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Diffstat (limited to 'db2/os/db_os_fid.c')
-rw-r--r--db2/os/db_os_fid.c126
1 files changed, 126 insertions, 0 deletions
diff --git a/db2/os/db_os_fid.c b/db2/os/db_os_fid.c
new file mode 100644
index 0000000000..8fa55fa56c
--- /dev/null
+++ b/db2/os/db_os_fid.c
@@ -0,0 +1,126 @@
+/*-
+ * See the file LICENSE for redistribution information.
+ *
+ * Copyright (c) 1996, 1997
+ * Sleepycat Software. All rights reserved.
+ */
+
+#include "config.h"
+
+#ifndef lint
+static const char sccsid[] = "@(#)db_os_fid.c 10.7 (Sleepycat) 8/21/97";
+#endif /* not lint */
+
+#ifndef NO_SYSTEM_INCLUDES
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#endif
+
+#include "db_int.h"
+#include "db_page.h"
+#include "os_ext.h"
+#include "common_ext.h"
+
+/*
+ * __db_fileid --
+ * Return a unique identifier for a file.
+ *
+ * PUBLIC: int __db_fileid __P((DB_ENV *, const char *, int, u_int8_t *));
+ */
+int
+__db_fileid(dbenv, fname, timestamp, fidp)
+ DB_ENV *dbenv;
+ const char *fname;
+ int timestamp;
+ u_int8_t *fidp;
+{
+ time_t now;
+ u_int8_t *p;
+ unsigned int i;
+
+#ifdef _WIN32
+ /*
+ * The documentation for GetFileInformationByHandle() states that the
+ * inode-type numbers are not constant between processes. Actually,
+ * they are, they're the NTFS MFT indexes. So, this works on NTFS,
+ * but perhaps not on other platforms, and perhaps not over a network.
+ * Can't think of a better solution right now.
+ */
+ int fd = 0;
+ HANDLE fh = 0;
+ BY_HANDLE_FILE_INFORMATION fi;
+ BOOL retval = FALSE;
+
+ /* Clear the buffer. */
+ memset(fidp, 0, DB_FILE_ID_LEN);
+
+ /* first we open the file, because we're not given a handle to it */
+ fd = open(fname,_O_RDONLY,_S_IREAD);
+ if (-1 == fd) {
+ /* If we can't open it, we're in trouble */
+ return (errno);
+ }
+
+ /* File open, get its info */
+ fh = (HANDLE)_get_osfhandle(fd);
+ if ((HANDLE)(-1) != fh) {
+ retval = GetFileInformationByHandle(fh,&fi);
+ }
+ close(fd);
+
+ /*
+ * We want the three 32-bit words which tell us the volume ID and
+ * the file ID. We make a crude attempt to copy the bytes over to
+ * the callers buffer.
+ *
+ * DBDB: really we should ensure that the bytes get packed the same
+ * way on all compilers, platforms etc.
+ */
+ if ( ((HANDLE)(-1) != fh) && (TRUE == retval) ) {
+ memcpy(fidp, &fi.nFileIndexLow, sizeof(u_int32_t));
+ fidp += sizeof(u_int32_t);
+ memcpy(fidp, &fi.nFileIndexHigh, sizeof(u_int32_t));
+ fidp += sizeof(u_int32_t);
+ memcpy(fidp, &fi.dwVolumeSerialNumber, sizeof(u_int32_t));
+ }
+#else
+ struct stat sb;
+
+ /* Clear the buffer. */
+ memset(fidp, 0, DB_FILE_ID_LEN);
+
+ /* Check for the unthinkable. */
+ if (sizeof(sb.st_ino) +
+ sizeof(sb.st_dev) + sizeof(time_t) > DB_FILE_ID_LEN)
+ return (EINVAL);
+
+ /* On UNIX, use a dev/inode pair. */
+ if (stat(fname, &sb)) {
+ __db_err(dbenv, "%s: %s", fname, strerror(errno));
+ return (errno);
+ }
+
+ /*
+ * Use the inode first and in reverse order, hopefully putting the
+ * distinguishing information early in the string.
+ */
+ for (p = (u_int8_t *)&sb.st_ino +
+ sizeof(sb.st_ino), i = 0; i < sizeof(sb.st_ino); ++i)
+ *fidp++ = *--p;
+ for (p = (u_int8_t *)&sb.st_dev +
+ sizeof(sb.st_dev), i = 0; i < sizeof(sb.st_dev); ++i)
+ *fidp++ = *--p;
+#endif
+ if (timestamp) {
+ (void)time(&now);
+ for (p = (u_int8_t *)&now +
+ sizeof(now), i = 0; i < sizeof(now); ++i)
+ *fidp++ = *--p;
+ }
+ return (0);
+}