1 files changed, 97 insertions, 0 deletions
diff --git a/lib/varstring.c b/lib/varstring.c
new file mode 100644
index 0000000..0107abd
--- /dev/null
+++ b/lib/varstring.c
@@ -0,0 +1,97 @@
+/* varstring.c: variable-length strings.
+
+Copyright (C) 1992 Free Software Foundation, Inc.
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+This program 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 General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+#include "config.h"
+
+#include "varstring.h"
+
+
+/* You use variable-length stringsd by calling `init_string' first, then
+   assigning to particular elements via `set_string_element'. The string
+   will initially be `INITIAL_SIZE' characters, and be incremented in
+   blocks of size `INCREMENT_SIZE'.  */
+
+#define INITIAL_SIZE 16
+#define INCREMENT_SIZE 64
+
+variable_string
+vs_init ()
+{
+  variable_string vs;
+
+  VS_CHARS (vs) = xmalloc (INITIAL_SIZE);
+  *VS_CHARS (vs) = 0;
+  VS_ALLOCATED (vs) = INITIAL_SIZE;
+  VS_USED (vs) = 0;
+
+  return vs;
+}
+
+
+/* Free the data we've allocated for VS.  */
+
+void
+vs_free (variable_string *vs)
+{
+  free (VS_CHARS (*vs));
+  VS_CHARS (*vs) = NULL;
+}
+
+
+/* We do not put a NULL after we insert NEW_CHAR at the (zero-based)
+   index LOC.  The caller is responsible for that.  */
+
+void
+vs_set_char (variable_string *vs, unsigned loc, char new_char)
+{
+  /* Do we need more space?  */
+  if (loc >= VS_ALLOCATED (*vs))
+    { /* Yes.  Make sure to allocate enough.  */
+      unsigned extra = MAX (INCREMENT_SIZE, loc - VS_ALLOCATED (*vs) + 1);
+      VS_CHARS (*vs) = xrealloc (VS_CHARS (*vs), VS_ALLOCATED (*vs) + extra);
+      VS_ALLOCATED (*vs) += extra;
+    }
+
+  VS_CHARS (*vs)[loc] = new_char;
+  VS_USED (*vs) = loc + 1;
+}
+
+
+/* Append NEW_CHAR to VS.  */
+
+void
+vs_append_char (variable_string *vs, char new_char)
+{
+  vs_set_char (vs, VS_USED (*vs), new_char);
+}
+
+
+variable_string
+vs_concat (variable_string vs1, variable_string vs2)
+{
+  variable_string vs;
+  unsigned used = VS_USED (vs1) + VS_USED (vs2);
+  
+  VS_CHARS (vs) = xmalloc (used + 1);
+  memcpy (VS_CHARS (vs), VS_CHARS (vs1), VS_USED (vs1));
+  memcpy (VS_CHARS (vs) + VS_USED (vs1), VS_CHARS (vs2), VS_USED (vs2));
+  VS_ALLOCATED (vs) = used + 1;
+  VS_USED (vs) = used;
+
+  return vs;
+}