v2/doc/google/api/doc_distribution.js

// Copyright 2019 Google LLC
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// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
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//     https://www.apache.org/licenses/LICENSE-2.0
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// Note: this file is purely for documentation. Any contents are not expected
// to be loaded as the JS file.

/**
 * `Distribution` contains summary statistics for a population of values. It
 * optionally contains a histogram representing the distribution of those values
 * across a set of buckets.
 *
 * The summary statistics are the count, mean, sum of the squared deviation from
 * the mean, the minimum, and the maximum of the set of population of values.
 * The histogram is based on a sequence of buckets and gives a count of values
 * that fall into each bucket. The boundaries of the buckets are given either
 * explicitly or by formulas for buckets of fixed or exponentially increasing
 * widths.
 *
 * Although it is not forbidden, it is generally a bad idea to include
 * non-finite values (infinities or NaNs) in the population of values, as this
 * will render the `mean` and `sum_of_squared_deviation` fields meaningless.
 *
 * @property {number} count
 *   The number of values in the population. Must be non-negative. This value
 *   must equal the sum of the values in `bucket_counts` if a histogram is
 *   provided.
 *
 * @property {number} mean
 *   The arithmetic mean of the values in the population. If `count` is zero
 *   then this field must be zero.
 *
 * @property {number} sumOfSquaredDeviation
 *   The sum of squared deviations from the mean of the values in the
 *   population. For values x_i this is:
 *
 *       Sum\[i=1..n](x_1 - mean)^2
 *
 *   Knuth, "The Art of Computer Programming", Vol. 2, page 323, 3rd edition
 *   describes Welford's method for accumulating this sum in one pass.
 *
 *   If `count` is zero then this field must be zero.
 *
 * @property {Object} range
 *   If specified, contains the range of the population values. The field
 *   must not be present if the `count` is zero.
 *
 *   This object should have the same structure as [Range]{@link google.api.Range}
 *
 * @property {Object} bucketOptions
 *   Defines the histogram bucket boundaries. If the distribution does not
 *   contain a histogram, then omit this field.
 *
 *   This object should have the same structure as [BucketOptions]{@link google.api.BucketOptions}
 *
 * @property {number[]} bucketCounts
 *   The number of values in each bucket of the histogram, as described in
 *   `bucket_options`. If the distribution does not have a histogram, then omit
 *   this field. If there is a histogram, then the sum of the values in
 *   `bucket_counts` must equal the value in the `count` field of the
 *   distribution.
 *
 *   If present, `bucket_counts` should contain N values, where N is the number
 *   of buckets specified in `bucket_options`. If you supply fewer than N
 *   values, the remaining values are assumed to be 0.
 *
 *   The order of the values in `bucket_counts` follows the bucket numbering
 *   schemes described for the three bucket types. The first value must be the
 *   count for the underflow bucket (number 0). The next N-2 values are the
 *   counts for the finite buckets (number 1 through N-2). The N'th value in
 *   `bucket_counts` is the count for the overflow bucket (number N-1).
 *
 * @property {Object[]} exemplars
 *   Must be in increasing order of `value` field.
 *
 *   This object should have the same structure as [Exemplar]{@link google.api.Exemplar}
 *
 * @typedef Distribution
 * @memberof google.api
 * @see [google.api.Distribution definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/api/distribution.proto}
 */
const Distribution = {
  // This is for documentation. Actual contents will be loaded by gRPC.

  /**
   * `BucketOptions` describes the bucket boundaries used to create a histogram
   * for the distribution. The buckets can be in a linear sequence, an
   * exponential sequence, or each bucket can be specified explicitly.
   * `BucketOptions` does not include the number of values in each bucket.
   *
   * A bucket has an inclusive lower bound and exclusive upper bound for the
   * values that are counted for that bucket. The upper bound of a bucket must
   * be strictly greater than the lower bound. The sequence of N buckets for a
   * distribution consists of an underflow bucket (number 0), zero or more
   * finite buckets (number 1 through N - 2) and an overflow bucket (number N -
   * 1). The buckets are contiguous: the lower bound of bucket i (i > 0) is the
   * same as the upper bound of bucket i - 1. The buckets span the whole range
   * of finite values: lower bound of the underflow bucket is -infinity and the
   * upper bound of the overflow bucket is +infinity. The finite buckets are
   * so-called because both bounds are finite.
   *
   * @property {Object} linearBuckets
   *   The linear bucket.
   *
   *   This object should have the same structure as [Linear]{@link google.api.Linear}
   *
   * @property {Object} exponentialBuckets
   *   The exponential buckets.
   *
   *   This object should have the same structure as [Exponential]{@link google.api.Exponential}
   *
   * @property {Object} explicitBuckets
   *   The explicit buckets.
   *
   *   This object should have the same structure as [Explicit]{@link google.api.Explicit}
   *
   * @typedef BucketOptions
   * @memberof google.api
   * @see [google.api.Distribution.BucketOptions definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/api/distribution.proto}
   */
  BucketOptions: {
    // This is for documentation. Actual contents will be loaded by gRPC.

    /**
     * Specifies a linear sequence of buckets that all have the same width
     * (except overflow and underflow). Each bucket represents a constant
     * absolute uncertainty on the specific value in the bucket.
     *
     * There are `num_finite_buckets + 2` (= N) buckets. Bucket `i` has the
     * following boundaries:
     *
     *    Upper bound (0 <= i < N-1):     offset + (width * i).
     *    Lower bound (1 <= i < N):       offset + (width * (i - 1)).
     *
     * @property {number} numFiniteBuckets
     *   Must be greater than 0.
     *
     * @property {number} width
     *   Must be greater than 0.
     *
     * @property {number} offset
     *   Lower bound of the first bucket.
     *
     * @typedef Linear
     * @memberof google.api
     * @see [google.api.Distribution.BucketOptions.Linear definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/api/distribution.proto}
     */
    Linear: {
      // This is for documentation. Actual contents will be loaded by gRPC.
    },

    /**
     * Specifies an exponential sequence of buckets that have a width that is
     * proportional to the value of the lower bound. Each bucket represents a
     * constant relative uncertainty on a specific value in the bucket.
     *
     * There are `num_finite_buckets + 2` (= N) buckets. Bucket `i` has the
     * following boundaries:
     *
     *    Upper bound (0 <= i < N-1):     scale * (growth_factor ^ i).
     *    Lower bound (1 <= i < N):       scale * (growth_factor ^ (i - 1)).
     *
     * @property {number} numFiniteBuckets
     *   Must be greater than 0.
     *
     * @property {number} growthFactor
     *   Must be greater than 1.
     *
     * @property {number} scale
     *   Must be greater than 0.
     *
     * @typedef Exponential
     * @memberof google.api
     * @see [google.api.Distribution.BucketOptions.Exponential definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/api/distribution.proto}
     */
    Exponential: {
      // This is for documentation. Actual contents will be loaded by gRPC.
    },

    /**
     * Specifies a set of buckets with arbitrary widths.
     *
     * There are `size(bounds) + 1` (= N) buckets. Bucket `i` has the following
     * boundaries:
     *
     *    Upper bound (0 <= i < N-1):     bounds[i]
     *    Lower bound (1 <= i < N);       bounds[i - 1]
     *
     * The `bounds` field must contain at least one element. If `bounds` has
     * only one element, then there are no finite buckets, and that single
     * element is the common boundary of the overflow and underflow buckets.
     *
     * @property {number[]} bounds
     *   The values must be monotonically increasing.
     *
     * @typedef Explicit
     * @memberof google.api
     * @see [google.api.Distribution.BucketOptions.Explicit definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/api/distribution.proto}
     */
    Explicit: {
      // This is for documentation. Actual contents will be loaded by gRPC.
    }
  }
};