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seaweedfs/weed/filesys/page_writer_pattern.go
chrislu 083d8e9ece add stream writer
this should improve streaming write performance, which is common in many cases, e.g., copying large files.

This is additional to improved random read write operations: 3e69d19380...19084d8791
2021-12-24 22:38:22 -08:00

45 lines
931 B
Go

package filesys
type WriterPattern struct {
isStreaming bool
lastWriteOffset int64
chunkSize int64
}
// For streaming write: only cache the first chunk
// For random write: fall back to temp file approach
// writes can only change from streaming mode to non-streaming mode
func NewWriterPattern(chunkSize int64) *WriterPattern {
return &WriterPattern{
isStreaming: true,
lastWriteOffset: -1,
chunkSize: chunkSize,
}
}
func (rp *WriterPattern) MonitorWriteAt(offset int64, size int) {
if rp.lastWriteOffset > offset {
rp.isStreaming = false
}
if rp.lastWriteOffset == -1 {
if offset != 0 {
rp.isStreaming = false
}
}
rp.lastWriteOffset = offset
}
func (rp *WriterPattern) IsStreamingMode() bool {
return rp.isStreaming
}
func (rp *WriterPattern) IsRandomMode() bool {
return !rp.isStreaming
}
func (rp *WriterPattern) Reset() {
rp.isStreaming = true
rp.lastWriteOffset = -1
}