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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"
static struct {
size_t len;
char **lines;
time_t *times;
} ring;
void ringAlloc(size_t len) {
if (len & (len - 1)) {
errx(EX_CONFIG, "ring length must be power of two: %zu", len);
}
ring.lines = calloc(len, sizeof(*ring.lines));
if (!ring.lines) err(EX_OSERR, "calloc");
ring.times = calloc(len, sizeof(*ring.times));
if (!ring.times) err(EX_OSERR, "calloc");
ring.len = len;
}
size_t producer;
void ringProduce(const char *line) {
size_t i = producer++ & (ring.len - 1);
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);
void *ptr = realloc(
consumers.ptr, sizeof(*consumers.ptr) * consumers.cap
);
if (!ptr) err(EX_OSERR, "realloc");
consumers.ptr = ptr;
}
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) > ring.len) {
warnx(
"consumer %s dropped %zu messages",
consumers.ptr[consumer].name, ringDiff(consumer) - ring.len
);
consumers.ptr[consumer].pos = producer - ring.len;
}
size_t i = consumers.ptr[consumer].pos & (ring.len - 1);
if (time) *time = ring.times[i];
assert(ring.lines[i]);
return ring.lines[i];
}
const char *ringConsume(time_t *time, size_t consumer) {
const char *line = ringPeek(time, consumer);
if (line) 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
);
}
}
static const size_t FileVersion[] = {
0x0165636E756F70,
0x0265636E756F70,
};
static int writeSize(FILE *file, size_t value) {
return (fwrite(&value, sizeof(value), 1, file) ? 0 : -1);
}
static int writeTime(FILE *file, time_t time) {
return (fwrite(&time, sizeof(time), 1, file) ? 0 : -1);
}
static int writeString(FILE *file, const char *str) {
return (fwrite(str, strlen(str) + 1, 1, file) ? 0 : -1);
}
int ringSave(FILE *file) {
if (writeSize(file, FileVersion[1])) return -1;
if (writeSize(file, ring.len)) return -1;
if (writeSize(file, producer)) return -1;
if (writeSize(file, consumers.len)) return -1;
for (size_t i = 0; i < consumers.len; ++i) {
if (writeString(file, consumers.ptr[i].name)) return -1;
if (writeSize(file, consumers.ptr[i].pos)) return -1;
}
for (size_t i = 0; i < ring.len; ++i) {
if (writeTime(file, ring.times[i])) return -1;
}
for (size_t i = 0; i < ring.len; ++i) {
if (!ring.lines[i]) break;
if (writeString(file, ring.lines[i])) return -1;
}
return 0;
}
static void readSize(FILE *file, size_t *value) {
fread(value, sizeof(*value), 1, file);
if (ferror(file)) err(EX_IOERR, "fread");
if (feof(file)) err(EX_DATAERR, "unexpected eof");
}
static void readTime(FILE *file, time_t *time) {
fread(time, sizeof(*time), 1, file);
if (ferror(file)) err(EX_IOERR, "fread");
if (feof(file)) err(EX_DATAERR, "unexpected eof");
}
static void readString(FILE *file, char **buf, size_t *cap) {
ssize_t len = getdelim(buf, cap, '\0', file);
if (len < 0 && !feof(file)) err(EX_IOERR, "getdelim");
}
void ringLoad(FILE *file) {
size_t version;
fread(&version, sizeof(version), 1, file);
if (ferror(file)) err(EX_IOERR, "fread");
if (feof(file)) return;
if (version != FileVersion[0] && version != FileVersion[1]) {
errx(EX_DATAERR, "unknown file version %zX", version);
}
size_t saveLen = 4096;
if (version == FileVersion[1]) readSize(file, &saveLen);
if (saveLen > ring.len) {
errx(EX_DATAERR, "cannot load save with larger ring");
}
readSize(file, &producer);
char *buf = NULL;
size_t cap = 0;
size_t len;
readSize(file, &len);
for (size_t i = 0; i < len; ++i) {
readString(file, &buf, &cap);
size_t consumer = ringConsumer(buf);
readSize(file, &consumers.ptr[consumer].pos);
}
for (size_t i = 0; i < saveLen; ++i) {
readTime(file, &ring.times[i]);
}
for (size_t i = 0; i < saveLen; ++i) {
readString(file, &buf, &cap);
if (feof(file)) break;
ring.lines[i] = strdup(buf);
if (!ring.lines[i]) err(EX_OSERR, "strdup");
}
free(buf);
if (ring.len > saveLen) {
producer %= saveLen;
for (size_t i = 0; i < consumers.len; ++i) {
struct Consumer *consumer = &consumers.ptr[i];
consumer->pos %= saveLen;
if (consumer->pos > producer) consumer->pos = 0;
}
}
}
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