1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2005-2008 Poul-Henning Kamp
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * $FreeBSD$
29 */
30
31#include <assert.h>
32#include <stdio.h>
33#include <string.h>
34#include <stdlib.h>
35#include <unistd.h>
36#include <stdint.h>
37#include <time.h>
38#include <sys/endian.h>
39
40#include <zlib.h>
41
42#include "fifolog.h"
43#include "libfifolog_int.h"
44#include "fifolog_write.h"
45#include "miniobj.h"
46
47static int fifolog_write_gzip(struct fifolog_writer *f, time_t now);
48
49#define ALLOC(ptr, size) do {                   \
50	(*(ptr)) = calloc(1, size);             \
51	assert(*(ptr) != NULL);                 \
52} while (0)
53
54
55const char *fifolog_write_statnames[] = {
56	[FIFOLOG_PT_BYTES_PRE] =	"Bytes before compression",
57	[FIFOLOG_PT_BYTES_POST] =	"Bytes after compression",
58	[FIFOLOG_PT_WRITES] =		"Writes",
59	[FIFOLOG_PT_FLUSH] =		"Flushes",
60	[FIFOLOG_PT_SYNC] =		"Syncs",
61	[FIFOLOG_PT_RUNTIME] =		"Runtime"
62};
63
64/**********************************************************************
65 * Check that everything is all right
66 */
67static void
68fifolog_write_assert(const struct fifolog_writer *f)
69{
70
71	CHECK_OBJ_NOTNULL(f, FIFOLOG_WRITER_MAGIC);
72	assert(f->ff->zs->next_out + f->ff->zs->avail_out == \
73	    f->obuf + f->obufsize);
74}
75
76/**********************************************************************
77 * Allocate/Destroy a new fifolog writer instance
78 */
79
80struct fifolog_writer *
81fifolog_write_new(void)
82{
83	struct fifolog_writer *f;
84
85	ALLOC_OBJ(f, FIFOLOG_WRITER_MAGIC);
86	assert(f != NULL);
87	return (f);
88}
89
90void
91fifolog_write_destroy(struct fifolog_writer *f)
92{
93
94	free(f->obuf);
95	free(f->ibuf);
96	FREE_OBJ(f);
97}
98
99/**********************************************************************
100 * Open/Close the fifolog
101 */
102
103void
104fifolog_write_close(struct fifolog_writer *f)
105{
106	time_t now;
107
108	CHECK_OBJ_NOTNULL(f, FIFOLOG_WRITER_MAGIC);
109	fifolog_write_assert(f);
110
111	f->cleanup = 1;
112	time(&now);
113	fifolog_write_gzip(f, now);
114	fifolog_write_assert(f);
115	fifolog_int_close(&f->ff);
116	free(f->ff);
117}
118
119const char *
120fifolog_write_open(struct fifolog_writer *f, const char *fn,
121    unsigned writerate, unsigned syncrate, unsigned compression)
122{
123	const char *es;
124	int i;
125	time_t now;
126	off_t o;
127
128	CHECK_OBJ_NOTNULL(f, FIFOLOG_WRITER_MAGIC);
129
130	/* Check for legal compression value */
131	if (compression > Z_BEST_COMPRESSION)
132		return ("Illegal compression value");
133
134	f->writerate = writerate;
135	f->syncrate = syncrate;
136	f->compression = compression;
137
138	/* Reset statistics */
139	memset(f->cnt, 0, sizeof f->cnt);
140
141	es = fifolog_int_open(&f->ff, fn, 1);
142	if (es != NULL)
143		return (es);
144	es = fifolog_int_findend(f->ff, &o);
145	if (es != NULL)
146		return (es);
147	i = fifolog_int_read(f->ff, o);
148	if (i)
149		return ("Read error, looking for seq");
150	f->seq = be32dec(f->ff->recbuf);
151	if (f->seq == 0) {
152		/* Empty fifolog */
153		f->seq = random();
154	} else {
155		f->recno = o + 1;
156		f->seq++;
157	}
158
159	f->obufsize = f->ff->recsize;
160	ALLOC(&f->obuf, f->obufsize);
161
162	f->ibufsize = f->obufsize * 10;
163	ALLOC(&f->ibuf, f->ibufsize);
164	f->ibufptr = 0;
165
166	i = deflateInit(f->ff->zs, (int)f->compression);
167	assert(i == Z_OK);
168
169	f->flag |= FIFOLOG_FLG_RESTART;
170	f->flag |= FIFOLOG_FLG_SYNC;
171	f->ff->zs->next_out = f->obuf + 9;
172	f->ff->zs->avail_out = f->obufsize - 9;
173
174	time(&now);
175	f->starttime = now;
176	f->lastsync = now;
177	f->lastwrite = now;
178
179	fifolog_write_assert(f);
180	return (NULL);
181}
182
183/**********************************************************************
184 * Write an output record
185 * Returns -1 if there are trouble writing data
186 */
187
188static int
189fifolog_write_output(struct fifolog_writer *f, int fl, time_t now)
190{
191	long h, l = f->ff->zs->next_out - f->obuf;
192	ssize_t i, w;
193	int retval = 0;
194
195	h = 4;					/* seq */
196	be32enc(f->obuf, f->seq);
197	f->obuf[h] = f->flag;
198	h += 1;					/* flag */
199	if (f->flag & FIFOLOG_FLG_SYNC) {
200		be32enc(f->obuf + h, now);
201		h += 4;				/* timestamp */
202	}
203
204	assert(l <= (long)f->ff->recsize);	/* NB: l includes h */
205	assert(l >= h);
206
207	/* We will never write an entirely empty buffer */
208	if (l == h)
209		return (0);
210
211	if (l < (long)f->ff->recsize && fl == Z_NO_FLUSH)
212		return (0);
213
214	w = f->ff->recsize - l;
215	if (w >  255) {
216		be32enc(f->obuf + f->ff->recsize - 4, w);
217		f->obuf[4] |= FIFOLOG_FLG_4BYTE;
218	} else if (w > 0) {
219		f->obuf[f->ff->recsize - 1] = (uint8_t)w;
220		f->obuf[4] |= FIFOLOG_FLG_1BYTE;
221	}
222
223	f->cnt[FIFOLOG_PT_BYTES_POST] += l - h;
224
225	i = pwrite(f->ff->fd, f->obuf, f->ff->recsize,
226	    (f->recno + 1) * f->ff->recsize);
227	if (i != f->ff->recsize)
228		retval = -1;
229	else
230		retval = 1;
231
232	f->cnt[FIFOLOG_PT_WRITES]++;
233	f->cnt[FIFOLOG_PT_RUNTIME] = now - f->starttime;
234
235	f->lastwrite = now;
236	/*
237	 * We increment these even on error, so as to properly skip bad,
238	 * sectors or other light trouble.
239	 */
240	f->seq++;
241	f->recno++;
242
243	/*
244	 * Ensure we wrap recno once we hit the file size (in records.)
245	 */
246	if (f->recno >= f->ff->logsize)
247		/* recno 0 is header; skip */
248		f->recno = 1;
249
250	f->flag = 0;
251
252	memset(f->obuf, 0, f->obufsize);
253	f->ff->zs->next_out = f->obuf + 5;
254	f->ff->zs->avail_out = f->obufsize - 5;
255	return (retval);
256}
257
258/**********************************************************************
259 * Run the compression engine
260 * Returns -1 if there are trouble writing data
261 */
262
263static int
264fifolog_write_gzip(struct fifolog_writer *f, time_t now)
265{
266	int i, fl, retval = 0;
267
268	assert(now != 0);
269	if (f->cleanup || now >= (int)(f->lastsync + f->syncrate)) {
270		f->cleanup = 0;
271		fl = Z_FINISH;
272		f->cnt[FIFOLOG_PT_SYNC]++;
273	} else if (now >= (int)(f->lastwrite + f->writerate)) {
274		fl = Z_SYNC_FLUSH;
275		f->cnt[FIFOLOG_PT_FLUSH]++;
276	} else if (f->ibufptr == 0)
277		return (0);
278	else
279		fl = Z_NO_FLUSH;
280
281	f->ff->zs->avail_in = f->ibufptr;
282	f->ff->zs->next_in = f->ibuf;
283
284	while (1) {
285		i = deflate(f->ff->zs, fl);
286		assert(i == Z_OK || i == Z_BUF_ERROR || i == Z_STREAM_END);
287
288		i = fifolog_write_output(f, fl, now);
289		if (i == 0)
290			break;
291		if (i < 0)
292			retval = -1;
293	}
294	assert(f->ff->zs->avail_in == 0);
295	f->ibufptr = 0;
296	if (fl == Z_FINISH) {
297		f->flag |= FIFOLOG_FLG_SYNC;
298		f->ff->zs->next_out = f->obuf + 9;
299		f->ff->zs->avail_out = f->obufsize - 9;
300		f->lastsync = now;
301		assert(Z_OK == deflateReset(f->ff->zs));
302	}
303	return (retval);
304}
305
306/**********************************************************************
307 * Poll to see if we need to flush out a record
308 * Returns -1 if there are trouble writing data
309 */
310
311int
312fifolog_write_poll(struct fifolog_writer *f, time_t now)
313{
314
315	if (now == 0)
316		time(&now);
317	return (fifolog_write_gzip(f, now));
318}
319
320/**********************************************************************
321 * Attempt to write an entry into the ibuf.
322 * Return zero if there is no space, one otherwise
323 */
324
325int
326fifolog_write_record(struct fifolog_writer *f, uint32_t id, time_t now,
327    const void *ptr, ssize_t len)
328{
329	const unsigned char *p;
330	uint8_t buf[9];
331	ssize_t bufl;
332
333	fifolog_write_assert(f);
334	assert(!(id & (FIFOLOG_TIMESTAMP|FIFOLOG_LENGTH)));
335	assert(ptr != NULL);
336
337	p = ptr;
338	if (len == 0) {
339		len = strlen(ptr);
340		len++;
341	} else {
342		assert(len <= 255);
343		id |= FIFOLOG_LENGTH;
344	}
345	assert (len > 0);
346
347	/* Do a timestamp, if needed */
348	if (now == 0)
349		time(&now);
350
351	if (now != f->last)
352		id |= FIFOLOG_TIMESTAMP;
353
354	/* Emit instance+flag */
355	be32enc(buf, id);
356	bufl = 4;
357
358	if (id & FIFOLOG_TIMESTAMP) {
359		be32enc(buf + bufl, (uint32_t)now);
360		bufl += 4;
361	}
362	if (id & FIFOLOG_LENGTH)
363		buf[bufl++] = (u_char)len;
364
365	if (bufl + len + f->ibufptr > f->ibufsize)
366		return (0);
367
368	memcpy(f->ibuf + f->ibufptr, buf, bufl);
369	f->ibufptr += bufl;
370	memcpy(f->ibuf + f->ibufptr, p, len);
371	f->ibufptr += len;
372	f->cnt[FIFOLOG_PT_BYTES_PRE] += bufl + len;
373
374	if (id & FIFOLOG_TIMESTAMP)
375		f->last = now;
376	return (1);
377}
378
379/**********************************************************************
380 * Write an entry, polling the gzip/writer until success.
381 * Long binary entries are broken into 255 byte chunks.
382 * Returns -1 if there are problems writing data
383 */
384
385int
386fifolog_write_record_poll(struct fifolog_writer *f, uint32_t id, time_t now,
387    const void *ptr, ssize_t len)
388{
389	u_int l;
390	const unsigned char *p;
391	int retval = 0;
392
393	if (now == 0)
394		time(&now);
395	fifolog_write_assert(f);
396
397	assert(!(id & (FIFOLOG_TIMESTAMP|FIFOLOG_LENGTH)));
398	assert(ptr != NULL);
399
400	if (len == 0) {
401		if (!fifolog_write_record(f, id, now, ptr, len)) {
402			if (fifolog_write_gzip(f, now) < 0)
403				retval = -1;
404			/* The string could be too long for the ibuf, so... */
405			if (!fifolog_write_record(f, id, now, ptr, len))
406				retval = -1;
407		}
408	} else {
409		for (p = ptr; len > 0; len -= l, p += l) {
410			l = len;
411			if (l > 255)
412				l = 255;
413			while (!fifolog_write_record(f, id, now, p, l))
414				if (fifolog_write_gzip(f, now) < 0)
415					retval = -1;
416		}
417	}
418	if (fifolog_write_gzip(f, now) < 0)
419		retval = -1;
420	fifolog_write_assert(f);
421	return (retval);
422}
423