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Theodosius/Examples/Theodosius-Usermode/asmjit/core/zonetree.h

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4 years ago
// AsmJit - Machine code generation for C++
//
// * Official AsmJit Home Page: https://asmjit.com
// * Official Github Repository: https://github.com/asmjit/asmjit
//
// Copyright (c) 2008-2020 The AsmJit Authors
//
// This software is provided 'as-is', without any express or implied
// warranty. In no event will the authors be held liable for any damages
// arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented; you must not
// claim that you wrote the original software. If you use this software
// in a product, an acknowledgment in the product documentation would be
// appreciated but is not required.
// 2. Altered source versions must be plainly marked as such, and must not be
// misrepresented as being the original software.
// 3. This notice may not be removed or altered from any source distribution.
#ifndef ASMJIT_CORE_ZONETREE_H_INCLUDED
#define ASMJIT_CORE_ZONETREE_H_INCLUDED
#include "../core/support.h"
ASMJIT_BEGIN_NAMESPACE
//! \addtogroup asmjit_zone
//! \{
// ============================================================================
// [asmjit::ZoneTreeNode]
// ============================================================================
//! RB-Tree node.
//!
//! The color is stored in a least significant bit of the `left` node.
//!
//! WARNING: Always use accessors to access left and right children.
class ZoneTreeNode {
public:
ASMJIT_NONCOPYABLE(ZoneTreeNode)
enum : uintptr_t {
kRedMask = 0x1,
kPtrMask = ~kRedMask
};
uintptr_t _rbNodeData[Globals::kLinkCount];
//! \name Construction & Destruction
//! \{
inline ZoneTreeNode() noexcept
: _rbNodeData { 0, 0 } {}
//! \}
//! \name Accessors
//! \{
inline bool isRed() const noexcept { return static_cast<bool>(_rbNodeData[0] & kRedMask); }
inline bool hasChild(size_t i) const noexcept { return _rbNodeData[i] > kRedMask; }
inline bool hasLeft() const noexcept { return _rbNodeData[0] > kRedMask; }
inline bool hasRight() const noexcept { return _rbNodeData[1] != 0; }
template<typename T = ZoneTreeNode>
inline T* child(size_t i) const noexcept { return static_cast<T*>(_getChild(i)); }
template<typename T = ZoneTreeNode>
inline T* left() const noexcept { return static_cast<T*>(_getLeft()); }
template<typename T = ZoneTreeNode>
inline T* right() const noexcept { return static_cast<T*>(_getRight()); }
//! \}
//! \cond INTERNAL
//! \name Internal
//! \{
inline ZoneTreeNode* _getChild(size_t i) const noexcept { return (ZoneTreeNode*)(_rbNodeData[i] & kPtrMask); }
inline ZoneTreeNode* _getLeft() const noexcept { return (ZoneTreeNode*)(_rbNodeData[0] & kPtrMask); }
inline ZoneTreeNode* _getRight() const noexcept { return (ZoneTreeNode*)(_rbNodeData[1]); }
inline void _setChild(size_t i, ZoneTreeNode* node) noexcept { _rbNodeData[i] = (_rbNodeData[i] & kRedMask) | (uintptr_t)node; }
inline void _setLeft(ZoneTreeNode* node) noexcept { _rbNodeData[0] = (_rbNodeData[0] & kRedMask) | (uintptr_t)node; }
inline void _setRight(ZoneTreeNode* node) noexcept { _rbNodeData[1] = (uintptr_t)node; }
inline void _makeRed() noexcept { _rbNodeData[0] |= kRedMask; }
inline void _makeBlack() noexcept { _rbNodeData[0] &= kPtrMask; }
//! Tests whether the node is RED (RED node must be non-null and must have RED flag set).
static inline bool _isValidRed(ZoneTreeNode* node) noexcept { return node && node->isRed(); }
//! \}
//! \endcond
};
//! RB-Tree node casted to `NodeT`.
template<typename NodeT>
class ZoneTreeNodeT : public ZoneTreeNode {
public:
ASMJIT_NONCOPYABLE(ZoneTreeNodeT)
//! \name Construction & Destruction
//! \{
inline ZoneTreeNodeT() noexcept
: ZoneTreeNode() {}
//! \}
//! \name Accessors
//! \{
inline NodeT* child(size_t i) const noexcept { return static_cast<NodeT*>(_getChild(i)); }
inline NodeT* left() const noexcept { return static_cast<NodeT*>(_getLeft()); }
inline NodeT* right() const noexcept { return static_cast<NodeT*>(_getRight()); }
//! \}
};
// ============================================================================
// [asmjit::ZoneTree]
// ============================================================================
//! RB-Tree.
template<typename NodeT>
class ZoneTree {
public:
ASMJIT_NONCOPYABLE(ZoneTree)
typedef NodeT Node;
NodeT* _root;
//! \name Construction & Destruction
//! \{
inline ZoneTree() noexcept
: _root(nullptr) {}
inline ZoneTree(ZoneTree&& other) noexcept
: _root(other._root) {}
inline void reset() noexcept { _root = nullptr; }
//! \}
//! \name Accessors
//! \{
inline bool empty() const noexcept { return _root == nullptr; }
inline NodeT* root() const noexcept { return static_cast<NodeT*>(_root); }
//! \}
//! \name Utilities
//! \{
inline void swap(ZoneTree& other) noexcept {
std::swap(_root, other._root);
}
template<typename CompareT = Support::Compare<Support::kSortAscending>>
void insert(NodeT* node, const CompareT& cmp = CompareT()) noexcept {
// Node to insert must not contain garbage.
ASMJIT_ASSERT(!node->hasLeft());
ASMJIT_ASSERT(!node->hasRight());
ASMJIT_ASSERT(!node->isRed());
if (!_root) {
_root = node;
return;
}
ZoneTreeNode head; // False root node,
head._setRight(_root); // having root on the right.
ZoneTreeNode* g = nullptr; // Grandparent.
ZoneTreeNode* p = nullptr; // Parent.
ZoneTreeNode* t = &head; // Iterator.
ZoneTreeNode* q = _root; // Query.
size_t dir = 0; // Direction for accessing child nodes.
size_t last = 0; // Not needed to initialize, but makes some tools happy.
node->_makeRed(); // New nodes are always red and violations fixed appropriately.
// Search down the tree.
for (;;) {
if (!q) {
// Insert new node at the bottom.
q = node;
p->_setChild(dir, node);
}
else if (_isValidRed(q->_getLeft()) && _isValidRed(q->_getRight())) {
// Color flip.
q->_makeRed();
q->_getLeft()->_makeBlack();
q->_getRight()->_makeBlack();
}
// Fix red violation.
if (_isValidRed(q) && _isValidRed(p))
t->_setChild(t->_getRight() == g,
q == p->_getChild(last) ? _singleRotate(g, !last) : _doubleRotate(g, !last));
// Stop if found.
if (q == node)
break;
last = dir;
dir = cmp(*static_cast<NodeT*>(q), *static_cast<NodeT*>(node)) < 0;
// Update helpers.
if (g) t = g;
g = p;
p = q;
q = q->_getChild(dir);
}
// Update root and make it black.
_root = static_cast<NodeT*>(head._getRight());
_root->_makeBlack();
}
//! Remove node from RBTree.
template<typename CompareT = Support::Compare<Support::kSortAscending>>
void remove(ZoneTreeNode* node, const CompareT& cmp = CompareT()) noexcept {
ZoneTreeNode head; // False root node,
head._setRight(_root); // having root on the right.
ZoneTreeNode* g = nullptr; // Grandparent.
ZoneTreeNode* p = nullptr; // Parent.
ZoneTreeNode* q = &head; // Query.
ZoneTreeNode* f = nullptr; // Found item.
ZoneTreeNode* gf = nullptr; // Found grandparent.
size_t dir = 1; // Direction (0 or 1).
// Search and push a red down.
while (q->hasChild(dir)) {
size_t last = dir;
// Update helpers.
g = p;
p = q;
q = q->_getChild(dir);
dir = cmp(*static_cast<NodeT*>(q), *static_cast<NodeT*>(node)) < 0;
// Save found node.
if (q == node) {
f = q;
gf = g;
}
// Push the red node down.
if (!_isValidRed(q) && !_isValidRed(q->_getChild(dir))) {
if (_isValidRed(q->_getChild(!dir))) {
ZoneTreeNode* child = _singleRotate(q, dir);
p->_setChild(last, child);
p = child;
}
else if (!_isValidRed(q->_getChild(!dir)) && p->_getChild(!last)) {
ZoneTreeNode* s = p->_getChild(!last);
if (!_isValidRed(s->_getChild(!last)) && !_isValidRed(s->_getChild(last))) {
// Color flip.
p->_makeBlack();
s->_makeRed();
q->_makeRed();
}
else {
size_t dir2 = g->_getRight() == p;
ZoneTreeNode* child = g->_getChild(dir2);
if (_isValidRed(s->_getChild(last))) {
child = _doubleRotate(p, last);
g->_setChild(dir2, child);
}
else if (_isValidRed(s->_getChild(!last))) {
child = _singleRotate(p, last);
g->_setChild(dir2, child);
}
// Ensure correct coloring.
q->_makeRed();
child->_makeRed();
child->_getLeft()->_makeBlack();
child->_getRight()->_makeBlack();
}
}
}
}
// Replace and remove.
ASMJIT_ASSERT(f != nullptr);
ASMJIT_ASSERT(f != &head);
ASMJIT_ASSERT(q != &head);
p->_setChild(p->_getRight() == q,
q->_getChild(q->_getLeft() == nullptr));
// NOTE: The original algorithm used a trick to just copy 'key/value' to
// `f` and mark `q` for deletion. But this is unacceptable here as we
// really want to destroy the passed `node`. So, we have to make sure that
// we have really removed `f` and not `q`.
if (f != q) {
ASMJIT_ASSERT(f != &head);
ASMJIT_ASSERT(f != gf);
ZoneTreeNode* n = gf ? gf : &head;
dir = (n == &head) ? 1 : cmp(*static_cast<NodeT*>(n), *static_cast<NodeT*>(node)) < 0;
for (;;) {
if (n->_getChild(dir) == f) {
n->_setChild(dir, q);
// RAW copy, including the color.
q->_rbNodeData[0] = f->_rbNodeData[0];
q->_rbNodeData[1] = f->_rbNodeData[1];
break;
}
n = n->_getChild(dir);
// Cannot be true as we know that it must reach `f` in few iterations.
ASMJIT_ASSERT(n != nullptr);
dir = cmp(*static_cast<NodeT*>(n), *static_cast<NodeT*>(node)) < 0;
}
}
// Update root and make it black.
_root = static_cast<NodeT*>(head._getRight());
if (_root) _root->_makeBlack();
}
template<typename KeyT, typename CompareT = Support::Compare<Support::kSortAscending>>
ASMJIT_INLINE NodeT* get(const KeyT& key, const CompareT& cmp = CompareT()) const noexcept {
ZoneTreeNode* node = _root;
while (node) {
auto result = cmp(*static_cast<const NodeT*>(node), key);
if (result == 0) break;
// Go left or right depending on the `result`.
node = node->_getChild(result < 0);
}
return static_cast<NodeT*>(node);
}
//! \}
//! \cond INTERNAL
//! \name Internal
//! \{
static inline bool _isValidRed(ZoneTreeNode* node) noexcept { return ZoneTreeNode::_isValidRed(node); }
//! Single rotation.
static ASMJIT_INLINE ZoneTreeNode* _singleRotate(ZoneTreeNode* root, size_t dir) noexcept {
ZoneTreeNode* save = root->_getChild(!dir);
root->_setChild(!dir, save->_getChild(dir));
save->_setChild( dir, root);
root->_makeRed();
save->_makeBlack();
return save;
}
//! Double rotation.
static ASMJIT_INLINE ZoneTreeNode* _doubleRotate(ZoneTreeNode* root, size_t dir) noexcept {
root->_setChild(!dir, _singleRotate(root->_getChild(!dir), !dir));
return _singleRotate(root, dir);
}
//! \}
//! \endcond
};
//! \}
ASMJIT_END_NAMESPACE
#endif // ASMJIT_CORE_ZONETREE_H_INCLUDED