initial import

1 files changed, 177 insertions, 0 deletions

diff --git a/stdio/memstream.c b/stdio/memstream.c
new file mode 100644
index 0000000000..704eca53b3
--- /dev/null
+++ b/stdio/memstream.c
@@ -0,0 +1,177 @@
+/* Copyright (C) 1991, 1992, 1994 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 <stdlib.h>
+#include <string.h>
+
+struct memstream_info
+  {
+    char **buffer;
+    size_t *bufsize;
+  };
+
+/* Enlarge STREAM's buffer.  */
+static void
+DEFUN(enlarge_buffer, (stream, c),
+      register FILE *stream AND int c)
+{
+  struct memstream_info *info = (struct memstream_info *) stream->__cookie;
+  size_t need;
+
+  if (stream->__put_limit != stream->__buffer)
+    /* Record how much has actually been written into the buffer.  */
+    *info->bufsize = stream->__bufp - stream->__buffer;
+
+  if (stream->__target != -1
+      && stream->__target > *info->bufsize)
+    /* 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 buffer
+       up to the target address.  */
+    need = stream->__target;
+  else
+    need = *info->bufsize;
+
+  /* We always need an extra character in the buffer.  Either we are
+     writing C, or we are flushing and need to write a NUL terminator.  */
+  ++need;
+
+  if (stream->__bufsize < need)
+    {
+      /* Enlarge the buffer.  */
+      char *newbuf;
+      size_t newsize;
+      if (stream->__bufsize * 2 < need)
+	newsize = need;
+      else
+	newsize = stream->__bufsize * 2;
+      newbuf = (char *) realloc ((PTR) stream->__buffer, newsize);
+      if (newbuf == NULL)
+	{
+	  stream->__error = 1;
+	  return;
+	}
+      *info->buffer = stream->__buffer = newbuf;
+      stream->__bufsize = newsize;
+    }
+
+  stream->__target = stream->__offset = 0;
+  stream->__get_limit = stream->__bufp = stream->__buffer + *info->bufsize;
+  stream->__put_limit = stream->__buffer + stream->__bufsize;
+
+  need -= stream->__bufp - stream->__buffer + 1;
+  if (need > 0)
+    {
+      /* We are extending the buffer after an fseek; zero-fill new space.  */
+      bzero (stream->__bufp, need);
+      stream->__bufp += need;
+    }
+
+  if (c != EOF)
+    *stream->__bufp++ = (unsigned char) c;
+  else
+    *stream->__bufp = '\0';
+}
+
+/* Seek function for memstreams.
+   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 info is consistent.  */
+      *pos += *((struct memstream_info *) cookie)->bufsize;
+      return 0;
+
+    default:
+      __libc_fatal ("memstream::seek called with bogus WHENCE\n");
+      return -1;
+    }
+}
+
+static int
+DEFUN(free_info, (cookie), PTR cookie)
+{
+#if 0
+  struct memstream_info *info = (struct memstream_info *) cookie;
+  char *buf;
+
+  buf = (char *) realloc ((PTR) *info->buffer, *info->bufsize);
+  if (buf != NULL)
+    *info->buffer = buf;
+#endif
+
+  free (cookie);
+
+  return 0;
+}
+
+/* Open a stream that writes into a malloc'd buffer that is expanded as
+   necessary.  *BUFLOC and *SIZELOC are updated with the buffer's location
+   and the number of characters written on fflush or fclose.  */
+FILE *
+DEFUN(open_memstream, (bufloc, sizeloc),
+      char **bufloc AND size_t *sizeloc)
+{
+  FILE *stream;
+  struct memstream_info *info;
+
+  if (bufloc == NULL || sizeloc == NULL)
+    {
+      errno = EINVAL;
+      return NULL;
+    }
+
+  stream = fmemopen ((char *) NULL, BUFSIZ, "w+");
+  if (stream == NULL)
+    return NULL;
+
+  info = (struct memstream_info *) malloc (sizeof (struct memstream_info));
+  if (info == NULL)
+    {
+      int save = errno;
+      (void) fclose (stream);
+      errno = save;
+      return NULL;
+    }
+
+  stream->__room_funcs.__output = enlarge_buffer;
+  stream->__io_funcs.__seek = seek;
+  stream->__io_funcs.__close = free_info;
+  stream->__cookie = (PTR) info;
+  stream->__userbuf = 1;
+
+  info->buffer = bufloc;
+  info->bufsize = sizeloc;
+
+  *bufloc = stream->__buffer;
+
+  return stream;
+}