xref: /freebsd/usr.sbin/fifolog/lib/fifolog_write_poll.c (revision 911f0260390e18cf85f3dbf2c719b593efdc1e3c)
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  * $FreeBSD$
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 
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 
263 static int
264 fifolog_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 
311 int
312 fifolog_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 
325 int
326 fifolog_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 
385 int
386 fifolog_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