mirror of
https://github.com/chrislusf/seaweedfs
synced 2024-06-16 23:51:15 +02:00
36 lines
790 B
Go
36 lines
790 B
Go
package filer
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type ReaderPattern struct {
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isSequentialCounter int64
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lastReadStopOffset int64
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}
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const ModeChangeLimit = 3
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// For streaming read: only cache the first chunk
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// For random read: only fetch the requested range, instead of the whole chunk
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func NewReaderPattern() *ReaderPattern {
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return &ReaderPattern{
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isSequentialCounter: 0,
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lastReadStopOffset: 0,
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}
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}
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func (rp *ReaderPattern) MonitorReadAt(offset int64, size int) {
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if rp.lastReadStopOffset == offset {
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if rp.isSequentialCounter < ModeChangeLimit {
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rp.isSequentialCounter++
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}
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} else {
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if rp.isSequentialCounter > -ModeChangeLimit {
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rp.isSequentialCounter--
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}
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}
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rp.lastReadStopOffset = offset + int64(size)
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}
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func (rp *ReaderPattern) IsRandomMode() bool {
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return rp.isSequentialCounter < 0
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}
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