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authorJason Downs <downsj@downsj.com>2008-11-21 21:33:39 +0000
committerJason Downs <downsj@downsj.com>2008-11-21 21:33:39 +0000
commit10fe387708ddfba6449b9abd74cfbdf67d495465 (patch)
tree50115c0708c762940f580d081c73495bf148101a /src/update.c
downloadgdbm-10fe387708ddfba6449b9abd74cfbdf67d495465.tar.gz
gdbm-10fe387708ddfba6449b9abd74cfbdf67d495465.tar.bz2
Initial revision
Diffstat (limited to 'src/update.c')
-rw-r--r--src/update.c119
1 files changed, 119 insertions, 0 deletions
diff --git a/src/update.c b/src/update.c
new file mode 100644
index 0000000..390f4f6
--- /dev/null
+++ b/src/update.c
@@ -0,0 +1,119 @@
+/* update.c - The routines for updating the file to a consistent state. */
+
+/* This file is part of GDBM, the GNU data base manager.
+ Copyright (C) 1990, 1991, 1993, 2007 Free Software Foundation, Inc.
+
+ This program 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 3, or (at your option)
+ any later version.
+
+ This program 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 this program; if not, write to the Free Software Foundation,
+ Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+
+/* Include system configuration before all else. */
+#include "autoconf.h"
+
+#include "gdbmdefs.h"
+
+static void write_header (gdbm_file_info *);
+
+/* This procedure writes the header back to the file described by DBF. */
+
+static void
+write_header (gdbm_file_info *dbf)
+{
+ int num_bytes; /* Return value for write. */
+ off_t file_pos; /* Return value for lseek. */
+
+ file_pos = __lseek (dbf, 0L, L_SET);
+ if (file_pos != 0) _gdbm_fatal (dbf, "lseek error");
+ num_bytes = __write (dbf, dbf->header, dbf->header->block_size);
+ if (num_bytes != dbf->header->block_size)
+ _gdbm_fatal (dbf, "write error");
+
+ /* Sync the file if fast_write is FALSE or it's mapped. */
+ if (dbf->mapped_region != NULL || dbf->fast_write == FALSE)
+ __fsync (dbf);
+}
+
+
+/* After all changes have been made in memory, we now write them
+ all to disk. */
+void
+_gdbm_end_update (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)
+ {
+ 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, dbf->header->dir, L_SET);
+ if (file_pos != dbf->header->dir) _gdbm_fatal (dbf, "lseek error");
+ num_bytes = __write (dbf, 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 == FALSE || dbf->mapped_region != NULL))
+ __fsync (dbf);
+ }
+
+ /* 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. */
+
+void
+_gdbm_fatal (gdbm_file_info *dbf, const char *val)
+{
+ if ((dbf != NULL) && (dbf->fatal_err != NULL))
+ (*dbf->fatal_err) (val);
+ else
+ {
+ write (STDERR_FILENO, "gdbm fatal: ", 12);
+ if (val != NULL)
+ write (STDERR_FILENO, val, strlen(val));
+ write (STDERR_FILENO, "\n", 1);
+ }
+ exit (1);
+ /* NOTREACHED */
+}

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