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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 16:11:47 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 16:11:47 +0000
commit758f820bcc0f68aeebac1717e537ca13a320b909 (patch)
tree48111ece75cf4f98316848b37a7e26356e00669e /lib/freadahead.c
parentInitial commit. (diff)
downloadcoreutils-upstream.tar.xz
coreutils-upstream.zip
Adding upstream version 9.1.upstream/9.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'lib/freadahead.c')
-rw-r--r--lib/freadahead.c103
1 files changed, 103 insertions, 0 deletions
diff --git a/lib/freadahead.c b/lib/freadahead.c
new file mode 100644
index 0000000..829d03b
--- /dev/null
+++ b/lib/freadahead.c
@@ -0,0 +1,103 @@
+/* Retrieve information about a FILE stream.
+ Copyright (C) 2007-2022 Free Software Foundation, Inc.
+
+ This file is free software: you can redistribute it and/or modify
+ it under the terms of the GNU Lesser General Public License as
+ published by the Free Software Foundation; either version 2.1 of the
+ License, or (at your option) any later version.
+
+ This file is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with this program. If not, see <https://www.gnu.org/licenses/>. */
+
+#include <config.h>
+
+/* Specification. */
+#include "freadahead.h"
+
+#include <stdlib.h>
+#include "stdio-impl.h"
+
+#if defined __DragonFly__
+/* Defined in libc, but not declared in <stdio.h>. */
+extern size_t __sreadahead (FILE *);
+#endif
+
+/* This file is not used on systems that have the __freadahead function,
+ namely musl libc. */
+
+size_t
+freadahead (FILE *fp)
+{
+#if defined _IO_EOF_SEEN || defined _IO_ftrylockfile || __GNU_LIBRARY__ == 1
+ /* GNU libc, BeOS, Haiku, Linux libc5 */
+ if (fp->_IO_write_ptr > fp->_IO_write_base)
+ return 0;
+ return (fp->_IO_read_end - fp->_IO_read_ptr)
+ + (fp->_flags & _IO_IN_BACKUP ? fp->_IO_save_end - fp->_IO_save_base :
+ 0);
+#elif defined __sferror || defined __DragonFly__ || defined __ANDROID__
+ /* FreeBSD, NetBSD, OpenBSD, DragonFly, Mac OS X, Cygwin, Minix 3, Android */
+ if ((fp_->_flags & __SWR) != 0 || fp_->_r < 0)
+ return 0;
+# if defined __DragonFly__
+ return __sreadahead (fp);
+# else
+ return fp_->_r
+ + (HASUB (fp) ? fp_->_ur : 0);
+# endif
+#elif defined __EMX__ /* emx+gcc */
+ if ((fp->_flags & _IOWRT) != 0)
+ return 0;
+ /* Note: fp->_ungetc_count > 0 implies fp->_rcount <= 0,
+ fp->_ungetc_count = 0 implies fp->_rcount >= 0. */
+ /* equivalent to
+ (fp->_ungetc_count == 0 ? fp->_rcount : fp->_ungetc_count - fp->_rcount) */
+ return (fp->_rcount > 0 ? fp->_rcount : fp->_ungetc_count - fp->_rcount);
+#elif defined __minix /* Minix */
+ if ((fp_->_flags & _IOWRITING) != 0)
+ return 0;
+ return fp_->_count;
+#elif defined _IOERR /* AIX, HP-UX, IRIX, OSF/1, Solaris, OpenServer, UnixWare, mingw, MSVC, NonStop Kernel, OpenVMS */
+ if ((fp_->_flag & _IOWRT) != 0)
+ return 0;
+ return fp_->_cnt;
+#elif defined __UCLIBC__ /* uClibc */
+# ifdef __STDIO_BUFFERS
+ if (fp->__modeflags & __FLAG_WRITING)
+ return 0;
+ return (fp->__bufread - fp->__bufpos)
+ + (fp->__modeflags & __FLAG_UNGOT ? 1 : 0);
+# else
+ return 0;
+# endif
+#elif defined __QNX__ /* QNX */
+ if ((fp->_Mode & 0x2000 /* _MWRITE */) != 0)
+ return 0;
+ /* fp->_Buf <= fp->_Next <= fp->_Rend,
+ and fp->_Rend may be overridden by fp->_Rsave. */
+ return ((fp->_Rsave ? fp->_Rsave : fp->_Rend) - fp->_Next)
+ + (fp->_Mode & 0x4000 /* _MBYTE */
+ ? (fp->_Back + sizeof (fp->_Back)) - fp->_Rback
+ : 0);
+#elif defined __MINT__ /* Atari FreeMiNT */
+ if (!fp->__mode.__read)
+ return 0;
+ return (fp->__pushed_back
+ ? fp->__get_limit - fp->__pushback_bufp + 1
+ : fp->__get_limit - fp->__bufp);
+#elif defined EPLAN9 /* Plan9 */
+ if (fp->state == 4 /* WR */ || fp->rp >= fp->wp)
+ return 0;
+ return fp->wp - fp->rp;
+#elif defined SLOW_BUT_NO_HACKS /* users can define this */
+ abort ();
+ return 0;
+#else
+ #error "Please port gnulib freadahead.c to your platform! Look at the definition of fflush, fread, ungetc on your system, then report this to bug-gnulib."
+#endif
+}