timings

README

go-timings

Go package implementing interface and methods for background timing monitors

Documentation

Exmaple

import (
       "context"
       "github.com/sfomuseum/go-timings"
       "os"       
)

func main() {

	ctx := context.Background()
	
	monitor, _ := timings.NewMonitor(ctx, "counter://PT60S")

	monitor.Start(ctx, os.Stderr)
	defer monitor.Stop(ctx)

	monitor.Signal(ctx)	// increments by 1
}

Documentation

Overview

package timings provides an interface and methods for background timing monitors

Index

• func RegisterMonitor(ctx context.Context, scheme string, init_func MonitorInitializationFunc) error
• func Schemes() []string
• type CounterMonitor
  • func (t *CounterMonitor) Signal(ctx context.Context, args ...interface{}) error
  • func (t *CounterMonitor) Start(ctx context.Context, wr io.Writer) error
  • func (t *CounterMonitor) Stop(ctx context.Context) error
• type Monitor
  • func NewCounterMonitor(ctx context.Context, uri string) (Monitor, error)
  • func NewMonitor(ctx context.Context, uri string) (Monitor, error)
  • func NewNullMonitor(ctx context.Context, uri string) (Monitor, error)
  • func NewSinceMonitor(ctx context.Context, uri string) (Monitor, error)
• type MonitorInitializationFunc
• type NullMonitor
  • func (nm *NullMonitor) Signal(ctx context.Context, args ...interface{}) error
  • func (nm *NullMonitor) Start(ctx context.Context, wr io.Writer) error
  • func (nm *NullMonitor) Stop(ctx context.Context) error
• type SinceEvent
• type SinceMonitor
  • func (t *SinceMonitor) Signal(ctx context.Context, args ...interface{}) error
  • func (t *SinceMonitor) Start(ctx context.Context, wr io.Writer) error
  • func (t *SinceMonitor) Stop(ctx context.Context) error
• type SinceResponse
  • func (s SinceResponse) String() string

Functions

func RegisterMonitor

func RegisterMonitor(ctx context.Context, scheme string, init_func MonitorInitializationFunc) error

RegisterMonitor registers 'scheme' as a key pointing to 'init_func' in an internal lookup table used to create new `Monitor` instances by the `NewMonitor` method.

func Schemes

func Schemes() []string

Schemes returns the list of schemes that have been registered.

Types

type CounterMonitor

type CounterMonitor struct {
	Monitor
	// contains filtered or unexported fields
}

type CounterMonitor implements the `Monitor` interface providing a background timings mechanism that tracks incrementing events.

func (*CounterMonitor) Signal

func (t *CounterMonitor) Signal(ctx context.Context, args ...interface{}) error

Signal will cause the background monitors counter to be incremented by one.

func (*CounterMonitor) Start

func (t *CounterMonitor) Start(ctx context.Context, wr io.Writer) error

Start() will cause background monitoring to begin, dispatching notifications to wr.

func (*CounterMonitor) Stop

func (t *CounterMonitor) Stop(ctx context.Context) error

Stop() will cause background monitoring to be halted.

type Monitor

type Monitor interface {
	// The Start method starts the monitor dispatching notifications to an io.Writer instance
	Start(context.Context, io.Writer) error
	// The Stop method will stop monitoring
	Stop(context.Context) error
	// The Signal method will dispatch messages to the monitoring process
	Signal(context.Context, ...interface{}) error
}

type Monitor provides a common interface for timings-based monitors

func NewCounterMonitor

func NewCounterMonitor(ctx context.Context, uri string) (Monitor, error)

NewCounterMonitor creates a new `CounterMonitor` instance that will dispatch notifications using a time.Ticker configured by 'uri' which is expected to take the form of:

counter://?duration={ISO8601_DURATION}

Where {ISO8601_DURATION} is a valid ISO8601 duration string.

func NewMonitor

func NewMonitor(ctx context.Context, uri string) (Monitor, error)

NewMonitor returns a new `Monitor` instance configured by 'uri'. The value of 'uri' is parsed as a `url.URL` and its scheme is used as the key for a corresponding `MonitorInitializationFunc` function used to instantiate the new `Monitor`. It is assumed that the scheme (and initialization function) have been registered by the `RegisterMonitor` method.

func NewNullMonitor

func NewNullMonitor(ctx context.Context, uri string) (Monitor, error)

NewNullMonitor() creates a new `NullMonitor` which does nothing.

null://

func NewSinceMonitor

func NewSinceMonitor(ctx context.Context, uri string) (Monitor, error)

NewSinceMonitor creates a new `SinceMonitor` instance that will dispatch notifications using a time.Ticker configured by 'uri' which is expected to take the form of:

since://

type MonitorInitializationFunc

type MonitorInitializationFunc func(ctx context.Context, uri string) (Monitor, error)

MonitorInitializationFunc is a function defined by individual monitor package and used to create an instance of that monitor

type NullMonitor

type NullMonitor struct {
	Monitor
}

type NullMonitor implements the `Monitor` interface but does nothing.

func (*NullMonitor) Signal

func (nm *NullMonitor) Signal(ctx context.Context, args ...interface{}) error

Signal() is a no-op and nothing will happen.

func (*NullMonitor) Start

func (nm *NullMonitor) Start(ctx context.Context, wr io.Writer) error

Start() will cause monitoring to begin, which in this means nothing will happen and no events will be written to 'wr'.

func (*NullMonitor) Stop

func (nm *NullMonitor) Stop(ctx context.Context) error

Stop() will cause monitoring to be halted.

type SinceEvent

type SinceEvent uint8

const (
	SinceStart SinceEvent = iota
	SinceStop
)

type SinceMonitor

type SinceMonitor struct {
	Monitor
	// contains filtered or unexported fields
}

type SinceMonitor implements the `Monitor` interface providing a background timings mechanism that tracks the duration of time between events.

func (*SinceMonitor) Signal

func (t *SinceMonitor) Signal(ctx context.Context, args ...interface{}) error

Signal will cause the background monitors since to be incremented by one.

func (*SinceMonitor) Start

func (t *SinceMonitor) Start(ctx context.Context, wr io.Writer) error

Start() will cause background monitoring to begin, dispatching notifications to wr in the form of JSON-encoded `SinceResponse` values.

func (*SinceMonitor) Stop

func (t *SinceMonitor) Stop(ctx context.Context) error

Stop() will cause background monitoring to be halted.

type SinceResponse

type SinceResponse struct {
	// Label is a string that was included with a `Signal` event
	Label string `json:"message"`
	// Duration is the string representation of a `time.Duuration` which is the amount of time that elapsed between `Signal` events
	Duration string `json:"duration"`
	// Timestamp is the Unix timestamp when the `SinceResponse` was created
	Timestamp int64 `json:"timestamp"`
}

SinceResponse is a struct containing information related to a "since" timing event.

func (SinceResponse) String

func (s SinceResponse) String() string

String() returns a string representation of the response.