util-vserver-0.30.208

[util-vserver.git] / ensc_vector / vector-unique.c

diff --git a/ensc_vector/vector-unique.c b/ensc_vector/vector-unique.c
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+// $Id: vector-unique.c,v 1.1 2004/02/06 14:47:18 ensc Exp $    --*- c -*--
+
+// Copyright (C) 2004 Enrico Scholz <enrico.scholz@informatik.tu-chemnitz.de>
+//  
+// 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; version 2 of the License.
+//  
+// 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+
+#ifdef HAVE_CONFIG_H
+#  include <config.h>
+#endif
+
+#include "vector.h"
+
+#include <assert.h>
+#include <string.h>
+
+  // TODO: do not iterate from begin to end but in the reverse direction. This should be more
+  // effective.
+void
+Vector_unique(struct Vector *vec, int (*compare)(const void *, const void *))
+{
+  size_t               idx;
+  
+  if (vec->count<2) return;
+
+  for (idx=0; idx+1<vec->count; ++idx) {
+    char       *ptr      = (char *)(vec->data) + idx*vec->elem_size;
+    char       *next_ptr = ptr + vec->elem_size;
+    size_t     next_idx  = idx + 1;
+
+    while (next_idx<vec->count &&
+          compare(ptr, next_ptr)==0) {
+      ++next_idx;
+      next_ptr += vec->elem_size;
+    }
+
+    if (next_idx==vec->count)
+      vec->count = idx+1;
+    else if (next_idx-idx > 1) {
+      memmove(ptr + vec->elem_size,
+             next_ptr, (vec->count - next_idx)*vec->elem_size);
+      vec->count -= (next_idx-idx-1);
+    }
+  }
+}
+