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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
//
//===----------------------------------------------------------------------===//
///
/// \file
/// 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/IntrusiveRefCntPtr.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); }
/// validateTree - A utility method that checks that the balancing and
/// ordering invariants of the tree are satisfied. 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);
}
};
template <typename ImutInfo>
struct IntrusiveRefCntPtrInfo<ImutAVLTree<ImutInfo>> {
static void retain(ImutAVLTree<ImutInfo> *Tree) { Tree->retain(); }
static void release(ImutAVLTree<ImutInfo> *Tree) { Tree->release(); }
};
//===----------------------------------------------------------------------===//
// 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 function 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 {
SmallVector<uintptr_t,20> stack;
public:
using iterator_category = std::bidirectional_iterator_tag;
using value_type = ImutAVLTree<ImutInfo>;
using difference_type = std::ptrdiff_t;
using pointer = value_type *;
using reference = value_type &;
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 {
using InternalIteratorTy = ImutAVLTreeGenericIterator<ImutInfo>;
InternalIteratorTy InternalItr;
public:
using iterator_category = std::bidirectional_iterator_tag;
using value_type = ImutAVLTree<ImutInfo>;
using difference_type = std::ptrdiff_t;
using pointer = value_type *;
using reference = value_type &;
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:
IntrusiveRefCntPtr<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) {}
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.
[[nodiscard]] ImmutableSet add(ImmutableSet Old, value_type_ref V) {
TreeTy *NewT = F.add(Old.Root.get(), 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.
[[nodiscard]] ImmutableSet remove(ImmutableSet Old, value_type_ref V) {
TreeTy *NewT = F.remove(Old.Root.get(), 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.get()) : Root == RHS.Root;
}
bool operator!=(const ImmutableSet &RHS) const {
return Root && RHS.Root ? Root->isNotEqual(*RHS.Root.get())
: Root != RHS.Root;
}
TreeTy *getRoot() {
if (Root) { Root->retain(); }
return Root.get();
}
TreeTy *getRootWithoutRetain() const { return Root.get(); }
/// 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<ImmutableSet>;
iterator begin() const { return iterator(Root.get()); }
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.get());
}
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:
IntrusiveRefCntPtr<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.
ImmutableSetRef(TreeTy *R, FactoryTy *F) : Root(R), Factory(F) {}
static ImmutableSetRef getEmptySet(FactoryTy *F) {
return ImmutableSetRef(0, F);
}
ImmutableSetRef add(value_type_ref V) {
return ImmutableSetRef(Factory->add(Root.get(), V), Factory);
}
ImmutableSetRef remove(value_type_ref V) {
return ImmutableSetRef(Factory->remove(Root.get(), 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.get()) : Root.get());
}
TreeTy *getRootWithoutRetain() const { return Root.get(); }
bool operator==(const ImmutableSetRef &RHS) const {
return Root && RHS.Root ? Root->isEqual(*RHS.Root.get()) : Root == RHS.Root;
}
bool operator!=(const ImmutableSetRef &RHS) const {
return Root && RHS.Root ? Root->isNotEqual(*RHS.Root.get())
: 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.get()); }
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.get());
}
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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