influxdb/storage/points_writer.go

133 lines
3.3 KiB
Go

package storage
import (
"context"
"fmt"
"time"
"github.com/influxdata/influxdb/v2/kit/platform"
"github.com/influxdata/influxdb/v2"
"github.com/influxdata/influxdb/v2/models"
)
// PointsWriter describes the ability to write points into a storage engine.
type PointsWriter interface {
WritePoints(ctx context.Context, orgID platform.ID, bucketID platform.ID, points []models.Point) error
}
// LoggingPointsWriter wraps an underlying points writer but writes logs to
// another bucket when an error occurs.
type LoggingPointsWriter struct {
// Wrapped points writer. Errored writes from here will be logged.
Underlying PointsWriter
// Service used to look up logging bucket.
BucketFinder BucketFinder
// Name of the bucket to log to.
LogBucketName string
}
// WritePoints writes points to the underlying PointsWriter. Logs on error.
func (w *LoggingPointsWriter) WritePoints(ctx context.Context, orgID platform.ID, bucketID platform.ID, p []models.Point) error {
if len(p) == 0 {
return nil
}
// Write to underlying writer and exit immediately if successful.
err := w.Underlying.WritePoints(ctx, orgID, bucketID, p)
if err == nil {
return nil
}
// Attempt to lookup log bucket.
bkts, n, e := w.BucketFinder.FindBuckets(ctx, influxdb.BucketFilter{
OrganizationID: &orgID,
Name: &w.LogBucketName,
})
if e != nil {
return e
} else if n == 0 {
return fmt.Errorf("logging bucket not found: %q", w.LogBucketName)
}
// Log error to bucket.
pt, e := models.NewPoint(
"write_errors",
nil,
models.Fields{"error": err.Error()},
time.Now(),
)
if e != nil {
return e
}
if e := w.Underlying.WritePoints(ctx, orgID, bkts[0].ID, []models.Point{pt}); e != nil {
return e
}
return err
}
type BufferedPointsWriter struct {
buf []models.Point
orgID platform.ID
bucketID platform.ID
n int
wr PointsWriter
err error
}
func NewBufferedPointsWriter(orgID platform.ID, bucketID platform.ID, size int, pointswriter PointsWriter) *BufferedPointsWriter {
return &BufferedPointsWriter{
buf: make([]models.Point, size),
orgID: orgID,
bucketID: bucketID,
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, b.orgID, b.bucketID, 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.orgID, b.bucketID, b.buf[:b.n])
if b.err != nil {
return b.err
}
b.n = 0
return nil
}