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/* Copyright (C) 2019 C. McEnroe <june@causal.agency>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <assert.h>
#include <err.h>
#include <stdlib.h>
#include <sysexits.h>
#include <time.h>
#include "bounce.h"
enum { RingLen = 4096 };
static_assert(!(RingLen & (RingLen - 1)), "power of two RingLen");
static struct {
char *lines[RingLen];
time_t times[RingLen];
size_t write;
} ring;
void ringProduce(const char *line) {
size_t i = ring.write++ % RingLen;
if (ring.lines[i]) free(ring.lines[i]);
ring.times[i] = time(NULL);
ring.lines[i] = strdup(line);
if (!ring.lines[i]) err(EX_OSERR, "strdup");
}
static struct {
char **names;
size_t *ptrs;
size_t cap, len;
} read;
size_t ringConsumer(const char *name) {
for (size_t i = 0; i < read.len; ++i) {
if (!strcmp(read.names[i], name)) return i;
}
if (read.len == read.cap) {
read.cap = (read.cap ? read.cap * 2 : 8);
read.names = realloc(read.names, sizeof(*read.names) * read.cap);
if (!read.names) err(EX_OSERR, "realloc");
read.ptrs = realloc(read.ptrs, sizeof(*read.ptrs) * read.cap);
if (!read.ptrs) err(EX_OSERR, "realloc");
}
read.names[read.len] = strdup(name);
if (!read.names[read.len]) err(EX_OSERR, "strdup");
read.ptrs[read.len] = 0;
return read.len++;
}
size_t ringDiff(size_t consumer) {
assert(consumer < read.len);
return ring.write - read.ptrs[consumer];
}
const char *ringConsume(time_t *time, size_t consumer) {
assert(consumer < read.len);
if (!ringDiff(consumer)) return NULL;
if (ringDiff(consumer) > RingLen) {
read.ptrs[consumer] = ring.write - RingLen;
}
size_t i = read.ptrs[consumer]++ % RingLen;
if (time) *time = ring.times[i];
return ring.lines[i];
}
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