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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-14 13:40:54 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-14 13:40:54 +0000
commit317c0644ccf108aa23ef3fd8358bd66c2840bfc0 (patch)
treec417b3d25c86b775989cb5ac042f37611b626c8a /deps/hdr_histogram/hdr_histogram.c
parentInitial commit. (diff)
downloadredis-317c0644ccf108aa23ef3fd8358bd66c2840bfc0.tar.xz
redis-317c0644ccf108aa23ef3fd8358bd66c2840bfc0.zip
Adding upstream version 5:7.2.4.upstream/5%7.2.4
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'deps/hdr_histogram/hdr_histogram.c')
-rw-r--r--deps/hdr_histogram/hdr_histogram.c1229
1 files changed, 1229 insertions, 0 deletions
diff --git a/deps/hdr_histogram/hdr_histogram.c b/deps/hdr_histogram/hdr_histogram.c
new file mode 100644
index 0000000..f469347
--- /dev/null
+++ b/deps/hdr_histogram/hdr_histogram.c
@@ -0,0 +1,1229 @@
+/**
+ * hdr_histogram.c
+ * Written by Michael Barker and released to the public domain,
+ * as explained at http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+#include <stdlib.h>
+#include <stdbool.h>
+#include <math.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdint.h>
+#include <errno.h>
+#include <inttypes.h>
+
+#include "hdr_histogram.h"
+#include "hdr_tests.h"
+#include "hdr_atomic.h"
+
+#ifndef HDR_MALLOC_INCLUDE
+#define HDR_MALLOC_INCLUDE "hdr_malloc.h"
+#endif
+
+#include HDR_MALLOC_INCLUDE
+
+/* ###### ####### ## ## ## ## ######## ###### */
+/* ## ## ## ## ## ## ### ## ## ## ## */
+/* ## ## ## ## ## #### ## ## ## */
+/* ## ## ## ## ## ## ## ## ## ###### */
+/* ## ## ## ## ## ## #### ## ## */
+/* ## ## ## ## ## ## ## ### ## ## ## */
+/* ###### ####### ####### ## ## ## ###### */
+
+static int32_t normalize_index(const struct hdr_histogram* h, int32_t index)
+{
+ int32_t normalized_index;
+ int32_t adjustment = 0;
+ if (h->normalizing_index_offset == 0)
+ {
+ return index;
+ }
+
+ normalized_index = index - h->normalizing_index_offset;
+
+ if (normalized_index < 0)
+ {
+ adjustment = h->counts_len;
+ }
+ else if (normalized_index >= h->counts_len)
+ {
+ adjustment = -h->counts_len;
+ }
+
+ return normalized_index + adjustment;
+}
+
+static int64_t counts_get_direct(const struct hdr_histogram* h, int32_t index)
+{
+ return h->counts[index];
+}
+
+static int64_t counts_get_normalised(const struct hdr_histogram* h, int32_t index)
+{
+ return counts_get_direct(h, normalize_index(h, index));
+}
+
+static void counts_inc_normalised(
+ struct hdr_histogram* h, int32_t index, int64_t value)
+{
+ int32_t normalised_index = normalize_index(h, index);
+ h->counts[normalised_index] += value;
+ h->total_count += value;
+}
+
+static void counts_inc_normalised_atomic(
+ struct hdr_histogram* h, int32_t index, int64_t value)
+{
+ int32_t normalised_index = normalize_index(h, index);
+
+ hdr_atomic_add_fetch_64(&h->counts[normalised_index], value);
+ hdr_atomic_add_fetch_64(&h->total_count, value);
+}
+
+static void update_min_max(struct hdr_histogram* h, int64_t value)
+{
+ h->min_value = (value < h->min_value && value != 0) ? value : h->min_value;
+ h->max_value = (value > h->max_value) ? value : h->max_value;
+}
+
+static void update_min_max_atomic(struct hdr_histogram* h, int64_t value)
+{
+ int64_t current_min_value;
+ int64_t current_max_value;
+ do
+ {
+ current_min_value = hdr_atomic_load_64(&h->min_value);
+
+ if (0 == value || current_min_value <= value)
+ {
+ break;
+ }
+ }
+ while (!hdr_atomic_compare_exchange_64(&h->min_value, &current_min_value, value));
+
+ do
+ {
+ current_max_value = hdr_atomic_load_64(&h->max_value);
+
+ if (value <= current_max_value)
+ {
+ break;
+ }
+ }
+ while (!hdr_atomic_compare_exchange_64(&h->max_value, &current_max_value, value));
+}
+
+
+/* ## ## ######## #### ## #### ######## ## ## */
+/* ## ## ## ## ## ## ## ## ## */
+/* ## ## ## ## ## ## ## #### */
+/* ## ## ## ## ## ## ## ## */
+/* ## ## ## ## ## ## ## ## */
+/* ## ## ## ## ## ## ## ## */
+/* ####### ## #### ######## #### ## ## */
+
+static int64_t power(int64_t base, int64_t exp)
+{
+ int64_t result = 1;
+ while(exp)
+ {
+ result *= base; exp--;
+ }
+ return result;
+}
+
+#if defined(_MSC_VER)
+# if defined(_WIN64)
+# pragma intrinsic(_BitScanReverse64)
+# else
+# pragma intrinsic(_BitScanReverse)
+# endif
+#endif
+
+static int32_t count_leading_zeros_64(int64_t value)
+{
+#if defined(_MSC_VER)
+ uint32_t leading_zero = 0;
+#if defined(_WIN64)
+ _BitScanReverse64(&leading_zero, value);
+#else
+ uint32_t high = value >> 32;
+ if (_BitScanReverse(&leading_zero, high))
+ {
+ leading_zero += 32;
+ }
+ else
+ {
+ uint32_t low = value & 0x00000000FFFFFFFF;
+ _BitScanReverse(&leading_zero, low);
+ }
+#endif
+ return 63 - leading_zero; /* smallest power of 2 containing value */
+#else
+ return __builtin_clzll(value); /* smallest power of 2 containing value */
+#endif
+}
+
+static int32_t get_bucket_index(const struct hdr_histogram* h, int64_t value)
+{
+ int32_t pow2ceiling = 64 - count_leading_zeros_64(value | h->sub_bucket_mask); /* smallest power of 2 containing value */
+ return pow2ceiling - h->unit_magnitude - (h->sub_bucket_half_count_magnitude + 1);
+}
+
+static int32_t get_sub_bucket_index(int64_t value, int32_t bucket_index, int32_t unit_magnitude)
+{
+ return (int32_t)(value >> (bucket_index + unit_magnitude));
+}
+
+static int32_t counts_index(const struct hdr_histogram* h, int32_t bucket_index, int32_t sub_bucket_index)
+{
+ /* Calculate the index for the first entry in the bucket: */
+ /* (The following is the equivalent of ((bucket_index + 1) * subBucketHalfCount) ): */
+ int32_t bucket_base_index = (bucket_index + 1) << h->sub_bucket_half_count_magnitude;
+ /* Calculate the offset in the bucket: */
+ int32_t offset_in_bucket = sub_bucket_index - h->sub_bucket_half_count;
+ /* The following is the equivalent of ((sub_bucket_index - subBucketHalfCount) + bucketBaseIndex; */
+ return bucket_base_index + offset_in_bucket;
+}
+
+static int64_t value_from_index(int32_t bucket_index, int32_t sub_bucket_index, int32_t unit_magnitude)
+{
+ return ((int64_t) sub_bucket_index) << (bucket_index + unit_magnitude);
+}
+
+int32_t counts_index_for(const struct hdr_histogram* h, int64_t value)
+{
+ int32_t bucket_index = get_bucket_index(h, value);
+ int32_t sub_bucket_index = get_sub_bucket_index(value, bucket_index, h->unit_magnitude);
+
+ return counts_index(h, bucket_index, sub_bucket_index);
+}
+
+int64_t hdr_value_at_index(const struct hdr_histogram *h, int32_t index)
+{
+ int32_t bucket_index = (index >> h->sub_bucket_half_count_magnitude) - 1;
+ int32_t sub_bucket_index = (index & (h->sub_bucket_half_count - 1)) + h->sub_bucket_half_count;
+
+ if (bucket_index < 0)
+ {
+ sub_bucket_index -= h->sub_bucket_half_count;
+ bucket_index = 0;
+ }
+
+ return value_from_index(bucket_index, sub_bucket_index, h->unit_magnitude);
+}
+
+int64_t hdr_size_of_equivalent_value_range(const struct hdr_histogram* h, int64_t value)
+{
+ int32_t bucket_index = get_bucket_index(h, value);
+ int32_t sub_bucket_index = get_sub_bucket_index(value, bucket_index, h->unit_magnitude);
+ int32_t adjusted_bucket = (sub_bucket_index >= h->sub_bucket_count) ? (bucket_index + 1) : bucket_index;
+ return INT64_C(1) << (h->unit_magnitude + adjusted_bucket);
+}
+
+static int64_t size_of_equivalent_value_range_given_bucket_indices(
+ const struct hdr_histogram *h,
+ int32_t bucket_index,
+ int32_t sub_bucket_index)
+{
+ const int32_t adjusted_bucket = (sub_bucket_index >= h->sub_bucket_count) ? (bucket_index + 1) : bucket_index;
+ return INT64_C(1) << (h->unit_magnitude + adjusted_bucket);
+}
+
+static int64_t lowest_equivalent_value(const struct hdr_histogram* h, int64_t value)
+{
+ int32_t bucket_index = get_bucket_index(h, value);
+ int32_t sub_bucket_index = get_sub_bucket_index(value, bucket_index, h->unit_magnitude);
+ return value_from_index(bucket_index, sub_bucket_index, h->unit_magnitude);
+}
+
+static int64_t lowest_equivalent_value_given_bucket_indices(
+ const struct hdr_histogram *h,
+ int32_t bucket_index,
+ int32_t sub_bucket_index)
+{
+ return value_from_index(bucket_index, sub_bucket_index, h->unit_magnitude);
+}
+
+int64_t hdr_next_non_equivalent_value(const struct hdr_histogram *h, int64_t value)
+{
+ return lowest_equivalent_value(h, value) + hdr_size_of_equivalent_value_range(h, value);
+}
+
+static int64_t highest_equivalent_value(const struct hdr_histogram* h, int64_t value)
+{
+ return hdr_next_non_equivalent_value(h, value) - 1;
+}
+
+int64_t hdr_median_equivalent_value(const struct hdr_histogram *h, int64_t value)
+{
+ return lowest_equivalent_value(h, value) + (hdr_size_of_equivalent_value_range(h, value) >> 1);
+}
+
+static int64_t non_zero_min(const struct hdr_histogram* h)
+{
+ if (INT64_MAX == h->min_value)
+ {
+ return INT64_MAX;
+ }
+
+ return lowest_equivalent_value(h, h->min_value);
+}
+
+void hdr_reset_internal_counters(struct hdr_histogram* h)
+{
+ int min_non_zero_index = -1;
+ int max_index = -1;
+ int64_t observed_total_count = 0;
+ int i;
+
+ for (i = 0; i < h->counts_len; i++)
+ {
+ int64_t count_at_index;
+
+ if ((count_at_index = counts_get_direct(h, i)) > 0)
+ {
+ observed_total_count += count_at_index;
+ max_index = i;
+ if (min_non_zero_index == -1 && i != 0)
+ {
+ min_non_zero_index = i;
+ }
+ }
+ }
+
+ if (max_index == -1)
+ {
+ h->max_value = 0;
+ }
+ else
+ {
+ int64_t max_value = hdr_value_at_index(h, max_index);
+ h->max_value = highest_equivalent_value(h, max_value);
+ }
+
+ if (min_non_zero_index == -1)
+ {
+ h->min_value = INT64_MAX;
+ }
+ else
+ {
+ h->min_value = hdr_value_at_index(h, min_non_zero_index);
+ }
+
+ h->total_count = observed_total_count;
+}
+
+static int32_t buckets_needed_to_cover_value(int64_t value, int32_t sub_bucket_count, int32_t unit_magnitude)
+{
+ int64_t smallest_untrackable_value = ((int64_t) sub_bucket_count) << unit_magnitude;
+ int32_t buckets_needed = 1;
+ while (smallest_untrackable_value <= value)
+ {
+ if (smallest_untrackable_value > INT64_MAX / 2)
+ {
+ return buckets_needed + 1;
+ }
+ smallest_untrackable_value <<= 1;
+ buckets_needed++;
+ }
+
+ return buckets_needed;
+}
+
+/* ## ## ######## ## ## ####### ######## ## ## */
+/* ### ### ## ### ### ## ## ## ## ## ## */
+/* #### #### ## #### #### ## ## ## ## #### */
+/* ## ### ## ###### ## ### ## ## ## ######## ## */
+/* ## ## ## ## ## ## ## ## ## ## */
+/* ## ## ## ## ## ## ## ## ## ## */
+/* ## ## ######## ## ## ####### ## ## ## */
+
+int hdr_calculate_bucket_config(
+ int64_t lowest_discernible_value,
+ int64_t highest_trackable_value,
+ int significant_figures,
+ struct hdr_histogram_bucket_config* cfg)
+{
+ int32_t sub_bucket_count_magnitude;
+ int64_t largest_value_with_single_unit_resolution;
+
+ if (lowest_discernible_value < 1 ||
+ significant_figures < 1 || 5 < significant_figures ||
+ lowest_discernible_value * 2 > highest_trackable_value)
+ {
+ return EINVAL;
+ }
+
+ cfg->lowest_discernible_value = lowest_discernible_value;
+ cfg->significant_figures = significant_figures;
+ cfg->highest_trackable_value = highest_trackable_value;
+
+ largest_value_with_single_unit_resolution = 2 * power(10, significant_figures);
+ sub_bucket_count_magnitude = (int32_t) ceil(log((double)largest_value_with_single_unit_resolution) / log(2));
+ cfg->sub_bucket_half_count_magnitude = ((sub_bucket_count_magnitude > 1) ? sub_bucket_count_magnitude : 1) - 1;
+
+ double unit_magnitude = log((double)lowest_discernible_value) / log(2);
+ if (INT32_MAX < unit_magnitude)
+ {
+ return EINVAL;
+ }
+
+ cfg->unit_magnitude = (int32_t) unit_magnitude;
+ cfg->sub_bucket_count = (int32_t) pow(2, (cfg->sub_bucket_half_count_magnitude + 1));
+ cfg->sub_bucket_half_count = cfg->sub_bucket_count / 2;
+ cfg->sub_bucket_mask = ((int64_t) cfg->sub_bucket_count - 1) << cfg->unit_magnitude;
+
+ if (cfg->unit_magnitude + cfg->sub_bucket_half_count_magnitude > 61)
+ {
+ return EINVAL;
+ }
+
+ cfg->bucket_count = buckets_needed_to_cover_value(highest_trackable_value, cfg->sub_bucket_count, (int32_t)cfg->unit_magnitude);
+ cfg->counts_len = (cfg->bucket_count + 1) * (cfg->sub_bucket_count / 2);
+
+ return 0;
+}
+
+void hdr_init_preallocated(struct hdr_histogram* h, struct hdr_histogram_bucket_config* cfg)
+{
+ h->lowest_discernible_value = cfg->lowest_discernible_value;
+ h->highest_trackable_value = cfg->highest_trackable_value;
+ h->unit_magnitude = (int32_t)cfg->unit_magnitude;
+ h->significant_figures = (int32_t)cfg->significant_figures;
+ h->sub_bucket_half_count_magnitude = cfg->sub_bucket_half_count_magnitude;
+ h->sub_bucket_half_count = cfg->sub_bucket_half_count;
+ h->sub_bucket_mask = cfg->sub_bucket_mask;
+ h->sub_bucket_count = cfg->sub_bucket_count;
+ h->min_value = INT64_MAX;
+ h->max_value = 0;
+ h->normalizing_index_offset = 0;
+ h->conversion_ratio = 1.0;
+ h->bucket_count = cfg->bucket_count;
+ h->counts_len = cfg->counts_len;
+ h->total_count = 0;
+}
+
+int hdr_init(
+ int64_t lowest_discernible_value,
+ int64_t highest_trackable_value,
+ int significant_figures,
+ struct hdr_histogram** result)
+{
+ int64_t* counts;
+ struct hdr_histogram_bucket_config cfg;
+ struct hdr_histogram* histogram;
+
+ int r = hdr_calculate_bucket_config(lowest_discernible_value, highest_trackable_value, significant_figures, &cfg);
+ if (r)
+ {
+ return r;
+ }
+
+ counts = (int64_t*) hdr_calloc((size_t) cfg.counts_len, sizeof(int64_t));
+ if (!counts)
+ {
+ return ENOMEM;
+ }
+
+ histogram = (struct hdr_histogram*) hdr_calloc(1, sizeof(struct hdr_histogram));
+ if (!histogram)
+ {
+ hdr_free(counts);
+ return ENOMEM;
+ }
+
+ histogram->counts = counts;
+
+ hdr_init_preallocated(histogram, &cfg);
+ *result = histogram;
+
+ return 0;
+}
+
+void hdr_close(struct hdr_histogram* h)
+{
+ if (h) {
+ hdr_free(h->counts);
+ hdr_free(h);
+ }
+}
+
+int hdr_alloc(int64_t highest_trackable_value, int significant_figures, struct hdr_histogram** result)
+{
+ return hdr_init(1, highest_trackable_value, significant_figures, result);
+}
+
+/* reset a histogram to zero. */
+void hdr_reset(struct hdr_histogram *h)
+{
+ h->total_count=0;
+ h->min_value = INT64_MAX;
+ h->max_value = 0;
+ memset(h->counts, 0, (sizeof(int64_t) * h->counts_len));
+}
+
+size_t hdr_get_memory_size(struct hdr_histogram *h)
+{
+ return sizeof(struct hdr_histogram) + h->counts_len * sizeof(int64_t);
+}
+
+/* ## ## ######## ######## ### ######## ######## ###### */
+/* ## ## ## ## ## ## ## ## ## ## ## ## */
+/* ## ## ## ## ## ## ## ## ## ## ## */
+/* ## ## ######## ## ## ## ## ## ###### ###### */
+/* ## ## ## ## ## ######### ## ## ## */
+/* ## ## ## ## ## ## ## ## ## ## ## */
+/* ####### ## ######## ## ## ## ######## ###### */
+
+
+bool hdr_record_value(struct hdr_histogram* h, int64_t value)
+{
+ return hdr_record_values(h, value, 1);
+}
+
+bool hdr_record_value_atomic(struct hdr_histogram* h, int64_t value)
+{
+ return hdr_record_values_atomic(h, value, 1);
+}
+
+bool hdr_record_values(struct hdr_histogram* h, int64_t value, int64_t count)
+{
+ int32_t counts_index;
+
+ if (value < 0)
+ {
+ return false;
+ }
+
+ counts_index = counts_index_for(h, value);
+
+ if (counts_index < 0 || h->counts_len <= counts_index)
+ {
+ return false;
+ }
+
+ counts_inc_normalised(h, counts_index, count);
+ update_min_max(h, value);
+
+ return true;
+}
+
+bool hdr_record_values_atomic(struct hdr_histogram* h, int64_t value, int64_t count)
+{
+ int32_t counts_index;
+
+ if (value < 0)
+ {
+ return false;
+ }
+
+ counts_index = counts_index_for(h, value);
+
+ if (counts_index < 0 || h->counts_len <= counts_index)
+ {
+ return false;
+ }
+
+ counts_inc_normalised_atomic(h, counts_index, count);
+ update_min_max_atomic(h, value);
+
+ return true;
+}
+
+bool hdr_record_corrected_value(struct hdr_histogram* h, int64_t value, int64_t expected_interval)
+{
+ return hdr_record_corrected_values(h, value, 1, expected_interval);
+}
+
+bool hdr_record_corrected_value_atomic(struct hdr_histogram* h, int64_t value, int64_t expected_interval)
+{
+ return hdr_record_corrected_values_atomic(h, value, 1, expected_interval);
+}
+
+bool hdr_record_corrected_values(struct hdr_histogram* h, int64_t value, int64_t count, int64_t expected_interval)
+{
+ int64_t missing_value;
+
+ if (!hdr_record_values(h, value, count))
+ {
+ return false;
+ }
+
+ if (expected_interval <= 0 || value <= expected_interval)
+ {
+ return true;
+ }
+
+ missing_value = value - expected_interval;
+ for (; missing_value >= expected_interval; missing_value -= expected_interval)
+ {
+ if (!hdr_record_values(h, missing_value, count))
+ {
+ return false;
+ }
+ }
+
+ return true;
+}
+
+bool hdr_record_corrected_values_atomic(struct hdr_histogram* h, int64_t value, int64_t count, int64_t expected_interval)
+{
+ int64_t missing_value;
+
+ if (!hdr_record_values_atomic(h, value, count))
+ {
+ return false;
+ }
+
+ if (expected_interval <= 0 || value <= expected_interval)
+ {
+ return true;
+ }
+
+ missing_value = value - expected_interval;
+ for (; missing_value >= expected_interval; missing_value -= expected_interval)
+ {
+ if (!hdr_record_values_atomic(h, missing_value, count))
+ {
+ return false;
+ }
+ }
+
+ return true;
+}
+
+int64_t hdr_add(struct hdr_histogram* h, const struct hdr_histogram* from)
+{
+ struct hdr_iter iter;
+ int64_t dropped = 0;
+ hdr_iter_recorded_init(&iter, from);
+
+ while (hdr_iter_next(&iter))
+ {
+ int64_t value = iter.value;
+ int64_t count = iter.count;
+
+ if (!hdr_record_values(h, value, count))
+ {
+ dropped += count;
+ }
+ }
+
+ return dropped;
+}
+
+int64_t hdr_add_while_correcting_for_coordinated_omission(
+ struct hdr_histogram* h, struct hdr_histogram* from, int64_t expected_interval)
+{
+ struct hdr_iter iter;
+ int64_t dropped = 0;
+ hdr_iter_recorded_init(&iter, from);
+
+ while (hdr_iter_next(&iter))
+ {
+ int64_t value = iter.value;
+ int64_t count = iter.count;
+
+ if (!hdr_record_corrected_values(h, value, count, expected_interval))
+ {
+ dropped += count;
+ }
+ }
+
+ return dropped;
+}
+
+
+
+/* ## ## ### ## ## ## ######## ###### */
+/* ## ## ## ## ## ## ## ## ## ## */
+/* ## ## ## ## ## ## ## ## ## */
+/* ## ## ## ## ## ## ## ###### ###### */
+/* ## ## ######### ## ## ## ## ## */
+/* ## ## ## ## ## ## ## ## ## ## */
+/* ### ## ## ######## ####### ######## ###### */
+
+
+int64_t hdr_max(const struct hdr_histogram* h)
+{
+ if (0 == h->max_value)
+ {
+ return 0;
+ }
+
+ return highest_equivalent_value(h, h->max_value);
+}
+
+int64_t hdr_min(const struct hdr_histogram* h)
+{
+ if (0 < hdr_count_at_index(h, 0))
+ {
+ return 0;
+ }
+
+ return non_zero_min(h);
+}
+
+static int64_t get_value_from_idx_up_to_count(const struct hdr_histogram* h, int64_t count_at_percentile)
+{
+ int64_t count_to_idx = 0;
+
+ count_at_percentile = 0 < count_at_percentile ? count_at_percentile : 1;
+ for (int32_t idx = 0; idx < h->counts_len; idx++)
+ {
+ count_to_idx += h->counts[idx];
+ if (count_to_idx >= count_at_percentile)
+ {
+ return hdr_value_at_index(h, idx);
+ }
+ }
+
+ return 0;
+}
+
+
+int64_t hdr_value_at_percentile(const struct hdr_histogram* h, double percentile)
+{
+ double requested_percentile = percentile < 100.0 ? percentile : 100.0;
+ int64_t count_at_percentile =
+ (int64_t) (((requested_percentile / 100) * h->total_count) + 0.5);
+ int64_t value_from_idx = get_value_from_idx_up_to_count(h, count_at_percentile);
+ if (percentile == 0.0)
+ {
+ return lowest_equivalent_value(h, value_from_idx);
+ }
+ return highest_equivalent_value(h, value_from_idx);
+}
+
+int hdr_value_at_percentiles(const struct hdr_histogram *h, const double *percentiles, int64_t *values, size_t length)
+{
+ if (NULL == percentiles || NULL == values)
+ {
+ return EINVAL;
+ }
+
+ struct hdr_iter iter;
+ const int64_t total_count = h->total_count;
+ // to avoid allocations we use the values array for intermediate computation
+ // i.e. to store the expected cumulative count at each percentile
+ for (size_t i = 0; i < length; i++)
+ {
+ const double requested_percentile = percentiles[i] < 100.0 ? percentiles[i] : 100.0;
+ const int64_t count_at_percentile =
+ (int64_t) (((requested_percentile / 100) * total_count) + 0.5);
+ values[i] = count_at_percentile > 1 ? count_at_percentile : 1;
+ }
+
+ hdr_iter_init(&iter, h);
+ int64_t total = 0;
+ size_t at_pos = 0;
+ while (hdr_iter_next(&iter) && at_pos < length)
+ {
+ total += iter.count;
+ while (at_pos < length && total >= values[at_pos])
+ {
+ values[at_pos] = highest_equivalent_value(h, iter.value);
+ at_pos++;
+ }
+ }
+ return 0;
+}
+
+double hdr_mean(const struct hdr_histogram* h)
+{
+ struct hdr_iter iter;
+ int64_t total = 0;
+
+ hdr_iter_init(&iter, h);
+
+ while (hdr_iter_next(&iter))
+ {
+ if (0 != iter.count)
+ {
+ total += iter.count * hdr_median_equivalent_value(h, iter.value);
+ }
+ }
+
+ return (total * 1.0) / h->total_count;
+}
+
+double hdr_stddev(const struct hdr_histogram* h)
+{
+ double mean = hdr_mean(h);
+ double geometric_dev_total = 0.0;
+
+ struct hdr_iter iter;
+ hdr_iter_init(&iter, h);
+
+ while (hdr_iter_next(&iter))
+ {
+ if (0 != iter.count)
+ {
+ double dev = (hdr_median_equivalent_value(h, iter.value) * 1.0) - mean;
+ geometric_dev_total += (dev * dev) * iter.count;
+ }
+ }
+
+ return sqrt(geometric_dev_total / h->total_count);
+}
+
+bool hdr_values_are_equivalent(const struct hdr_histogram* h, int64_t a, int64_t b)
+{
+ return lowest_equivalent_value(h, a) == lowest_equivalent_value(h, b);
+}
+
+int64_t hdr_lowest_equivalent_value(const struct hdr_histogram* h, int64_t value)
+{
+ return lowest_equivalent_value(h, value);
+}
+
+int64_t hdr_count_at_value(const struct hdr_histogram* h, int64_t value)
+{
+ return counts_get_normalised(h, counts_index_for(h, value));
+}
+
+int64_t hdr_count_at_index(const struct hdr_histogram* h, int32_t index)
+{
+ return counts_get_normalised(h, index);
+}
+
+
+/* #### ######## ######## ######## ### ######## ####### ######## ###### */
+/* ## ## ## ## ## ## ## ## ## ## ## ## ## ## */
+/* ## ## ## ## ## ## ## ## ## ## ## ## ## */
+/* ## ## ###### ######## ## ## ## ## ## ######## ###### */
+/* ## ## ## ## ## ######### ## ## ## ## ## ## */
+/* ## ## ## ## ## ## ## ## ## ## ## ## ## ## */
+/* #### ## ######## ## ## ## ## ## ####### ## ## ###### */
+
+
+static bool has_buckets(struct hdr_iter* iter)
+{
+ return iter->counts_index < iter->h->counts_len;
+}
+
+static bool has_next(struct hdr_iter* iter)
+{
+ return iter->cumulative_count < iter->total_count;
+}
+
+static bool move_next(struct hdr_iter* iter)
+{
+ iter->counts_index++;
+
+ if (!has_buckets(iter))
+ {
+ return false;
+ }
+
+ iter->count = counts_get_normalised(iter->h, iter->counts_index);
+ iter->cumulative_count += iter->count;
+ const int64_t value = hdr_value_at_index(iter->h, iter->counts_index);
+ const int32_t bucket_index = get_bucket_index(iter->h, value);
+ const int32_t sub_bucket_index = get_sub_bucket_index(value, bucket_index, iter->h->unit_magnitude);
+ const int64_t leq = lowest_equivalent_value_given_bucket_indices(iter->h, bucket_index, sub_bucket_index);
+ const int64_t size_of_equivalent_value_range = size_of_equivalent_value_range_given_bucket_indices(
+ iter->h, bucket_index, sub_bucket_index);
+ iter->lowest_equivalent_value = leq;
+ iter->value = value;
+ iter->highest_equivalent_value = leq + size_of_equivalent_value_range - 1;
+ iter->median_equivalent_value = leq + (size_of_equivalent_value_range >> 1);
+
+ return true;
+}
+
+static int64_t peek_next_value_from_index(struct hdr_iter* iter)
+{
+ return hdr_value_at_index(iter->h, iter->counts_index + 1);
+}
+
+static bool next_value_greater_than_reporting_level_upper_bound(
+ struct hdr_iter *iter, int64_t reporting_level_upper_bound)
+{
+ if (iter->counts_index >= iter->h->counts_len)
+ {
+ return false;
+ }
+
+ return peek_next_value_from_index(iter) > reporting_level_upper_bound;
+}
+
+static bool basic_iter_next(struct hdr_iter *iter)
+{
+ if (!has_next(iter) || iter->counts_index >= iter->h->counts_len)
+ {
+ return false;
+ }
+
+ move_next(iter);
+
+ return true;
+}
+
+static void update_iterated_values(struct hdr_iter* iter, int64_t new_value_iterated_to)
+{
+ iter->value_iterated_from = iter->value_iterated_to;
+ iter->value_iterated_to = new_value_iterated_to;
+}
+
+static bool all_values_iter_next(struct hdr_iter* iter)
+{
+ bool result = move_next(iter);
+
+ if (result)
+ {
+ update_iterated_values(iter, iter->value);
+ }
+
+ return result;
+}
+
+void hdr_iter_init(struct hdr_iter* iter, const struct hdr_histogram* h)
+{
+ iter->h = h;
+
+ iter->counts_index = -1;
+ iter->total_count = h->total_count;
+ iter->count = 0;
+ iter->cumulative_count = 0;
+ iter->value = 0;
+ iter->highest_equivalent_value = 0;
+ iter->value_iterated_from = 0;
+ iter->value_iterated_to = 0;
+
+ iter->_next_fp = all_values_iter_next;
+}
+
+bool hdr_iter_next(struct hdr_iter* iter)
+{
+ return iter->_next_fp(iter);
+}
+
+/* ######## ######## ######## ###### ######## ## ## ######## #### ## ######## ###### */
+/* ## ## ## ## ## ## ## ## ### ## ## ## ## ## ## ## */
+/* ## ## ## ## ## ## ## #### ## ## ## ## ## ## */
+/* ######## ###### ######## ## ###### ## ## ## ## ## ## ###### ###### */
+/* ## ## ## ## ## ## ## #### ## ## ## ## ## */
+/* ## ## ## ## ## ## ## ## ### ## ## ## ## ## ## */
+/* ## ######## ## ## ###### ######## ## ## ## #### ######## ######## ###### */
+
+static bool percentile_iter_next(struct hdr_iter* iter)
+{
+ int64_t temp, half_distance, percentile_reporting_ticks;
+
+ struct hdr_iter_percentiles* percentiles = &iter->specifics.percentiles;
+
+ if (!has_next(iter))
+ {
+ if (percentiles->seen_last_value)
+ {
+ return false;
+ }
+
+ percentiles->seen_last_value = true;
+ percentiles->percentile = 100.0;
+
+ return true;
+ }
+
+ if (iter->counts_index == -1 && !basic_iter_next(iter))
+ {
+ return false;
+ }
+
+ do
+ {
+ double current_percentile = (100.0 * (double) iter->cumulative_count) / iter->h->total_count;
+ if (iter->count != 0 &&
+ percentiles->percentile_to_iterate_to <= current_percentile)
+ {
+ update_iterated_values(iter, highest_equivalent_value(iter->h, iter->value));
+
+ percentiles->percentile = percentiles->percentile_to_iterate_to;
+ temp = (int64_t)(log(100 / (100.0 - (percentiles->percentile_to_iterate_to))) / log(2)) + 1;
+ half_distance = (int64_t) pow(2, (double) temp);
+ percentile_reporting_ticks = percentiles->ticks_per_half_distance * half_distance;
+ percentiles->percentile_to_iterate_to += 100.0 / percentile_reporting_ticks;
+
+ return true;
+ }
+ }
+ while (basic_iter_next(iter));
+
+ return true;
+}
+
+void hdr_iter_percentile_init(struct hdr_iter* iter, const struct hdr_histogram* h, int32_t ticks_per_half_distance)
+{
+ iter->h = h;
+
+ hdr_iter_init(iter, h);
+
+ iter->specifics.percentiles.seen_last_value = false;
+ iter->specifics.percentiles.ticks_per_half_distance = ticks_per_half_distance;
+ iter->specifics.percentiles.percentile_to_iterate_to = 0.0;
+ iter->specifics.percentiles.percentile = 0.0;
+
+ iter->_next_fp = percentile_iter_next;
+}
+
+static void format_line_string(char* str, size_t len, int significant_figures, format_type format)
+{
+#if defined(_MSC_VER)
+#define snprintf _snprintf
+#pragma warning(push)
+#pragma warning(disable: 4996)
+#endif
+ const char* format_str = "%s%d%s";
+
+ switch (format)
+ {
+ case CSV:
+ snprintf(str, len, format_str, "%.", significant_figures, "f,%f,%d,%.2f\n");
+ break;
+ case CLASSIC:
+ snprintf(str, len, format_str, "%12.", significant_figures, "f %12f %12d %12.2f\n");
+ break;
+ default:
+ snprintf(str, len, format_str, "%12.", significant_figures, "f %12f %12d %12.2f\n");
+ }
+#if defined(_MSC_VER)
+#undef snprintf
+#pragma warning(pop)
+#endif
+}
+
+
+/* ######## ######## ###### ####### ######## ######## ######## ######## */
+/* ## ## ## ## ## ## ## ## ## ## ## ## ## ## */
+/* ## ## ## ## ## ## ## ## ## ## ## ## ## */
+/* ######## ###### ## ## ## ######## ## ## ###### ## ## */
+/* ## ## ## ## ## ## ## ## ## ## ## ## ## */
+/* ## ## ## ## ## ## ## ## ## ## ## ## ## ## */
+/* ## ## ######## ###### ####### ## ## ######## ######## ######## */
+
+
+static bool recorded_iter_next(struct hdr_iter* iter)
+{
+ while (basic_iter_next(iter))
+ {
+ if (iter->count != 0)
+ {
+ update_iterated_values(iter, iter->value);
+
+ iter->specifics.recorded.count_added_in_this_iteration_step = iter->count;
+ return true;
+ }
+ }
+
+ return false;
+}
+
+void hdr_iter_recorded_init(struct hdr_iter* iter, const struct hdr_histogram* h)
+{
+ hdr_iter_init(iter, h);
+
+ iter->specifics.recorded.count_added_in_this_iteration_step = 0;
+
+ iter->_next_fp = recorded_iter_next;
+}
+
+/* ## #### ## ## ######## ### ######## */
+/* ## ## ### ## ## ## ## ## ## */
+/* ## ## #### ## ## ## ## ## ## */
+/* ## ## ## ## ## ###### ## ## ######## */
+/* ## ## ## #### ## ######### ## ## */
+/* ## ## ## ### ## ## ## ## ## */
+/* ######## #### ## ## ######## ## ## ## ## */
+
+
+static bool iter_linear_next(struct hdr_iter* iter)
+{
+ struct hdr_iter_linear* linear = &iter->specifics.linear;
+
+ linear->count_added_in_this_iteration_step = 0;
+
+ if (has_next(iter) ||
+ next_value_greater_than_reporting_level_upper_bound(
+ iter, linear->next_value_reporting_level_lowest_equivalent))
+ {
+ do
+ {
+ if (iter->value >= linear->next_value_reporting_level_lowest_equivalent)
+ {
+ update_iterated_values(iter, linear->next_value_reporting_level);
+
+ linear->next_value_reporting_level += linear->value_units_per_bucket;
+ linear->next_value_reporting_level_lowest_equivalent =
+ lowest_equivalent_value(iter->h, linear->next_value_reporting_level);
+
+ return true;
+ }
+
+ if (!move_next(iter))
+ {
+ return true;
+ }
+
+ linear->count_added_in_this_iteration_step += iter->count;
+ }
+ while (true);
+ }
+
+ return false;
+}
+
+
+void hdr_iter_linear_init(struct hdr_iter* iter, const struct hdr_histogram* h, int64_t value_units_per_bucket)
+{
+ hdr_iter_init(iter, h);
+
+ iter->specifics.linear.count_added_in_this_iteration_step = 0;
+ iter->specifics.linear.value_units_per_bucket = value_units_per_bucket;
+ iter->specifics.linear.next_value_reporting_level = value_units_per_bucket;
+ iter->specifics.linear.next_value_reporting_level_lowest_equivalent = lowest_equivalent_value(h, value_units_per_bucket);
+
+ iter->_next_fp = iter_linear_next;
+}
+
+void hdr_iter_linear_set_value_units_per_bucket(struct hdr_iter* iter, int64_t value_units_per_bucket)
+{
+ iter->specifics.linear.value_units_per_bucket = value_units_per_bucket;
+}
+
+/* ## ####### ###### ### ######## #### ######## ## ## ## ## #### ###### */
+/* ## ## ## ## ## ## ## ## ## ## ## ## ## ### ### ## ## ## */
+/* ## ## ## ## ## ## ## ## ## ## ## ## #### #### ## ## */
+/* ## ## ## ## #### ## ## ######## ## ## ######### ## ### ## ## ## */
+/* ## ## ## ## ## ######### ## ## ## ## ## ## ## ## ## ## */
+/* ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## */
+/* ######## ####### ###### ## ## ## ## #### ## ## ## ## ## #### ###### */
+
+static bool log_iter_next(struct hdr_iter *iter)
+{
+ struct hdr_iter_log* logarithmic = &iter->specifics.log;
+
+ logarithmic->count_added_in_this_iteration_step = 0;
+
+ if (has_next(iter) ||
+ next_value_greater_than_reporting_level_upper_bound(
+ iter, logarithmic->next_value_reporting_level_lowest_equivalent))
+ {
+ do
+ {
+ if (iter->value >= logarithmic->next_value_reporting_level_lowest_equivalent)
+ {
+ update_iterated_values(iter, logarithmic->next_value_reporting_level);
+
+ logarithmic->next_value_reporting_level *= (int64_t)logarithmic->log_base;
+ logarithmic->next_value_reporting_level_lowest_equivalent = lowest_equivalent_value(iter->h, logarithmic->next_value_reporting_level);
+
+ return true;
+ }
+
+ if (!move_next(iter))
+ {
+ return true;
+ }
+
+ logarithmic->count_added_in_this_iteration_step += iter->count;
+ }
+ while (true);
+ }
+
+ return false;
+}
+
+void hdr_iter_log_init(
+ struct hdr_iter* iter,
+ const struct hdr_histogram* h,
+ int64_t value_units_first_bucket,
+ double log_base)
+{
+ hdr_iter_init(iter, h);
+ iter->specifics.log.count_added_in_this_iteration_step = 0;
+ iter->specifics.log.log_base = log_base;
+ iter->specifics.log.next_value_reporting_level = value_units_first_bucket;
+ iter->specifics.log.next_value_reporting_level_lowest_equivalent = lowest_equivalent_value(h, value_units_first_bucket);
+
+ iter->_next_fp = log_iter_next;
+}
+
+/* Printing. */
+
+static const char* format_head_string(format_type format)
+{
+ switch (format)
+ {
+ case CSV:
+ return "%s,%s,%s,%s\n";
+ case CLASSIC:
+ default:
+ return "%12s %12s %12s %12s\n\n";
+ }
+}
+
+static const char CLASSIC_FOOTER[] =
+ "#[Mean = %12.3f, StdDeviation = %12.3f]\n"
+ "#[Max = %12.3f, Total count = %12" PRIu64 "]\n"
+ "#[Buckets = %12d, SubBuckets = %12d]\n";
+
+int hdr_percentiles_print(
+ struct hdr_histogram* h, FILE* stream, int32_t ticks_per_half_distance,
+ double value_scale, format_type format)
+{
+ char line_format[25];
+ const char* head_format;
+ int rc = 0;
+ struct hdr_iter iter;
+ struct hdr_iter_percentiles * percentiles;
+
+ format_line_string(line_format, 25, h->significant_figures, format);
+ head_format = format_head_string(format);
+
+ hdr_iter_percentile_init(&iter, h, ticks_per_half_distance);
+
+ if (fprintf(
+ stream, head_format,
+ "Value", "Percentile", "TotalCount", "1/(1-Percentile)") < 0)
+ {
+ rc = EIO;
+ goto cleanup;
+ }
+
+ percentiles = &iter.specifics.percentiles;
+ while (hdr_iter_next(&iter))
+ {
+ double value = iter.highest_equivalent_value / value_scale;
+ double percentile = percentiles->percentile / 100.0;
+ int64_t total_count = iter.cumulative_count;
+ double inverted_percentile = (1.0 / (1.0 - percentile));
+
+ if (fprintf(
+ stream, line_format, value, percentile, total_count, inverted_percentile) < 0)
+ {
+ rc = EIO;
+ goto cleanup;
+ }
+ }
+
+ if (CLASSIC == format)
+ {
+ double mean = hdr_mean(h) / value_scale;
+ double stddev = hdr_stddev(h) / value_scale;
+ double max = hdr_max(h) / value_scale;
+
+ if (fprintf(
+ stream, CLASSIC_FOOTER, mean, stddev, max,
+ h->total_count, h->bucket_count, h->sub_bucket_count) < 0)
+ {
+ rc = EIO;
+ goto cleanup;
+ }
+ }
+
+ cleanup:
+ return rc;
+}