xref: /freebsd/usr.sbin/fifolog/lib/fifolog_write_poll.c (revision cdebaff820b2a4915a16cedfd511823d78aab171)
1 /*-
2  * Copyright (c) 2005-2008 Poul-Henning Kamp
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
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 
45 static 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 
53 const 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  */
65 static void
66 fifolog_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 
78 struct fifolog_writer *
79 fifolog_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 
88 void
89 fifolog_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 
101 void
102 fifolog_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 
117 const char *
118 fifolog_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 
186 static int
187 fifolog_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 	f->flag = 0;
241 
242 	memset(f->obuf, 0, f->obufsize);
243 	f->ff->zs->next_out = f->obuf + 5;
244 	f->ff->zs->avail_out = f->obufsize - 5;
245 	return (retval);
246 }
247 
248 /**********************************************************************
249  * Run the compression engine
250  * Returns -1 if there are trouble writing data
251  */
252 
253 static int
254 fifolog_write_gzip(struct fifolog_writer *f, time_t now)
255 {
256 	int i, fl, retval = 0;
257 
258 	assert(now != 0);
259 	if (f->cleanup || now >= (int)(f->lastsync + f->syncrate)) {
260 		f->cleanup = 0;
261 		fl = Z_FINISH;
262 		f->cnt[FIFOLOG_PT_SYNC]++;
263 	} else if (now >= (int)(f->lastwrite + f->writerate)) {
264 		fl = Z_SYNC_FLUSH;
265 		f->cnt[FIFOLOG_PT_FLUSH]++;
266 	} else if (f->ibufptr == 0)
267 		return (0);
268 	else
269 		fl = Z_NO_FLUSH;
270 
271 	f->ff->zs->avail_in = f->ibufptr;
272 	f->ff->zs->next_in = f->ibuf;
273 
274 	while (1) {
275 		i = deflate(f->ff->zs, fl);
276 		assert(i == Z_OK || i == Z_BUF_ERROR || i == Z_STREAM_END);
277 
278 		i = fifolog_write_output(f, fl, now);
279 		if (i == 0)
280 			break;
281 		if (i < 0)
282 			retval = -1;
283 	}
284 	assert(f->ff->zs->avail_in == 0);
285 	f->ibufptr = 0;
286 	if (fl == Z_FINISH) {
287 		f->flag |= FIFOLOG_FLG_SYNC;
288 		f->ff->zs->next_out = f->obuf + 9;
289 		f->ff->zs->avail_out = f->obufsize - 9;
290 		f->lastsync = now;
291 		assert(Z_OK == deflateReset(f->ff->zs));
292 	}
293 	return (retval);
294 }
295 
296 /**********************************************************************
297  * Poll to see if we need to flush out a record
298  * Returns -1 if there are trouble writing data
299  */
300 
301 int
302 fifolog_write_poll(struct fifolog_writer *f, time_t now)
303 {
304 
305 	if (now == 0)
306 		time(&now);
307 	return (fifolog_write_gzip(f, now));
308 }
309 
310 /**********************************************************************
311  * Attempt to write an entry into the ibuf.
312  * Return zero if there is no space, one otherwise
313  */
314 
315 int
316 fifolog_write_record(struct fifolog_writer *f, uint32_t id, time_t now,
317     const void *ptr, ssize_t len)
318 {
319 	const unsigned char *p;
320 	uint8_t buf[9];
321 	ssize_t bufl;
322 
323 	fifolog_write_assert(f);
324 	assert(!(id & (FIFOLOG_TIMESTAMP|FIFOLOG_LENGTH)));
325 	assert(ptr != NULL);
326 
327 	p = ptr;
328 	if (len == 0) {
329 		len = strlen(ptr);
330 		len++;
331 	} else {
332 		assert(len <= 255);
333 		id |= FIFOLOG_LENGTH;
334 	}
335 	assert (len > 0);
336 
337 	/* Do a timestamp, if needed */
338 	if (now == 0)
339 		time(&now);
340 
341 	if (now != f->last)
342 		id |= FIFOLOG_TIMESTAMP;
343 
344 	/* Emit instance+flag */
345 	be32enc(buf, id);
346 	bufl = 4;
347 
348 	if (id & FIFOLOG_TIMESTAMP) {
349 		be32enc(buf + bufl, (uint32_t)now);
350 		bufl += 4;
351 	}
352 	if (id & FIFOLOG_LENGTH)
353 		buf[bufl++] = (u_char)len;
354 
355 	if (bufl + len + f->ibufptr > f->ibufsize)
356 		return (0);
357 
358 	memcpy(f->ibuf + f->ibufptr, buf, bufl);
359 	f->ibufptr += bufl;
360 	memcpy(f->ibuf + f->ibufptr, p, len);
361 	f->ibufptr += len;
362 	f->cnt[FIFOLOG_PT_BYTES_PRE] += bufl + len;
363 
364 	if (id & FIFOLOG_TIMESTAMP)
365 		f->last = now;
366 	return (1);
367 }
368 
369 /**********************************************************************
370  * Write an entry, polling the gzip/writer until success.
371  * Long binary entries are broken into 255 byte chunks.
372  * Returns -1 if there are problems writing data
373  */
374 
375 int
376 fifolog_write_record_poll(struct fifolog_writer *f, uint32_t id, time_t now,
377     const void *ptr, ssize_t len)
378 {
379 	u_int l;
380 	const unsigned char *p;
381 	int retval = 0;
382 
383 	if (now == 0)
384 		time(&now);
385 	fifolog_write_assert(f);
386 
387 	assert(!(id & (FIFOLOG_TIMESTAMP|FIFOLOG_LENGTH)));
388 	assert(ptr != NULL);
389 
390 	if (len == 0) {
391 		if (!fifolog_write_record(f, id, now, ptr, len)) {
392 			if (fifolog_write_gzip(f, now) < 0)
393 				retval = -1;
394 			/* The string could be too long for the ibuf, so... */
395 			if (!fifolog_write_record(f, id, now, ptr, len))
396 				retval = -1;
397 		}
398 	} else {
399 		for (p = ptr; len > 0; len -= l, p += l) {
400 			l = len;
401 			if (l > 255)
402 				l = 255;
403 			while (!fifolog_write_record(f, id, now, p, l))
404 				if (fifolog_write_gzip(f, now) < 0)
405 					retval = -1;
406 		}
407 	}
408 	if (fifolog_write_gzip(f, now) < 0)
409 		retval = -1;
410 	fifolog_write_assert(f);
411 	return (retval);
412 }
413