From 2888604d2818fee0ef364566c30f566bf7d0dd00 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 12 Feb 2023 09:41:42 +0100 Subject: Merging upstream version 2.11.0. Signed-off-by: Daniel Baumann --- src/ext/hg64.h | 88 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 88 insertions(+) create mode 100644 src/ext/hg64.h (limited to 'src/ext/hg64.h') diff --git a/src/ext/hg64.h b/src/ext/hg64.h new file mode 100644 index 0000000..21ec3d3 --- /dev/null +++ b/src/ext/hg64.h @@ -0,0 +1,88 @@ +/* + * hg64 - 64-bit histograms + * + * Written by Tony Finch + * + * Copyright (C) Internet Systems Consortium, Inc. ("ISC") + * + * SPDX-License-Identifier: MPL-2.0 + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, you can obtain one at https://mozilla.org/MPL/2.0/. + */ + +#ifndef HG64_H +#define HG64_H 1 + +typedef struct hg64 hg64; + +/* + * Allocate a new histogram. `sigbits` must be between 1 and 15 + * inclusive; it is the number of significant bits of each value + * to use when mapping values to buckets. + */ +hg64* hg64_create(unsigned sigbits); + +/* + * Free the memory used by a histogram + */ +void hg64_destroy(hg64* hg); + +/* + * Add 1 to the value's bucket + */ +void hg64_inc(hg64* hg, uint64_t value); + +/* + * Get information about a bucket. This can be used as an iterator, + * by initializing `key` to zero and incrementing by one or using + * `hg64_next()` until `hg64_get()` returns `false`. The number of + * iterations is a little less than `1 << (6 + sigbits)`. + * + * If `pmin` is non-NULL it is set to the bucket's minimum inclusive value. + * + * If `pmax` is non-NULL it is set to the bucket's maximum inclusive value. + * + * If `pcount` is non-NULL it is set to the bucket's counter, which + * can be zero. (Empty buckets are included in the iterator.) + */ +bool hg64_get(hg64* hg, unsigned key, + uint64_t* pmin, uint64_t* pmax, uint64_t* pcount); + +/* + * Skip to the next key, omitting groups of nonexistent buckets. + */ +unsigned hg64_next(hg64* hg, unsigned key); + +/* + * Get summary statistics about the histogram. + * + * If `pmean` is non-NULL it is set to the mean of the recorded data. + * + * If `pvar` is non-NULL it is set to the variance of the recorded + * data. The standard deviation is the square root of the variance. + */ +void hg64_mean_variance(hg64* hg, double* pmean, double* pvar); + +/* + * Increase the counts in `target` by the counts recorded in `source` + */ +void hg64_merge(hg64* target, hg64* source); + +/* + * diff = a - b + */ +void hg64_diff(hg64* a, hg64* b, hg64* diff); + +/* + * Get highest key with non-zero value. Returns 0 if all values are 0. + */ +unsigned hg64_max_key(hg64* hg); + +/* + * Get lowest key with non-zero value. Returns 0 if all values are 0. + */ +unsigned hg64_min_key(hg64* hg); + +#endif -- cgit v1.2.3