| 1 | import { Duration } from '@aws-cdk/core';
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| 2 | import { IMetric, MetricConfig, MetricExpressionConfig, MetricStatConfig } from '../metric-types';
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| 3 | /**
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| 4 | * Return a unique string representation for this metric.
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| 5 | *
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| 6 | * Can be used to determine as a hash key to determine if 2 Metric objects
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| 7 | * represent the same metric. Excludes rendering properties.
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| 8 | */
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| 9 | export declare function metricKey(metric: IMetric): string;
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| 10 | /**
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| 11 | * Return the period of a metric
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| 12 | *
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| 13 | * For a stat metric, return the immediate period.
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| 14 | *
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| 15 | * For an expression metric, all metrics used in it have been made to have the
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| 16 | * same period, so we return the period of the first inner metric.
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| 17 | */
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| 18 | export declare function metricPeriod(metric: IMetric): Duration;
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| 19 | /**
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| 20 | * Given a metric object, inspect it and call the correct function for the type of output
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| 21 | *
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| 22 | * In addition to the metric object itself, takes a callback object with two
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| 23 | * methods, to be invoked for the particular type of metric.
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| 24 | *
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| 25 | * If the metric represent a metric query (nominally generated through an
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| 26 | * instantiation of `Metric` but can be generated by any class that implements
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| 27 | * `IMetric`) a particular field in its `toMetricConfig()` output will be set
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| 28 | * (to wit, `metricStat`) and the `withStat()` callback will be called with
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| 29 | * that object.
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| 30 | *
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| 31 | * If the metric represents an expression (usually by instantiating `MathExpression`
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| 32 | * but users can implement `IMetric` arbitrarily) the `mathExpression` field
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| 33 | * will be set in the object returned from `toMetricConfig` and the callback
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| 34 | * called `withExpression` will be applied to that object.
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| 35 | *
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| 36 | * Will return the values returned by the callbacks.
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| 37 | *
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| 38 | * To be used as such:
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| 39 | *
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| 40 | * ```ts
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| 41 | * const ret = dispatchMetric(someMetric, {
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| 42 | * withStat(stat) {
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| 43 | * // do something with stat
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| 44 | * return 1;
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| 45 | * },
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| 46 | * withExpression(expr) {
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| 47 | * // do something with expr
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| 48 | * return 2;
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| 49 | * },
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| 50 | * });
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| 51 | * ```
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| 52 | *
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| 53 | * This function encapsulates some type analysis that would otherwise have to be
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| 54 | * repeated in all places where code needs to make a distinction on the type
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| 55 | * of metric object that is being passed.
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| 56 | */
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| 57 | export declare function dispatchMetric<A, B>(metric: IMetric, fns: {
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| 58 | withStat: (x: MetricStatConfig, c: MetricConfig) => A;
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| 59 | withExpression: (x: MetricExpressionConfig, c: MetricConfig) => B;
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| 60 | }): A | B;
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