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authorvitalyisaev <vitalyisaev@yandex-team.com>2023-06-29 10:00:50 +0300
committervitalyisaev <vitalyisaev@yandex-team.com>2023-06-29 10:00:50 +0300
commit6ffe9e53658409f212834330e13564e4952558f6 (patch)
tree85b1e00183517648b228aafa7c8fb07f5276f419 /contrib/libs/llvm14/include/llvm/ADT/EquivalenceClasses.h
parent726057070f9c5a91fc10fde0d5024913d10f1ab9 (diff)
downloadydb-6ffe9e53658409f212834330e13564e4952558f6.tar.gz
YQ Connector: support managed ClickHouse
Со стороны dqrun можно обратиться к инстансу коннектора, который работает на streaming стенде, и извлечь данные из облачного CH.
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+#pragma once
+
+#ifdef __GNUC__
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wunused-parameter"
+#endif
+
+//===- llvm/ADT/EquivalenceClasses.h - Generic Equiv. Classes ---*- 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
+/// Generic implementation of equivalence classes through the use Tarjan's
+/// efficient union-find algorithm.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_ADT_EQUIVALENCECLASSES_H
+#define LLVM_ADT_EQUIVALENCECLASSES_H
+
+#include <cassert>
+#include <cstddef>
+#include <cstdint>
+#include <iterator>
+#include <set>
+
+namespace llvm {
+
+/// EquivalenceClasses - This represents a collection of equivalence classes and
+/// supports three efficient operations: insert an element into a class of its
+/// own, union two classes, and find the class for a given element. In
+/// addition to these modification methods, it is possible to iterate over all
+/// of the equivalence classes and all of the elements in a class.
+///
+/// This implementation is an efficient implementation that only stores one copy
+/// of the element being indexed per entry in the set, and allows any arbitrary
+/// type to be indexed (as long as it can be ordered with operator< or a
+/// comparator is provided).
+///
+/// Here is a simple example using integers:
+///
+/// \code
+/// EquivalenceClasses<int> EC;
+/// EC.unionSets(1, 2); // insert 1, 2 into the same set
+/// EC.insert(4); EC.insert(5); // insert 4, 5 into own sets
+/// EC.unionSets(5, 1); // merge the set for 1 with 5's set.
+///
+/// for (EquivalenceClasses<int>::iterator I = EC.begin(), E = EC.end();
+/// I != E; ++I) { // Iterate over all of the equivalence sets.
+/// if (!I->isLeader()) continue; // Ignore non-leader sets.
+/// for (EquivalenceClasses<int>::member_iterator MI = EC.member_begin(I);
+/// MI != EC.member_end(); ++MI) // Loop over members in this set.
+/// cerr << *MI << " "; // Print member.
+/// cerr << "\n"; // Finish set.
+/// }
+/// \endcode
+///
+/// This example prints:
+/// 4
+/// 5 1 2
+///
+template <class ElemTy, class Compare = std::less<ElemTy>>
+class EquivalenceClasses {
+ /// ECValue - The EquivalenceClasses data structure is just a set of these.
+ /// Each of these represents a relation for a value. First it stores the
+ /// value itself, which provides the ordering that the set queries. Next, it
+ /// provides a "next pointer", which is used to enumerate all of the elements
+ /// in the unioned set. Finally, it defines either a "end of list pointer" or
+ /// "leader pointer" depending on whether the value itself is a leader. A
+ /// "leader pointer" points to the node that is the leader for this element,
+ /// if the node is not a leader. A "end of list pointer" points to the last
+ /// node in the list of members of this list. Whether or not a node is a
+ /// leader is determined by a bit stolen from one of the pointers.
+ class ECValue {
+ friend class EquivalenceClasses;
+
+ mutable const ECValue *Leader, *Next;
+ ElemTy Data;
+
+ // ECValue ctor - Start out with EndOfList pointing to this node, Next is
+ // Null, isLeader = true.
+ ECValue(const ElemTy &Elt)
+ : Leader(this), Next((ECValue*)(intptr_t)1), Data(Elt) {}
+
+ const ECValue *getLeader() const {
+ if (isLeader()) return this;
+ if (Leader->isLeader()) return Leader;
+ // Path compression.
+ return Leader = Leader->getLeader();
+ }
+
+ const ECValue *getEndOfList() const {
+ assert(isLeader() && "Cannot get the end of a list for a non-leader!");
+ return Leader;
+ }
+
+ void setNext(const ECValue *NewNext) const {
+ assert(getNext() == nullptr && "Already has a next pointer!");
+ Next = (const ECValue*)((intptr_t)NewNext | (intptr_t)isLeader());
+ }
+
+ public:
+ ECValue(const ECValue &RHS) : Leader(this), Next((ECValue*)(intptr_t)1),
+ Data(RHS.Data) {
+ // Only support copying of singleton nodes.
+ assert(RHS.isLeader() && RHS.getNext() == nullptr && "Not a singleton!");
+ }
+
+ bool isLeader() const { return (intptr_t)Next & 1; }
+ const ElemTy &getData() const { return Data; }
+
+ const ECValue *getNext() const {
+ return (ECValue*)((intptr_t)Next & ~(intptr_t)1);
+ }
+ };
+
+ /// A wrapper of the comparator, to be passed to the set.
+ struct ECValueComparator {
+ using is_transparent = void;
+
+ ECValueComparator() : compare(Compare()) {}
+
+ bool operator()(const ECValue &lhs, const ECValue &rhs) const {
+ return compare(lhs.Data, rhs.Data);
+ }
+
+ template <typename T>
+ bool operator()(const T &lhs, const ECValue &rhs) const {
+ return compare(lhs, rhs.Data);
+ }
+
+ template <typename T>
+ bool operator()(const ECValue &lhs, const T &rhs) const {
+ return compare(lhs.Data, rhs);
+ }
+
+ const Compare compare;
+ };
+
+ /// TheMapping - This implicitly provides a mapping from ElemTy values to the
+ /// ECValues, it just keeps the key as part of the value.
+ std::set<ECValue, ECValueComparator> TheMapping;
+
+public:
+ EquivalenceClasses() = default;
+ EquivalenceClasses(const EquivalenceClasses &RHS) {
+ operator=(RHS);
+ }
+
+ const EquivalenceClasses &operator=(const EquivalenceClasses &RHS) {
+ TheMapping.clear();
+ for (iterator I = RHS.begin(), E = RHS.end(); I != E; ++I)
+ if (I->isLeader()) {
+ member_iterator MI = RHS.member_begin(I);
+ member_iterator LeaderIt = member_begin(insert(*MI));
+ for (++MI; MI != member_end(); ++MI)
+ unionSets(LeaderIt, member_begin(insert(*MI)));
+ }
+ return *this;
+ }
+
+ //===--------------------------------------------------------------------===//
+ // Inspection methods
+ //
+
+ /// iterator* - Provides a way to iterate over all values in the set.
+ using iterator = typename std::set<ECValue>::const_iterator;
+
+ iterator begin() const { return TheMapping.begin(); }
+ iterator end() const { return TheMapping.end(); }
+
+ bool empty() const { return TheMapping.empty(); }
+
+ /// member_* Iterate over the members of an equivalence class.
+ class member_iterator;
+ member_iterator member_begin(iterator I) const {
+ // Only leaders provide anything to iterate over.
+ return member_iterator(I->isLeader() ? &*I : nullptr);
+ }
+ member_iterator member_end() const {
+ return member_iterator(nullptr);
+ }
+
+ /// findValue - Return an iterator to the specified value. If it does not
+ /// exist, end() is returned.
+ iterator findValue(const ElemTy &V) const {
+ return TheMapping.find(V);
+ }
+
+ /// getLeaderValue - Return the leader for the specified value that is in the
+ /// set. It is an error to call this method for a value that is not yet in
+ /// the set. For that, call getOrInsertLeaderValue(V).
+ const ElemTy &getLeaderValue(const ElemTy &V) const {
+ member_iterator MI = findLeader(V);
+ assert(MI != member_end() && "Value is not in the set!");
+ return *MI;
+ }
+
+ /// getOrInsertLeaderValue - Return the leader for the specified value that is
+ /// in the set. If the member is not in the set, it is inserted, then
+ /// returned.
+ const ElemTy &getOrInsertLeaderValue(const ElemTy &V) {
+ member_iterator MI = findLeader(insert(V));
+ assert(MI != member_end() && "Value is not in the set!");
+ return *MI;
+ }
+
+ /// getNumClasses - Return the number of equivalence classes in this set.
+ /// Note that this is a linear time operation.
+ unsigned getNumClasses() const {
+ unsigned NC = 0;
+ for (iterator I = begin(), E = end(); I != E; ++I)
+ if (I->isLeader()) ++NC;
+ return NC;
+ }
+
+ //===--------------------------------------------------------------------===//
+ // Mutation methods
+
+ /// insert - Insert a new value into the union/find set, ignoring the request
+ /// if the value already exists.
+ iterator insert(const ElemTy &Data) {
+ return TheMapping.insert(ECValue(Data)).first;
+ }
+
+ /// findLeader - Given a value in the set, return a member iterator for the
+ /// equivalence class it is in. This does the path-compression part that
+ /// makes union-find "union findy". This returns an end iterator if the value
+ /// is not in the equivalence class.
+ member_iterator findLeader(iterator I) const {
+ if (I == TheMapping.end()) return member_end();
+ return member_iterator(I->getLeader());
+ }
+ member_iterator findLeader(const ElemTy &V) const {
+ return findLeader(TheMapping.find(V));
+ }
+
+ /// union - Merge the two equivalence sets for the specified values, inserting
+ /// them if they do not already exist in the equivalence set.
+ member_iterator unionSets(const ElemTy &V1, const ElemTy &V2) {
+ iterator V1I = insert(V1), V2I = insert(V2);
+ return unionSets(findLeader(V1I), findLeader(V2I));
+ }
+ member_iterator unionSets(member_iterator L1, member_iterator L2) {
+ assert(L1 != member_end() && L2 != member_end() && "Illegal inputs!");
+ if (L1 == L2) return L1; // Unifying the same two sets, noop.
+
+ // Otherwise, this is a real union operation. Set the end of the L1 list to
+ // point to the L2 leader node.
+ const ECValue &L1LV = *L1.Node, &L2LV = *L2.Node;
+ L1LV.getEndOfList()->setNext(&L2LV);
+
+ // Update L1LV's end of list pointer.
+ L1LV.Leader = L2LV.getEndOfList();
+
+ // Clear L2's leader flag:
+ L2LV.Next = L2LV.getNext();
+
+ // L2's leader is now L1.
+ L2LV.Leader = &L1LV;
+ return L1;
+ }
+
+ // isEquivalent - Return true if V1 is equivalent to V2. This can happen if
+ // V1 is equal to V2 or if they belong to one equivalence class.
+ bool isEquivalent(const ElemTy &V1, const ElemTy &V2) const {
+ // Fast path: any element is equivalent to itself.
+ if (V1 == V2)
+ return true;
+ auto It = findLeader(V1);
+ return It != member_end() && It == findLeader(V2);
+ }
+
+ class member_iterator {
+ friend class EquivalenceClasses;
+
+ const ECValue *Node;
+
+ public:
+ using iterator_category = std::forward_iterator_tag;
+ using value_type = const ElemTy;
+ using size_type = std::size_t;
+ using difference_type = std::ptrdiff_t;
+ using pointer = value_type *;
+ using reference = value_type &;
+
+ explicit member_iterator() = default;
+ explicit member_iterator(const ECValue *N) : Node(N) {}
+
+ reference operator*() const {
+ assert(Node != nullptr && "Dereferencing end()!");
+ return Node->getData();
+ }
+ pointer operator->() const { return &operator*(); }
+
+ member_iterator &operator++() {
+ assert(Node != nullptr && "++'d off the end of the list!");
+ Node = Node->getNext();
+ return *this;
+ }
+
+ member_iterator operator++(int) { // postincrement operators.
+ member_iterator tmp = *this;
+ ++*this;
+ return tmp;
+ }
+
+ bool operator==(const member_iterator &RHS) const {
+ return Node == RHS.Node;
+ }
+ bool operator!=(const member_iterator &RHS) const {
+ return Node != RHS.Node;
+ }
+ };
+};
+
+} // end namespace llvm
+
+#endif // LLVM_ADT_EQUIVALENCECLASSES_H
+
+#ifdef __GNUC__
+#pragma GCC diagnostic pop
+#endif