VictoriaMetrics/lib/protoparser/graphite/streamparser.go
Aliaksandr Valialkin 6a1aab88fd lib/protoparser: metrics renaming: vm_protoparser_<type>_* -> vm_protoparser_*{type="<type>"}
This should improve composability of these metrics in PromQL queries
2020-02-28 20:19:59 +02:00

130 lines
2.9 KiB
Go

package graphite
import (
"fmt"
"io"
"net"
"runtime"
"sync"
"time"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/protoparser/common"
"github.com/VictoriaMetrics/metrics"
)
// ParseStream parses Graphite lines from r and calls callback for the parsed rows.
//
// The callback can be called multiple times for streamed data from r.
//
// callback shouldn't hold rows after returning.
func ParseStream(r io.Reader, callback func(rows []Row) error) error {
ctx := getStreamContext()
defer putStreamContext(ctx)
for ctx.Read(r) {
if err := callback(ctx.Rows.Rows); err != nil {
return err
}
}
return ctx.Error()
}
const flushTimeout = 3 * time.Second
func (ctx *streamContext) Read(r io.Reader) bool {
readCalls.Inc()
if ctx.err != nil {
return false
}
if c, ok := r.(net.Conn); ok {
if err := c.SetReadDeadline(time.Now().Add(flushTimeout)); err != nil {
readErrors.Inc()
ctx.err = fmt.Errorf("cannot set read deadline: %s", err)
return false
}
}
ctx.reqBuf, ctx.tailBuf, ctx.err = common.ReadLinesBlock(r, ctx.reqBuf, ctx.tailBuf)
if ctx.err != nil {
if ne, ok := ctx.err.(net.Error); ok && ne.Timeout() {
// Flush the read data on timeout and try reading again.
ctx.err = nil
} else {
if ctx.err != io.EOF {
readErrors.Inc()
ctx.err = fmt.Errorf("cannot read graphite plaintext protocol data: %s", ctx.err)
}
return false
}
}
ctx.Rows.Unmarshal(bytesutil.ToUnsafeString(ctx.reqBuf))
rowsRead.Add(len(ctx.Rows.Rows))
// Fill missing timestamps with the current timestamp rounded to seconds.
currentTimestamp := time.Now().Unix()
rows := ctx.Rows.Rows
for i := range rows {
r := &rows[i]
if r.Timestamp == 0 {
r.Timestamp = currentTimestamp
}
}
// Convert timestamps from seconds to milliseconds.
for i := range rows {
rows[i].Timestamp *= 1e3
}
return true
}
type streamContext struct {
Rows Rows
reqBuf []byte
tailBuf []byte
err error
}
func (ctx *streamContext) Error() error {
if ctx.err == io.EOF {
return nil
}
return ctx.err
}
func (ctx *streamContext) reset() {
ctx.Rows.Reset()
ctx.reqBuf = ctx.reqBuf[:0]
ctx.tailBuf = ctx.tailBuf[:0]
ctx.err = nil
}
var (
readCalls = metrics.NewCounter(`vm_protoparser_read_calls_total{type="graphite"}`)
readErrors = metrics.NewCounter(`vm_protoparser_read_errors_total{type="graphite"}`)
rowsRead = metrics.NewCounter(`vm_protoparser_rows_read_total{type="graphite"}`)
)
func getStreamContext() *streamContext {
select {
case ctx := <-streamContextPoolCh:
return ctx
default:
if v := streamContextPool.Get(); v != nil {
return v.(*streamContext)
}
return &streamContext{}
}
}
func putStreamContext(ctx *streamContext) {
ctx.reset()
select {
case streamContextPoolCh <- ctx:
default:
streamContextPool.Put(ctx)
}
}
var streamContextPool sync.Pool
var streamContextPoolCh = make(chan *streamContext, runtime.GOMAXPROCS(-1))