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llvm-mirror/include/llvm/ADT/ImmutableSet.h
Chandler Carruth ae65e281f3 Update the file headers across all of the LLVM projects in the monorepo 
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00

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//===--- ImmutableSet.h - Immutable (functional) set interface --*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file defines the ImutAVLTree and ImmutableSet classes.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ADT_IMMUTABLESET_H
#define LLVM_ADT_IMMUTABLESET_H
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/FoldingSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/iterator.h"
#include "llvm/Support/Allocator.h"
#include "llvm/Support/ErrorHandling.h"
#include <cassert>
#include <cstdint>
#include <functional>
#include <iterator>
#include <new>
#include <vector>
namespace llvm {
//===----------------------------------------------------------------------===//
// Immutable AVL-Tree Definition.
//===----------------------------------------------------------------------===//
template <typename ImutInfo> class ImutAVLFactory;
template <typename ImutInfo> class ImutIntervalAVLFactory;
template <typename ImutInfo> class ImutAVLTreeInOrderIterator;
template <typename ImutInfo> class ImutAVLTreeGenericIterator;
template <typename ImutInfo >
class ImutAVLTree {
public:
using key_type_ref = typename ImutInfo::key_type_ref;
using value_type = typename ImutInfo::value_type;
using value_type_ref = typename ImutInfo::value_type_ref;
using Factory = ImutAVLFactory<ImutInfo>;
using iterator = ImutAVLTreeInOrderIterator<ImutInfo>;
friend class ImutAVLFactory<ImutInfo>;
friend class ImutIntervalAVLFactory<ImutInfo>;
friend class ImutAVLTreeGenericIterator<ImutInfo>;
//===----------------------------------------------------===//
// Public Interface.
//===----------------------------------------------------===//
/// Return a pointer to the left subtree. This value
/// is NULL if there is no left subtree.
ImutAVLTree *getLeft() const { return left; }
/// Return a pointer to the right subtree. This value is
/// NULL if there is no right subtree.
ImutAVLTree *getRight() const { return right; }
/// getHeight - Returns the height of the tree. A tree with no subtrees
/// has a height of 1.
unsigned getHeight() const { return height; }
/// getValue - Returns the data value associated with the tree node.
const value_type& getValue() const { return value; }
/// find - Finds the subtree associated with the specified key value.
/// This method returns NULL if no matching subtree is found.
ImutAVLTree* find(key_type_ref K) {
ImutAVLTree *T = this;
while (T) {
key_type_ref CurrentKey = ImutInfo::KeyOfValue(T->getValue());
if (ImutInfo::isEqual(K,CurrentKey))
return T;
else if (ImutInfo::isLess(K,CurrentKey))
T = T->getLeft();
else
T = T->getRight();
}
return nullptr;
}
/// getMaxElement - Find the subtree associated with the highest ranged
/// key value.
ImutAVLTree* getMaxElement() {
ImutAVLTree *T = this;
ImutAVLTree *Right = T->getRight();
while (Right) { T = Right; Right = T->getRight(); }
return T;
}
/// size - Returns the number of nodes in the tree, which includes
/// both leaves and non-leaf nodes.
unsigned size() const {
unsigned n = 1;
if (const ImutAVLTree* L = getLeft())
n += L->size();
if (const ImutAVLTree* R = getRight())
n += R->size();
return n;
}
/// begin - Returns an iterator that iterates over the nodes of the tree
/// in an inorder traversal. The returned iterator thus refers to the
/// the tree node with the minimum data element.
iterator begin() const { return iterator(this); }
/// end - Returns an iterator for the tree that denotes the end of an
/// inorder traversal.
iterator end() const { return iterator(); }
bool isElementEqual(value_type_ref V) const {
// Compare the keys.
if (!ImutInfo::isEqual(ImutInfo::KeyOfValue(getValue()),
ImutInfo::KeyOfValue(V)))
return false;
// Also compare the data values.
if (!ImutInfo::isDataEqual(ImutInfo::DataOfValue(getValue()),
ImutInfo::DataOfValue(V)))
return false;
return true;
}
bool isElementEqual(const ImutAVLTree* RHS) const {
return isElementEqual(RHS->getValue());
}
/// isEqual - Compares two trees for structural equality and returns true
/// if they are equal. This worst case performance of this operation is
// linear in the sizes of the trees.
bool isEqual(const ImutAVLTree& RHS) const {
if (&RHS == this)
return true;
iterator LItr = begin(), LEnd = end();
iterator RItr = RHS.begin(), REnd = RHS.end();
while (LItr != LEnd && RItr != REnd) {
if (&*LItr == &*RItr) {
LItr.skipSubTree();
RItr.skipSubTree();
continue;
}
if (!LItr->isElementEqual(&*RItr))
return false;
++LItr;
++RItr;
}
return LItr == LEnd && RItr == REnd;
}
/// isNotEqual - Compares two trees for structural inequality. Performance
/// is the same is isEqual.
bool isNotEqual(const ImutAVLTree& RHS) const { return !isEqual(RHS); }
/// contains - Returns true if this tree contains a subtree (node) that
/// has an data element that matches the specified key. Complexity
/// is logarithmic in the size of the tree.
bool contains(key_type_ref K) { return (bool) find(K); }
/// foreach - A member template the accepts invokes operator() on a functor
/// object (specifed by Callback) for every node/subtree in the tree.
/// Nodes are visited using an inorder traversal.
template <typename Callback>
void foreach(Callback& C) {
if (ImutAVLTree* L = getLeft())
L->foreach(C);
C(value);
if (ImutAVLTree* R = getRight())
R->foreach(C);
}
/// validateTree - A utility method that checks that the balancing and
/// ordering invariants of the tree are satisifed. It is a recursive
/// method that returns the height of the tree, which is then consumed
/// by the enclosing validateTree call. External callers should ignore the
/// return value. An invalid tree will cause an assertion to fire in
/// a debug build.
unsigned validateTree() const {
unsigned HL = getLeft() ? getLeft()->validateTree() : 0;
unsigned HR = getRight() ? getRight()->validateTree() : 0;
(void) HL;
(void) HR;
assert(getHeight() == ( HL > HR ? HL : HR ) + 1
&& "Height calculation wrong");
assert((HL > HR ? HL-HR : HR-HL) <= 2
&& "Balancing invariant violated");
assert((!getLeft() ||
ImutInfo::isLess(ImutInfo::KeyOfValue(getLeft()->getValue()),
ImutInfo::KeyOfValue(getValue()))) &&
"Value in left child is not less that current value");
assert(!(getRight() ||
ImutInfo::isLess(ImutInfo::KeyOfValue(getValue()),
ImutInfo::KeyOfValue(getRight()->getValue()))) &&
"Current value is not less that value of right child");
return getHeight();
}
//===----------------------------------------------------===//
// Internal values.
//===----------------------------------------------------===//
private:
Factory *factory;
ImutAVLTree *left;
ImutAVLTree *right;
ImutAVLTree *prev = nullptr;
ImutAVLTree *next = nullptr;
unsigned height : 28;
bool IsMutable : 1;
bool IsDigestCached : 1;
bool IsCanonicalized : 1;
value_type value;
uint32_t digest = 0;
uint32_t refCount = 0;
//===----------------------------------------------------===//
// Internal methods (node manipulation; used by Factory).
//===----------------------------------------------------===//
private:
/// ImutAVLTree - Internal constructor that is only called by
/// ImutAVLFactory.
ImutAVLTree(Factory *f, ImutAVLTree* l, ImutAVLTree* r, value_type_ref v,
unsigned height)
: factory(f), left(l), right(r), height(height), IsMutable(true),
IsDigestCached(false), IsCanonicalized(false), value(v)
{
if (left) left->retain();
if (right) right->retain();
}
/// isMutable - Returns true if the left and right subtree references
/// (as well as height) can be changed. If this method returns false,
/// the tree is truly immutable. Trees returned from an ImutAVLFactory
/// object should always have this method return true. Further, if this
/// method returns false for an instance of ImutAVLTree, all subtrees
/// will also have this method return false. The converse is not true.
bool isMutable() const { return IsMutable; }
/// hasCachedDigest - Returns true if the digest for this tree is cached.
/// This can only be true if the tree is immutable.
bool hasCachedDigest() const { return IsDigestCached; }
//===----------------------------------------------------===//
// Mutating operations. A tree root can be manipulated as
// long as its reference has not "escaped" from internal
// methods of a factory object (see below). When a tree
// pointer is externally viewable by client code, the
// internal "mutable bit" is cleared to mark the tree
// immutable. Note that a tree that still has its mutable
// bit set may have children (subtrees) that are themselves
// immutable.
//===----------------------------------------------------===//
/// markImmutable - Clears the mutable flag for a tree. After this happens,
/// it is an error to call setLeft(), setRight(), and setHeight().
void markImmutable() {
assert(isMutable() && "Mutable flag already removed.");
IsMutable = false;
}
/// markedCachedDigest - Clears the NoCachedDigest flag for a tree.
void markedCachedDigest() {
assert(!hasCachedDigest() && "NoCachedDigest flag already removed.");
IsDigestCached = true;
}
/// setHeight - Changes the height of the tree. Used internally by
/// ImutAVLFactory.
void setHeight(unsigned h) {
assert(isMutable() && "Only a mutable tree can have its height changed.");
height = h;
}
static uint32_t computeDigest(ImutAVLTree *L, ImutAVLTree *R,
value_type_ref V) {
uint32_t digest = 0;
if (L)
digest += L->computeDigest();
// Compute digest of stored data.
FoldingSetNodeID ID;
ImutInfo::Profile(ID,V);
digest += ID.ComputeHash();
if (R)
digest += R->computeDigest();
return digest;
}
uint32_t computeDigest() {
// Check the lowest bit to determine if digest has actually been
// pre-computed.
if (hasCachedDigest())
return digest;
uint32_t X = computeDigest(getLeft(), getRight(), getValue());
digest = X;
markedCachedDigest();
return X;
}
//===----------------------------------------------------===//
// Reference count operations.
//===----------------------------------------------------===//
public:
void retain() { ++refCount; }
void release() {
assert(refCount > 0);
if (--refCount == 0)
destroy();
}
void destroy() {
if (left)
left->release();
if (right)
right->release();
if (IsCanonicalized) {
if (next)
next->prev = prev;
if (prev)
prev->next = next;
else
factory->Cache[factory->maskCacheIndex(computeDigest())] = next;
}
// We need to clear the mutability bit in case we are
// destroying the node as part of a sweep in ImutAVLFactory::recoverNodes().
IsMutable = false;
factory->freeNodes.push_back(this);
}
};
//===----------------------------------------------------------------------===//
// Immutable AVL-Tree Factory class.
//===----------------------------------------------------------------------===//
template <typename ImutInfo >
class ImutAVLFactory {
friend class ImutAVLTree<ImutInfo>;
using TreeTy = ImutAVLTree<ImutInfo>;
using value_type_ref = typename TreeTy::value_type_ref;
using key_type_ref = typename TreeTy::key_type_ref;
using CacheTy = DenseMap<unsigned, TreeTy*>;
CacheTy Cache;
uintptr_t Allocator;
std::vector<TreeTy*> createdNodes;
std::vector<TreeTy*> freeNodes;
bool ownsAllocator() const {
return (Allocator & 0x1) == 0;
}
BumpPtrAllocator& getAllocator() const {
return *reinterpret_cast<BumpPtrAllocator*>(Allocator & ~0x1);
}
//===--------------------------------------------------===//
// Public interface.
//===--------------------------------------------------===//
public:
ImutAVLFactory()
: Allocator(reinterpret_cast<uintptr_t>(new BumpPtrAllocator())) {}
ImutAVLFactory(BumpPtrAllocator& Alloc)
: Allocator(reinterpret_cast<uintptr_t>(&Alloc) | 0x1) {}
~ImutAVLFactory() {
if (ownsAllocator()) delete &getAllocator();
}
TreeTy* add(TreeTy* T, value_type_ref V) {
T = add_internal(V,T);
markImmutable(T);
recoverNodes();
return T;
}
TreeTy* remove(TreeTy* T, key_type_ref V) {
T = remove_internal(V,T);
markImmutable(T);
recoverNodes();
return T;
}
TreeTy* getEmptyTree() const { return nullptr; }
protected:
//===--------------------------------------------------===//
// A bunch of quick helper functions used for reasoning
// about the properties of trees and their children.
// These have succinct names so that the balancing code
// is as terse (and readable) as possible.
//===--------------------------------------------------===//
bool isEmpty(TreeTy* T) const { return !T; }
unsigned getHeight(TreeTy* T) const { return T ? T->getHeight() : 0; }
TreeTy* getLeft(TreeTy* T) const { return T->getLeft(); }
TreeTy* getRight(TreeTy* T) const { return T->getRight(); }
value_type_ref getValue(TreeTy* T) const { return T->value; }
// Make sure the index is not the Tombstone or Entry key of the DenseMap.
static unsigned maskCacheIndex(unsigned I) { return (I & ~0x02); }
unsigned incrementHeight(TreeTy* L, TreeTy* R) const {
unsigned hl = getHeight(L);
unsigned hr = getHeight(R);
return (hl > hr ? hl : hr) + 1;
}
static bool compareTreeWithSection(TreeTy* T,
typename TreeTy::iterator& TI,
typename TreeTy::iterator& TE) {
typename TreeTy::iterator I = T->begin(), E = T->end();
for ( ; I!=E ; ++I, ++TI) {
if (TI == TE || !I->isElementEqual(&*TI))
return false;
}
return true;
}
//===--------------------------------------------------===//
// "createNode" is used to generate new tree roots that link
// to other trees. The functon may also simply move links
// in an existing root if that root is still marked mutable.
// This is necessary because otherwise our balancing code
// would leak memory as it would create nodes that are
// then discarded later before the finished tree is
// returned to the caller.
//===--------------------------------------------------===//
TreeTy* createNode(TreeTy* L, value_type_ref V, TreeTy* R) {
BumpPtrAllocator& A = getAllocator();
TreeTy* T;
if (!freeNodes.empty()) {
T = freeNodes.back();
freeNodes.pop_back();
assert(T != L);
assert(T != R);
} else {
T = (TreeTy*) A.Allocate<TreeTy>();
}
new (T) TreeTy(this, L, R, V, incrementHeight(L,R));
createdNodes.push_back(T);
return T;
}
TreeTy* createNode(TreeTy* newLeft, TreeTy* oldTree, TreeTy* newRight) {
return createNode(newLeft, getValue(oldTree), newRight);
}
void recoverNodes() {
for (unsigned i = 0, n = createdNodes.size(); i < n; ++i) {
TreeTy *N = createdNodes[i];
if (N->isMutable() && N->refCount == 0)
N->destroy();
}
createdNodes.clear();
}
/// balanceTree - Used by add_internal and remove_internal to
/// balance a newly created tree.
TreeTy* balanceTree(TreeTy* L, value_type_ref V, TreeTy* R) {
unsigned hl = getHeight(L);
unsigned hr = getHeight(R);
if (hl > hr + 2) {
assert(!isEmpty(L) && "Left tree cannot be empty to have a height >= 2");
TreeTy *LL = getLeft(L);
TreeTy *LR = getRight(L);
if (getHeight(LL) >= getHeight(LR))
return createNode(LL, L, createNode(LR,V,R));
assert(!isEmpty(LR) && "LR cannot be empty because it has a height >= 1");
TreeTy *LRL = getLeft(LR);
TreeTy *LRR = getRight(LR);
return createNode(createNode(LL,L,LRL), LR, createNode(LRR,V,R));
}
if (hr > hl + 2) {
assert(!isEmpty(R) && "Right tree cannot be empty to have a height >= 2");
TreeTy *RL = getLeft(R);
TreeTy *RR = getRight(R);
if (getHeight(RR) >= getHeight(RL))
return createNode(createNode(L,V,RL), R, RR);
assert(!isEmpty(RL) && "RL cannot be empty because it has a height >= 1");
TreeTy *RLL = getLeft(RL);
TreeTy *RLR = getRight(RL);
return createNode(createNode(L,V,RLL), RL, createNode(RLR,R,RR));
}
return createNode(L,V,R);
}
/// add_internal - Creates a new tree that includes the specified
/// data and the data from the original tree. If the original tree
/// already contained the data item, the original tree is returned.
TreeTy* add_internal(value_type_ref V, TreeTy* T) {
if (isEmpty(T))
return createNode(T, V, T);
assert(!T->isMutable());
key_type_ref K = ImutInfo::KeyOfValue(V);
key_type_ref KCurrent = ImutInfo::KeyOfValue(getValue(T));
if (ImutInfo::isEqual(K,KCurrent))
return createNode(getLeft(T), V, getRight(T));
else if (ImutInfo::isLess(K,KCurrent))
return balanceTree(add_internal(V, getLeft(T)), getValue(T), getRight(T));
else
return balanceTree(getLeft(T), getValue(T), add_internal(V, getRight(T)));
}
/// remove_internal - Creates a new tree that includes all the data
/// from the original tree except the specified data. If the
/// specified data did not exist in the original tree, the original
/// tree is returned.
TreeTy* remove_internal(key_type_ref K, TreeTy* T) {
if (isEmpty(T))
return T;
assert(!T->isMutable());
key_type_ref KCurrent = ImutInfo::KeyOfValue(getValue(T));
if (ImutInfo::isEqual(K,KCurrent)) {
return combineTrees(getLeft(T), getRight(T));
} else if (ImutInfo::isLess(K,KCurrent)) {
return balanceTree(remove_internal(K, getLeft(T)),
getValue(T), getRight(T));
} else {
return balanceTree(getLeft(T), getValue(T),
remove_internal(K, getRight(T)));
}
}
TreeTy* combineTrees(TreeTy* L, TreeTy* R) {
if (isEmpty(L))
return R;
if (isEmpty(R))
return L;
TreeTy* OldNode;
TreeTy* newRight = removeMinBinding(R,OldNode);
return balanceTree(L, getValue(OldNode), newRight);
}
TreeTy* removeMinBinding(TreeTy* T, TreeTy*& Noderemoved) {
assert(!isEmpty(T));
if (isEmpty(getLeft(T))) {
Noderemoved = T;
return getRight(T);
}
return balanceTree(removeMinBinding(getLeft(T), Noderemoved),
getValue(T), getRight(T));
}
/// markImmutable - Clears the mutable bits of a root and all of its
/// descendants.
void markImmutable(TreeTy* T) {
if (!T || !T->isMutable())
return;
T->markImmutable();
markImmutable(getLeft(T));
markImmutable(getRight(T));
}
public:
TreeTy *getCanonicalTree(TreeTy *TNew) {
if (!TNew)
return nullptr;
if (TNew->IsCanonicalized)
return TNew;
// Search the hashtable for another tree with the same digest, and
// if find a collision compare those trees by their contents.
unsigned digest = TNew->computeDigest();
TreeTy *&entry = Cache[maskCacheIndex(digest)];
do {
if (!entry)
break;
for (TreeTy *T = entry ; T != nullptr; T = T->next) {
// Compare the Contents('T') with Contents('TNew')
typename TreeTy::iterator TI = T->begin(), TE = T->end();
if (!compareTreeWithSection(TNew, TI, TE))
continue;
if (TI != TE)
continue; // T has more contents than TNew.
// Trees did match! Return 'T'.
if (TNew->refCount == 0)
TNew->destroy();
return T;
}
entry->prev = TNew;
TNew->next = entry;
}
while (false);
entry = TNew;
TNew->IsCanonicalized = true;
return TNew;
}
};
//===----------------------------------------------------------------------===//
// Immutable AVL-Tree Iterators.
//===----------------------------------------------------------------------===//
template <typename ImutInfo>
class ImutAVLTreeGenericIterator
: public std::iterator<std::bidirectional_iterator_tag,
ImutAVLTree<ImutInfo>> {
SmallVector<uintptr_t,20> stack;
public:
enum VisitFlag { VisitedNone=0x0, VisitedLeft=0x1, VisitedRight=0x3,
Flags=0x3 };
using TreeTy = ImutAVLTree<ImutInfo>;
ImutAVLTreeGenericIterator() = default;
ImutAVLTreeGenericIterator(const TreeTy *Root) {
if (Root) stack.push_back(reinterpret_cast<uintptr_t>(Root));
}
TreeTy &operator*() const {
assert(!stack.empty());
return *reinterpret_cast<TreeTy *>(stack.back() & ~Flags);
}
TreeTy *operator->() const { return &*this; }
uintptr_t getVisitState() const {
assert(!stack.empty());
return stack.back() & Flags;
}
bool atEnd() const { return stack.empty(); }
bool atBeginning() const {
return stack.size() == 1 && getVisitState() == VisitedNone;
}
void skipToParent() {
assert(!stack.empty());
stack.pop_back();
if (stack.empty())
return;
switch (getVisitState()) {
case VisitedNone:
stack.back() |= VisitedLeft;
break;
case VisitedLeft:
stack.back() |= VisitedRight;
break;
default:
llvm_unreachable("Unreachable.");
}
}
bool operator==(const ImutAVLTreeGenericIterator &x) const {
return stack == x.stack;
}
bool operator!=(const ImutAVLTreeGenericIterator &x) const {
return !(*this == x);
}
ImutAVLTreeGenericIterator &operator++() {
assert(!stack.empty());
TreeTy* Current = reinterpret_cast<TreeTy*>(stack.back() & ~Flags);
assert(Current);
switch (getVisitState()) {
case VisitedNone:
if (TreeTy* L = Current->getLeft())
stack.push_back(reinterpret_cast<uintptr_t>(L));
else
stack.back() |= VisitedLeft;
break;
case VisitedLeft:
if (TreeTy* R = Current->getRight())
stack.push_back(reinterpret_cast<uintptr_t>(R));
else
stack.back() |= VisitedRight;
break;
case VisitedRight:
skipToParent();
break;
default:
llvm_unreachable("Unreachable.");
}
return *this;
}
ImutAVLTreeGenericIterator &operator--() {
assert(!stack.empty());
TreeTy* Current = reinterpret_cast<TreeTy*>(stack.back() & ~Flags);
assert(Current);
switch (getVisitState()) {
case VisitedNone:
stack.pop_back();
break;
case VisitedLeft:
stack.back() &= ~Flags; // Set state to "VisitedNone."
if (TreeTy* L = Current->getLeft())
stack.push_back(reinterpret_cast<uintptr_t>(L) | VisitedRight);
break;
case VisitedRight:
stack.back() &= ~Flags;
stack.back() |= VisitedLeft;
if (TreeTy* R = Current->getRight())
stack.push_back(reinterpret_cast<uintptr_t>(R) | VisitedRight);
break;
default:
llvm_unreachable("Unreachable.");
}
return *this;
}
};
template <typename ImutInfo>
class ImutAVLTreeInOrderIterator
: public std::iterator<std::bidirectional_iterator_tag,
ImutAVLTree<ImutInfo>> {
using InternalIteratorTy = ImutAVLTreeGenericIterator<ImutInfo>;
InternalIteratorTy InternalItr;
public:
using TreeTy = ImutAVLTree<ImutInfo>;
ImutAVLTreeInOrderIterator(const TreeTy* Root) : InternalItr(Root) {
if (Root)
++*this; // Advance to first element.
}
ImutAVLTreeInOrderIterator() : InternalItr() {}
bool operator==(const ImutAVLTreeInOrderIterator &x) const {
return InternalItr == x.InternalItr;
}
bool operator!=(const ImutAVLTreeInOrderIterator &x) const {
return !(*this == x);
}
TreeTy &operator*() const { return *InternalItr; }
TreeTy *operator->() const { return &*InternalItr; }
ImutAVLTreeInOrderIterator &operator++() {
do ++InternalItr;
while (!InternalItr.atEnd() &&
InternalItr.getVisitState() != InternalIteratorTy::VisitedLeft);
return *this;
}
ImutAVLTreeInOrderIterator &operator--() {
do --InternalItr;
while (!InternalItr.atBeginning() &&
InternalItr.getVisitState() != InternalIteratorTy::VisitedLeft);
return *this;
}
void skipSubTree() {
InternalItr.skipToParent();
while (!InternalItr.atEnd() &&
InternalItr.getVisitState() != InternalIteratorTy::VisitedLeft)
++InternalItr;
}
};
/// Generic iterator that wraps a T::TreeTy::iterator and exposes
/// iterator::getValue() on dereference.
template <typename T>
struct ImutAVLValueIterator
: iterator_adaptor_base<
ImutAVLValueIterator<T>, typename T::TreeTy::iterator,
typename std::iterator_traits<
typename T::TreeTy::iterator>::iterator_category,
const typename T::value_type> {
ImutAVLValueIterator() = default;
explicit ImutAVLValueIterator(typename T::TreeTy *Tree)
: ImutAVLValueIterator::iterator_adaptor_base(Tree) {}
typename ImutAVLValueIterator::reference operator*() const {
return this->I->getValue();
}
};
//===----------------------------------------------------------------------===//
// Trait classes for Profile information.
//===----------------------------------------------------------------------===//
/// Generic profile template. The default behavior is to invoke the
/// profile method of an object. Specializations for primitive integers
/// and generic handling of pointers is done below.
template <typename T>
struct ImutProfileInfo {
using value_type = const T;
using value_type_ref = const T&;
static void Profile(FoldingSetNodeID &ID, value_type_ref X) {
FoldingSetTrait<T>::Profile(X,ID);
}
};
/// Profile traits for integers.
template <typename T>
struct ImutProfileInteger {
using value_type = const T;
using value_type_ref = const T&;
static void Profile(FoldingSetNodeID &ID, value_type_ref X) {
ID.AddInteger(X);
}
};
#define PROFILE_INTEGER_INFO(X)\
template<> struct ImutProfileInfo<X> : ImutProfileInteger<X> {};
PROFILE_INTEGER_INFO(char)
PROFILE_INTEGER_INFO(unsigned char)
PROFILE_INTEGER_INFO(short)
PROFILE_INTEGER_INFO(unsigned short)
PROFILE_INTEGER_INFO(unsigned)
PROFILE_INTEGER_INFO(signed)
PROFILE_INTEGER_INFO(long)
PROFILE_INTEGER_INFO(unsigned long)
PROFILE_INTEGER_INFO(long long)
PROFILE_INTEGER_INFO(unsigned long long)
#undef PROFILE_INTEGER_INFO
/// Profile traits for booleans.
template <>
struct ImutProfileInfo<bool> {
using value_type = const bool;
using value_type_ref = const bool&;
static void Profile(FoldingSetNodeID &ID, value_type_ref X) {
ID.AddBoolean(X);
}
};
/// Generic profile trait for pointer types. We treat pointers as
/// references to unique objects.
template <typename T>
struct ImutProfileInfo<T*> {
using value_type = const T*;
using value_type_ref = value_type;
static void Profile(FoldingSetNodeID &ID, value_type_ref X) {
ID.AddPointer(X);
}
};
//===----------------------------------------------------------------------===//
// Trait classes that contain element comparison operators and type
// definitions used by ImutAVLTree, ImmutableSet, and ImmutableMap. These
// inherit from the profile traits (ImutProfileInfo) to include operations
// for element profiling.
//===----------------------------------------------------------------------===//
/// ImutContainerInfo - Generic definition of comparison operations for
/// elements of immutable containers that defaults to using
/// std::equal_to<> and std::less<> to perform comparison of elements.
template <typename T>
struct ImutContainerInfo : public ImutProfileInfo<T> {
using value_type = typename ImutProfileInfo<T>::value_type;
using value_type_ref = typename ImutProfileInfo<T>::value_type_ref;
using key_type = value_type;
using key_type_ref = value_type_ref;
using data_type = bool;
using data_type_ref = bool;
static key_type_ref KeyOfValue(value_type_ref D) { return D; }
static data_type_ref DataOfValue(value_type_ref) { return true; }
static bool isEqual(key_type_ref LHS, key_type_ref RHS) {
return std::equal_to<key_type>()(LHS,RHS);
}
static bool isLess(key_type_ref LHS, key_type_ref RHS) {
return std::less<key_type>()(LHS,RHS);
}
static bool isDataEqual(data_type_ref, data_type_ref) { return true; }
};
/// ImutContainerInfo - Specialization for pointer values to treat pointers
/// as references to unique objects. Pointers are thus compared by
/// their addresses.
template <typename T>
struct ImutContainerInfo<T*> : public ImutProfileInfo<T*> {
using value_type = typename ImutProfileInfo<T*>::value_type;
using value_type_ref = typename ImutProfileInfo<T*>::value_type_ref;
using key_type = value_type;
using key_type_ref = value_type_ref;
using data_type = bool;
using data_type_ref = bool;
static key_type_ref KeyOfValue(value_type_ref D) { return D; }
static data_type_ref DataOfValue(value_type_ref) { return true; }
static bool isEqual(key_type_ref LHS, key_type_ref RHS) { return LHS == RHS; }
static bool isLess(key_type_ref LHS, key_type_ref RHS) { return LHS < RHS; }
static bool isDataEqual(data_type_ref, data_type_ref) { return true; }
};
//===----------------------------------------------------------------------===//
// Immutable Set
//===----------------------------------------------------------------------===//
template <typename ValT, typename ValInfo = ImutContainerInfo<ValT>>
class ImmutableSet {
public:
using value_type = typename ValInfo::value_type;
using value_type_ref = typename ValInfo::value_type_ref;
using TreeTy = ImutAVLTree<ValInfo>;
private:
TreeTy *Root;
public:
/// Constructs a set from a pointer to a tree root. In general one
/// should use a Factory object to create sets instead of directly
/// invoking the constructor, but there are cases where make this
/// constructor public is useful.
explicit ImmutableSet(TreeTy* R) : Root(R) {
if (Root) { Root->retain(); }
}
ImmutableSet(const ImmutableSet &X) : Root(X.Root) {
if (Root) { Root->retain(); }
}
~ImmutableSet() {
if (Root) { Root->release(); }
}
ImmutableSet &operator=(const ImmutableSet &X) {
if (Root != X.Root) {
if (X.Root) { X.Root->retain(); }
if (Root) { Root->release(); }
Root = X.Root;
}
return *this;
}
class Factory {
typename TreeTy::Factory F;
const bool Canonicalize;
public:
Factory(bool canonicalize = true)
: Canonicalize(canonicalize) {}
Factory(BumpPtrAllocator& Alloc, bool canonicalize = true)
: F(Alloc), Canonicalize(canonicalize) {}
Factory(const Factory& RHS) = delete;
void operator=(const Factory& RHS) = delete;
/// getEmptySet - Returns an immutable set that contains no elements.
ImmutableSet getEmptySet() {
return ImmutableSet(F.getEmptyTree());
}
/// add - Creates a new immutable set that contains all of the values
/// of the original set with the addition of the specified value. If
/// the original set already included the value, then the original set is
/// returned and no memory is allocated. The time and space complexity
/// of this operation is logarithmic in the size of the original set.
/// The memory allocated to represent the set is released when the
/// factory object that created the set is destroyed.
LLVM_NODISCARD ImmutableSet add(ImmutableSet Old, value_type_ref V) {
TreeTy *NewT = F.add(Old.Root, V);
return ImmutableSet(Canonicalize ? F.getCanonicalTree(NewT) : NewT);
}
/// remove - Creates a new immutable set that contains all of the values
/// of the original set with the exception of the specified value. If
/// the original set did not contain the value, the original set is
/// returned and no memory is allocated. The time and space complexity
/// of this operation is logarithmic in the size of the original set.
/// The memory allocated to represent the set is released when the
/// factory object that created the set is destroyed.
LLVM_NODISCARD ImmutableSet remove(ImmutableSet Old, value_type_ref V) {
TreeTy *NewT = F.remove(Old.Root, V);
return ImmutableSet(Canonicalize ? F.getCanonicalTree(NewT) : NewT);
}
BumpPtrAllocator& getAllocator() { return F.getAllocator(); }
typename TreeTy::Factory *getTreeFactory() const {
return const_cast<typename TreeTy::Factory *>(&F);
}
};
friend class Factory;
/// Returns true if the set contains the specified value.
bool contains(value_type_ref V) const {
return Root ? Root->contains(V) : false;
}
bool operator==(const ImmutableSet &RHS) const {
return Root && RHS.Root ? Root->isEqual(*RHS.Root) : Root == RHS.Root;
}
bool operator!=(const ImmutableSet &RHS) const {
return Root && RHS.Root ? Root->isNotEqual(*RHS.Root) : Root != RHS.Root;
}
TreeTy *getRoot() {
if (Root) { Root->retain(); }
return Root;
}
TreeTy *getRootWithoutRetain() const {
return Root;
}
/// isEmpty - Return true if the set contains no elements.
bool isEmpty() const { return !Root; }
/// isSingleton - Return true if the set contains exactly one element.
/// This method runs in constant time.
bool isSingleton() const { return getHeight() == 1; }
template <typename Callback>
void foreach(Callback& C) { if (Root) Root->foreach(C); }
template <typename Callback>
void foreach() { if (Root) { Callback C; Root->foreach(C); } }
//===--------------------------------------------------===//
// Iterators.
//===--------------------------------------------------===//
using iterator = ImutAVLValueIterator<ImmutableSet>;
iterator begin() const { return iterator(Root); }
iterator end() const { return iterator(); }
//===--------------------------------------------------===//
// Utility methods.
//===--------------------------------------------------===//
unsigned getHeight() const { return Root ? Root->getHeight() : 0; }
static void Profile(FoldingSetNodeID &ID, const ImmutableSet &S) {
ID.AddPointer(S.Root);
}
void Profile(FoldingSetNodeID &ID) const { return Profile(ID, *this); }
//===--------------------------------------------------===//
// For testing.
//===--------------------------------------------------===//
void validateTree() const { if (Root) Root->validateTree(); }
};
// NOTE: This may some day replace the current ImmutableSet.
template <typename ValT, typename ValInfo = ImutContainerInfo<ValT>>
class ImmutableSetRef {
public:
using value_type = typename ValInfo::value_type;
using value_type_ref = typename ValInfo::value_type_ref;
using TreeTy = ImutAVLTree<ValInfo>;
using FactoryTy = typename TreeTy::Factory;
private:
TreeTy *Root;
FactoryTy *Factory;
public:
/// Constructs a set from a pointer to a tree root. In general one
/// should use a Factory object to create sets instead of directly
/// invoking the constructor, but there are cases where make this
/// constructor public is useful.
explicit ImmutableSetRef(TreeTy* R, FactoryTy *F)
: Root(R),
Factory(F) {
if (Root) { Root->retain(); }
}
ImmutableSetRef(const ImmutableSetRef &X)
: Root(X.Root),
Factory(X.Factory) {
if (Root) { Root->retain(); }
}
~ImmutableSetRef() {
if (Root) { Root->release(); }
}
ImmutableSetRef &operator=(const ImmutableSetRef &X) {
if (Root != X.Root) {
if (X.Root) { X.Root->retain(); }
if (Root) { Root->release(); }
Root = X.Root;
Factory = X.Factory;
}
return *this;
}
static ImmutableSetRef getEmptySet(FactoryTy *F) {
return ImmutableSetRef(0, F);
}
ImmutableSetRef add(value_type_ref V) {
return ImmutableSetRef(Factory->add(Root, V), Factory);
}
ImmutableSetRef remove(value_type_ref V) {
return ImmutableSetRef(Factory->remove(Root, V), Factory);
}
/// Returns true if the set contains the specified value.
bool contains(value_type_ref V) const {
return Root ? Root->contains(V) : false;
}
ImmutableSet<ValT> asImmutableSet(bool canonicalize = true) const {
return ImmutableSet<ValT>(canonicalize ?
Factory->getCanonicalTree(Root) : Root);
}
TreeTy *getRootWithoutRetain() const {
return Root;
}
bool operator==(const ImmutableSetRef &RHS) const {
return Root && RHS.Root ? Root->isEqual(*RHS.Root) : Root == RHS.Root;
}
bool operator!=(const ImmutableSetRef &RHS) const {
return Root && RHS.Root ? Root->isNotEqual(*RHS.Root) : Root != RHS.Root;
}
/// isEmpty - Return true if the set contains no elements.
bool isEmpty() const { return !Root; }
/// isSingleton - Return true if the set contains exactly one element.
/// This method runs in constant time.
bool isSingleton() const { return getHeight() == 1; }
//===--------------------------------------------------===//
// Iterators.
//===--------------------------------------------------===//
using iterator = ImutAVLValueIterator<ImmutableSetRef>;
iterator begin() const { return iterator(Root); }
iterator end() const { return iterator(); }
//===--------------------------------------------------===//
// Utility methods.
//===--------------------------------------------------===//
unsigned getHeight() const { return Root ? Root->getHeight() : 0; }
static void Profile(FoldingSetNodeID &ID, const ImmutableSetRef &S) {
ID.AddPointer(S.Root);
}
void Profile(FoldingSetNodeID &ID) const { return Profile(ID, *this); }
//===--------------------------------------------------===//
// For testing.
//===--------------------------------------------------===//
void validateTree() const { if (Root) Root->validateTree(); }
};
} // end namespace llvm
#endif // LLVM_ADT_IMMUTABLESET_H
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