1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
|
// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
#pragma once
#include "btreeremover.h"
#include "btreerootbase.hpp"
namespace vespalib::btree {
template <typename KeyT, typename DataT, typename AggrT, size_t INTERNAL_SLOTS,
size_t LEAF_SLOTS, class AggrCalcT>
template <typename NodeType, typename NodeTypeRefPair, class Iterator>
void
BTreeRemoverBase<KeyT, DataT, AggrT, INTERNAL_SLOTS, LEAF_SLOTS, AggrCalcT>::
steal(InternalNodeType *pNode,
BTreeNode::Ref sNodeRef,
NodeType * sNode, uint32_t idx, NodeAllocatorType &allocator,
[[maybe_unused]] const AggrCalcT &aggrCalc,
Iterator &itr,
uint32_t level)
{
BTreeNode::Ref leftVictimRef = BTreeNode::Ref();
NodeType * leftVictim = nullptr;
BTreeNode::Ref rightVictimRef = BTreeNode::Ref();
NodeType * rightVictim = nullptr;
if (idx > 0) {
leftVictimRef = pNode->get_child_relaxed(idx - 1);
leftVictim = allocator.template mapRef<NodeType>(leftVictimRef);
}
if (idx + 1 < pNode->validSlots()) {
rightVictimRef = pNode->get_child_relaxed(idx + 1);
rightVictim = allocator.template mapRef<NodeType>(rightVictimRef);
}
if (leftVictim != nullptr &&
leftVictim->validSlots() + sNode->validSlots() <=
NodeType::maxSlots())
{
uint32_t stolen = leftVictim->validSlots();
sNode->stealAllFromLeftNode(leftVictim);
pNode->update(idx, sNode->getLastKey(), sNodeRef);
pNode->remove(idx - 1);
allocator.holdNode(leftVictimRef, leftVictim);
itr.adjustSteal(level, true, stolen);
} else if (rightVictim != nullptr &&
rightVictim->validSlots() + sNode->validSlots() <=
NodeType::maxSlots())
{
sNode->stealAllFromRightNode(rightVictim);
pNode->update(idx, sNode->getLastKey(), sNodeRef);
pNode->remove(idx + 1);
allocator.holdNode(rightVictimRef, rightVictim);
} else if (leftVictim != nullptr &&
(rightVictim == nullptr ||
leftVictim->validSlots() > rightVictim->validSlots()))
{
if (leftVictim->getFrozen()) {
NodeTypeRefPair thawed =
allocator.thawNode(leftVictimRef, leftVictim);
leftVictimRef = thawed.ref;
leftVictim = thawed.data;
}
uint32_t oldLeftValid = leftVictim->validSlots();
sNode->stealSomeFromLeftNode(leftVictim, allocator);
uint32_t stolen = oldLeftValid - leftVictim->validSlots();
pNode->update(idx, sNode->getLastKey(), sNodeRef);
pNode->update(idx - 1, leftVictim->getLastKey(), leftVictimRef);
if constexpr (AggrCalcT::hasAggregated()) {
Aggregator::recalc(*leftVictim, allocator, aggrCalc);
}
itr.adjustSteal(level, false, stolen);
} else if (rightVictim != nullptr) {
if (rightVictim->getFrozen()) {
NodeTypeRefPair thawed =
allocator.thawNode(rightVictimRef, rightVictim);
rightVictimRef = thawed.ref;
rightVictim = thawed.data;
}
sNode->stealSomeFromRightNode(rightVictim, allocator);
pNode->update(idx, sNode->getLastKey(), sNodeRef);
pNode->update(idx + 1, rightVictim->getLastKey(), rightVictimRef);
if constexpr (AggrCalcT::hasAggregated()) {
Aggregator::recalc(*rightVictim, allocator, aggrCalc);
}
}
if constexpr (AggrCalcT::hasAggregated()) {
Aggregator::recalc(*sNode, allocator, aggrCalc);
}
}
template <typename KeyT, typename DataT, typename AggrT, typename CompareT,
typename TraitsT, class AggrCalcT>
void
BTreeRemover<KeyT, DataT, AggrT, CompareT, TraitsT, AggrCalcT>::
remove(BTreeNode::Ref &root,
Iterator &itr,
const AggrCalcT &aggrCalc)
{
assert(itr.valid());
root = itr.thaw(root);
uint32_t idx = itr.getLeafNodeIdx();
LeafNodeType * lnode = itr.getLeafNode();
if (lnode->validSlots() == 1u) {
itr.removeLast(root);
root = BTreeNode::Ref();
return;
}
NodeAllocatorType &allocator(itr.getAllocator());
AggrT oldca(AggrCalcT::hasAggregated() ? lnode->getAggregated() : AggrT());
AggrT ca;
if constexpr (AggrCalcT::hasAggregated()) {
bool need_aggregation_recalc;
if constexpr (AggrCalcT::aggregate_over_values()) {
need_aggregation_recalc = aggrCalc.remove(lnode->getAggregated(), aggrCalc.getVal(lnode->getData(idx)));
} else {
need_aggregation_recalc = aggrCalc.remove(lnode->getAggregated(), aggrCalc.getVal(lnode->getKey(idx)));
}
lnode->remove(idx);
if (need_aggregation_recalc) {
Aggregator::recalc(*lnode, aggrCalc);
}
} else {
lnode->remove(idx);
}
if constexpr (AggrCalcT::hasAggregated()) {
ca = lnode->getAggregated();
}
bool steppedBack = idx >= lnode->validSlots();
if (steppedBack) {
itr.setLeafNodeIdx(itr.getLeafNodeIdx() - 1);
--idx;
}
uint32_t level = 0;
uint32_t levels = itr.getPathSize();
InternalNodeType *node = nullptr;
for (; level < levels; ++level) {
typename Iterator::PathElement &pe = itr.getPath(level);
node = pe.getWNode();
idx = pe.getIdx();
AggrT olda(AggrCalcT::hasAggregated() ?
node->getAggregated() : AggrT());
BTreeNode::Ref subNode = node->get_child_relaxed(idx);
node->update(idx, allocator.getLastKey(subNode), subNode);
node->decValidLeaves(1);
if (level == 0) {
LeafNodeType * sNode = allocator.mapLeafRef(subNode);
assert(sNode == lnode);
if (!sNode->isAtLeastHalfFull()) {
// too few elements in sub node, steal from left or
// right sibling
ParentType::template steal<LeafNodeType,
LeafNodeTypeRefPair>
(node, subNode, sNode, idx, allocator, aggrCalc,
itr, level);
}
} else {
InternalNodeType * sNode = allocator.mapInternalRef(subNode);
if (!sNode->isAtLeastHalfFull()) {
// too few elements in sub node, steal from left or
// right sibling
ParentType::template steal<InternalNodeType,
InternalNodeTypeRefPair>
(node, subNode, sNode, idx, allocator, aggrCalc,
itr, level);
}
}
if constexpr (AggrCalcT::hasAggregated()) {
if (aggrCalc.remove(node->getAggregated(), oldca, ca)) {
Aggregator::recalc(*node, allocator, aggrCalc);
}
ca = node->getAggregated();
oldca = olda;
}
}
if (level > 0 && node->validSlots() == 1) {
root = itr.removeLevel(root, node);
}
if (steppedBack)
++itr;
}
}
|
