AVL: creation, destroy, add
diff --git a/include/grpc/support/avl.h b/include/grpc/support/avl.h
new file mode 100644
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+++ b/include/grpc/support/avl.h
@@ -0,0 +1,67 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_SUPPORT_AVL_H
+#define GRPC_SUPPORT_AVL_H
+
+#include <grpc/support/sync.h>
+
+typedef struct gpr_avl_node {
+ gpr_refcount refs;
+ void *key;
+ void *value;
+ struct gpr_avl_node *left;
+ struct gpr_avl_node *right;
+ long height;
+} gpr_avl_node;
+
+typedef struct gpr_avl_vtable {
+ void (*destroy_key)(void *key);
+ void *(*copy_key)(void *key);
+ long (*compare_keys)(void *key1, void *key2);
+ void (*destroy_value)(void *value);
+ void *(*copy_value)(void *value);
+} gpr_avl_vtable;
+
+typedef struct gpr_avl {
+ const gpr_avl_vtable *vtable;
+ gpr_avl_node *root;
+} gpr_avl;
+
+gpr_avl gpr_avl_create(const gpr_avl_vtable *vtable);
+void gpr_avl_destroy(gpr_avl avl);
+gpr_avl gpr_avl_add(gpr_avl avl, void *key, void *value);
+gpr_avl gpr_avl_remove(gpr_avl avl, void *key);
+void *gpr_avl_get(gpr_avl avl, void *key);
+
+#endif