VictoriaMetrics/lib/protoparser/promremotewrite/streamparser.go
Aliaksandr Valialkin d5dddb0953 all: use %w instead of %s for wrapping errors in fmt.Errorf
This will simplify examining the returned errors such as httpserver.ErrorWithStatusCode .
See https://blog.golang.org/go1.13-errors for details.
2020-06-30 23:05:11 +03:00

125 lines
3.3 KiB
Go

package promremotewrite
import (
"flag"
"fmt"
"io"
"net/http"
"runtime"
"sync"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/prompb"
"github.com/VictoriaMetrics/metrics"
"github.com/golang/snappy"
)
var maxInsertRequestSize = flag.Int("maxInsertRequestSize", 32*1024*1024, "The maximum size in bytes of a single Prometheus remote_write API request")
// ParseStream parses Prometheus remote_write message req and calls callback for the parsed timeseries.
//
// callback shouldn't hold timeseries after returning.
func ParseStream(req *http.Request, callback func(timeseries []prompb.TimeSeries) error) error {
ctx := getPushCtx()
defer putPushCtx(ctx)
if err := ctx.Read(req); err != nil {
return err
}
return callback(ctx.wr.Timeseries)
}
type pushCtx struct {
wr prompb.WriteRequest
reqBuf []byte
}
func (ctx *pushCtx) reset() {
ctx.wr.Reset()
ctx.reqBuf = ctx.reqBuf[:0]
}
func (ctx *pushCtx) Read(r *http.Request) error {
readCalls.Inc()
var err error
ctx.reqBuf, err = readSnappy(ctx.reqBuf[:0], r.Body)
if err != nil {
readErrors.Inc()
return fmt.Errorf("cannot read prompb.WriteRequest: %w", err)
}
if err = ctx.wr.Unmarshal(ctx.reqBuf); err != nil {
unmarshalErrors.Inc()
return fmt.Errorf("cannot unmarshal prompb.WriteRequest with size %d bytes: %w", len(ctx.reqBuf), err)
}
rows := 0
tss := ctx.wr.Timeseries
for i := range tss {
rows += len(tss[i].Samples)
}
rowsRead.Add(rows)
return nil
}
var (
readCalls = metrics.NewCounter(`vm_protoparser_read_calls_total{type="promremotewrite"}`)
readErrors = metrics.NewCounter(`vm_protoparser_read_errors_total{type="promremotewrite"}`)
rowsRead = metrics.NewCounter(`vm_protoparser_rows_read_total{type="promremotewrite"}`)
unmarshalErrors = metrics.NewCounter(`vm_protoparser_unmarshal_errors{type="promremotewrite"}`)
)
func getPushCtx() *pushCtx {
select {
case ctx := <-pushCtxPoolCh:
return ctx
default:
if v := pushCtxPool.Get(); v != nil {
return v.(*pushCtx)
}
return &pushCtx{}
}
}
func putPushCtx(ctx *pushCtx) {
ctx.reset()
select {
case pushCtxPoolCh <- ctx:
default:
pushCtxPool.Put(ctx)
}
}
var pushCtxPool sync.Pool
var pushCtxPoolCh = make(chan *pushCtx, runtime.GOMAXPROCS(-1))
func readSnappy(dst []byte, r io.Reader) ([]byte, error) {
lr := io.LimitReader(r, int64(*maxInsertRequestSize)+1)
bb := bodyBufferPool.Get()
reqLen, err := bb.ReadFrom(lr)
if err != nil {
bodyBufferPool.Put(bb)
return dst, fmt.Errorf("cannot read compressed request: %w", err)
}
if reqLen > int64(*maxInsertRequestSize) {
return dst, fmt.Errorf("too big packed request; mustn't exceed `-maxInsertRequestSize=%d` bytes", *maxInsertRequestSize)
}
buf := dst[len(dst):cap(dst)]
buf, err = snappy.Decode(buf, bb.B)
bodyBufferPool.Put(bb)
if err != nil {
err = fmt.Errorf("cannot decompress request with length %d: %w", reqLen, err)
return dst, err
}
if len(buf) > *maxInsertRequestSize {
return dst, fmt.Errorf("too big unpacked request; mustn't exceed `-maxInsertRequestSize=%d` bytes; got %d bytes", *maxInsertRequestSize, len(buf))
}
if len(buf) > 0 && len(dst) < cap(dst) && &buf[0] == &dst[len(dst):cap(dst)][0] {
dst = dst[:len(dst)+len(buf)]
} else {
dst = append(dst, buf...)
}
return dst, nil
}
var bodyBufferPool bytesutil.ByteBufferPool