messages

Documentation

Overview

Package messages provides the types needed to collect metrics via the go rpc calls and the REST API mentioned in the tricorder package.

Index

• Variables
• func AsJsonWithSubType(value interface{}, kind, subType types.Type, unit units.Unit) (jsonValue interface{}, jsonKind, jsonSubType types.Type)
• func ZeroValue(t types.Type) (interface{}, error)
• type Distribution
  • func (d *Distribution) Type() types.Type
• type Metric
  • func (m *Metric) ConvertToGoRPC() error
  • func (m *Metric) ConvertToJson()
• type MetricList
• type RangeWithCount

Variables

var (
	// The MetricServer.GetMetric RPC call returns this if no
	// metric with given path exists.
	ErrMetricNotFound = errors.New("messages: No metric found.")
)

Functions

func AsJsonWithSubType

func AsJsonWithSubType(
	value interface{}, kind, subType types.Type, unit units.Unit) (
	jsonValue interface{}, jsonKind, jsonSubType types.Type)

AsJsonWithSubType takes a metric value, kind, subtype, and unit and returns an acceptable JSON value, kind, and subType for given unit. If kind is types.List, subType indicates the type of elements in the list. Otherwise, caller should pass types.Unknown for subType. Likewise, if returned jsonKind is types.List, jsonSubType is the type of elements in the list. Otherwise jsonSubType is types.Unknown.

func ZeroValue

func ZeroValue(t types.Type) (interface{}, error)

ZeroValue works like types.Type.SafeZeroValue, but unlike the types.Type version, this method can also return zero values for types in this package.

Types

type Distribution

type Distribution struct {
	// The minimum value
	Min float64 `json:"min"`
	// The maximum value
	Max float64 `json:"max"`
	// The average value
	Average float64 `json:"average"`
	// The approximate median value
	Median float64 `json:"median"`
	// The sum
	Sum float64 `json:"sum"`
	// The total number of values
	Count uint64 `json:"count"`
	// This field is incremented by 1 each time this distribution changes.
	Generation uint64 `json:"generation"`
	// This field is true if this distribution is not cumulative.
	IsNotCumulative bool `json:"isNotCumulative,omitempty"`
	// The number of values within each range
	Ranges []*RangeWithCount `json:"ranges,omitempty"`
}

Distribution represents a distribution of values.

func (*Distribution) Type

func (d *Distribution) Type() types.Type

type Metric

type Metric struct {
	// The absolute path to this metric
	Path string `json:"path"`
	// The description of this metric
	Description string `json:"description"`
	// The unit of measurement this metric represents
	Unit units.Unit `json:"unit,omitempty"`
	// The metric's type
	Kind types.Type `json:"kind"`
	// The sub-type if type is an aggregate such as List.
	SubType types.Type `json:"subType,omitempty"`
	// The size in bits of metric's value if Kind is
	// types.IntXX, types.UintXX, or types.FloatXX.
	Bits int `json:"bits,omitempty"`
	// value stored here
	Value interface{} `json:"value"`
	// TimeStamp of metric value.
	// For JSON this is seconds since Jan 1, 1970 as a string as
	// "1234567890.999999999"
	// For Go RPC this is a time.Time.
	// This is an optional field. In Go RPC, it can be nil; in JSON, it
	// can be the empty string.
	TimeStamp interface{} `json:"timestamp"`
	// GroupId of the metric's region. Metrics with the same group Id
	// will always have the same timestamp.
	GroupId int `json:"groupId"`
}

Metric represents a single metric The type of the actual value stored in the Value field depends on the value of the Kind field.

The chart below lists what type Value contains for each value of the Kind and Subtype field:

Kind		SubType			Actual type
types.Bool				bool
types.Int8				int8
types.Int16				int16
types.Int32				int32
types.Int64				int64
types.Uint8				uint8
types.Uint16				uint16
types.Uint32				uint32
types.Uint64				uint64
types.Float32				float32
types.Float64				float64
types.String				string
types.Dist				*messages.Distribution
types.Time				string: Seconds since Jan 1, 1970 GMT. 9 digits after the decimal point.
types.Duration				string: Seconds with 9 digits after the decimal point.
types.GoTime				time.Time (Go RPC only)
types.GoDuration			time.Duration (Go RPC only)
types.List	types.Bool		[]bool
types.List	types.Int8		[]int8
types.List	types.Int16		[]int16
types.List	types.Int32		[]int32
types.List	types.Int64		[]int64
types.List	types.Uint8		[]uint8
types.List	types.Uint16		[]uint16
types.List	types.Uint32		[]uint32
types.List	types.Uint64		[]uint64
types.List	types.Float32		[]float32
types.List	types.Float64		[]float64
types.List	types.String		[]string
types.List	types.Time		[]string
types.List	types.Duration		[]string
types.List	types.GoTime		[]time.Time (Go RPC only)
types.List	types.GoDuration	[]time.Duration (Go RPC only)

func (*Metric) ConvertToGoRPC

func (m *Metric) ConvertToGoRPC() error

ConvertToGoRPC changes this metric in place to be go rpc compatible.

func (*Metric) ConvertToJson

func (m *Metric) ConvertToJson()

ConvertToJson changes this metric in place to be json compatible.

type MetricList

type MetricList []*Metric

MetricList represents a list of metrics. Clients should treat MetricList instances as immutable. In particular, clients should not modify contained Metric instances in place.

type RangeWithCount

type RangeWithCount struct {
	// Represents the lower bound of the range inclusive.
	// Ignore for the lowest range which never has a lower bound.
	Lower float64 `json:"lower"`
	// Represents the upper bound of the range exclusive.
	// Ignore for the highest range which never has a upper bound.
	Upper float64 `json:"upper"`
	// The number of values falling within the range.
	Count uint64 `json:"count"`
}

RangeWithCount represents the number of values within a particular range.