influxdb/storage/points_writer.go

71 lines
1.6 KiB
Go

package storage
import (
"context"
"github.com/influxdata/influxdb/models"
)
// PointsWriter describes the ability to write points into a storage engine.
type PointsWriter interface {
WritePoints(context.Context, []models.Point) error
}
type BufferedPointsWriter struct {
buf []models.Point
n int
wr PointsWriter
err error
}
func NewBufferedPointsWriter(size int, pointswriter PointsWriter) *BufferedPointsWriter {
return &BufferedPointsWriter{
buf: make([]models.Point, size),
wr: pointswriter,
}
}
// WritePoints writes the points to the underlying PointsWriter.
func (b *BufferedPointsWriter) WritePoints(ctx context.Context, p []models.Point) error {
for len(p) > b.Available() && b.err == nil {
if b.Buffered() == 0 {
// Large write, empty buffer.
// Write directly from p to avoid copy.
b.err = b.wr.WritePoints(ctx, p)
return b.err
}
n := copy(b.buf[b.n:], p)
b.n += n
b.err = b.Flush(ctx)
p = p[n:]
}
if b.err != nil {
return b.err
}
b.n += copy(b.buf[b.n:], p)
return nil
}
// Available returns how many models.Points are unused in the buffer.
func (b *BufferedPointsWriter) Available() int { return len(b.buf) - b.n }
// Buffered returns the number of models.Points that have been written into the current buffer.
func (b *BufferedPointsWriter) Buffered() int { return b.n }
// Flush writes any buffered data to the underlying PointsWriter.
func (b *BufferedPointsWriter) Flush(ctx context.Context) error {
if b.err != nil {
return b.err
}
if b.n == 0 {
return nil
}
b.err = b.wr.WritePoints(ctx, b.buf[:b.n])
if b.err != nil {
return b.err
}
b.n = 0
return nil
}