61 lines
2.3 KiB
C
61 lines
2.3 KiB
C
/* -------------------------------------------------------------------------
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*
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* rbtree.h
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* interface for PostgreSQL generic Red-Black binary tree package
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*
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* Copyright (c) 2009-2012, PostgreSQL Global Development Group
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*
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* IDENTIFICATION
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* src/include/utils/rbtree.h
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*
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* -------------------------------------------------------------------------
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*/
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#ifndef RBTREE_H
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#define RBTREE_H
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/*
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* RBNode is intended to be used as the first field of a larger struct,
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* whose additional fields carry whatever payload data the caller needs
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* for a tree entry. (The total size of that larger struct is passed to
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* rb_create.) RBNode is declared here to support this usage, but
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* callers must treat it as an opaque struct.
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*/
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typedef struct RBNode {
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char iteratorState; /* workspace for iterating through tree */
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char color; /* node's current color, red or black */
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struct RBNode* left; /* left child, or RBNIL if none */
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struct RBNode* right; /* right child, or RBNIL if none */
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struct RBNode* parent; /* parent, or NULL (not RBNIL!) if none */
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} RBNode;
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/* Opaque struct representing a whole tree */
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typedef struct RBTree RBTree;
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/* Available tree iteration orderings */
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typedef enum RBOrderControl {
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LeftRightWalk, /* inorder: left child, node, right child */
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RightLeftWalk, /* reverse inorder: right, node, left */
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DirectWalk, /* preorder: node, left child, right child */
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InvertedWalk /* postorder: left child, right child, node */
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} RBOrderControl;
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/* Support functions to be provided by caller */
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typedef int (*rb_comparator)(const RBNode* a, const RBNode* b, void* arg);
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typedef void (*rb_combiner)(RBNode* existing, const RBNode* newdata, void* arg);
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typedef RBNode* (*rb_allocfunc)(void* arg);
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typedef void (*rb_freefunc)(RBNode* x, void* arg);
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extern RBTree* rb_create(Size node_size, rb_comparator comparator, rb_combiner combiner, rb_allocfunc allocfunc,
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rb_freefunc freefunc, void* arg);
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extern RBNode* rb_find(RBTree* rb, const RBNode* data);
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extern RBNode* rb_leftmost(RBTree* rb);
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extern RBNode* rb_insert(RBTree* rb, const RBNode* data, bool* isNew);
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extern void rb_delete(RBTree* rb, RBNode* node);
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extern void rb_begin_iterate(RBTree* rb, RBOrderControl ctrl);
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extern RBNode* rb_iterate(RBTree* rb);
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#endif /* RBTREE_H */
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