sbin/jscan/jsession.c

   1 /*
   2  * Copyright (c) 2005 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Matthew Dillon <dillon@backplane.com>
   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  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  * 3. Neither the name of The DragonFly Project nor the names of its
  18  *    contributors may be used to endorse or promote products derived
  19  *    from this software without specific, prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  * $DragonFly: src/sbin/jscan/jsession.c,v 1.3 2005/09/07 19:10:09 dillon Exp $
  35  */
  36
  37 #include "jscan.h"
  38
  39 void
  40 jsession_init(struct jsession *ss, struct jfile *jfin,
  41               enum jdirection direction,
  42               const char *transid_file, int64_t transid)
  43 {
  44     bzero(ss, sizeof(*ss));
  45     ss->ss_jfin = jfin;
  46     ss->ss_direction = direction;
  47     ss->ss_transid = transid;
  48     ss->ss_transid_file = transid_file;
  49     ss->ss_transid_fd = -1;
  50 }
  51
  52 /*
  53  * Update the last-processed transid.  If operating in the reverse
  54  * direction we have to write out transid - 1 so the next reverse
  55  * processing operation does not re-execute the transid just executed
  56  * and so the next forward processing operation does.
  57  */
  58 void
  59 jsession_update_transid(struct jsession *ss __unused, int64_t transid)
  60 {
  61     char buf[32];
  62
  63     if (ss->ss_transid_file) {
  64         if (ss->ss_transid_fd < 0) {
  65             ss->ss_transid_fd = open(ss->ss_transid_file, O_RDWR|O_CREAT, 0666);
  66         }
  67         if (ss->ss_transid_fd < 0) {
  68             fprintf(stderr, "Cannot open/create %s\n", ss->ss_transid_file);
  69             exit(1);
  70         }
  71         if (ss->ss_direction == JD_FORWARDS)
  72             snprintf(buf, sizeof(buf), "%016llx\n", transid);
  73         else
  74             snprintf(buf, sizeof(buf), "%016llx\n", transid - 1);
  75         lseek(ss->ss_transid_fd, 0L, 0);
  76         write(ss->ss_transid_fd, buf, strlen(buf));
  77         if (fsync_opt > 1)
  78             fsync(ss->ss_transid_fd);
  79     }
  80 }
  81
  82 /*
  83  * Returns non-zero if the data can be dumped into the specified session.
  84  */
  85 int
  86 jsession_check(struct jsession *ss, struct jdata *jd)
  87 {
  88     if (ss->ss_direction == JD_FORWARDS) {
  89         if (jd->jd_transid > ss->ss_transid)
  90             return(1);
  91     } else {
  92         if (jd->jd_transid <= ss->ss_transid)
  93             return(1);
  94     }
  95     return(0);
  96 }
  97
  98 void
  99 jsession_term(struct jsession *ss)
 100 {
 101    if (ss->ss_transid_fd >= 0) {
 102         close(ss->ss_transid_fd);
 103         ss->ss_transid_fd = -1;
 104    }
 105 }
 106