usr.sbin/fifolog/lib/fifolog_write_poll.c

   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 }