mirror of
https://github.com/seaweedfs/seaweedfs.git
synced 2024-12-05 11:39:02 +08:00
a48ebd7c73
a possible fix for https://github.com/chrislusf/seaweedfs/issues/2065
290 lines
8.5 KiB
Go
290 lines
8.5 KiB
Go
package filesys
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import (
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"io"
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"log"
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"os"
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)
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type WrittenIntervalNode struct {
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DataOffset int64
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TempOffset int64
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Size int64
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Next *WrittenIntervalNode
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}
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type WrittenIntervalLinkedList struct {
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tempFile *os.File
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Head *WrittenIntervalNode
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Tail *WrittenIntervalNode
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}
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type WrittenContinuousIntervals struct {
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tempFile *os.File
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lastOffset int64
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lists []*WrittenIntervalLinkedList
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}
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func (list *WrittenIntervalLinkedList) Offset() int64 {
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return list.Head.DataOffset
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}
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func (list *WrittenIntervalLinkedList) Size() int64 {
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return list.Tail.DataOffset + list.Tail.Size - list.Head.DataOffset
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}
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func (list *WrittenIntervalLinkedList) addNodeToTail(node *WrittenIntervalNode) {
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// 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)
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if list.Tail.TempOffset+list.Tail.Size == node.TempOffset {
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// already connected
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list.Tail.Size += node.Size
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} else {
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list.Tail.Next = node
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list.Tail = node
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}
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}
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func (list *WrittenIntervalLinkedList) addNodeToHead(node *WrittenIntervalNode) {
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// 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)
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node.Next = list.Head
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list.Head = node
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}
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func (list *WrittenIntervalLinkedList) ReadData(buf []byte, start, stop int64) {
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t := list.Head
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for {
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nodeStart, nodeStop := max(start, t.DataOffset), min(stop, t.DataOffset+t.Size)
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if nodeStart < nodeStop {
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// glog.V(4).Infof("copying start=%d stop=%d t=[%d,%d) => bufSize=%d nodeStart=%d, nodeStop=%d", start, stop, t.DataOffset, t.DataOffset+t.Size, len(buf), nodeStart, nodeStop)
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list.tempFile.ReadAt(buf[nodeStart-start:nodeStop-start], t.TempOffset + nodeStart - t.DataOffset)
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}
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if t.Next == nil {
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break
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}
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t = t.Next
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}
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}
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func (c *WrittenContinuousIntervals) TotalSize() (total int64) {
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for _, list := range c.lists {
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total += list.Size()
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}
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return
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}
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func (list *WrittenIntervalLinkedList) subList(start, stop int64) *WrittenIntervalLinkedList {
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var nodes []*WrittenIntervalNode
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for t := list.Head; t != nil; t = t.Next {
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nodeStart, nodeStop := max(start, t.DataOffset), min(stop, t.DataOffset+t.Size)
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if nodeStart >= nodeStop {
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// skip non overlapping WrittenIntervalNode
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continue
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}
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nodes = append(nodes, &WrittenIntervalNode{
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TempOffset: t.TempOffset + nodeStart - t.DataOffset,
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DataOffset: nodeStart,
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Size: nodeStop - nodeStart,
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Next: nil,
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})
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}
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for i := 1; i < len(nodes); i++ {
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nodes[i-1].Next = nodes[i]
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}
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return &WrittenIntervalLinkedList{
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tempFile: list.tempFile,
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Head: nodes[0],
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Tail: nodes[len(nodes)-1],
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}
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}
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func (c *WrittenContinuousIntervals) debug() {
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log.Printf("++")
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for _, l := range c.lists {
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log.Printf("++++")
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for t := l.Head; ; t = t.Next {
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log.Printf("[%d,%d) => [%d,%d) %d", t.DataOffset, t.DataOffset+t.Size, t.TempOffset, t.TempOffset+t.Size, t.Size)
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if t.Next == nil {
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break
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}
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}
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log.Printf("----")
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}
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log.Printf("--")
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}
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func (c *WrittenContinuousIntervals) AddInterval(tempOffset int64, dataSize int, dataOffset int64) {
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interval := &WrittenIntervalNode{DataOffset: dataOffset, TempOffset: tempOffset, Size: int64(dataSize)}
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// append to the tail and return
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if len(c.lists) == 1 {
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lastSpan := c.lists[0]
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if lastSpan.Tail.DataOffset+lastSpan.Tail.Size == dataOffset {
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lastSpan.addNodeToTail(interval)
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return
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}
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}
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var newLists []*WrittenIntervalLinkedList
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for _, list := range c.lists {
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// if list is to the left of new interval, add to the new list
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if list.Tail.DataOffset+list.Tail.Size <= interval.DataOffset {
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newLists = append(newLists, list)
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}
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// if list is to the right of new interval, add to the new list
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if interval.DataOffset+interval.Size <= list.Head.DataOffset {
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newLists = append(newLists, list)
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}
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// if new interval overwrite the right part of the list
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if list.Head.DataOffset < interval.DataOffset && interval.DataOffset < list.Tail.DataOffset+list.Tail.Size {
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// create a new list of the left part of existing list
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newLists = append(newLists, list.subList(list.Offset(), interval.DataOffset))
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}
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// if new interval overwrite the left part of the list
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if list.Head.DataOffset < interval.DataOffset+interval.Size && interval.DataOffset+interval.Size < list.Tail.DataOffset+list.Tail.Size {
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// create a new list of the right part of existing list
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newLists = append(newLists, list.subList(interval.DataOffset+interval.Size, list.Tail.DataOffset+list.Tail.Size))
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}
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// skip anything that is fully overwritten by the new interval
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}
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c.lists = newLists
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// add the new interval to the lists, connecting neighbor lists
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var prevList, nextList *WrittenIntervalLinkedList
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for _, list := range c.lists {
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if list.Head.DataOffset == interval.DataOffset+interval.Size {
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nextList = list
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break
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}
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}
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for _, list := range c.lists {
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if list.Head.DataOffset+list.Size() == dataOffset {
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list.addNodeToTail(interval)
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prevList = list
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break
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}
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}
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if prevList != nil && nextList != nil {
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// 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)
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prevList.Tail.Next = nextList.Head
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prevList.Tail = nextList.Tail
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c.removeList(nextList)
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} else if nextList != nil {
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// add to head was not done when checking
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nextList.addNodeToHead(interval)
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}
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if prevList == nil && nextList == nil {
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c.lists = append(c.lists, &WrittenIntervalLinkedList{
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tempFile: c.tempFile,
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Head: interval,
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Tail: interval,
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})
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}
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return
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}
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func (c *WrittenContinuousIntervals) RemoveLargestIntervalLinkedList() *WrittenIntervalLinkedList {
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var maxSize int64
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maxIndex := -1
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for k, list := range c.lists {
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if maxSize <= list.Size() {
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maxSize = list.Size()
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maxIndex = k
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}
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}
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if maxSize <= 0 {
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return nil
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}
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t := c.lists[maxIndex]
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t.tempFile = c.tempFile
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c.lists = append(c.lists[0:maxIndex], c.lists[maxIndex+1:]...)
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return t
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}
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func (c *WrittenContinuousIntervals) removeList(target *WrittenIntervalLinkedList) {
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index := -1
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for k, list := range c.lists {
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if list.Offset() == target.Offset() {
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index = k
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}
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}
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if index < 0 {
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return
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}
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c.lists = append(c.lists[0:index], c.lists[index+1:]...)
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}
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func (c *WrittenContinuousIntervals) ReadDataAt(data []byte, startOffset int64) (maxStop int64) {
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for _, list := range c.lists {
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start := max(startOffset, list.Offset())
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stop := min(startOffset+int64(len(data)), list.Offset()+list.Size())
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if start < stop {
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list.ReadData(data[start-startOffset:], start, stop)
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maxStop = max(maxStop, stop)
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}
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}
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return
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}
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func (l *WrittenIntervalLinkedList) ToReader(start int64, stop int64) io.Reader {
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// TODO: optimize this to avoid another loop
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var readers []io.Reader
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for t := l.Head; ; t = t.Next {
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startOffset, stopOffset := max(t.DataOffset, start), min(t.DataOffset+t.Size, stop)
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if startOffset < stopOffset {
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// glog.V(4).Infof("ToReader read [%d,%d) from [%d,%d) %d", t.DataOffset, t.DataOffset+t.Size, t.TempOffset, t.TempOffset+t.Size, t.Size)
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readers = append(readers, newFileSectionReader(l.tempFile, startOffset-t.DataOffset+t.TempOffset, startOffset, stopOffset-startOffset))
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}
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if t.Next == nil {
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break
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}
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}
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if len(readers) == 1 {
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return readers[0]
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}
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return io.MultiReader(readers...)
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}
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type FileSectionReader struct {
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file *os.File
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tempStartOffset int64
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Offset int64
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dataStart int64
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dataStop int64
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}
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var _ = io.Reader(&FileSectionReader{})
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func newFileSectionReader(tempfile *os.File, offset int64, dataOffset int64, size int64) *FileSectionReader {
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return &FileSectionReader{
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file: tempfile,
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tempStartOffset: offset,
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Offset: offset,
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dataStart: dataOffset,
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dataStop: dataOffset + size,
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}
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}
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func (f *FileSectionReader) Read(p []byte) (n int, err error) {
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remaining := (f.dataStop - f.dataStart) - (f.Offset - f.tempStartOffset)
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if remaining <= 0 {
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return 0, io.EOF
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}
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dataLen := min(remaining, int64(len(p)))
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// glog.V(4).Infof("reading [%d,%d) from %v [%d,%d)/[%d,%d) %d", f.Offset-f.tempStartOffset+f.dataStart, f.Offset-f.tempStartOffset+f.dataStart+dataLen, f.file.Name(), f.Offset, f.Offset+dataLen, f.tempStartOffset, f.tempStartOffset+f.dataStop-f.dataStart, f.dataStop-f.dataStart)
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n, err = f.file.ReadAt(p[:dataLen], f.Offset)
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if n > 0 {
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f.Offset += int64(n)
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} else {
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err = io.EOF
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}
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return
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}
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