core: Add rbtree based hash table

Signed-off-by: Anand V. Avati <avati@dev.gluster.com>

BUG: 145 (NFSv3 related additions to 2.1 task list)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=145

1 files changed, 122 insertions, 0 deletions

diff --git a/contrib/rbtree/rb.h b/contrib/rbtree/rb.h
new file mode 100644
index 00000000000..c8858b55682
--- /dev/null
+++ b/contrib/rbtree/rb.h
@@ -0,0 +1,122 @@
+/* Produced by texiweb from libavl.w. */
+
+/* libavl - library for manipulation of binary trees.
+   Copyright (C) 1998-2002, 2004 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 of the
+   License, 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., 59 Temple Place - Suite 330, Boston, MA
+   02111-1307, USA.
+
+   The author may be contacted at <blp@gnu.org> on the Internet, or
+   write to Ben Pfaff, Stanford University, Computer Science Dept., 353
+   Serra Mall, Stanford CA 94305, USA.
+*/
+
+#ifndef RB_H
+#define RB_H 1
+
+#include <stddef.h>
+
+/* Function types. */
+typedef int rb_comparison_func (const void *rb_a, const void *rb_b,
+                                 void *rb_param);
+typedef void rb_item_func (void *rb_item, void *rb_param);
+typedef void *rb_copy_func (void *rb_item, void *rb_param);
+
+#ifndef LIBAVL_ALLOCATOR
+#define LIBAVL_ALLOCATOR
+/* Memory allocator. */
+struct libavl_allocator
+  {
+    void *(*libavl_malloc) (struct libavl_allocator *, size_t libavl_size);
+    void (*libavl_free) (struct libavl_allocator *, void *libavl_block);
+  };
+#endif
+
+/* Default memory allocator. */
+extern struct libavl_allocator rb_allocator_default;
+void *rb_malloc (struct libavl_allocator *, size_t);
+void rb_free (struct libavl_allocator *, void *);
+
+/* Maximum RB height. */
+#ifndef RB_MAX_HEIGHT
+#define RB_MAX_HEIGHT 48
+#endif
+
+/* Tree data structure. */
+struct rb_table
+  {
+    struct rb_node *rb_root;          /* Tree's root. */
+    rb_comparison_func *rb_compare;   /* Comparison function. */
+    void *rb_param;                    /* Extra argument to |rb_compare|. */
+    struct libavl_allocator *rb_alloc; /* Memory allocator. */
+    size_t rb_count;                   /* Number of items in tree. */
+    unsigned long rb_generation;       /* Generation number. */
+  };
+
+/* Color of a red-black node. */
+enum rb_color
+  {
+    RB_BLACK,   /* Black. */
+    RB_RED      /* Red. */
+  };
+
+/* A red-black tree node. */
+struct rb_node
+  {
+    struct rb_node *rb_link[2];   /* Subtrees. */
+    void *rb_data;                /* Pointer to data. */
+    unsigned char rb_color;       /* Color. */
+  };
+
+/* RB traverser structure. */
+struct rb_traverser
+  {
+    struct rb_table *rb_table;        /* Tree being traversed. */
+    struct rb_node *rb_node;          /* Current node in tree. */
+    struct rb_node *rb_stack[RB_MAX_HEIGHT];
+                                        /* All the nodes above |rb_node|. */
+    size_t rb_height;                  /* Number of nodes in |rb_parent|. */
+    unsigned long rb_generation;       /* Generation number. */
+  };
+
+/* Table functions. */
+struct rb_table *rb_create (rb_comparison_func *, void *,
+                              struct libavl_allocator *);
+struct rb_table *rb_copy (const struct rb_table *, rb_copy_func *,
+                            rb_item_func *, struct libavl_allocator *);
+void rb_destroy (struct rb_table *, rb_item_func *);
+void **rb_probe (struct rb_table *, void *);
+void *rb_insert (struct rb_table *, void *);
+void *rb_replace (struct rb_table *, void *);
+void *rb_delete (struct rb_table *, const void *);
+void *rb_find (const struct rb_table *, const void *);
+void rb_assert_insert (struct rb_table *, void *);
+void *rb_assert_delete (struct rb_table *, void *);
+
+#define rb_count(table) ((size_t) (table)->rb_count)
+
+/* Table traverser functions. */
+void rb_t_init (struct rb_traverser *, struct rb_table *);
+void *rb_t_first (struct rb_traverser *, struct rb_table *);
+void *rb_t_last (struct rb_traverser *, struct rb_table *);
+void *rb_t_find (struct rb_traverser *, struct rb_table *, void *);
+void *rb_t_insert (struct rb_traverser *, struct rb_table *, void *);
+void *rb_t_copy (struct rb_traverser *, const struct rb_traverser *);
+void *rb_t_next (struct rb_traverser *);
+void *rb_t_prev (struct rb_traverser *);
+void *rb_t_cur (struct rb_traverser *);
+void *rb_t_replace (struct rb_traverser *, void *);
+
+#endif /* rb.h */