1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
|
/* update.c - The routines for updating the file to a consistent state. */
/* This file is part of GDBM, the GNU data base manager, by Philip A. Nelson.
Copyright (C) 1990, 1991, 1993 Free Software Foundation, Inc.
GDBM is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
GDBM is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GDBM; see the file COPYING. If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
You may contact the author by:
e-mail: phil@cs.wwu.edu
us-mail: Philip A. Nelson
Computer Science Department
Western Washington University
Bellingham, WA 98226
*************************************************************************/
/* include system configuration before all else. */
#include "autoconf.h"
#include "gdbmdefs.h"
static void write_header _ARGS((gdbm_file_info *));
/* This procedure writes the header back to the file described by DBF. */
static void
write_header (dbf)
gdbm_file_info *dbf;
{
int num_bytes; /* Return value for write. */
off_t file_pos; /* Return value for lseek. */
file_pos = lseek (dbf->desc, 0L, L_SET);
if (file_pos != 0) _gdbm_fatal (dbf, "lseek error");
num_bytes = write (dbf->desc, dbf->header, dbf->header->block_size);
if (num_bytes != dbf->header->block_size)
_gdbm_fatal (dbf, "write error");
/* Wait for all output to be done. */
if (!dbf->fast_write)
fsync (dbf->desc);
}
/* After all changes have been made in memory, we now write them
all to disk. */
void
_gdbm_end_update (dbf)
gdbm_file_info *dbf;
{
int num_bytes; /* Return value for write. */
off_t file_pos; /* Return value for lseek. */
/* Write the current bucket. */
if (dbf->bucket_changed && (dbf->cache_entry != NULL))
{
_gdbm_write_bucket (dbf, dbf->cache_entry);
dbf->bucket_changed = FALSE;
}
/* Write the other changed buckets if there are any. */
if (dbf->second_changed)
{
if(dbf->bucket_cache != NULL)
{
register int index;
for (index = 0; index < dbf->cache_size; index++)
{
if (dbf->bucket_cache[index].ca_changed)
_gdbm_write_bucket (dbf, &dbf->bucket_cache[index]);
}
}
dbf->second_changed = FALSE;
}
/* Write the directory. */
if (dbf->directory_changed)
{
file_pos = lseek (dbf->desc, dbf->header->dir, L_SET);
if (file_pos != dbf->header->dir) _gdbm_fatal (dbf, "lseek error");
num_bytes = write (dbf->desc, dbf->dir, dbf->header->dir_size);
if (num_bytes != dbf->header->dir_size)
_gdbm_fatal (dbf, "write error");
dbf->directory_changed = FALSE;
if (!dbf->header_changed && !dbf->fast_write)
fsync (dbf->desc);
}
/* Final write of the header. */
if (dbf->header_changed)
{
write_header (dbf);
dbf->header_changed = FALSE;
}
}
/* If a fatal error is detected, come here and exit. VAL tells which fatal
error occured. */
int
_gdbm_fatal (dbf, val)
gdbm_file_info *dbf;
char *val;
{
if (dbf->fatal_err != NULL)
(*dbf->fatal_err) (val);
else
fprintf (stderr, "gdbm fatal: %s.\n", val);
exit (-1);
/* NOTREACHED */
}
|
