VictoriaMetrics/lib/protoparser/vmimport/streamparser.go
2020-07-10 12:00:58 +03:00

111 lines
2.6 KiB
Go

package vmimport
import (
"flag"
"fmt"
"io"
"net/http"
"runtime"
"sync"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/protoparser/common"
"github.com/VictoriaMetrics/metrics"
)
var maxLineLen = flag.Int("import.maxLineLen", 100*1024*1024, "The maximum length in bytes of a single line accepted by /api/v1/import")
// ParseStream parses /api/v1/import lines from req and calls callback for the parsed rows.
//
// The callback can be called multiple times for streamed data from req.
//
// callback shouldn't hold rows after returning.
func ParseStream(req *http.Request, callback func(rows []Row) error) error {
r := req.Body
if req.Header.Get("Content-Encoding") == "gzip" {
zr, err := common.GetGzipReader(r)
if err != nil {
return fmt.Errorf("cannot read gzipped vmimport data: %w", err)
}
defer common.PutGzipReader(zr)
r = zr
}
ctx := getStreamContext()
defer putStreamContext(ctx)
for ctx.Read(r) {
if err := callback(ctx.Rows.Rows); err != nil {
return err
}
}
return ctx.Error()
}
func (ctx *streamContext) Read(r io.Reader) bool {
readCalls.Inc()
if ctx.err != nil {
return false
}
ctx.reqBuf, ctx.tailBuf, ctx.err = common.ReadLinesBlockExt(r, ctx.reqBuf, ctx.tailBuf, *maxLineLen)
if ctx.err != nil {
if ctx.err != io.EOF {
readErrors.Inc()
ctx.err = fmt.Errorf("cannot read vmimport data: %w", ctx.err)
}
return false
}
ctx.Rows.Unmarshal(bytesutil.ToUnsafeString(ctx.reqBuf))
rowsRead.Add(len(ctx.Rows.Rows))
return true
}
var (
readCalls = metrics.NewCounter(`vm_protoparser_read_calls_total{type="vmimport"}`)
readErrors = metrics.NewCounter(`vm_protoparser_read_errors_total{type="vmimport"}`)
rowsRead = metrics.NewCounter(`vm_protoparser_rows_read_total{type="vmimport"}`)
)
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
}
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))