tally: Adapt bucket_of to Samba coding conventions

[ccan] / ccan / tally / tally.c

diff --git a/ccan/tally/tally.c b/ccan/tally/tally.c
index b3ac863ba68119aedc59973b72c1d3716bb35867..7eec70d39323429e259e08f04d195fd97472f57b 100644 (file)
--- a/ccan/tally/tally.c
+++ b/ccan/tally/tally.c
@@ -1,4 +1,4 @@
-#include "config.h"
+/* Licensed under LGPLv3+ - see LICENSE file for details */
 #include <ccan/tally/tally.h>
 #include <ccan/build_assert/build_assert.h>
 #include <ccan/likely/likely.h>
@@ -7,6 +7,7 @@
 #include <string.h>
 #include <stdio.h>
 #include <assert.h>
+#include <stdlib.h>
 
 #define SIZET_BITS (sizeof(size_t)*CHAR_BIT)
 
@@ -24,29 +25,36 @@ struct tally *tally_new(unsigned buckets)
        struct tally *tally;
 
        /* There is always 1 bucket. */
-       if (buckets == 0)
+       if (buckets == 0) {
                buckets = 1;
+       }
+
+       /* Overly cautious check for overflow. */
+       if (sizeof(*tally) * buckets / sizeof(*tally) != buckets) {
+               return NULL;
+       }
 
-       /* Check for overflow. */
-       if (buckets && SIZE_MAX / buckets < sizeof(tally->counts[0]))
+       tally = (struct tally *)malloc(
+               sizeof(*tally) + sizeof(tally->counts[0])*(buckets-1));
+       if (tally == NULL) {
                return NULL;
-       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;
-               tally->buckets = buckets;
-               tally->step_bits = 0;
-               memset(tally->counts, 0, sizeof(tally->counts[0])*buckets);
        }
+
+       tally->max = ((size_t)1 << (SIZET_BITS - 1));
+       tally->min = ~tally->max;
+       tally->total[0] = tally->total[1] = 0;
+       tally->buckets = buckets;
+       tally->step_bits = 0;
+       memset(tally->counts, 0, sizeof(tally->counts[0])*buckets);
        return tally;
 }
 
 static unsigned bucket_of(ssize_t min, unsigned step_bits, ssize_t val)
 {
        /* Don't over-shift. */
-       if (step_bits == SIZET_BITS)
+       if (step_bits == SIZET_BITS) {
                return 0;
+       }
        assert(step_bits < SIZET_BITS);
        return (size_t)(val - min) >> step_bits;
 }
@@ -322,7 +330,7 @@ ssize_t tally_total(const struct tally *tally, ssize_t *overflow)
        }
 
        /* If result is negative, make sure we can represent it. */
-       if (tally->total[1] & (1 << (SIZET_BITS-1))) {
+       if (tally->total[1] & ((size_t)1 << (SIZET_BITS-1))) {
                /* Must have only underflowed once, and must be able to
                 * represent result at ssize_t. */
                if ((~tally->total[1])+1 != 0
@@ -448,21 +456,24 @@ char *tally_histogram(const struct tally *tally,
                        largest_bucket = tally->counts[i];
        }
 
-       p = graph = malloc(height * (width + 1) + 1);
+       p = graph = (char *)malloc(height * (width + 1) + 1);
        if (!graph) {
                free(tmp);
                return NULL;
        }
 
        for (i = 0; i < height; i++) {
-               unsigned covered = 1;
-               count = (double)tally->counts[i] / largest_bucket * (width-1)+1;
+               unsigned covered = 1, row;
+
+               /* People expect minimum at the bottom. */
+               row = height - i - 1;
+               count = (double)tally->counts[row] / largest_bucket * (width-1)+1;
 
-               if (i == 0)
+               if (row == 0)
                        covered = snprintf(p, width, "%zi", tally->min);
-               else if (i == height - 1)
+               else if (row == height - 1)
                        covered = snprintf(p, width, "%zi", tally->max);
-               else if (i == bucket_of(tally->min, tally->step_bits, 0))
+               else if (row == bucket_of(tally->min, tally->step_bits, 0))
                        *p = '+';
                else
                        *p = '|';