micro/util/buffer/buffer.go
Vasiliy Tolstov 653bd386cc util/buffer: add DelayedBuffer
Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>
2024-12-29 01:57:41 +03:00

86 lines
1.5 KiB
Go

package buffer
import (
"io"
"sync"
"time"
)
var _ io.WriteCloser = (*DelayedBuffer)(nil)
// DelayedBuffer is the buffer that holds items until either the buffer filled or a specified time limit is reached
type DelayedBuffer struct {
mu sync.Mutex
maxWait time.Duration
flushTime time.Time
buffer chan []byte
ticker *time.Ticker
w io.Writer
err error
}
func NewDelayedBuffer(size int, maxWait time.Duration, w io.Writer) *DelayedBuffer {
b := &DelayedBuffer{
buffer: make(chan []byte, size),
ticker: time.NewTicker(maxWait),
w: w,
flushTime: time.Now(),
maxWait: maxWait,
}
b.loop()
return b
}
func (b *DelayedBuffer) loop() {
go func() {
for range b.ticker.C {
b.mu.Lock()
if time.Since(b.flushTime) > b.maxWait {
b.flush()
}
b.mu.Unlock()
}
}()
}
func (b *DelayedBuffer) flush() {
bufLen := len(b.buffer)
if bufLen > 0 {
tmp := make([][]byte, bufLen)
for i := 0; i < bufLen; i++ {
tmp[i] = <-b.buffer
}
for _, t := range tmp {
_, b.err = b.w.Write(t)
}
b.flushTime = time.Now()
}
}
func (b *DelayedBuffer) Put(items ...[]byte) {
b.mu.Lock()
for _, item := range items {
select {
case b.buffer <- item:
default:
b.flush()
b.buffer <- item
}
}
b.mu.Unlock()
}
func (b *DelayedBuffer) Close() error {
b.mu.Lock()
b.flush()
close(b.buffer)
b.ticker.Stop()
b.mu.Unlock()
return b.err
}
func (b *DelayedBuffer) Write(data []byte) (int, error) {
b.Put(data)
return len(data), b.err
}