Implements: ICounters, IReconfigurable, ICounterTimingCallback

Description

The CachedCounters class allows you to create performace counters that measure and store those values in memory.

Important points

• Child classes can implement saving of the counters into various different destinations.

Configuration parameters

options:

• interval: interval in milliseconds to save current counters measurements (default: 5 mins)
• reset_timeout: timeout in milliseconds to reset the counters. 0 disables the reset (default: 0)

Constructors

Creates a new CachedCounters object.

public constructor()

Fields

_interval

Default time interval.

protected _interval = 300000

_cache

A dictionary containing the cached values.

protected _cache: { [id: string]: Counter }

_updated

A boolean value that indicates whether the counter has been updated or not.

protected _updated: boolean

_lastDumpTime

Time of the last dump.

protected _lastDumpTime: Date

_lastResetTime

Last time when was reset timer

protected _lastResetTime: Date

_resetTimeout

Timeout to reset timer

protected _resetTimeout: number

Instance methods

beginTiming

Begins measurement of execution time interval. It returns CounterTiming object which has to be called at CounterTiming.endTiming to end the measurement and update the counter.

public beginTiming(name: string): CounterTiming

• name: string - a counter name of Interval type.
• returns: CounterTiming - a callback object to end timing.

clear

Clears (resets) a counter specified by its name.

public clear(name: string): void

• name: string - a counter name to clear.

clearAll

Clears (resets) all counters.

public clearAll(): void

configure

Configures component by passing configuration parameters.

public configure(config: ConfigParams): void

• config: ConfigParams - configuration parameters to be set.

dump

Dumps (saves) the current values of counters.

public dump(): void

endTiming

Ends measurement of execution elapsed time and updates specified counter.

public endTiming(name: string, elapsed: number): void

• name: string - a counter name
• elapsed: number - execution elapsed time in milliseconds to update the counter.

get

Gets a counter specified by its name. It counter does not exist or its type doesn’t match the specified type it creates a new one.

public get(name: string, typ: CounterType): Counter

• name: string - a counter name to retrieve.
• typ: CounterType - a counter type.
• returns: Counter - an existing or newly created counter of the specified type.

getAll

Gets all captured counters.

public getAll(): Counter[]

• returns: Counter[] - a list with counters.

getInterval

Gets the counters dump/save interval.

public getInterval(): number

• returns: number - the interval in milliseconds.

increment

Increments counter by given value.

public increment(name: string, value: number): void

• name: string - a counter name of Increment type.
• value: number - a value to add to the counter.

incrementOne

Increments counter by 1.

public incrementOne(name: string): void

• name: string - a counter name of Increment type.

last

Records the last calculated measurement value. Usually this method is used by metrics calculated externally.

public last(name: string, value: number): void

• name: string - a counter name of Last type.
• value: number - a last value to record.

setInterval

Sets the counters dump/save interval.

public setInterval(value: number): void

• value: number - a new interval in milliseconds.

stats

Calculates min/average/max statistics based on the current and previous values.

public stats(name: string, value: number): void

• name: string - a counter name of Statistics type
• value: number - a value to update statistics

timestamp

Records the given timestamp.

public timestamp(name: string, value: Date): void

• name: string - a counter name of Timestamp type.
• value: Date - a timestamp to record.

timestampNow

Records the current time as a timestamp.

public timestampNow(name: string): void

• name: string - a counter name of Timestamp type.

update

Makes counter measurements as updated and dumps them when timeout expires.

protected update()

Abstract methods

save

Saves the current counters measurements.

protected abstract save(counters: Counter[]): void

• counters: Counter[] - current counters measurements to be saved.