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
|
package filesys
import (
"bytes"
"io"
"math"
)
type IntervalNode struct {
Data []byte
Offset int64
Size int64
Next *IntervalNode
}
type IntervalLinkedList struct {
Head *IntervalNode
Tail *IntervalNode
}
type ContinuousIntervals struct {
lists []*IntervalLinkedList
}
func (list *IntervalLinkedList) Offset() int64 {
return list.Head.Offset
}
func (list *IntervalLinkedList) Size() int64 {
return list.Tail.Offset + list.Tail.Size - list.Head.Offset
}
func (list *IntervalLinkedList) addNodeToTail(node *IntervalNode) {
// glog.V(4).Infof("add to tail [%d,%d) + [%d,%d) => [%d,%d)", list.Head.Offset, list.Tail.Offset+list.Tail.Size, node.Offset, node.Offset+node.Size, list.Head.Offset, node.Offset+node.Size)
list.Tail.Next = node
list.Tail = node
}
func (list *IntervalLinkedList) addNodeToHead(node *IntervalNode) {
// glog.V(4).Infof("add to head [%d,%d) + [%d,%d) => [%d,%d)", node.Offset, node.Offset+node.Size, list.Head.Offset, list.Tail.Offset+list.Tail.Size, node.Offset, list.Tail.Offset+list.Tail.Size)
node.Next = list.Head
list.Head = node
}
func (list *IntervalLinkedList) ReadData(buf []byte, start, stop int64) {
t := list.Head
for {
nodeStart, nodeStop := max(start, t.Offset), min(stop, t.Offset+t.Size)
if nodeStart < nodeStop {
// glog.V(0).Infof("copying start=%d stop=%d t=[%d,%d) t.data=%d => bufSize=%d nodeStart=%d, nodeStop=%d", start, stop, t.Offset, t.Offset+t.Size, len(t.Data), len(buf), nodeStart, nodeStop)
copy(buf[nodeStart-start:], t.Data[nodeStart-t.Offset:nodeStop-t.Offset])
}
if t.Next == nil {
break
}
t = t.Next
}
}
func (c *ContinuousIntervals) TotalSize() (total int64) {
for _, list := range c.lists {
total += list.Size()
}
return
}
func subList(list *IntervalLinkedList, start, stop int64) *IntervalLinkedList {
var nodes []*IntervalNode
for t := list.Head; t != nil; t = t.Next {
nodeStart, nodeStop := max(start, t.Offset), min(stop, t.Offset+t.Size)
if nodeStart >= nodeStop {
// skip non overlapping IntervalNode
continue
}
nodes = append(nodes, &IntervalNode{
Data: t.Data[nodeStart-t.Offset : nodeStop-t.Offset],
Offset: nodeStart,
Size: nodeStop-nodeStart,
Next: nil,
})
}
for i := 1; i < len(nodes); i++ {
nodes[i-1].Next = nodes[i]
}
return &IntervalLinkedList{
Head: nodes[0],
Tail: nodes[len(nodes)-1],
}
}
func (c *ContinuousIntervals) AddInterval(data []byte, offset int64) {
interval := &IntervalNode{Data: data, Offset: offset, Size: int64(len(data))}
var newLists []*IntervalLinkedList
for _, list := range c.lists {
// if list is to the left of new interval, add to the new list
if list.Tail.Offset+list.Tail.Size <= interval.Offset {
newLists = append(newLists, list)
}
// if list is to the right of new interval, add to the new list
if interval.Offset+interval.Size <= list.Head.Offset {
newLists = append(newLists, list)
}
// if new interval overwrite the right part of the list
if list.Head.Offset < interval.Offset && interval.Offset < list.Tail.Offset+list.Tail.Size {
// create a new list of the left part of existing list
newLists = append(newLists, subList(list, list.Offset(), interval.Offset))
}
// if new interval overwrite the left part of the list
if list.Head.Offset < interval.Offset+interval.Size && interval.Offset+interval.Size < list.Tail.Offset+list.Tail.Size {
// create a new list of the right part of existing list
newLists = append(newLists, subList(list, interval.Offset+interval.Size, list.Tail.Offset+list.Tail.Size))
}
// skip anything that is fully overwritten by the new interval
}
c.lists = newLists
// add the new interval to the lists, connecting neighbor lists
var prevList, nextList *IntervalLinkedList
for _, list := range c.lists {
if list.Head.Offset == interval.Offset+interval.Size {
nextList = list
break
}
}
for _, list := range c.lists {
if list.Head.Offset+list.Size() == offset {
list.addNodeToTail(interval)
prevList = list
break
}
}
if prevList != nil && nextList != nil {
// glog.V(4).Infof("connecting [%d,%d) + [%d,%d) => [%d,%d)", prevList.Head.Offset, prevList.Tail.Offset+prevList.Tail.Size, nextList.Head.Offset, nextList.Tail.Offset+nextList.Tail.Size, prevList.Head.Offset, nextList.Tail.Offset+nextList.Tail.Size)
prevList.Tail.Next = nextList.Head
prevList.Tail = nextList.Tail
c.removeList(nextList)
} else if nextList != nil {
// add to head was not done when checking
nextList.addNodeToHead(interval)
}
if prevList == nil && nextList == nil {
c.lists = append(c.lists, &IntervalLinkedList{
Head: interval,
Tail: interval,
})
}
return
}
func (c *ContinuousIntervals) RemoveLargestIntervalLinkedList() *IntervalLinkedList {
var maxSize int64
maxIndex := -1
for k, list := range c.lists {
if maxSize <= list.Size() {
maxSize = list.Size()
maxIndex = k
}
}
if maxSize <= 0 {
return nil
}
t := c.lists[maxIndex]
c.lists = append(c.lists[0:maxIndex], c.lists[maxIndex+1:]...)
return t
}
func (c *ContinuousIntervals) removeList(target *IntervalLinkedList) {
index := -1
for k, list := range c.lists {
if list.Offset() == target.Offset() {
index = k
}
}
if index < 0 {
return
}
c.lists = append(c.lists[0:index], c.lists[index+1:]...)
}
func (c *ContinuousIntervals) ReadData(data []byte, startOffset int64) (offset int64, size int) {
var minOffset int64 = math.MaxInt64
var maxStop int64
for _, list := range c.lists {
start := max(startOffset, list.Offset())
stop := min(startOffset+int64(len(data)), list.Offset()+list.Size())
if start <= stop {
list.ReadData(data[start-startOffset:], start, stop)
minOffset = min(minOffset, start)
maxStop = max(maxStop, stop)
}
}
if minOffset == math.MaxInt64 {
return 0, 0
}
offset = minOffset
size = int(maxStop - offset)
return
}
func (l *IntervalLinkedList) ToReader() io.Reader {
var readers []io.Reader
t := l.Head
readers = append(readers, bytes.NewReader(t.Data))
for t.Next != nil {
t = t.Next
readers = append(readers, bytes.NewReader(t.Data))
}
return io.MultiReader(readers...)
}
|
