From: Rusty Russell
Date: Sat, 25 Sep 2010 02:15:12 +0000 (+0930)
Subject: tally: don't add extra bucket unless buckets == 0
X-Git-Url: https://git.ozlabs.org/?p=ccan;a=commitdiff_plain;h=097857e6c09bf9696797fe08cd4241b8315f9c9a
tally: don't add extra bucket unless buckets == 0
That way we match our comment about optimal tally_new() arg matching histogram height.
---
diff --git a/ccan/tally/tally.c b/ccan/tally/tally.c
index 9f2a4591..b3ac863b 100644
--- a/ccan/tally/tally.c
+++ b/ccan/tally/tally.c
@@ -16,25 +16,28 @@ struct tally {
size_t total[2];
/* This allows limited frequency analysis. */
unsigned buckets, step_bits;
- size_t counts[1 /* [buckets] */ ];
+ size_t counts[1 /* Actually: [buckets] */ ];
};
struct tally *tally_new(unsigned buckets)
{
struct tally *tally;
+ /* There is always 1 bucket. */
+ if (buckets == 0)
+ buckets = 1;
+
/* Check for overflow. */
if (buckets && SIZE_MAX / buckets < sizeof(tally->counts[0]))
return NULL;
- tally = malloc(sizeof(*tally) + sizeof(tally->counts[0])*buckets);
+ tally = malloc(sizeof(*tally) + sizeof(tally->counts[0])*(buckets-1));
if (tally) {
tally->max = ((size_t)1 << (SIZET_BITS - 1));
tally->min = ~tally->max;
tally->total[0] = tally->total[1] = 0;
- /* There is always 1 bucket. */
- tally->buckets = buckets+1;
+ tally->buckets = buckets;
tally->step_bits = 0;
- memset(tally->counts, 0, sizeof(tally->counts[0])*(buckets+1));
+ memset(tally->counts, 0, sizeof(tally->counts[0])*buckets);
}
return tally;
}
@@ -422,7 +425,7 @@ char *tally_histogram(const struct tally *tally,
} else {
/* We create a temporary then renormalize so < height. */
/* FIXME: Antialias properly! */
- tmp = tally_new(tally->buckets-1);
+ tmp = tally_new(tally->buckets);
if (!tmp)
return NULL;
tmp->min = tally->min;
diff --git a/ccan/tally/test/run-renormalize.c b/ccan/tally/test/run-renormalize.c
index 5ec8b678..7c141528 100644
--- a/ccan/tally/test/run-renormalize.c
+++ b/ccan/tally/test/run-renormalize.c
@@ -3,7 +3,7 @@
int main(void)
{
- struct tally *tally = tally_new(1);
+ struct tally *tally = tally_new(2);
plan_tests(4);
tally->min = 0;