Revert "Reduce memory allocations in handlePacket"

bridge_test.go

@@ -315,54 +315,3 @@ func TestHandlePacket(t *testing.T) {
 		}
 	}
 }
-
-func BenchmarkUDPListener(b *testing.B) {
-	scenarios := []struct {
-		name    string
-		metrics [][]byte
-	}{
-		{
-			name:    "simple counter",
-			metrics: [][]byte{[]byte("counter:2|c")},
-		}, {
-			name:    "simple gauge",
-			metrics: [][]byte{[]byte("gauge:10|g")},
-		}, {
-			name:    "simple timing",
-			metrics: [][]byte{[]byte("timing:200|ms")},
-		}, {
-			name:    "simple histogram",
-			metrics: [][]byte{[]byte("histogram:200|h")},
-		}, {
-			name:    "simple distribution",
-			metrics: [][]byte{[]byte("distribution:200|d")},
-		}, {
-			name:    "simple_tags",
-			metrics: [][]byte{[]byte("simple_tags:100|c|#tag1:bar,tag2:baz")},
-		}, {
-			name:    "datadog tag extension with complex tags",
-			metrics: [][]byte{[]byte("foo:100|c|#09digits:0,tag.with.dots:1")},
-		}, {
-			name:    "datadog many tags",
-			metrics: [][]byte{[]byte("cpu_throttle_time_ms:1.1|ms|#action:test,application:testapp,application_component:testcomp,application_role:test_role,category:category,controller:controller,deployed_to:production,kube_deployment:deploy,kube_namespace:kube-production,method:get,version:rails5_2,status:200,status_range:2xx)}")},
-		}, {
-			name:    "datadog tag extension with sampling",
-			metrics: [][]byte{[]byte("foo:100|c|@0.1|#tag1:bar,#tag2:baz")},
-		}, {
-			name:    "combined multiline metrics",
-			metrics: [][]byte{[]byte("foo:200|ms:300|ms:5|c|@0.1:6|g\nbar:1|c:5|ms")},
-		},
-	}
-	for _, s := range scenarios {
-		l := &StatsDUDPListener{}
-		b.Run(s.name, func(b *testing.B) {
-			events := make(chan Events, len(s.metrics)*b.N)
-			defer close(events)
-			for i := 1; i <= b.N; i++ {
-				for _, m := range s.metrics {
-					l.handlePacket(m, events)
-				}
-			}
-		})
-	}
-}

exporter.go

@@ -25,7 +25,6 @@ import (
 	"strings"
 	"time"
 	"unicode/utf8"
-	"unsafe"
 
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/common/log"
@@ -743,7 +742,6 @@ func parseDogStatsDTagsToLabels(component string) map[string]string {
 }
 
 func lineToEvents(line string) Events {
-	linesReceived.Inc()
 	events := Events{}
 	if line == "" {
 		return events
@@ -866,26 +864,12 @@ func (l *StatsDUDPListener) Listen(e chan<- Events) {
 
 func (l *StatsDUDPListener) handlePacket(packet []byte, e chan<- Events) {
 	udpPackets.Inc()
-
+	lines := strings.Split(string(packet), "\n")
 	events := Events{}
-	// Convert the []byte array into a string w/o copying or allocating new
+	for _, line := range lines {
-	// memory, then walk the string looking for newlines to avoid memory
+		linesReceived.Inc()
-	// allocation from Split.
-	p := *(*string)(unsafe.Pointer(&packet))
-	offset := 0
-	for i, c := range p {
-		if c == '\n' {
-			line := p[offset:i]
-			events = append(events, lineToEvents(line)...)
-			offset = i + 1
-		}
-	}
-
-	if offset < len(p) {
-		line := p[offset:]
 		events = append(events, lineToEvents(line)...)
 	}
-
 	e <- events
 }
 
@@ -928,6 +912,7 @@ func (l *StatsDTCPListener) handleConn(c *net.TCPConn, e chan<- Events) {
 			log.Debugf("Read %s failed: line too long", c.RemoteAddr())
 			break
 		}
+		linesReceived.Inc()
 		e <- lineToEvents(string(line))
 	}
 }
@@ -957,6 +942,7 @@ func (l *StatsDUnixgramListener) handlePacket(packet []byte, e chan<- Events) {
 	lines := strings.Split(string(packet), "\n")
 	events := Events{}
 	for _, line := range lines {
+		linesReceived.Inc()
 		events = append(events, lineToEvents(line)...)
 	}
 	e <- events