1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
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
29#include <assert.h>
30#include <stdio.h>
31#include <string.h>
32#include <stdlib.h>
33#include <unistd.h>
34#include <stdint.h>
35#include <time.h>
36#include <sys/endian.h>
37
38#include <zlib.h>
39
40#include "fifolog.h"
41#include "libfifolog_int.h"
42#include "fifolog_write.h"
43#include "miniobj.h"
44
45static int fifolog_write_gzip(struct fifolog_writer *f, time_t now);
46
47#define ALLOC(ptr, size) do {                   \
48	(*(ptr)) = calloc(1, size);             \
49	assert(*(ptr) != NULL);                 \
50} while (0)
51
52
53const char *fifolog_write_statnames[] = {
54	[FIFOLOG_PT_BYTES_PRE] =	"Bytes before compression",
55	[FIFOLOG_PT_BYTES_POST] =	"Bytes after compression",
56	[FIFOLOG_PT_WRITES] =		"Writes",
57	[FIFOLOG_PT_FLUSH] =		"Flushes",
58	[FIFOLOG_PT_SYNC] =		"Syncs",
59	[FIFOLOG_PT_RUNTIME] =		"Runtime"
60};
61
62/**********************************************************************
63 * Check that everything is all right
64 */
65static void
66fifolog_write_assert(const struct fifolog_writer *f)
67{
68
69	CHECK_OBJ_NOTNULL(f, FIFOLOG_WRITER_MAGIC);
70	assert(f->ff->zs->next_out + f->ff->zs->avail_out == \
71	    f->obuf + f->obufsize);
72}
73
74/**********************************************************************
75 * Allocate/Destroy a new fifolog writer instance
76 */
77
78struct fifolog_writer *
79fifolog_write_new(void)
80{
81	struct fifolog_writer *f;
82
83	ALLOC_OBJ(f, FIFOLOG_WRITER_MAGIC);
84	assert(f != NULL);
85	return (f);
86}
87
88void
89fifolog_write_destroy(struct fifolog_writer *f)
90{
91
92	free(f->obuf);
93	free(f->ibuf);
94	FREE_OBJ(f);
95}
96
97/**********************************************************************
98 * Open/Close the fifolog
99 */
100
101void
102fifolog_write_close(struct fifolog_writer *f)
103{
104	time_t now;
105
106	CHECK_OBJ_NOTNULL(f, FIFOLOG_WRITER_MAGIC);
107	fifolog_write_assert(f);
108
109	f->cleanup = 1;
110	time(&now);
111	fifolog_write_gzip(f, now);
112	fifolog_write_assert(f);
113	fifolog_int_close(&f->ff);
114	free(f->ff);
115}
116
117const char *
118fifolog_write_open(struct fifolog_writer *f, const char *fn,
119    unsigned writerate, unsigned syncrate, unsigned compression)
120{
121	const char *es;
122	int i;
123	time_t now;
124	off_t o;
125
126	CHECK_OBJ_NOTNULL(f, FIFOLOG_WRITER_MAGIC);
127
128	/* Check for legal compression value */
129	if (compression > Z_BEST_COMPRESSION)
130		return ("Illegal compression value");
131
132	f->writerate = writerate;
133	f->syncrate = syncrate;
134	f->compression = compression;
135
136	/* Reset statistics */
137	memset(f->cnt, 0, sizeof f->cnt);
138
139	es = fifolog_int_open(&f->ff, fn, 1);
140	if (es != NULL)
141		return (es);
142	es = fifolog_int_findend(f->ff, &o);
143	if (es != NULL)
144		return (es);
145	i = fifolog_int_read(f->ff, o);
146	if (i)
147		return ("Read error, looking for seq");
148	f->seq = be32dec(f->ff->recbuf);
149	if (f->seq == 0) {
150		/* Empty fifolog */
151		f->seq = random();
152	} else {
153		f->recno = o + 1;
154		f->seq++;
155	}
156
157	f->obufsize = f->ff->recsize;
158	ALLOC(&f->obuf, f->obufsize);
159
160	f->ibufsize = f->obufsize * 10;
161	ALLOC(&f->ibuf, f->ibufsize);
162	f->ibufptr = 0;
163
164	i = deflateInit(f->ff->zs, (int)f->compression);
165	assert(i == Z_OK);
166
167	f->flag |= FIFOLOG_FLG_RESTART;
168	f->flag |= FIFOLOG_FLG_SYNC;
169	f->ff->zs->next_out = f->obuf + 9;
170	f->ff->zs->avail_out = f->obufsize - 9;
171
172	time(&now);
173	f->starttime = now;
174	f->lastsync = now;
175	f->lastwrite = now;
176
177	fifolog_write_assert(f);
178	return (NULL);
179}
180
181/**********************************************************************
182 * Write an output record
183 * Returns -1 if there are trouble writing data
184 */
185
186static int
187fifolog_write_output(struct fifolog_writer *f, int fl, time_t now)
188{
189	long h, l = f->ff->zs->next_out - f->obuf;
190	ssize_t i, w;
191	int retval = 0;
192
193	h = 4;					/* seq */
194	be32enc(f->obuf, f->seq);
195	f->obuf[h] = f->flag;
196	h += 1;					/* flag */
197	if (f->flag & FIFOLOG_FLG_SYNC) {
198		be32enc(f->obuf + h, now);
199		h += 4;				/* timestamp */
200	}
201
202	assert(l <= (long)f->ff->recsize);	/* NB: l includes h */
203	assert(l >= h);
204
205	/* We will never write an entirely empty buffer */
206	if (l == h)
207		return (0);
208
209	if (l < (long)f->ff->recsize && fl == Z_NO_FLUSH)
210		return (0);
211
212	w = f->ff->recsize - l;
213	if (w >  255) {
214		be32enc(f->obuf + f->ff->recsize - 4, w);
215		f->obuf[4] |= FIFOLOG_FLG_4BYTE;
216	} else if (w > 0) {
217		f->obuf[f->ff->recsize - 1] = (uint8_t)w;
218		f->obuf[4] |= FIFOLOG_FLG_1BYTE;
219	}
220
221	f->cnt[FIFOLOG_PT_BYTES_POST] += l - h;
222
223	i = pwrite(f->ff->fd, f->obuf, f->ff->recsize,
224	    (f->recno + 1) * f->ff->recsize);
225	if (i != f->ff->recsize)
226		retval = -1;
227	else
228		retval = 1;
229
230	f->cnt[FIFOLOG_PT_WRITES]++;
231	f->cnt[FIFOLOG_PT_RUNTIME] = now - f->starttime;
232
233	f->lastwrite = now;
234	/*
235	 * We increment these even on error, so as to properly skip bad,
236	 * sectors or other light trouble.
237	 */
238	f->seq++;
239	f->recno++;
240
241	/*
242	 * Ensure we wrap recno once we hit the file size (in records.)
243	 */
244	if (f->recno >= f->ff->logsize)
245		/* recno 0 is header; skip */
246		f->recno = 1;
247
248	f->flag = 0;
249
250	memset(f->obuf, 0, f->obufsize);
251	f->ff->zs->next_out = f->obuf + 5;
252	f->ff->zs->avail_out = f->obufsize - 5;
253	return (retval);
254}
255
256/**********************************************************************
257 * Run the compression engine
258 * Returns -1 if there are trouble writing data
259 */
260
261static int
262fifolog_write_gzip(struct fifolog_writer *f, time_t now)
263{
264	int i, fl, retval = 0;
265
266	assert(now != 0);
267	if (f->cleanup || now >= (int)(f->lastsync + f->syncrate)) {
268		f->cleanup = 0;
269		fl = Z_FINISH;
270		f->cnt[FIFOLOG_PT_SYNC]++;
271	} else if (now >= (int)(f->lastwrite + f->writerate)) {
272		fl = Z_SYNC_FLUSH;
273		f->cnt[FIFOLOG_PT_FLUSH]++;
274	} else if (f->ibufptr == 0)
275		return (0);
276	else
277		fl = Z_NO_FLUSH;
278
279	f->ff->zs->avail_in = f->ibufptr;
280	f->ff->zs->next_in = f->ibuf;
281
282	while (1) {
283		i = deflate(f->ff->zs, fl);
284		assert(i == Z_OK || i == Z_BUF_ERROR || i == Z_STREAM_END);
285
286		i = fifolog_write_output(f, fl, now);
287		if (i == 0)
288			break;
289		if (i < 0)
290			retval = -1;
291	}
292	assert(f->ff->zs->avail_in == 0);
293	f->ibufptr = 0;
294	if (fl == Z_FINISH) {
295		f->flag |= FIFOLOG_FLG_SYNC;
296		f->ff->zs->next_out = f->obuf + 9;
297		f->ff->zs->avail_out = f->obufsize - 9;
298		f->lastsync = now;
299		assert(Z_OK == deflateReset(f->ff->zs));
300	}
301	return (retval);
302}
303
304/**********************************************************************
305 * Poll to see if we need to flush out a record
306 * Returns -1 if there are trouble writing data
307 */
308
309int
310fifolog_write_poll(struct fifolog_writer *f, time_t now)
311{
312
313	if (now == 0)
314		time(&now);
315	return (fifolog_write_gzip(f, now));
316}
317
318/**********************************************************************
319 * Attempt to write an entry into the ibuf.
320 * Return zero if there is no space, one otherwise
321 */
322
323int
324fifolog_write_record(struct fifolog_writer *f, uint32_t id, time_t now,
325    const void *ptr, ssize_t len)
326{
327	const unsigned char *p;
328	uint8_t buf[9];
329	ssize_t bufl;
330
331	fifolog_write_assert(f);
332	assert(!(id & (FIFOLOG_TIMESTAMP|FIFOLOG_LENGTH)));
333	assert(ptr != NULL);
334
335	p = ptr;
336	if (len == 0) {
337		len = strlen(ptr);
338		len++;
339	} else {
340		assert(len <= 255);
341		id |= FIFOLOG_LENGTH;
342	}
343	assert (len > 0);
344
345	/* Do a timestamp, if needed */
346	if (now == 0)
347		time(&now);
348
349	if (now != f->last)
350		id |= FIFOLOG_TIMESTAMP;
351
352	/* Emit instance+flag */
353	be32enc(buf, id);
354	bufl = 4;
355
356	if (id & FIFOLOG_TIMESTAMP) {
357		be32enc(buf + bufl, (uint32_t)now);
358		bufl += 4;
359	}
360	if (id & FIFOLOG_LENGTH)
361		buf[bufl++] = (u_char)len;
362
363	if (bufl + len + f->ibufptr > f->ibufsize)
364		return (0);
365
366	memcpy(f->ibuf + f->ibufptr, buf, bufl);
367	f->ibufptr += bufl;
368	memcpy(f->ibuf + f->ibufptr, p, len);
369	f->ibufptr += len;
370	f->cnt[FIFOLOG_PT_BYTES_PRE] += bufl + len;
371
372	if (id & FIFOLOG_TIMESTAMP)
373		f->last = now;
374	return (1);
375}
376
377/**********************************************************************
378 * Write an entry, polling the gzip/writer until success.
379 * Long binary entries are broken into 255 byte chunks.
380 * Returns -1 if there are problems writing data
381 */
382
383int
384fifolog_write_record_poll(struct fifolog_writer *f, uint32_t id, time_t now,
385    const void *ptr, ssize_t len)
386{
387	u_int l;
388	const unsigned char *p;
389	int retval = 0;
390
391	if (now == 0)
392		time(&now);
393	fifolog_write_assert(f);
394
395	assert(!(id & (FIFOLOG_TIMESTAMP|FIFOLOG_LENGTH)));
396	assert(ptr != NULL);
397
398	if (len == 0) {
399		if (!fifolog_write_record(f, id, now, ptr, len)) {
400			if (fifolog_write_gzip(f, now) < 0)
401				retval = -1;
402			/* The string could be too long for the ibuf, so... */
403			if (!fifolog_write_record(f, id, now, ptr, len))
404				retval = -1;
405		}
406	} else {
407		for (p = ptr; len > 0; len -= l, p += l) {
408			l = len;
409			if (l > 255)
410				l = 255;
411			while (!fifolog_write_record(f, id, now, p, l))
412				if (fifolog_write_gzip(f, now) < 0)
413					retval = -1;
414		}
415	}
416	if (fifolog_write_gzip(f, now) < 0)
417		retval = -1;
418	fifolog_write_assert(f);
419	return (retval);
420}
421