtree(Offset.first), Offset.second));
1527 // When inserting before end(), make sure we have a valid path.
1528 if (!this->valid()) {
1529 this->treeDecrement();
1530 ++this->pathOffset(Level-1);
1533 // Insert into the branch node at level-1.
1534 NodeRef NR = this->pathNode(Level-1);
1535 unsigned Offset = this->pathOffset(Level-1);
1536 assert(NR.size() < Branch::Capacity && "Branch overflow");
1537 NR.branch().insert(Offset, NR.size(), Node, Stop);
1538 setNodeSize(Level - 1, NR.size() + 1);
1542 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1543 void IntervalMap<KeyT, ValT, N, Traits>::
1544 iterator::insert(KeyT a, KeyT b, ValT y) {
1545 if (this->branched())
1546 return treeInsert(a, b, y);
1547 IdxPair IP = this->map->rootLeaf().insertFrom(this->rootOffset,
1548 this->map->rootSize,
1550 if (IP.second <= RootLeaf::Capacity) {
1551 this->rootOffset = IP.first;
1552 this->map->rootSize = IP.second;
1555 IdxPair Offset = this->map->branchRoot(this->rootOffset);
1556 this->rootOffset = Offset.first;
1557 this->path.push_back(std::make_pair(
1558 this->map->rootBranch().subtree(Offset.first), Offset.second));
1559 treeInsert(a, b, y);
1563 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1564 void IntervalMap<KeyT, ValT, N, Traits>::
1565 iterator::treeInsert(KeyT a, KeyT b, ValT y) {
1566 if (!this->valid()) {
1567 // end() has an empty path. Go back to the last leaf node and use an
1568 // invalid offset instead.
1569 this->treeDecrement();
1570 ++this->treeLeafOffset();
1572 IdxPair IP = this->treeLeaf().insertFrom(this->treeLeafOffset(),
1573 this->treeLeafSize(), a, b, y);
1574 this->treeLeafOffset() = IP.first;
1575 if (IP.second <= Leaf::Capacity) {
1576 setNodeSize(this->map->height - 1, IP.second);
1577 if (IP.first == IP.second - 1)
1578 setNodeStop(this->map->height - 1, this->treeLeaf().stop(IP.first));
1581 // Leaf node has no space.
1583 IP = this->treeLeaf().insertFrom(this->treeLeafOffset(),
1584 this->treeLeafSize(), a, b, y);
1585 this->treeLeafOffset() = IP.first;
1586 setNodeSize(this->map->height-1, IP.second);
1587 if (IP.first == IP.second - 1)
1588 setNodeStop(this->map->height - 1, this->treeLeaf().stop(IP.first));
1590 // FIXME: Handle cross-node coalescing.
1593 // overflowLeaf - Distribute entries of the current leaf node evenly among
1594 // its siblings and ensure that the current node is not full.
1595 // This may require allocating a new node.
1596 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1597 void IntervalMap<KeyT, ValT, N, Traits>::
1598 iterator::overflowLeaf() {
1599 unsigned CurSize[4];
1602 unsigned Elements = 0;
1603 unsigned Offset = this->treeLeafOffset();
1605 // Do we have a left sibling?
1606 NodeRef LeftSib = this->leftSibling(this->map->height-1);
1608 Offset += Elements = CurSize[Nodes] = LeftSib.size();
1609 Node[Nodes++] = &LeftSib.leaf();
1612 // Current leaf node.
1613 Elements += CurSize[Nodes] = this->treeLeafSize();
1614 Node[Nodes++] = &this->treeLeaf();
1616 // Do we have a right sibling?
1617 NodeRef RightSib = this->rightSibling(this->map->height-1);
1619 Offset += Elements = CurSize[Nodes] = RightSib.size();
1620 Node[Nodes++] = &RightSib.leaf();
1623 // Do we need to allocate a new node?
1624 unsigned NewNode = 0;
1625 if (Elements + 1 > Nodes * Leaf::Capacity) {
1626 // Insert NewNode at the penultimate position, or after a single node.
1627 NewNode = Nodes == 1 ? 1 : Nodes - 1;
1628 CurSize[Nodes] = CurSize[NewNode];
1629 Node[Nodes] = Node[NewNode];
1630 CurSize[NewNode] = 0;
1631 Node[NewNode] = this->map->allocLeaf();
1635 // Compute the new element distribution.
1636 unsigned NewSize[4];
1638 IntervalMapImpl::distribute(Nodes, Elements, Leaf::Capacity,
1639 CurSize, NewSize, Offset, true);
1641 // Move current location to the leftmost node.
1643 this->treeDecrement();
1645 // Move elements right.
1646 for (int n = Nodes - 1; n; --n) {
1647 if (CurSize[n] == NewSize[n])
1649 for (int m = n - 1; m != -1; --m) {
1650 int d = Node[n]->adjLeftSib(CurSize[n], *Node[m], CurSize[m],
1651 NewSize[n] - CurSize[n]);
1654 // Keep going if the current node was exhausted.
1655 if (CurSize[n] >= NewSize[n])
1660 // Move elements left.
1661 for (unsigned n = 0; n != Nodes - 1; ++n) {
1662 if (CurSize[n] == NewSize[n])
1664 for (unsigned m = n + 1; m != Nodes; ++m) {
1665 int d = Node[m]->adjLeftSib(CurSize[m], *Node[n], CurSize[n],
1666 CurSize[n] - NewSize[n]);
1669 // Keep going if the current node was exhausted.
1670 if (CurSize[n] >= NewSize[n])
1676 for (unsigned n = 0; n != Nodes; n++)
1677 assert(CurSize[n] == NewSize[n] && "Insufficient element shuffle");
1680 // Elements have been rearranged, now update node sizes and stops.
1683 KeyT Stop = Node[Pos]->stop(NewSize[Pos]-1);
1684 if (NewNode && Pos == NewNode)
1685 insertNode(this->map->height - 1, NodeRef(Node[Pos], NewSize[Pos]), Stop);
1687 setNodeSize(this->map->height - 1, NewSize[Pos]);
1688 setNodeStop(this->map->height - 1, Stop);
1690 if (Pos + 1 == Nodes)
1692 this->treeIncrement();
1696 // Where was I? Find NewOffset.
1697 while(Pos != NewOffset.first) {
1698 this->treeDecrement();
1701 this->treeLeafOffset() = NewOffset.second;