#include <stdio.h>
#include <assert.h>
-#define MAX_STEP_BITS (sizeof(size_t)*CHAR_BIT)
+#define SIZET_BITS (sizeof(size_t)*CHAR_BIT)
/* We use power of 2 steps. I tried being tricky, but it got buggy. */
struct tally {
ssize_t min, max;
size_t total[2];
/* This allows limited frequency analysis. */
- size_t buckets;
- size_t step_bits;
- size_t counts[1 /* [buckets] */ ];
+ unsigned buckets, step_bits;
+ size_t counts[1 /* Actually: [buckets] */ ];
};
-struct tally *tally_new(size_t 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) {
- /* SSIZE_MAX isn't portable, so make it one of these types. */
- BUILD_ASSERT(sizeof(tally->min) == sizeof(int)
- || sizeof(tally->min) == sizeof(long)
- || sizeof(tally->min) == sizeof(long long));
- if (sizeof(tally->min) == sizeof(int)) {
- tally->min = INT_MAX;
- tally->max = INT_MIN;
- } else if (sizeof(tally->min) == sizeof(long)) {
- tally->min = LONG_MAX;
- tally->max = LONG_MIN;
- } else if (sizeof(tally->min) == sizeof(long long)) {
- tally->min = (ssize_t)LLONG_MAX;
- tally->max = (ssize_t)LLONG_MIN;
- }
+ 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;
}
static unsigned bucket_of(ssize_t min, unsigned step_bits, ssize_t val)
{
/* Don't over-shift. */
- if (step_bits == MAX_STEP_BITS)
+ if (step_bits == SIZET_BITS)
return 0;
- assert(step_bits < MAX_STEP_BITS);
+ assert(step_bits < SIZET_BITS);
return (size_t)(val - min) >> step_bits;
}
static ssize_t bucket_min(ssize_t min, unsigned step_bits, unsigned b)
{
/* Don't over-shift. */
- if (step_bits == MAX_STEP_BITS)
+ if (step_bits == SIZET_BITS)
return min;
- assert(step_bits < MAX_STEP_BITS);
+ assert(step_bits < SIZET_BITS);
return min + ((ssize_t)b << step_bits);
}
return divls64(tally->total[1], tally->total[0], count);
}
+ssize_t tally_total(const struct tally *tally, ssize_t *overflow)
+{
+ if (overflow) {
+ *overflow = tally->total[1];
+ return tally->total[0];
+ }
+
+ /* If result is negative, make sure we can represent it. */
+ 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
+ || (ssize_t)tally->total[0] >= 0) {
+ /* Underflow, return minimum. */
+ return (ssize_t)((size_t)1 << (SIZET_BITS - 1));
+ }
+ } else {
+ /* Result is positive, must not have overflowed, and must be
+ * able to represent as ssize_t. */
+ if (tally->total[1] || (ssize_t)tally->total[0] < 0) {
+ /* Overflow. Return maximum. */
+ return (ssize_t)~((size_t)1 << (SIZET_BITS - 1));
+ }
+ }
+ return tally->total[0];
+}
+
static ssize_t bucket_range(const struct tally *tally, unsigned b, size_t *err)
{
ssize_t min, max;
} 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;
memcpy(tmp->counts, tally->counts,
sizeof(tally->counts[0]) * tmp->buckets);
while ((max_bucket = get_max_bucket(tmp)) >= height)
- renormalize(tmp, tmp->min, tmp->max *= 2);
+ renormalize(tmp, tmp->min, tmp->max * 2);
/* Restore max */
tmp->max = tally->max;
tally = tmp;
free(tmp);
return NULL;
}
+
for (i = 0; i < height; i++) {
- unsigned covered = 0;
- count = (double)tally->counts[i] / largest_bucket * width;
+ 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);
- if (covered) {
- if (covered > width)
- covered = width;
- p += covered;
- if (count > covered)
- count -= covered;
- else
- count = 0;
- }
+ else if (row == bucket_of(tally->min, tally->step_bits, 0))
+ *p = '+';
+ else
+ *p = '|';
+
+ if (covered > width)
+ covered = width;
+ p += covered;
+
+ if (count > covered)
+ count -= covered;
+ else
+ count = 0;
+
memset(p, '*', count);
p += count;
*p = '\n';
projects / ccan / blobdiff