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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 <stdio.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];
} ring;
size_t producer;
void ringProduce(const char *line) {
size_t i = producer++ % 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");
}
struct Consumer {
char *name;
size_t pos;
};
static struct {
struct Consumer *ptr;
size_t cap, len;
} consumers;
size_t ringConsumer(const char *name) {
for (size_t i = 0; i < consumers.len; ++i) {
if (!strcmp(consumers.ptr[i].name, name)) return i;
}
if (consumers.len == consumers.cap) {
consumers.cap = (consumers.cap ? consumers.cap * 2 : 8);
// FIXME: Keep old pointer around for saving when exiting for error.
consumers.ptr = realloc(
consumers.ptr, sizeof(*consumers.ptr) * consumers.cap
);
if (!consumers.ptr) err(EX_OSERR, "realloc");
}
struct Consumer *consumer = &consumers.ptr[consumers.len];
consumer->pos = 0;
consumer->name = strdup(name);
if (!consumer->name) err(EX_OSERR, "strdup");
return consumers.len++;
}
size_t ringDiff(size_t consumer) {
assert(consumer < consumers.len);
return producer - consumers.ptr[consumer].pos;
}
const char *ringPeek(time_t *time, size_t consumer) {
if (!ringDiff(consumer)) return NULL;
if (ringDiff(consumer) > RingLen) {
consumers.ptr[consumer].pos = producer - RingLen;
}
size_t i = consumers.ptr[consumer].pos % RingLen;
if (time) *time = ring.times[i];
return ring.lines[i];
}
const char *ringConsume(time_t *time, size_t consumer) {
const char *line = ringPeek(time, consumer);
consumers.ptr[consumer].pos++;
return line;
}
void ringInfo(void) {
fprintf(stderr, "producer: %zu\n", producer);
for (size_t i = 0; i < consumers.len; ++i) {
fprintf(
stderr, "consumer %s: %zu (%zu)\n",
consumers.ptr[i].name,
consumers.ptr[i].pos, producer - consumers.ptr[i].pos
);
}
}
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