Initial version.

src/nxt_rbtree.h

@@ -0,0 +1,120 @@
+
+/*
+ * Copyright (C) Igor Sysoev
+ * Copyright (C) NGINX, Inc.
+ */
+
+#ifndef _NXT_RBTREE_H_INCLUDED_
+#define _NXT_RBTREE_H_INCLUDED_
+
+
+typedef struct nxt_rbtree_node_s  nxt_rbtree_node_t;
+
+struct nxt_rbtree_node_s {
+    nxt_rbtree_node_t  *left;
+    nxt_rbtree_node_t  *right;
+    nxt_rbtree_node_t  *parent;
+
+    uint8_t            color;
+    uint8_t            spare;
+};
+
+
+typedef struct {
+    nxt_rbtree_node_t  *left;
+    nxt_rbtree_node_t  *right;
+    nxt_rbtree_node_t  *parent;
+} nxt_rbtree_part_t;
+
+
+#define NXT_RBTREE_NODE(node)                                                 \
+    nxt_rbtree_part_t  node;                                                  \
+    uint8_t            color
+
+
+#define NXT_RBTREE_NODE_INIT  { NULL, NULL, NULL }, 0
+
+
+typedef struct {
+    nxt_rbtree_node_t  sentinel;
+} nxt_rbtree_t;
+
+
+typedef void (*nxt_rbtree_insert_t)(nxt_rbtree_node_t *root,
+    nxt_rbtree_node_t *node, nxt_rbtree_node_t *sentinel);
+
+typedef nxt_int_t (*nxt_rbtree_compare_t)(nxt_rbtree_node_t *node1,
+    nxt_rbtree_node_t *node2);
+
+
+#define                                                                       \
+nxt_rbtree_root(tree)                                                         \
+    ((tree)->sentinel.left)
+
+
+#define nxt_rbtree_sentinel(tree)                                             \
+    (&(tree)->sentinel)
+
+
+#define nxt_rbtree_is_empty(tree)                                             \
+    (nxt_rbtree_root(tree) == nxt_rbtree_sentinel(tree))
+
+
+#define nxt_rbtree_min(tree)                                                  \
+    nxt_rbtree_branch_min(tree, &(tree)->sentinel)
+
+
+nxt_inline nxt_rbtree_node_t *
+nxt_rbtree_branch_min(nxt_rbtree_t *tree, nxt_rbtree_node_t *node)
+{
+    while (node->left != nxt_rbtree_sentinel(tree)) {
+        node = node->left;
+    }
+
+    return node;
+}
+
+
+#define nxt_rbtree_is_there_successor(tree, node)                             \
+    ((node) != nxt_rbtree_sentinel(tree))
+
+
+nxt_inline nxt_rbtree_node_t *
+nxt_rbtree_node_successor(nxt_rbtree_t *tree, nxt_rbtree_node_t *node)
+{
+    nxt_rbtree_node_t  *parent;
+
+    if (node->right != nxt_rbtree_sentinel(tree)) {
+        return nxt_rbtree_branch_min(tree, node->right);
+    }
+
+    for ( ;; ) {
+        parent = node->parent;
+
+        /*
+         * Explicit test for a root node is not required here, because
+         * the root node is always the left child of the sentinel.
+         */
+        if (node == parent->left) {
+            return parent;
+        }
+
+        node = parent;
+    }
+}
+
+
+NXT_EXPORT void nxt_rbtree_init(nxt_rbtree_t *tree,
+    nxt_rbtree_compare_t compare, nxt_rbtree_insert_t insert);
+NXT_EXPORT void nxt_rbtree_insert(nxt_rbtree_t *tree, nxt_rbtree_part_t *node);
+NXT_EXPORT nxt_rbtree_node_t *nxt_rbtree_find(nxt_rbtree_t *tree,
+    nxt_rbtree_part_t *node);
+NXT_EXPORT nxt_rbtree_node_t *nxt_rbtree_find_less_or_equal(nxt_rbtree_t *tree,
+    nxt_rbtree_part_t *node);
+NXT_EXPORT nxt_rbtree_node_t *
+    nxt_rbtree_find_greater_or_equal(nxt_rbtree_t *tree,
+    nxt_rbtree_part_t *node);
+NXT_EXPORT void nxt_rbtree_delete(nxt_rbtree_t *tree, nxt_rbtree_part_t *node);
+
+
+#endif /* _NXT_RBTREE_H_INCLUDED_ */