Add line protocol uint64 support (#3946)

Makefile

@@ -4,6 +4,7 @@ BRANCH := $(shell git rev-parse --abbrev-ref HEAD)
 COMMIT := $(shell git rev-parse --short HEAD)
 GOFILES ?= $(shell git ls-files '*.go')
 GOFMT ?= $(shell gofmt -l $(filter-out plugins/parsers/influx/machine.go, $(GOFILES)))
+BUILDFLAGS ?= 
 
 ifdef GOBIN
 PATH := $(GOBIN):$(PATH)
@@ -35,7 +36,7 @@ deps:
 	gdm restore
 
 telegraf:
-	go build -i -o $(TELEGRAF) -ldflags "$(LDFLAGS)" ./cmd/telegraf/telegraf.go
+	go build -i -o $(TELEGRAF) -ldflags "$(LDFLAGS)" $(BUILDFLAGS) ./cmd/telegraf/telegraf.go
 
 go-install:
 	go install -ldflags "-w -s $(LDFLAGS)" ./cmd/telegraf
@@ -61,6 +62,9 @@ fmtcheck:
 	fi
 	@echo '[INFO] done.'
 
+uint64:
+	BUILDFLAGS="-tags uint64" $(MAKE) all
+
 lint:
 	golint ./...
 
@@ -99,4 +103,4 @@ docker-image:
 plugins/parsers/influx/machine.go: plugins/parsers/influx/machine.go.rl
 	ragel -Z -G2 $^ -o $@
 
-.PHONY: deps telegraf install test test-windows lint vet test-all package clean docker-image fmtcheck
+.PHONY: deps telegraf install test test-windows lint vet test-all package clean docker-image fmtcheck uint64

metric/metric.go

@@ -11,6 +11,16 @@ import (
 
 const MaxInt = int(^uint(0) >> 1)
 
+// enableUint64Support will enable uint64 support if set to true.
+var enableUint64Support = false
+
+// EnableUintSupport manually enables uint support for convertValue.
+// This function will be removed in the future and only exists for unit tests during the
+// transition.
+func EnableUintSupport() {
+	enableUint64Support = true
+}
+
 type metric struct {
 	name   string
 	tags   []*telegraf.Tag
@@ -265,11 +275,14 @@ func convertField(v interface{}) interface{} {
 			return int64(MaxInt)
 		}
 	case uint64:
-		if v <= uint64(MaxInt) {
-			return int64(v)
-		} else {
-			return int64(MaxInt)
+		if enableUint64Support == false {
+			if v <= uint64(MaxInt) {
+				return int64(v)
+			} else {
+				return int64(MaxInt)
+			}
 		}
+		return uint64(v)
 	case []byte:
 		return string(v)
 	case int32:

metric/uint_support.go

@@ -0,0 +1,7 @@
+// +build uint64
+
+package metric
+
+func init() {
+	EnableUintSupport()
+}

plugins/parsers/influx/escape.go

@@ -63,6 +63,12 @@ func parseIntBytes(b []byte, base int, bitSize int) (i int64, err error) {
 	return strconv.ParseInt(s, base, bitSize)
 }
 
+// parseUintBytes is a zero-alloc wrapper around strconv.ParseUint.
+func parseUintBytes(b []byte, base int, bitSize int) (i uint64, err error) {
+	s := unsafeBytesToString(b)
+	return strconv.ParseUint(s, base, bitSize)
+}
+
 // parseFloatBytes is a zero-alloc wrapper around strconv.ParseFloat.
 func parseFloatBytes(b []byte, bitSize int) (float64, error) {
 	s := unsafeBytesToString(b)

plugins/parsers/influx/handler.go

@@ -54,6 +54,16 @@ func (h *MetricHandler) AddInt(key []byte, value []byte) {
 	h.builder.AddField(fk, fv)
 }
 
+func (h *MetricHandler) AddUint(key []byte, value []byte) {
+	fk := unescape(key)
+	fv, err := parseUintBytes(bytes.TrimSuffix(value, []byte("u")), 10, 64)
+	if err != nil {
+		log.Errorf("E! Received unparseable uint value: %q", value)
+		return
+	}
+	h.builder.AddField(fk, fv)
+}
+
 func (h *MetricHandler) AddFloat(key []byte, value []byte) {
 	fk := unescape(key)
 	fv, err := parseFloatBytes(value, 64)