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package filesys
import "fmt"
type WriterPattern struct {
isStreaming bool
lastWriteOffset int64
chunkSize int64
fileName string
}
// 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(fileName string, chunkSize int64) *WriterPattern {
return &WriterPattern{
isStreaming: true,
lastWriteOffset: 0,
chunkSize: chunkSize,
fileName: fileName,
}
}
func (rp *WriterPattern) MonitorWriteAt(offset int64, size int) {
if rp.lastWriteOffset == 0 {
}
if rp.lastWriteOffset > offset {
if rp.isStreaming {
fmt.Printf("file %s ==> non streaming at [%d,%d)\n", rp.fileName, offset, offset+int64(size))
}
fmt.Printf("write %s [%d,%d)\n", rp.fileName, offset, offset+int64(size))
rp.isStreaming = false
}
rp.lastWriteOffset = offset
}
func (rp *WriterPattern) IsStreamingMode() bool {
return rp.isStreaming
}
func (rp *WriterPattern) IsRandomMode() bool {
return !rp.isStreaming
}
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