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Diffstat (limited to 'StdLib/LibC/Stdio/makebuf.c')
| -rw-r--r-- | StdLib/LibC/Stdio/makebuf.c | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/StdLib/LibC/Stdio/makebuf.c b/StdLib/LibC/Stdio/makebuf.c new file mode 100644 index 0000000000..75c475c3a5 --- /dev/null +++ b/StdLib/LibC/Stdio/makebuf.c @@ -0,0 +1,132 @@ +/** @file
+ Implementation of internal file buffer allocation functions.
+
+ Copyright (c) 2010, Intel Corporation. All rights reserved.<BR>
+ This program and the accompanying materials are licensed and made available
+ under the terms and conditions of the BSD License that accompanies this
+ distribution. The full text of the license may be found at
+ http://opensource.org/licenses/bsd-license.php.
+
+ THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+ Copyright (c) 1990, 1993
+ The Regents of the University of California. All rights reserved.
+
+ This code is derived from software contributed to Berkeley by
+ Chris Torek.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions
+ are met:
+ - Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+ - Redistributions in binary form must reproduce the above copyright
+ notice, this list of conditions and the following disclaimer in the
+ documentation and/or other materials provided with the distribution.
+ - Neither the name of the University nor the names of its contributors
+ may be used to endorse or promote products derived from this software
+ without specific prior written permission.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
+ LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ POSSIBILITY OF SUCH DAMAGE.
+
+ NetBSD: makebuf.c,v 1.14 2003/08/07 16:43:28 agc Exp
+ makebuf.c 8.1 (Berkeley) 6/4/93
+**/
+#include <LibConfig.h>
+
+#include "namespace.h"
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/EfiSysCall.h>
+#include "reentrant.h"
+#include "local.h"
+#include <MainData.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.
+ */
+void
+__smakebuf(FILE *fp)
+{
+ void *p;
+ int flags;
+ size_t size;
+ int couldbetty;
+
+ _DIAGASSERT(fp != NULL);
+
+ if (fp->_flags & __SNBF) {
+ fp->_bf._base = fp->_p = fp->_nbuf;
+ fp->_bf._size = 1;
+ return;
+ }
+ flags = __swhatbuf(fp, &size, &couldbetty);
+ if ((p = malloc(size)) == NULL) {
+ fp->_flags |= __SNBF;
+ fp->_bf._base = fp->_p = fp->_nbuf;
+ fp->_bf._size = 1;
+ return;
+ }
+ gMD->cleanup = _cleanup;
+ flags |= __SMBF;
+ fp->_bf._base = fp->_p = p;
+ fp->_bf._size = (int)size;
+ if (couldbetty || isatty(fp->_file))
+ flags |= __SLBF;
+ fp->_flags |= flags;
+}
+
+/*
+ * Internal routine to determine `proper' buffering for a file.
+ */
+int
+__swhatbuf(FILE *fp, size_t *bufsize, int *couldbetty)
+{
+ struct stat st;
+
+ _DIAGASSERT(fp != NULL);
+ _DIAGASSERT(bufsize != NULL);
+ _DIAGASSERT(couldbetty != NULL);
+
+ if (fp->_file < 0 || fstat(fp->_file, &st) < 0) {
+ *couldbetty = 0;
+ *bufsize = BUFSIZ;
+ return (__SNPT);
+ }
+
+ /* could be a tty iff it is a character device */
+ *couldbetty = S_ISCHR(st.st_mode);
+ if (st.st_blksize == 0) {
+ *bufsize = BUFSIZ;
+ return (__SNPT);
+ }
+
+ /*
+ * Optimise fseek() only if it is a regular file. (The test for
+ * __sseek is mainly paranoia.) It is safe to set _blksize
+ * unconditionally; it will only be used if __SOPT is also set.
+ */
+ *bufsize = st.st_blksize;
+ fp->_blksize = st.st_blksize;
+ return ((st.st_mode & S_IFMT) == S_IFREG && fp->_seek == __sseek ?
+ __SOPT : __SNPT);
+}
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