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-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);
+}