Add 'AddValuesWithTime' function to accumulator

PLUGINS.md

@@ -28,7 +28,8 @@ type Plugin interface {
 }
 
 type Accumulator interface {
-	Add(name string, value interface{}, tags map[string]string)
+  Add(name string, value interface{}, tags map[string]string)
+  AddValuesWithTime(name string, values map[string]interface{}, tags map[string]string, timestamp time.Time)
 }
 ```
 
@@ -38,15 +39,19 @@ The way that a plugin emits metrics is by interacting with the Accumulator.
 
 The `Add` function takes 3 arguments:
 * **name**: A string which names the metric. For instance `bytes_read` or `faults`.
-* **value**: A value for the metric. Ths accepts 5 different types of value:
+* **value**: A value for the metric. This accepts 5 different types of value:
   * **int**: The most common type. All int types are accepted but favor using `int64`
   Useful for counters, etc.
   * **float**: Favor `float64`, useful for gauges, percentages, etc.
   * **bool**: `true` or `false`, useful to indicate the presence of a state. `light_on`, etc.
   * **string**: Typically used to indicate a message, or some kind of freeform information.
-  * **time.Time**: Useful for indicating when a state last occured, for instance `light_on_since`.
+  * **time.Time**: Useful for indicating when a state last occurred, for instance `light_on_since`.
 * **tags**: This is a map of strings to strings to describe the where or who about the metric. For instance, the `net` plugin adds a tag named `"interface"` set to the name of the network interface, like `"eth0"`.
 
+The `AddValuesWithTime` allows multiple values for a point to be passed. The values
+used are the same type profile as **value** above. The **timestamp** argument
+allows a point to be registered as having occurred at an arbitrary time.
+
 Let's say you've written a plugin that emits metrics abuot processes on the current host.
 
 ```go

accumulator.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"sort"
 	"strings"
+	"time"
 
 	"github.com/influxdb/influxdb/client"
 )
@@ -36,7 +37,7 @@ func (bp *BatchPoints) Add(name string, val interface{}, tags map[string]string)
 
 		sort.Strings(tg)
 
-		fmt.Printf("> [%s] %s=%v\n", strings.Join(tg, " "), name, val)
+		fmt.Printf("> [%s] %s value=%v\n", strings.Join(tg, " "), name, val)
 	}
 
 	bp.Points = append(bp.Points, client.Point{
@@ -47,3 +48,44 @@ func (bp *BatchPoints) Add(name string, val interface{}, tags map[string]string)
 		},
 	})
 }
+
+func (bp *BatchPoints) AddValuesWithTime(
+	name string,
+	values map[string]interface{},
+	tags map[string]string,
+	timestamp time.Time,
+) {
+	name = bp.Prefix + name
+
+	if bp.Config != nil {
+		if !bp.Config.ShouldPass(name) {
+			return
+		}
+	}
+
+	if bp.Debug {
+		var tg []string
+
+		for k, v := range tags {
+			tg = append(tg, fmt.Sprintf("%s=\"%s\"", k, v))
+		}
+
+		var vals []string
+
+		for k, v := range values {
+			vals = append(vals, fmt.Sprintf("%s=%v", k, v))
+		}
+
+		sort.Strings(tg)
+		sort.Strings(vals)
+
+		fmt.Printf("> [%s] %s %s\n", strings.Join(tg, " "), name, strings.Join(vals, " "))
+	}
+
+	bp.Points = append(bp.Points, client.Point{
+		Name:   name,
+		Tags:   tags,
+		Fields: values,
+		Time:   timestamp,
+	})
+}

plugins/registry.go

@@ -1,7 +1,22 @@
 package plugins
 
+import "time"
+
 type Accumulator interface {
+	// Create a named point with a value, decorating it with named tags
+	// NOTE: tags is expected to be owned by the caller, don't mutate
+	// it after passing to Add.
 	Add(name string, value interface{}, tags map[string]string)
+
+	// Create a named point with a set of values, decorating it with named tags
+	// NOTE: tags and values are expected to be owned by the caller, don't mutate
+	// them after passing to AddValuesWithTime.
+	AddValuesWithTime(
+		name string,
+		values map[string]interface{},
+		tags map[string]string,
+		timestamp time.Time,
+	)
 }
 
 type Plugin interface {

testutil/accumulator.go

@@ -1,11 +1,16 @@
 package testutil
 
-import "fmt"
+import (
+	"fmt"
+	"time"
+)
 
 type Point struct {
-	Name  string
-	Value interface{}
-	Tags  map[string]string
+	Name   string
+	Value  interface{}
+	Tags   map[string]string
+	Values map[string]interface{}
+	Time   time.Time
 }
 
 type Accumulator struct {
@@ -13,7 +18,31 @@ type Accumulator struct {
 }
 
 func (a *Accumulator) Add(name string, value interface{}, tags map[string]string) {
-	a.Points = append(a.Points, &Point{name, value, tags})
+	a.Points = append(
+		a.Points,
+		&Point{
+			Name:  name,
+			Value: value,
+			Tags:  tags,
+		},
+	)
+}
+
+func (a *Accumulator) AddValuesWithTime(
+	name string,
+	values map[string]interface{},
+	tags map[string]string,
+	timestamp time.Time,
+) {
+	a.Points = append(
+		a.Points,
+		&Point{
+			Name:   name,
+			Values: values,
+			Tags:   tags,
+			Time:   timestamp,
+		},
+	)
 }
 
 func (a *Accumulator) Get(name string) (*Point, bool) {