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 /// moveLeft - 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 moveLeft(unsigned i, unsigned j, unsigned Count) {
224 assert(j <= i && "Use moveRight shift elements right");
225 copy(*this, i, j, Count);
228 /// moveRight - 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 moveRight(unsigned i, unsigned j, unsigned Count) {
233 assert(i <= j && "Use moveLeft 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 moveLeft(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 moveRight(i, i + 1, Size - i);
254 /// transferToLeftSib - 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 transferToLeftSib(unsigned Size, NodeBase &Sib, unsigned SSize,
261 Sib.copy(*this, 0, SSize, Count);
262 erase(0, Count, Size);
265 /// transferToRightSib - Transfer elements to a right sibling node.
266 /// @param Size Number of elements in this.
267 /// @param Sib Right sibling node.
268 /// @param SSize Number of elements in sib.
269 /// @param Count Number of elements to transfer.
270 void transferToRightSib(unsigned Size, NodeBase &Sib, unsigned SSize,
272 Sib.moveRight(0, Count, SSize);
273 Sib.copy(*this, Size-Count, 0, Count);
276 /// adjustFromLeftSib - Adjust the number if elements in this node by moving
277 /// elements to or from a left sibling node.
278 /// @param Size Number of elements in this.
279 /// @param Sib Right sibling node.
280 /// @param SSize Number of elements in sib.
281 /// @param Add The number of elements to add to this node, possibly < 0.
282 /// @return Number of elements added to this node, possibly negative.
283 int adjustFromLeftSib(unsigned Size, NodeBase &Sib, unsigned SSize, int Add) {
285 // We want to grow, copy from sib.
286 unsigned Count = std::min(std::min(unsigned(Add), SSize), N - Size);
287 Sib.transferToRightSib(SSize, *this, Size, Count);
290 // We want to shrink, copy to sib.
291 unsigned Count = std::min(std::min(unsigned(-Add), Size), N - SSize);
292 transferToLeftSib(Size, Sib, SSize, Count);
299 //===----------------------------------------------------------------------===//
300 //--- NodeSizer ---//
301 //===----------------------------------------------------------------------===//
303 // Compute node sizes from key and value types.
305 // The branching factors are chosen to make nodes fit in three cache lines.
306 // This may not be possible if keys or values are very large. Such large objects
307 // are handled correctly, but a std::map would probably give better performance.
309 //===----------------------------------------------------------------------===//
312 // Cache line size. Most architectures have 32 or 64 byte cache lines.
313 // We use 64 bytes here because it provides good branching factors.
315 CacheLineBytes = 1 << Log2CacheLine,
316 DesiredNodeBytes = 3 * CacheLineBytes
319 template <typename KeyT, typename ValT>
322 // Compute the leaf node branching factor that makes a node fit in three
323 // cache lines. The branching factor must be at least 3, or some B+-tree
324 // balancing algorithms won't work.
325 // LeafSize can't be larger than CacheLineBytes. This is required by the
326 // PointerIntPair used by NodeRef.
327 DesiredLeafSize = DesiredNodeBytes /
328 static_cast<unsigned>(2*sizeof(KeyT)+sizeof(ValT)),
330 LeafSize = DesiredLeafSize > MinLeafSize ? DesiredLeafSize : MinLeafSize
333 typedef NodeBase<std::pair<KeyT, KeyT>, ValT, LeafSize> LeafBase;
336 // Now that we have the leaf branching factor, compute the actual allocation
337 // unit size by rounding up to a whole number of cache lines.
338 AllocBytes = (sizeof(LeafBase) + CacheLineBytes-1) & ~(CacheLineBytes-1),
340 // Determine the branching factor for branch nodes.
341 BranchSize = AllocBytes /
342 static_cast<unsigned>(sizeof(KeyT) + sizeof(void*))
345 /// Allocator - The recycling allocator used for both branch and leaf nodes.
346 /// This typedef is very likely to be identical for all IntervalMaps with
347 /// reasonably sized entries, so the same allocator can be shared among
348 /// different kinds of maps.
349 typedef RecyclingAllocator<BumpPtrAllocator, char,
350 AllocBytes, CacheLineBytes> Allocator;
355 //===----------------------------------------------------------------------===//
357 //===----------------------------------------------------------------------===//
359 // B+-tree nodes can be leaves or branches, so we need a polymorphic node
360 // pointer that can point to both kinds.
362 // All nodes are cache line aligned and the low 6 bits of a node pointer are
363 // always 0. These bits are used to store the number of elements in the
364 // referenced node. Besides saving space, placing node sizes in the parents
365 // allow tree balancing algorithms to run without faulting cache lines for nodes
366 // that may not need to be modified.
368 // A NodeRef doesn't know whether it references a leaf node or a branch node.
369 // It is the responsibility of the caller to use the correct types.
371 // Nodes are never supposed to be empty, and it is invalid to store a node size
372 // of 0 in a NodeRef. The valid range of sizes is 1-64.
374 //===----------------------------------------------------------------------===//
376 struct CacheAlignedPointerTraits {
377 static inline void *getAsVoidPointer(void *P) { return P; }
378 static inline void *getFromVoidPointer(void *P) { return P; }
379 enum { NumLowBitsAvailable = Log2CacheLine };
382 template <typename KeyT, typename ValT, typename Traits>
385 typedef LeafNode<KeyT, ValT, NodeSizer<KeyT, ValT>::LeafSize, Traits> Leaf;
386 typedef BranchNode<KeyT, ValT, NodeSizer<KeyT, ValT>::BranchSize,
390 PointerIntPair<void*, Log2CacheLine, unsigned, CacheAlignedPointerTraits> pip;
393 /// NodeRef - Create a null ref.
396 /// operator bool - Detect a null ref.
397 operator bool() const { return pip.getOpaqueValue(); }
399 /// NodeRef - Create a reference to the leaf node p with n elements.
400 NodeRef(Leaf *p, unsigned n) : pip(p, n - 1) {}
402 /// NodeRef - Create a reference to the branch node p with n elements.
403 NodeRef(Branch *p, unsigned n) : pip(p, n - 1) {}
405 /// size - Return the number of elements in the referenced node.
406 unsigned size() const { return pip.getInt() + 1; }
408 /// setSize - Update the node size.
409 void setSize(unsigned n) { pip.setInt(n - 1); }
411 /// leaf - Return the referenced leaf node.
412 /// Note there are no dynamic type checks.
414 return *reinterpret_cast<Leaf*>(pip.getPointer());
417 /// branch - Return the referenced branch node.
418 /// Note there are no dynamic type checks.
419 Branch &branch() const {
420 return *reinterpret_cast<Branch*>(pip.getPointer());
423 bool operator==(const NodeRef &RHS) const {
426 assert(pip.getPointer() != RHS.pip.getPointer() && "Inconsistent NodeRefs");
430 bool operator!=(const NodeRef &RHS) const {
431 return !operator==(RHS);
435 //===----------------------------------------------------------------------===//
436 //--- Leaf nodes ---//
437 //===----------------------------------------------------------------------===//
439 // Leaf nodes store up to N disjoint intervals with corresponding values.
441 // The intervals are kept sorted and fully coalesced so there are no adjacent
442 // intervals mapping to the same value.
444 // These constraints are always satisfied:
446 // - Traits::stopLess(key[i].start, key[i].stop) - Non-empty, sane intervals.
448 // - Traits::stopLess(key[i].stop, key[i + 1].start) - Sorted.
450 // - val[i] != val[i + 1] ||
451 // !Traits::adjacent(key[i].stop, key[i + 1].start) - Fully coalesced.
453 //===----------------------------------------------------------------------===//
455 template <typename KeyT, typename ValT, unsigned N, typename Traits>
456 class LeafNode : public NodeBase<std::pair<KeyT, KeyT>, ValT, N> {
458 const KeyT &start(unsigned i) const { return this->key[i].first; }
459 const KeyT &stop(unsigned i) const { return this->key[i].second; }
460 const ValT &value(unsigned i) const { return this->val[i]; }
462 KeyT &start(unsigned i) { return this->key[i].first; }
463 KeyT &stop(unsigned i) { return this->key[i].second; }
464 ValT &value(unsigned i) { return this->val[i]; }
466 /// findFrom - Find the first interval after i that may contain x.
467 /// @param i Starting index for the search.
468 /// @param Size Number of elements in node.
469 /// @param x Key to search for.
470 /// @return First index with !stopLess(key[i].stop, x), or size.
471 /// This is the first interval that can possibly contain x.
472 unsigned findFrom(unsigned i, unsigned Size, KeyT x) const {
473 assert(i <= Size && Size <= N && "Bad indices");
474 assert((i == 0 || Traits::stopLess(stop(i - 1), x)) &&
475 "Index is past the needed point");
476 while (i != Size && Traits::stopLess(stop(i), x)) ++i;
480 /// safeFind - Find an interval that is known to exist. This is the same as
481 /// findFrom except is it assumed that x is at least within range of the last
483 /// @param i Starting index for the search.
484 /// @param x Key to search for.
485 /// @return First index with !stopLess(key[i].stop, x), never size.
486 /// This is the first interval that can possibly contain x.
487 unsigned safeFind(unsigned i, KeyT x) const {
488 assert(i < N && "Bad index");
489 assert((i == 0 || Traits::stopLess(stop(i - 1), x)) &&
490 "Index is past the needed point");
491 while (Traits::stopLess(stop(i), x)) ++i;
492 assert(i < N && "Unsafe intervals");
496 /// safeLookup - Lookup mapped value for a safe key.
497 /// It is assumed that x is within range of the last entry.
498 /// @param x Key to search for.
499 /// @param NotFound Value to return if x is not in any interval.
500 /// @return The mapped value at x or NotFound.
501 ValT safeLookup(KeyT x, ValT NotFound) const {
502 unsigned i = safeFind(0, x);
503 return Traits::startLess(x, start(i)) ? NotFound : value(i);
506 IdxPair insertFrom(unsigned i, unsigned Size, KeyT a, KeyT b, ValT y);
507 unsigned extendStop(unsigned i, unsigned Size, KeyT b);
510 void dump(unsigned Size) {
511 errs() << " N" << this << " [shape=record label=\"{ " << Size << '/' << N;
512 for (unsigned i = 0; i != Size; ++i)
513 errs() << " | {" << start(i) << '-' << stop(i) << "|" << value(i) << '}';
520 /// insertFrom - Add mapping of [a;b] to y if possible, coalescing as much as
521 /// possible. This may cause the node to grow by 1, or it may cause the node
522 /// to shrink because of coalescing.
523 /// @param i Starting index = insertFrom(0, size, a)
524 /// @param Size Number of elements in node.
525 /// @param a Interval start.
526 /// @param b Interval stop.
527 /// @param y Value be mapped.
528 /// @return (insert position, new size), or (i, Capacity+1) on overflow.
529 template <typename KeyT, typename ValT, unsigned N, typename Traits>
530 IdxPair LeafNode<KeyT, ValT, N, Traits>::
531 insertFrom(unsigned i, unsigned Size, KeyT a, KeyT b, ValT y) {
532 assert(i <= Size && Size <= N && "Invalid index");
533 assert(!Traits::stopLess(b, a) && "Invalid interval");
535 // Verify the findFrom invariant.
536 assert((i == 0 || Traits::stopLess(stop(i - 1), a)));
537 assert((i == Size || !Traits::stopLess(stop(i), a)));
539 // Coalesce with previous interval.
540 if (i && value(i - 1) == y && Traits::adjacent(stop(i - 1), a))
541 return IdxPair(i - 1, extendStop(i - 1, Size, b));
545 return IdxPair(i, N + 1);
547 // Add new interval at end.
552 return IdxPair(i, Size + 1);
555 // Overlapping intervals?
556 if (!Traits::stopLess(b, start(i))) {
557 assert(value(i) == y && "Inconsistent values in overlapping intervals");
558 if (Traits::startLess(a, start(i)))
560 return IdxPair(i, extendStop(i, Size, b));
563 // Try to coalesce with following interval.
564 if (value(i) == y && Traits::adjacent(b, start(i))) {
566 return IdxPair(i, Size);
569 // We must insert before i. Detect overflow.
571 return IdxPair(i, N + 1);
574 this->shift(i, Size);
578 return IdxPair(i, Size + 1);
581 /// extendStop - Extend stop(i) to b, coalescing with following intervals.
582 /// @param i Interval to extend.
583 /// @param Size Number of elements in node.
584 /// @param b New interval end point.
585 /// @return New node size after coalescing.
586 template <typename KeyT, typename ValT, unsigned N, typename Traits>
587 unsigned LeafNode<KeyT, ValT, N, Traits>::
588 extendStop(unsigned i, unsigned Size, KeyT b) {
589 assert(i < Size && Size <= N && "Bad indices");
591 // Are we even extending the interval?
592 if (Traits::startLess(b, stop(i)))
595 // Find the first interval that may be preserved.
596 unsigned j = findFrom(i + 1, Size, b);
598 // Would key[i] overlap key[j] after the extension?
599 if (Traits::stopLess(b, start(j))) {
600 // Not overlapping. Perhaps adjacent and coalescable?
601 if (value(i) == value(j) && Traits::adjacent(b, start(j)))
604 // Overlap. Include key[j] in the new interval.
605 assert(value(i) == value(j) && "Overlapping values");
611 // Entries [i+1;j) were coalesced.
612 if (i + 1 < j && j < Size)
613 this->erase(i + 1, j, Size);
614 return Size - (j - (i + 1));
618 //===----------------------------------------------------------------------===//
619 //--- Branch nodes ---//
620 //===----------------------------------------------------------------------===//
622 // A branch node stores references to 1--N subtrees all of the same height.
624 // The key array in a branch node holds the rightmost stop key of each subtree.
625 // It is redundant to store the last stop key since it can be found in the
626 // parent node, but doing so makes tree balancing a lot simpler.
628 // It is unusual for a branch node to only have one subtree, but it can happen
629 // in the root node if it is smaller than the normal nodes.
631 // When all of the leaf nodes from all the subtrees are concatenated, they must
632 // satisfy the same constraints as a single leaf node. They must be sorted,
633 // sane, and fully coalesced.
635 //===----------------------------------------------------------------------===//
637 template <typename KeyT, typename ValT, unsigned N, typename Traits>
638 class BranchNode : public NodeBase<KeyT, NodeRef<KeyT, ValT, Traits>, N> {
639 typedef NodeRef<KeyT, ValT, Traits> NodeRefT;
641 const KeyT &stop(unsigned i) const { return this->key[i]; }
642 const NodeRefT &subtree(unsigned i) const { return this->val[i]; }
644 KeyT &stop(unsigned i) { return this->key[i]; }
645 NodeRefT &subtree(unsigned i) { return this->val[i]; }
647 /// findFrom - Find the first subtree after i that may contain x.
648 /// @param i Starting index for the search.
649 /// @param Size Number of elements in node.
650 /// @param x Key to search for.
651 /// @return First index with !stopLess(key[i], x), or size.
652 /// This is the first subtree that can possibly contain x.
653 unsigned findFrom(unsigned i, unsigned Size, KeyT x) const {
654 assert(i <= Size && Size <= N && "Bad indices");
655 assert((i == 0 || Traits::stopLess(stop(i - 1), x)) &&
656 "Index to findFrom is past the needed point");
657 while (i != Size && Traits::stopLess(stop(i), x)) ++i;
661 /// safeFind - Find a subtree that is known to exist. This is the same as
662 /// findFrom except is it assumed that x is in range.
663 /// @param i Starting index for the search.
664 /// @param x Key to search for.
665 /// @return First index with !stopLess(key[i], x), never size.
666 /// This is the first subtree that can possibly contain x.
667 unsigned safeFind(unsigned i, KeyT x) const {
668 assert(i < N && "Bad index");
669 assert((i == 0 || Traits::stopLess(stop(i - 1), x)) &&
670 "Index is past the needed point");
671 while (Traits::stopLess(stop(i), x)) ++i;
672 assert(i < N && "Unsafe intervals");
676 /// safeLookup - Get the subtree containing x, Assuming that x is in range.
677 /// @param x Key to search for.
678 /// @return Subtree containing x
679 NodeRefT safeLookup(KeyT x) const {
680 return subtree(safeFind(0, x));
683 /// insert - Insert a new (subtree, stop) pair.
684 /// @param i Insert position, following entries will be shifted.
685 /// @param Size Number of elements in node.
686 /// @param Node Subtree to insert.
687 /// @param Stop Last key in subtree.
688 void insert(unsigned i, unsigned Size, NodeRefT Node, KeyT Stop) {
689 assert(Size < N && "branch node overflow");
690 assert(i <= Size && "Bad insert position");
691 this->shift(i, Size);
697 void dump(unsigned Size) {
698 errs() << " N" << this << " [shape=record label=\"" << Size << '/' << N;
699 for (unsigned i = 0; i != Size; ++i)
700 errs() << " | <s" << i << "> " << stop(i);
702 for (unsigned i = 0; i != Size; ++i)
703 errs() << " N" << this << ":s" << i << " -> N"
704 << &subtree(i).branch() << ";\n";
710 } // namespace IntervalMapImpl
713 //===----------------------------------------------------------------------===//
714 //--- IntervalMap ----//
715 //===----------------------------------------------------------------------===//
717 template <typename KeyT, typename ValT,
718 unsigned N = IntervalMapImpl::NodeSizer<KeyT, ValT>::LeafSize,
719 typename Traits = IntervalMapInfo<KeyT> >
721 typedef IntervalMapImpl::NodeRef<KeyT, ValT, Traits> NodeRef;
722 typedef IntervalMapImpl::NodeSizer<KeyT, ValT> NodeSizer;
723 typedef typename NodeRef::Leaf Leaf;
724 typedef typename NodeRef::Branch Branch;
725 typedef IntervalMapImpl::LeafNode<KeyT, ValT, N, Traits> RootLeaf;
726 typedef IntervalMapImpl::IdxPair IdxPair;
728 // The RootLeaf capacity is given as a template parameter. We must compute the
729 // corresponding RootBranch capacity.
731 DesiredRootBranchCap = (sizeof(RootLeaf) - sizeof(KeyT)) /
732 (sizeof(KeyT) + sizeof(NodeRef)),
733 RootBranchCap = DesiredRootBranchCap ? DesiredRootBranchCap : 1
736 typedef IntervalMapImpl::BranchNode<KeyT, ValT, RootBranchCap, Traits> RootBranch;
738 // When branched, we store a global start key as well as the branch node.
739 struct RootBranchData {
745 RootDataSize = sizeof(RootBranchData) > sizeof(RootLeaf) ?
746 sizeof(RootBranchData) : sizeof(RootLeaf)
750 typedef typename NodeSizer::Allocator Allocator;
753 // The root data is either a RootLeaf or a RootBranchData instance.
754 // We can't put them in a union since C++03 doesn't allow non-trivial
755 // constructors in unions.
756 // Instead, we use a char array with pointer alignment. The alignment is
757 // ensured by the allocator member in the class, but still verified in the
758 // constructor. We don't support keys or values that are more aligned than a
760 char data[RootDataSize];
763 // 0: Leaves in root.
764 // 1: Root points to leaf.
765 // 2: root->branch->leaf ...
768 // Number of entries in the root node.
771 // Allocator used for creating external nodes.
772 Allocator &allocator;
774 /// dataAs - Represent data as a node type without breaking aliasing rules.
775 template <typename T>
785 const RootLeaf &rootLeaf() const {
786 assert(!branched() && "Cannot acces leaf data in branched root");
787 return dataAs<RootLeaf>();
789 RootLeaf &rootLeaf() {
790 assert(!branched() && "Cannot acces leaf data in branched root");
791 return dataAs<RootLeaf>();
793 RootBranchData &rootBranchData() const {
794 assert(branched() && "Cannot access branch data in non-branched root");
795 return dataAs<RootBranchData>();
797 RootBranchData &rootBranchData() {
798 assert(branched() && "Cannot access branch data in non-branched root");
799 return dataAs<RootBranchData>();
801 const RootBranch &rootBranch() const { return rootBranchData().node; }
802 RootBranch &rootBranch() { return rootBranchData().node; }
803 KeyT rootBranchStart() const { return rootBranchData().start; }
804 KeyT &rootBranchStart() { return rootBranchData().start; }
807 return new(allocator.template Allocate<Leaf>()) Leaf();
809 void deleteLeaf(Leaf *P) {
811 allocator.Deallocate(P);
814 Branch *allocBranch() {
815 return new(allocator.template Allocate<Branch>()) Branch();
817 void deleteBranch(Branch *P) {
819 allocator.Deallocate(P);
823 IdxPair branchRoot(unsigned Position);
824 IdxPair splitRoot(unsigned Position);
826 void switchRootToBranch() {
827 rootLeaf().~RootLeaf();
829 new (&rootBranchData()) RootBranchData();
832 void switchRootToLeaf() {
833 rootBranchData().~RootBranchData();
835 new(&rootLeaf()) RootLeaf();
838 bool branched() const { return height > 0; }
840 ValT treeSafeLookup(KeyT x, ValT NotFound) const;
841 void visitNodes(void (IntervalMap::*f)(NodeRef, unsigned Level));
842 void deleteNode(NodeRef Node, unsigned Level);
845 explicit IntervalMap(Allocator &a) : height(0), rootSize(0), allocator(a) {
846 assert((uintptr_t(data) & (alignOf<RootLeaf>() - 1)) == 0 &&
847 "Insufficient alignment");
848 new(&rootLeaf()) RootLeaf();
851 /// empty - Return true when no intervals are mapped.
853 return rootSize == 0;
856 /// start - Return the smallest mapped key in a non-empty map.
858 assert(!empty() && "Empty IntervalMap has no start");
859 return !branched() ? rootLeaf().start(0) : rootBranchStart();
862 /// stop - Return the largest mapped key in a non-empty map.
864 assert(!empty() && "Empty IntervalMap has no stop");
865 return !branched() ? rootLeaf().stop(rootSize - 1) :
866 rootBranch().stop(rootSize - 1);
869 /// lookup - Return the mapped value at x or NotFound.
870 ValT lookup(KeyT x, ValT NotFound = ValT()) const {
871 if (empty() || Traits::startLess(x, start()) || Traits::stopLess(stop(), x))
873 return branched() ? treeSafeLookup(x, NotFound) :
874 rootLeaf().safeLookup(x, NotFound);
877 /// insert - Add a mapping of [a;b] to y, coalesce with adjacent intervals.
878 /// It is assumed that no key in the interval is mapped to another value, but
879 /// overlapping intervals already mapped to y will be coalesced.
880 void insert(KeyT a, KeyT b, ValT y) {
881 find(a).insert(a, b, y);
884 /// clear - Remove all entries.
887 class const_iterator;
889 friend class const_iterator;
890 friend class iterator;
892 const_iterator begin() const {
904 const_iterator end() const {
916 /// find - Return an iterator pointing to the first interval ending at or
917 /// after x, or end().
918 const_iterator find(KeyT x) const {
924 iterator find(KeyT x) {
932 void dumpNode(NodeRef Node, unsigned Height);
936 /// treeSafeLookup - Return the mapped value at x or NotFound, assuming a
938 template <typename KeyT, typename ValT, unsigned N, typename Traits>
939 ValT IntervalMap<KeyT, ValT, N, Traits>::
940 treeSafeLookup(KeyT x, ValT NotFound) const {
941 assert(branched() && "treeLookup assumes a branched root");
943 NodeRef NR = rootBranch().safeLookup(x);
944 for (unsigned h = height-1; h; --h)
945 NR = NR.branch().safeLookup(x);
946 return NR.leaf().safeLookup(x, NotFound);
950 // branchRoot - Switch from a leaf root to a branched root.
951 // Return the new (root offset, node offset) corresponding to Position.
952 template <typename KeyT, typename ValT, unsigned N, typename Traits>
953 IntervalMapImpl::IdxPair IntervalMap<KeyT, ValT, N, Traits>::
954 branchRoot(unsigned Position) {
955 // How many external leaf nodes to hold RootLeaf+1?
956 const unsigned Nodes = RootLeaf::Capacity / Leaf::Capacity + 1;
958 // Compute element distribution among new nodes.
959 unsigned size[Nodes];
960 IdxPair NewOffset(0, Position);
962 // Is is very common for the root node to be smaller than external nodes.
966 NewOffset = distribute(Nodes, rootSize, Leaf::Capacity, NULL, size,
969 // Allocate new nodes.
972 for (unsigned n = 0; n != Nodes; ++n) {
973 node[n] = NodeRef(allocLeaf(), size[n]);
974 node[n].leaf().copy(rootLeaf(), pos, 0, size[n]);
978 // Destroy the old leaf node, construct branch node instead.
979 switchRootToBranch();
980 for (unsigned n = 0; n != Nodes; ++n) {
981 rootBranch().stop(n) = node[n].leaf().stop(size[n]-1);
982 rootBranch().subtree(n) = node[n];
984 rootBranchStart() = node[0].leaf().start(0);
989 // splitRoot - Split the current BranchRoot into multiple Branch nodes.
990 // Return the new (root offset, node offset) corresponding to Position.
991 template <typename KeyT, typename ValT, unsigned N, typename Traits>
992 IntervalMapImpl::IdxPair IntervalMap<KeyT, ValT, N, Traits>::
993 splitRoot(unsigned Position) {
994 // How many external leaf nodes to hold RootBranch+1?
995 const unsigned Nodes = RootBranch::Capacity / Branch::Capacity + 1;
997 // Compute element distribution among new nodes.
998 unsigned Size[Nodes];
999 IdxPair NewOffset(0, Position);
1001 // Is is very common for the root node to be smaller than external nodes.
1005 NewOffset = distribute(Nodes, rootSize, Leaf::Capacity, NULL, Size,
1008 // Allocate new nodes.
1010 NodeRef Node[Nodes];
1011 for (unsigned n = 0; n != Nodes; ++n) {
1012 Node[n] = NodeRef(allocBranch(), Size[n]);
1013 Node[n].branch().copy(rootBranch(), Pos, 0, Size[n]);
1017 for (unsigned n = 0; n != Nodes; ++n) {
1018 rootBranch().stop(n) = Node[n].branch().stop(Size[n]-1);
1019 rootBranch().subtree(n) = Node[n];
1025 /// visitNodes - Visit each external node.
1026 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1027 void IntervalMap<KeyT, ValT, N, Traits>::
1028 visitNodes(void (IntervalMap::*f)(NodeRef, unsigned Height)) {
1031 SmallVector<NodeRef, 4> Refs, NextRefs;
1033 // Collect level 0 nodes from the root.
1034 for (unsigned i = 0; i != rootSize; ++i)
1035 Refs.push_back(rootBranch().subtree(i));
1037 // Visit all branch nodes.
1038 for (unsigned h = height - 1; h; --h) {
1039 for (unsigned i = 0, e = Refs.size(); i != e; ++i) {
1040 Branch &B = Refs[i].branch();
1041 for (unsigned j = 0, s = Refs[i].size(); j != s; ++j)
1042 NextRefs.push_back(B.subtree(j));
1043 (this->*f)(Refs[i], h);
1046 Refs.swap(NextRefs);
1049 // Visit all leaf nodes.
1050 for (unsigned i = 0, e = Refs.size(); i != e; ++i)
1051 (this->*f)(Refs[i], 0);
1054 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1055 void IntervalMap<KeyT, ValT, N, Traits>::
1056 deleteNode(NodeRef Node, unsigned Level) {
1058 deleteBranch(&Node.branch());
1060 deleteLeaf(&Node.leaf());
1063 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1064 void IntervalMap<KeyT, ValT, N, Traits>::
1067 visitNodes(&IntervalMap::deleteNode);
1074 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1075 void IntervalMap<KeyT, ValT, N, Traits>::
1076 dumpNode(NodeRef Node, unsigned Height) {
1078 Node.branch().dump(Node.size());
1080 Node.leaf().dump(Node.size());
1083 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1084 void IntervalMap<KeyT, ValT, N, Traits>::
1086 errs() << "digraph {\n";
1088 rootBranch().dump(rootSize);
1090 rootLeaf().dump(rootSize);
1091 visitNodes(&IntervalMap::dumpNode);
1096 //===----------------------------------------------------------------------===//
1097 //--- const_iterator ----//
1098 //===----------------------------------------------------------------------===//
1100 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1101 class IntervalMap<KeyT, ValT, N, Traits>::const_iterator :
1102 public std::iterator<std::bidirectional_iterator_tag, ValT> {
1104 friend class IntervalMap;
1105 typedef std::pair<NodeRef, unsigned> PathEntry;
1106 typedef SmallVector<PathEntry, 4> Path;
1108 // The map referred to.
1111 // The offset into map's root node.
1112 unsigned rootOffset;
1114 // We store a full path from the root to the current position.
1116 // When rootOffset == map->rootSize, we are at end() and path() is empty.
1117 // Otherwise, when branched these conditions hold:
1119 // 1. path.front().first == rootBranch().subtree(rootOffset)
1120 // 2. path[i].first == path[i-1].first.branch().subtree(path[i-1].second)
1121 // 3. path.size() == map->height.
1123 // Thus, path.back() always refers to the current leaf node unless the root is
1126 // The path may be partially filled, but never between iterator calls.
1129 explicit const_iterator(IntervalMap &map)
1130 : map(&map), rootOffset(map.rootSize) {}
1132 bool branched() const {
1133 assert(map && "Invalid iterator");
1134 return map->branched();
1137 NodeRef pathNode(unsigned h) const { return path[h].first; }
1138 NodeRef &pathNode(unsigned h) { return path[h].first; }
1139 unsigned pathOffset(unsigned h) const { return path[h].second; }
1140 unsigned &pathOffset(unsigned h) { return path[h].second; }
1142 Leaf &treeLeaf() const {
1143 assert(branched() && path.size() == map->height);
1144 return path.back().first.leaf();
1146 unsigned treeLeafSize() const {
1147 assert(branched() && path.size() == map->height);
1148 return path.back().first.size();
1150 unsigned &treeLeafOffset() {
1151 assert(branched() && path.size() == map->height);
1152 return path.back().second;
1154 unsigned treeLeafOffset() const {
1155 assert(branched() && path.size() == map->height);
1156 return path.back().second;
1159 // Get the next node ptr for an incomplete path.
1160 NodeRef pathNextDown() {
1161 assert(path.size() < map->height && "Path is already complete");
1164 return map->rootBranch().subtree(rootOffset);
1166 return path.back().first.branch().subtree(path.back().second);
1169 void pathFillLeft();
1170 void pathFillFind(KeyT x);
1171 void pathFillRight();
1173 NodeRef leftSibling(unsigned level) const;
1174 NodeRef rightSibling(unsigned level) const;
1176 void treeIncrement();
1177 void treeDecrement();
1178 void treeFind(KeyT x);
1181 /// valid - Return true if the current position is valid, false for end().
1182 bool valid() const {
1183 assert(map && "Invalid iterator");
1184 return rootOffset < map->rootSize;
1187 /// start - Return the beginning of the current interval.
1188 const KeyT &start() const {
1189 assert(valid() && "Cannot access invalid iterator");
1190 return branched() ? treeLeaf().start(treeLeafOffset()) :
1191 map->rootLeaf().start(rootOffset);
1194 /// stop - Return the end of the current interval.
1195 const KeyT &stop() const {
1196 assert(valid() && "Cannot access invalid iterator");
1197 return branched() ? treeLeaf().stop(treeLeafOffset()) :
1198 map->rootLeaf().stop(rootOffset);
1201 /// value - Return the mapped value at the current interval.
1202 const ValT &value() const {
1203 assert(valid() && "Cannot access invalid iterator");
1204 return branched() ? treeLeaf().value(treeLeafOffset()) :
1205 map->rootLeaf().value(rootOffset);
1208 const ValT &operator*() const {
1212 bool operator==(const const_iterator &RHS) const {
1213 assert(map == RHS.map && "Cannot compare iterators from different maps");
1214 return rootOffset == RHS.rootOffset &&
1215 (!valid() || !branched() || path.back() == RHS.path.back());
1218 bool operator!=(const const_iterator &RHS) const {
1219 return !operator==(RHS);
1222 /// goToBegin - Move to the first interval in map.
1230 /// goToEnd - Move beyond the last interval in map.
1232 rootOffset = map->rootSize;
1236 /// preincrement - move to the next interval.
1237 const_iterator &operator++() {
1238 assert(valid() && "Cannot increment end()");
1241 else if (treeLeafOffset() != treeLeafSize() - 1)
1248 /// postincrement - Dont do that!
1249 const_iterator operator++(int) {
1250 const_iterator tmp = *this;
1255 /// predecrement - move to the previous interval.
1256 const_iterator &operator--() {
1258 assert(rootOffset && "Cannot decrement begin()");
1260 } else if (valid() && treeLeafOffset())
1267 /// postdecrement - Dont do that!
1268 const_iterator operator--(int) {
1269 const_iterator tmp = *this;
1274 /// find - Move to the first interval with stop >= x, or end().
1275 /// This is a full search from the root, the current position is ignored.
1280 rootOffset = map->rootLeaf().findFrom(0, map->rootSize, x);
1283 /// advanceTo - Move to the first interval with stop >= x, or end().
1284 /// The search is started from the current position, and no earlier positions
1285 /// can be found. This is much faster than find() for small moves.
1286 void advanceTo(KeyT x) {
1290 rootOffset = map->rootLeaf().findFrom(rootOffset, map->rootSize, x);
1295 // pathFillLeft - Complete path by following left-most branches.
1296 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1297 void IntervalMap<KeyT, ValT, N, Traits>::
1298 const_iterator::pathFillLeft() {
1299 NodeRef NR = pathNextDown();
1300 for (unsigned i = map->height - path.size() - 1; i; --i) {
1301 path.push_back(PathEntry(NR, 0));
1302 NR = NR.branch().subtree(0);
1304 path.push_back(PathEntry(NR, 0));
1307 // pathFillFind - Complete path by searching for x.
1308 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1309 void IntervalMap<KeyT, ValT, N, Traits>::
1310 const_iterator::pathFillFind(KeyT x) {
1311 NodeRef NR = pathNextDown();
1312 for (unsigned i = map->height - path.size() - 1; i; --i) {
1313 unsigned p = NR.branch().safeFind(0, x);
1314 path.push_back(PathEntry(NR, p));
1315 NR = NR.branch().subtree(p);
1317 path.push_back(PathEntry(NR, NR.leaf().safeFind(0, x)));
1320 // pathFillRight - Complete path by adding rightmost entries.
1321 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1322 void IntervalMap<KeyT, ValT, N, Traits>::
1323 const_iterator::pathFillRight() {
1324 NodeRef NR = pathNextDown();
1325 for (unsigned i = map->height - path.size() - 1; i; --i) {
1326 unsigned p = NR.size() - 1;
1327 path.push_back(PathEntry(NR, p));
1328 NR = NR.branch().subtree(p);
1330 path.push_back(PathEntry(NR, NR.size() - 1));
1333 /// leftSibling - find the left sibling node to path[level].
1334 /// @param level 0 is just below the root, map->height - 1 for the leaves.
1335 /// @return The left sibling NodeRef, or NULL.
1336 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1337 typename IntervalMap<KeyT, ValT, N, Traits>::NodeRef
1338 IntervalMap<KeyT, ValT, N, Traits>::
1339 const_iterator::leftSibling(unsigned level) const {
1340 assert(branched() && "Not at a branched node");
1341 assert(level <= path.size() && "Bad level");
1343 // Go up the tree until we can go left.
1345 while (h && pathOffset(h - 1) == 0)
1348 // We are at the first leaf node, no left sibling.
1349 if (!h && rootOffset == 0)
1352 // NR is the subtree containing our left sibling.
1354 pathNode(h - 1).branch().subtree(pathOffset(h - 1) - 1) :
1355 map->rootBranch().subtree(rootOffset - 1);
1357 // Keep right all the way down.
1358 for (; h != level; ++h)
1359 NR = NR.branch().subtree(NR.size() - 1);
1363 /// rightSibling - find the right sibling node to path[level].
1364 /// @param level 0 is just below the root, map->height - 1 for the leaves.
1365 /// @return The right sibling NodeRef, or NULL.
1366 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1367 typename IntervalMap<KeyT, ValT, N, Traits>::NodeRef
1368 IntervalMap<KeyT, ValT, N, Traits>::
1369 const_iterator::rightSibling(unsigned level) const {
1370 assert(branched() && "Not at a branched node");
1371 assert(level <= this->path.size() && "Bad level");
1373 // Go up the tree until we can go right.
1375 while (h && pathOffset(h - 1) == pathNode(h - 1).size() - 1)
1378 // We are at the last leaf node, no right sibling.
1379 if (!h && rootOffset == map->rootSize - 1)
1382 // NR is the subtree containing our right sibling.
1384 pathNode(h - 1).branch().subtree(pathOffset(h - 1) + 1) :
1385 map->rootBranch().subtree(rootOffset + 1);
1387 // Keep left all the way down.
1388 for (; h != level; ++h)
1389 NR = NR.branch().subtree(0);
1393 // treeIncrement - Move to the beginning of the next leaf node.
1394 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1395 void IntervalMap<KeyT, ValT, N, Traits>::
1396 const_iterator::treeIncrement() {
1397 assert(branched() && "treeIncrement is not for small maps");
1398 assert(path.size() == map->height && "inconsistent iterator");
1400 while (!path.empty() && path.back().second == path.back().first.size() - 1);
1406 ++path.back().second;
1410 // treeDecrement - Move to the end of the previous leaf node.
1411 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1412 void IntervalMap<KeyT, ValT, N, Traits>::
1413 const_iterator::treeDecrement() {
1414 assert(branched() && "treeDecrement is not for small maps");
1416 assert(path.size() == map->height && "inconsistent iterator");
1418 while (!path.empty() && path.back().second == 0);
1421 assert(rootOffset && "cannot treeDecrement() on begin()");
1424 --path.back().second;
1428 // treeFind - Find in a branched tree.
1429 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1430 void IntervalMap<KeyT, ValT, N, Traits>::
1431 const_iterator::treeFind(KeyT x) {
1433 rootOffset = map->rootBranch().findFrom(0, map->rootSize, x);
1439 //===----------------------------------------------------------------------===//
1440 //--- iterator ----//
1441 //===----------------------------------------------------------------------===//
1443 namespace IntervalMapImpl {
1445 /// distribute - Compute a new distribution of node elements after an overflow
1446 /// or underflow. Reserve space for a new element at Position, and compute the
1447 /// node that will hold Position after redistributing node elements.
1449 /// It is required that
1451 /// Elements == sum(CurSize), and
1452 /// Elements + Grow <= Nodes * Capacity.
1454 /// NewSize[] will be filled in such that:
1456 /// sum(NewSize) == Elements, and
1457 /// NewSize[i] <= Capacity.
1459 /// The returned index is the node where Position will go, so:
1461 /// sum(NewSize[0..idx-1]) <= Position
1462 /// sum(NewSize[0..idx]) >= Position
1464 /// The last equality, sum(NewSize[0..idx]) == Position, can only happen when
1465 /// Grow is set and NewSize[idx] == Capacity-1. The index points to the node
1466 /// before the one holding the Position'th element where there is room for an
1469 /// @param Nodes The number of nodes.
1470 /// @param Elements Total elements in all nodes.
1471 /// @param Capacity The capacity of each node.
1472 /// @param CurSize Array[Nodes] of current node sizes, or NULL.
1473 /// @param NewSize Array[Nodes] to receive the new node sizes.
1474 /// @param Position Insert position.
1475 /// @param Grow Reserve space for a new element at Position.
1476 /// @return (node, offset) for Position.
1477 IdxPair distribute(unsigned Nodes, unsigned Elements, unsigned Capacity,
1478 const unsigned *CurSize, unsigned NewSize[],
1479 unsigned Position, bool Grow);
1483 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1484 class IntervalMap<KeyT, ValT, N, Traits>::iterator : public const_iterator {
1485 friend class IntervalMap;
1486 typedef IntervalMapImpl::IdxPair IdxPair;
1488 explicit iterator(IntervalMap &map) : const_iterator(map) {}
1490 void setNodeSize(unsigned Level, unsigned Size);
1491 void setNodeStop(unsigned Level, KeyT Stop);
1492 void insertNode(unsigned Level, NodeRef Node, KeyT Stop);
1493 void overflowLeaf();
1494 void treeInsert(KeyT a, KeyT b, ValT y);
1497 /// insert - Insert mapping [a;b] -> y before the current position.
1498 void insert(KeyT a, KeyT b, ValT y);
1502 /// setNodeSize - Set the size of the node at path[level], updating both path
1503 /// and the real tree.
1504 /// @param level 0 is just below the root, map->height - 1 for the leaves.
1505 /// @param size New node size.
1506 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1507 void IntervalMap<KeyT, ValT, N, Traits>::
1508 iterator::setNodeSize(unsigned Level, unsigned Size) {
1509 this->pathNode(Level).setSize(Size);
1511 this->pathNode(Level-1).branch()
1512 .subtree(this->pathOffset(Level-1)).setSize(Size);
1514 this->map->rootBranch().subtree(this->rootOffset).setSize(Size);
1517 /// setNodeStop - Update the stop key of the current node at level and above.
1518 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1519 void IntervalMap<KeyT, ValT, N, Traits>::
1520 iterator::setNodeStop(unsigned Level, KeyT Stop) {
1522 this->pathNode(Level).branch().stop(this->pathOffset(Level)) = Stop;
1523 if (this->pathOffset(Level) != this->pathNode(Level).size() - 1)
1526 this->map->rootBranch().stop(this->rootOffset) = Stop;
1529 /// insertNode - insert a node before the current path at level.
1530 /// Leave the current path pointing at the new node.
1531 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1532 void IntervalMap<KeyT, ValT, N, Traits>::
1533 iterator::insertNode(unsigned Level, NodeRef Node, KeyT Stop) {
1535 // Insert into the root branch node.
1536 IntervalMap &IM = *this->map;
1537 if (IM.rootSize < RootBranch::Capacity) {
1538 IM.rootBranch().insert(this->rootOffset, IM.rootSize, Node, Stop);
1543 // We need to split the root while keeping our position.
1544 IdxPair Offset = IM.splitRoot(this->rootOffset);
1545 this->rootOffset = Offset.first;
1546 this->path.insert(this->path.begin(),std::make_pair(
1547 this->map->rootBranch().subtree(Offset.first), Offset.second));
1551 // When inserting before end(), make sure we have a valid path.
1552 if (!this->valid()) {
1553 this->treeDecrement();
1554 ++this->pathOffset(Level-1);
1557 // Insert into the branch node at level-1.
1558 NodeRef NR = this->pathNode(Level-1);
1559 unsigned Offset = this->pathOffset(Level-1);
1560 assert(NR.size() < Branch::Capacity && "Branch overflow");
1561 NR.branch().insert(Offset, NR.size(), Node, Stop);
1562 setNodeSize(Level - 1, NR.size() + 1);
1566 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1567 void IntervalMap<KeyT, ValT, N, Traits>::
1568 iterator::insert(KeyT a, KeyT b, ValT y) {
1569 if (this->branched())
1570 return treeInsert(a, b, y);
1571 IdxPair IP = this->map->rootLeaf().insertFrom(this->rootOffset,
1572 this->map->rootSize,
1574 if (IP.second <= RootLeaf::Capacity) {
1575 this->rootOffset = IP.first;
1576 this->map->rootSize = IP.second;
1579 IdxPair Offset = this->map->branchRoot(this->rootOffset);
1580 this->rootOffset = Offset.first;
1581 this->path.push_back(std::make_pair(
1582 this->map->rootBranch().subtree(Offset.first), Offset.second));
1583 treeInsert(a, b, y);
1587 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1588 void IntervalMap<KeyT, ValT, N, Traits>::
1589 iterator::treeInsert(KeyT a, KeyT b, ValT y) {
1590 if (!this->valid()) {
1591 // end() has an empty path. Go back to the last leaf node and use an
1592 // invalid offset instead.
1593 this->treeDecrement();
1594 ++this->treeLeafOffset();
1596 IdxPair IP = this->treeLeaf().insertFrom(this->treeLeafOffset(),
1597 this->treeLeafSize(), a, b, y);
1598 this->treeLeafOffset() = IP.first;
1599 if (IP.second <= Leaf::Capacity) {
1600 setNodeSize(this->map->height - 1, IP.second);
1601 if (IP.first == IP.second - 1)
1602 setNodeStop(this->map->height - 1, this->treeLeaf().stop(IP.first));
1605 // Leaf node has no space.
1607 IP = this->treeLeaf().insertFrom(this->treeLeafOffset(),
1608 this->treeLeafSize(), a, b, y);
1609 this->treeLeafOffset() = IP.first;
1610 setNodeSize(this->map->height-1, IP.second);
1611 if (IP.first == IP.second - 1)
1612 setNodeStop(this->map->height - 1, this->treeLeaf().stop(IP.first));
1614 // FIXME: Handle cross-node coalescing.
1617 // overflowLeaf - Distribute entries of the current leaf node evenly among
1618 // its siblings and ensure that the current node is not full.
1619 // This may require allocating a new node.
1620 template <typename KeyT, typename ValT, unsigned N, typename Traits>
1621 void IntervalMap<KeyT, ValT, N, Traits>::
1622 iterator::overflowLeaf() {
1623 unsigned CurSize[4];
1626 unsigned Elements = 0;
1627 unsigned Offset = this->treeLeafOffset();
1629 // Do we have a left sibling?
1630 NodeRef LeftSib = this->leftSibling(this->map->height-1);
1632 Offset += Elements = CurSize[Nodes] = LeftSib.size();
1633 Node[Nodes++] = &LeftSib.leaf();
1636 // Current leaf node.
1637 Elements += CurSize[Nodes] = this->treeLeafSize();
1638 Node[Nodes++] = &this->treeLeaf();
1640 // Do we have a right sibling?
1641 NodeRef RightSib = this->rightSibling(this->map->height-1);
1643 Offset += Elements = CurSize[Nodes] = RightSib.size();
1644 Node[Nodes++] = &RightSib.leaf();
1647 // Do we need to allocate a new node?
1648 unsigned NewNode = 0;
1649 if (Elements + 1 > Nodes * Leaf::Capacity) {
1650 // Insert NewNode at the penultimate position, or after a single node.
1651 NewNode = Nodes == 1 ? 1 : Nodes - 1;
1652 CurSize[Nodes] = CurSize[NewNode];
1653 Node[Nodes] = Node[NewNode];
1654 CurSize[NewNode] = 0;
1655 Node[NewNode] = this->map->allocLeaf();
1659 // Compute the new element distribution.
1660 unsigned NewSize[4];
1662 IntervalMapImpl::distribute(Nodes, Elements, Leaf::Capacity,
1663 CurSize, NewSize, Offset, true);
1665 // Move current location to the leftmost node.
1667 this->treeDecrement();
1669 // Move elements right.
1670 for (int n = Nodes - 1; n; --n) {
1671 if (CurSize[n] == NewSize[n])
1673 for (int m = n - 1; m != -1; --m) {
1674 int d = Node[n]->adjustFromLeftSib(CurSize[n], *Node[m], CurSize[m],
1675 NewSize[n] - CurSize[n]);
1678 // Keep going if the current node was exhausted.
1679 if (CurSize[n] >= NewSize[n])
1684 // Move elements left.
1685 for (unsigned n = 0; n != Nodes - 1; ++n) {
1686 if (CurSize[n] == NewSize[n])
1688 for (unsigned m = n + 1; m != Nodes; ++m) {
1689 int d = Node[m]->adjustFromLeftSib(CurSize[m], *Node[n], CurSize[n],
1690 CurSize[n] - NewSize[n]);
1693 // Keep going if the current node was exhausted.
1694 if (CurSize[n] >= NewSize[n])
1700 for (unsigned n = 0; n != Nodes; n++)
1701 assert(CurSize[n] == NewSize[n] && "Insufficient element shuffle");
1704 // Elements have been rearranged, now update node sizes and stops.
1707 KeyT Stop = Node[Pos]->stop(NewSize[Pos]-1);
1708 if (NewNode && Pos == NewNode)
1709 insertNode(this->map->height - 1, NodeRef(Node[Pos], NewSize[Pos]), Stop);
1711 setNodeSize(this->map->height - 1, NewSize[Pos]);
1712 setNodeStop(this->map->height - 1, Stop);
1714 if (Pos + 1 == Nodes)
1716 this->treeIncrement();
1720 // Where was I? Find NewOffset.
1721 while(Pos != NewOffset.first) {
1722 this->treeDecrement();
1725 this->treeLeafOffset() = NewOffset.second;