upstream/1.1.0_cvsrelease/1.1.0_cvs

1 files changed, 71 insertions, 0 deletions

diff --git a/gnu/lib/libg++/iostream/makebuf.C b/gnu/lib/libg++/iostream/makebuf.C
new file mode 100644
index 000000000000..592f59ec396a
--- /dev/null
+++ b/gnu/lib/libg++/iostream/makebuf.C
@@ -0,0 +1,71 @@
+/*
+ * Copyright (c) 1990 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms are permitted
+ * provided that the above copyright notice and this paragraph are
+ * duplicated in all such forms and that any documentation,
+ * advertising materials, and other materials related to such
+ * distribution and use acknowledge that the software was developed
+ * by the University of California, Berkeley.  The name of the
+ * University may not be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ */
+
+// Modified for GNU iostream by Per Bothner 1991.
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "%W% (Berkeley) %G%";
+#endif /* LIBC_SCCS and not lint */
+
+#include "ioprivate.h"
+#include "fstream.h"
+#include <sys/types.h>
+#include <sys/stat.h>
+
+/*
+ * Allocate a file buffer, or switch to unbuffered I/O.
+ * Per the ANSI C standard, ALL tty devices default to line buffered.
+ *
+ * As a side effect, we set __SOPT or __SNPT (en/dis-able fseek
+ * optimisation) right after the _fstat() that finds the buffer size.
+ */
+int filebuf::doallocate()
+{
+    register size_t size, couldbetty;
+    register char *p;
+    struct stat st;
+
+    if (fd() < 0 || _fstat(fd(), &st) < 0) {
+	couldbetty = 0;
+	size = _G_BUFSIZ;
+#if 0
+	/* do not try to optimise fseek() */
+	fp->_flags |= __SNPT;
+#endif
+    } else {
+	couldbetty = S_ISCHR(st.st_mode);
+#if _G_HAVE_ST_BLKSIZE
+	size = st.st_blksize <= 0 ? _G_BUFSIZ : st.st_blksize;
+#else
+	size = _G_BUFSIZ;
+#endif
+    }
+#ifdef USE_MALLOC_BUF
+    if ((p = malloc(size)) == NULL) {
+	unbuffered(1);
+//	fp->_bf._base = fp->_p = fp->_nbuf;
+//	fp->_bf._size = 1;
+	return EOF;
+    }
+#else
+    p = ALLOC_BUF(size);
+#endif
+    setb(p, p+size, 1);
+    if (couldbetty && _isatty(fd()))
+	_flags |= _S_LINE_BUF;
+    return 1;
+}