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 
47 static 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 
55 const 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  */
67 static void
68 fifolog_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 
80 struct fifolog_writer *
81 fifolog_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 
90 void
91 fifolog_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 
103 void
104 fifolog_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 
119 const char *
120 fifolog_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 
188 static int
189 fifolog_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 	f->flag = 0;
243 
244 	memset(f->obuf, 0, f->obufsize);
245 	f->ff->zs->next_out = f->obuf + 5;
246 	f->ff->zs->avail_out = f->obufsize - 5;
247 	return (retval);
248 }
249 
250 /**********************************************************************
251  * Run the compression engine
252  * Returns -1 if there are trouble writing data
253  */
254 
255 static int
256 fifolog_write_gzip(struct fifolog_writer *f, time_t now)
257 {
258 	int i, fl, retval = 0;
259 
260 	assert(now != 0);
261 	if (f->cleanup || now >= (int)(f->lastsync + f->syncrate)) {
262 		f->cleanup = 0;
263 		fl = Z_FINISH;
264 		f->cnt[FIFOLOG_PT_SYNC]++;
265 	} else if (now >= (int)(f->lastwrite + f->writerate)) {
266 		fl = Z_SYNC_FLUSH;
267 		f->cnt[FIFOLOG_PT_FLUSH]++;
268 	} else if (f->ibufptr == 0)
269 		return (0);
270 	else
271 		fl = Z_NO_FLUSH;
272 
273 	f->ff->zs->avail_in = f->ibufptr;
274 	f->ff->zs->next_in = f->ibuf;
275 
276 	while (1) {
277 		i = deflate(f->ff->zs, fl);
278 		assert(i == Z_OK || i == Z_BUF_ERROR || i == Z_STREAM_END);
279 
280 		i = fifolog_write_output(f, fl, now);
281 		if (i == 0)
282 			break;
283 		if (i < 0)
284 			retval = -1;
285 	}
286 	assert(f->ff->zs->avail_in == 0);
287 	f->ibufptr = 0;
288 	if (fl == Z_FINISH) {
289 		f->flag |= FIFOLOG_FLG_SYNC;
290 		f->ff->zs->next_out = f->obuf + 9;
291 		f->ff->zs->avail_out = f->obufsize - 9;
292 		f->lastsync = now;
293 		assert(Z_OK == deflateReset(f->ff->zs));
294 	}
295 	return (retval);
296 }
297 
298 /**********************************************************************
299  * Poll to see if we need to flush out a record
300  * Returns -1 if there are trouble writing data
301  */
302 
303 int
304 fifolog_write_poll(struct fifolog_writer *f, time_t now)
305 {
306 
307 	if (now == 0)
308 		time(&now);
309 	return (fifolog_write_gzip(f, now));
310 }
311 
312 /**********************************************************************
313  * Attempt to write an entry into the ibuf.
314  * Return zero if there is no space, one otherwise
315  */
316 
317 int
318 fifolog_write_record(struct fifolog_writer *f, uint32_t id, time_t now,
319     const void *ptr, ssize_t len)
320 {
321 	const unsigned char *p;
322 	uint8_t buf[9];
323 	ssize_t bufl;
324 
325 	fifolog_write_assert(f);
326 	assert(!(id & (FIFOLOG_TIMESTAMP|FIFOLOG_LENGTH)));
327 	assert(ptr != NULL);
328 
329 	p = ptr;
330 	if (len == 0) {
331 		len = strlen(ptr);
332 		len++;
333 	} else {
334 		assert(len <= 255);
335 		id |= FIFOLOG_LENGTH;
336 	}
337 	assert (len > 0);
338 
339 	/* Do a timestamp, if needed */
340 	if (now == 0)
341 		time(&now);
342 
343 	if (now != f->last)
344 		id |= FIFOLOG_TIMESTAMP;
345 
346 	/* Emit instance+flag */
347 	be32enc(buf, id);
348 	bufl = 4;
349 
350 	if (id & FIFOLOG_TIMESTAMP) {
351 		be32enc(buf + bufl, (uint32_t)now);
352 		bufl += 4;
353 	}
354 	if (id & FIFOLOG_LENGTH)
355 		buf[bufl++] = (u_char)len;
356 
357 	if (bufl + len + f->ibufptr > f->ibufsize)
358 		return (0);
359 
360 	memcpy(f->ibuf + f->ibufptr, buf, bufl);
361 	f->ibufptr += bufl;
362 	memcpy(f->ibuf + f->ibufptr, p, len);
363 	f->ibufptr += len;
364 	f->cnt[FIFOLOG_PT_BYTES_PRE] += bufl + len;
365 
366 	if (id & FIFOLOG_TIMESTAMP)
367 		f->last = now;
368 	return (1);
369 }
370 
371 /**********************************************************************
372  * Write an entry, polling the gzip/writer until success.
373  * Long binary entries are broken into 255 byte chunks.
374  * Returns -1 if there are problems writing data
375  */
376 
377 int
378 fifolog_write_record_poll(struct fifolog_writer *f, uint32_t id, time_t now,
379     const void *ptr, ssize_t len)
380 {
381 	u_int l;
382 	const unsigned char *p;
383 	int retval = 0;
384 
385 	if (now == 0)
386 		time(&now);
387 	fifolog_write_assert(f);
388 
389 	assert(!(id & (FIFOLOG_TIMESTAMP|FIFOLOG_LENGTH)));
390 	assert(ptr != NULL);
391 
392 	if (len == 0) {
393 		if (!fifolog_write_record(f, id, now, ptr, len)) {
394 			if (fifolog_write_gzip(f, now) < 0)
395 				retval = -1;
396 			/* The string could be too long for the ibuf, so... */
397 			if (!fifolog_write_record(f, id, now, ptr, len))
398 				retval = -1;
399 		}
400 	} else {
401 		for (p = ptr; len > 0; len -= l, p += l) {
402 			l = len;
403 			if (l > 255)
404 				l = 255;
405 			while (!fifolog_write_record(f, id, now, p, l))
406 				if (fifolog_write_gzip(f, now) < 0)
407 					retval = -1;
408 		}
409 	}
410 	if (fifolog_write_gzip(f, now) < 0)
411 		retval = -1;
412 	fifolog_write_assert(f);
413 	return (retval);
414 }
415