initial import

1 files changed, 187 insertions, 0 deletions

diff --git a/stdio/obstream.c b/stdio/obstream.c
new file mode 100644
index 0000000000..32f7220b59
--- /dev/null
+++ b/stdio/obstream.c
@@ -0,0 +1,187 @@
+/* Copyright (C) 1992 Free Software Foundation, Inc.
+This file is part of the GNU C Library.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C Library 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
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+#include <ansidecl.h>
+#include <stdio.h>
+#include <obstack.h>
+#include <stdarg.h>
+#include <string.h>
+
+/* Output-room function for obstack streams.  */
+
+static void
+DEFUN(grow, (stream, c), FILE *stream AND int c)
+{
+  struct obstack *const obstack = (struct obstack *) stream->__cookie;
+
+  /* Move the end of the object back to include only the portion
+     of the buffer which the user has already written into.  */ 
+  obstack_blank_fast (obstack, - (stream->__put_limit - stream->__bufp));
+
+  if (stream->__target > obstack_object_size (obstack))
+    {
+      /* Our target (where the buffer maps to) is always zero except when
+	 the user just did a SEEK_END fseek.  If he sought within the
+	 buffer, we need do nothing and will zero the target below.  If he
+	 sought past the end of the object, grow and zero-fill the object
+	 up to the target address.  */
+
+      obstack_blank (obstack,
+		     stream->__target - obstack_object_size (obstack));
+      /* fseek has just flushed us, so the put limit points
+	 to the end of the written data.  */
+      bzero (stream->__put_limit,
+	     stream->__target - stream->__bufsize);
+    }
+
+  if (c != EOF)
+    obstack_1grow (obstack, (unsigned char) c);
+
+  /* The stream buffer always maps exactly to the object on the top
+     of the obstack.  The start of the buffer is the start of the object.
+     The put limit points just past the end of the object.  On fflush, the
+     obstack is sync'd so the end of the object points just past the last
+     character written to the stream.  */
+
+  stream->__target = stream->__offset = 0;
+  stream->__buffer = obstack_base (obstack);
+  stream->__bufsize = obstack_room (obstack);
+  stream->__bufp = obstack_next_free (obstack);
+  stream->__get_limit = stream->__bufp;
+
+  if (c == EOF)
+    /* This is fflush.  Make the stream buffer, the object,
+       and the characters actually written all match.  */
+    stream->__put_limit = stream->__get_limit;
+  else
+    {
+      /* Extend the buffer (and the object) to include
+	 the rest of the obstack chunk (which is unitialized).
+	 Data past bufp is undefined.  */
+      stream->__put_limit = stream->__buffer + stream->__bufsize;
+      obstack_blank_fast (obstack, stream->__put_limit - stream->__bufp);
+    }
+}
+
+/* Seek function for obstack streams.
+   There is no external state to munge.  */
+
+static int
+DEFUN(seek, (cookie, pos, whence),
+      PTR cookie AND fpos_t *pos AND int whence)
+{
+  switch (whence)
+    {
+    case SEEK_SET:
+    case SEEK_CUR:
+      return 0;
+
+    case SEEK_END:
+      /* Return the position relative to the end of the object.
+	 fseek has just flushed us, so the obstack is consistent.  */
+      *pos += obstack_object_size ((struct obstack *) cookie);
+      return 0;
+
+    default:
+      __libc_fatal ("obstream::seek called with bogus WHENCE\n");
+      return -1;
+    }
+}
+
+/* Input room function for obstack streams.
+   Only what has been written to the stream can be read back.  */
+
+static int
+DEFUN(input, (stream), FILE *stream)
+{
+  /* Re-sync with the obstack, growing the object if necessary.  */
+  grow (stream, EOF);
+
+  if (stream->__bufp < stream->__get_limit)
+    return (unsigned char) *stream->__bufp++;
+
+  stream->__eof = 1;
+  return EOF;
+}
+
+/* Initialize STREAM to talk to OBSTACK.  */
+
+static void
+DEFUN(init_obstream, (stream, obstack),
+      FILE *stream AND struct obstack *obstack)
+{
+  stream->__mode.__write = 1;
+  stream->__mode.__read = 1;
+
+  /* Input can read only what has been written.  */
+  stream->__room_funcs.__input = input;
+
+  /* Do nothing for close.  */
+  stream->__io_funcs.__close = NULL;
+
+  /* When the buffer is full, grow the obstack.  */
+  stream->__room_funcs.__output = grow;
+
+  /* Seek within the object, and extend it.  */
+  stream->__io_funcs.__seek = seek;
+  stream->__target = stream->__offset = 0;
+
+  stream->__seen = 1;
+
+  /* Don't deallocate that buffer!  */
+  stream->__userbuf = 1;
+
+  /* We don't have to initialize the buffer.
+     The first read attempt will call grow, which will do all the work.  */
+}
+
+FILE *
+open_obstack_stream (obstack)
+     struct obstack *obstack;
+{
+  register FILE *stream;
+
+  stream = __newstream ();
+  if (stream == NULL)
+    return NULL;
+
+  init_obstream (stream, obstack);
+  return stream;
+}
+
+int
+DEFUN(obstack_vprintf, (obstack, format, args),
+      struct obstack *obstack AND const char *format AND va_list args)
+{
+  FILE f;
+  bzero (&f, sizeof (f));
+  init_obstream (&f, obstack);
+  return vfprintf (&f, format, args);
+}
+
+int
+DEFUN(obstack_printf, (obstack, format),
+      struct obstack *obstack AND const char *format DOTS)
+{
+  int result;
+  va_list ap;
+  va_start (ap, format);
+  result = obstack_vprintf (obstack, format, ap);
+  va_end (ap);
+  return result;
+}