From 00432ff260beba0bf6535d7fd1c0275de303ed57 Mon Sep 17 00:00:00 2001 From: Damien Lespiau Date: Sat, 27 Jun 2015 17:34:51 +0100 Subject: stats: Allow the underlying arrays to grow at will Chris mentioned he wanted to be able to measure a variable "for one second" and use igt_stats to store them. That's one case where we don't know the number of data points upfront. We should really support that, so here it is. v2: Just free ->sorted when a new capacity is needed. ensure_sorted_values() will then reallocate the array to the new capacity on demand (Chris) Signed-off-by: Damien Lespiau --- lib/igt_stats.c | 46 ++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 42 insertions(+), 4 deletions(-) (limited to 'lib/igt_stats.c') diff --git a/lib/igt_stats.c b/lib/igt_stats.c index caf3f374..665f1c99 100644 --- a/lib/igt_stats.c +++ b/lib/igt_stats.c @@ -63,6 +63,37 @@ * ]| */ +static unsigned int get_new_capacity(int need) +{ + unsigned int new_capacity; + + /* taken from Python's list */ + new_capacity = (need >> 6) + (need < 9 ? 3 : 6); + new_capacity += need; + + return new_capacity; +} + +static void igt_stats_ensure_capacity(igt_stats_t *stats, + unsigned int n_additional_values) +{ + unsigned int new_n_values = stats->n_values + n_additional_values; + unsigned int new_capacity; + + if (new_n_values <= stats->capacity) + return; + + new_capacity = get_new_capacity(new_n_values); + stats->values = realloc(stats->values, + sizeof(*stats->values) * new_capacity); + igt_assert(stats->values); + + stats->capacity = new_capacity; + + free(stats->sorted); + stats->sorted = NULL; +} + /** * igt_stats_init: * @stats: An #igt_stats_t instance @@ -78,9 +109,7 @@ void igt_stats_init(igt_stats_t *stats, unsigned int capacity) { memset(stats, 0, sizeof(*stats)); - stats->values = calloc(capacity, sizeof(*stats->values)); - igt_assert(stats->values); - stats->capacity = capacity; + igt_stats_ensure_capacity(stats, capacity); stats->min = U64_MAX; stats->max = 0; @@ -156,7 +185,8 @@ void igt_stats_set_population(igt_stats_t *stats, bool full_population) */ void igt_stats_push(igt_stats_t *stats, uint64_t value) { - igt_assert(stats->n_values < stats->capacity); + igt_stats_ensure_capacity(stats, 1); + stats->values[stats->n_values++] = value; stats->mean_variance_valid = false; @@ -181,6 +211,8 @@ void igt_stats_push_array(igt_stats_t *stats, { unsigned int i; + igt_stats_ensure_capacity(stats, n_values); + for (i = 0; i < n_values; i++) igt_stats_push(stats, values[i]); } @@ -240,6 +272,12 @@ static void igt_stats_ensure_sorted_values(igt_stats_t *stats) return; if (!stats->sorted) { + /* + * igt_stats_ensure_capacity() will free ->sorted when the + * capacity increases, which also correspond to an invalidation + * of the sorted array. We'll then reallocate it here on + * demand. + */ stats->sorted = calloc(stats->capacity, sizeof(*stats->values)); igt_assert(stats->sorted); } -- cgit v1.2.3