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
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
|
package filer
import (
"math"
"sync"
)
type IntervalValue interface {
SetStartStop(start, stop int64)
Clone() IntervalValue
}
type Interval[T IntervalValue] struct {
StartOffset int64
StopOffset int64
TsNs int64
Value T
Prev *Interval[T]
Next *Interval[T]
}
func (interval *Interval[T]) Size() int64 {
return interval.StopOffset - interval.StartOffset
}
// IntervalList mark written intervals within one page chunk
type IntervalList[T IntervalValue] struct {
head *Interval[T]
tail *Interval[T]
Lock sync.RWMutex
}
func NewIntervalList[T IntervalValue]() *IntervalList[T] {
list := &IntervalList[T]{
head: &Interval[T]{
StartOffset: -1,
StopOffset: -1,
},
tail: &Interval[T]{
StartOffset: math.MaxInt64,
StopOffset: math.MaxInt64,
},
}
return list
}
func (list *IntervalList[T]) Front() (interval *Interval[T]) {
return list.head.Next
}
func (list *IntervalList[T]) AppendInterval(interval *Interval[T]) {
list.Lock.Lock()
defer list.Lock.Unlock()
if list.head.Next == nil {
list.head.Next = interval
}
interval.Prev = list.tail.Prev
if list.tail.Prev != nil {
list.tail.Prev.Next = interval
}
list.tail.Prev = interval
}
func (list *IntervalList[T]) Overlay(startOffset, stopOffset, tsNs int64, value T) {
if startOffset >= stopOffset {
return
}
interval := &Interval[T]{
StartOffset: startOffset,
StopOffset: stopOffset,
TsNs: tsNs,
Value: value,
}
list.Lock.Lock()
defer list.Lock.Unlock()
list.overlayInterval(interval)
}
func (list *IntervalList[T]) InsertInterval(startOffset, stopOffset, tsNs int64, value T) {
interval := &Interval[T]{
StartOffset: startOffset,
StopOffset: stopOffset,
TsNs: tsNs,
Value: value,
}
list.Lock.Lock()
defer list.Lock.Unlock()
value.SetStartStop(startOffset, stopOffset)
list.insertInterval(interval)
}
func (list *IntervalList[T]) insertInterval(interval *Interval[T]) {
prev := list.head
next := prev.Next
for interval.StartOffset < interval.StopOffset {
if next == nil {
// add to the end
list.insertBetween(prev, interval, list.tail)
break
}
// interval is ahead of the next
if interval.StopOffset <= next.StartOffset {
list.insertBetween(prev, interval, next)
break
}
// interval is after the next
if next.StopOffset <= interval.StartOffset {
prev = next
next = next.Next
continue
}
// intersecting next and interval
if interval.TsNs >= next.TsNs {
// interval is newer
if next.StartOffset < interval.StartOffset {
// left side of next is ahead of interval
t := &Interval[T]{
StartOffset: next.StartOffset,
StopOffset: interval.StartOffset,
TsNs: next.TsNs,
Value: next.Value.Clone().(T),
}
t.Value.SetStartStop(t.StartOffset, t.StopOffset)
list.insertBetween(prev, t, interval)
next.StartOffset = interval.StartOffset
next.Value.SetStartStop(next.StartOffset, next.StopOffset)
prev = t
}
if interval.StopOffset < next.StopOffset {
// right side of next is after interval
next.StartOffset = interval.StopOffset
next.Value.SetStartStop(next.StartOffset, next.StopOffset)
list.insertBetween(prev, interval, next)
break
} else {
// next is covered
prev.Next = interval
next = next.Next
}
} else {
// next is newer
if interval.StartOffset < next.StartOffset {
// left side of interval is ahead of next
t := &Interval[T]{
StartOffset: interval.StartOffset,
StopOffset: next.StartOffset,
TsNs: interval.TsNs,
Value: interval.Value.Clone().(T),
}
t.Value.SetStartStop(t.StartOffset, t.StopOffset)
list.insertBetween(prev, t, next)
interval.StartOffset = next.StartOffset
interval.Value.SetStartStop(interval.StartOffset, interval.StopOffset)
}
if next.StopOffset < interval.StopOffset {
// right side of interval is after next
interval.StartOffset = next.StopOffset
interval.Value.SetStartStop(interval.StartOffset, interval.StopOffset)
} else {
// interval is covered
break
}
}
}
}
func (list *IntervalList[T]) insertBetween(a, interval, b *Interval[T]) {
a.Next = interval
b.Prev = interval
if a != list.head {
interval.Prev = a
}
if b != list.tail {
interval.Next = b
}
}
func (list *IntervalList[T]) overlayInterval(interval *Interval[T]) {
//t := list.head
//for ; t.Next != nil; t = t.Next {
// if t.TsNs > interval.TsNs {
// println("writes is out of order", t.TsNs-interval.TsNs, "ns")
// }
//}
p := list.head
for ; p.Next != nil && p.Next.StopOffset <= interval.StartOffset; p = p.Next {
}
q := list.tail
for ; q.Prev != nil && q.Prev.StartOffset >= interval.StopOffset; q = q.Prev {
}
// left side
// interval after p.Next start
if p.Next != nil && p.Next.StartOffset < interval.StartOffset {
t := &Interval[T]{
StartOffset: p.Next.StartOffset,
StopOffset: interval.StartOffset,
TsNs: p.Next.TsNs,
Value: p.Next.Value,
}
p.Next = t
if p != list.head {
t.Prev = p
}
t.Next = interval
interval.Prev = t
} else {
p.Next = interval
if p != list.head {
interval.Prev = p
}
}
// right side
// interval ends before p.Prev
if q.Prev != nil && interval.StopOffset < q.Prev.StopOffset {
t := &Interval[T]{
StartOffset: interval.StopOffset,
StopOffset: q.Prev.StopOffset,
TsNs: q.Prev.TsNs,
Value: q.Prev.Value,
}
q.Prev = t
if q != list.tail {
t.Next = q
}
interval.Next = t
t.Prev = interval
} else {
q.Prev = interval
if q != list.tail {
interval.Next = q
}
}
}
func (list *IntervalList[T]) Len() int {
list.Lock.RLock()
defer list.Lock.RUnlock()
var count int
for t := list.head; t != nil; t = t.Next {
count++
}
return count - 1
}
|
