Import BSDDB 4.7.25 (as of svn r89086)

common/db_byteorder.c

@@ -0,0 +1,63 @@
+/*-
+ * See the file LICENSE for redistribution information.
+ *
+ * Copyright (c) 1996,2008 Oracle.  All rights reserved.
+ *
+ * $Id: db_byteorder.c 63573 2008-05-23 21:43:21Z trent.nelson $
+ */
+
+#include "db_config.h"
+
+#include "db_int.h"
+
+/*
+ * __db_isbigendian --
+ *	Return 1 if big-endian (Motorola and Sparc), not little-endian
+ *	(Intel and Vax).  We do this work at run-time, rather than at
+ *	configuration time so cross-compilation and general embedded
+ *	system support is simpler.
+ *
+ * PUBLIC: int __db_isbigendian __P((void));
+ */
+int
+__db_isbigendian()
+{
+	union {					/* From Harbison & Steele.  */
+		long l;
+		char c[sizeof(long)];
+	} u;
+
+	u.l = 1;
+	return (u.c[sizeof(long) - 1] == 1);
+}
+
+/*
+ * __db_byteorder --
+ *	Return if we need to do byte swapping, checking for illegal
+ *	values.
+ *
+ * PUBLIC: int __db_byteorder __P((ENV *, int));
+ */
+int
+__db_byteorder(env, lorder)
+	ENV *env;
+	int lorder;
+{
+	switch (lorder) {
+	case 0:
+		break;
+	case 1234:
+		if (!F_ISSET(env, ENV_LITTLEENDIAN))
+			return (DB_SWAPBYTES);
+		break;
+	case 4321:
+		if (F_ISSET(env, ENV_LITTLEENDIAN))
+			return (DB_SWAPBYTES);
+		break;
+	default:
+		__db_errx(env,
+	    "unsupported byte order, only big and little-endian supported");
+		return (EINVAL);
+	}
+	return (0);
+}