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Diffstat (limited to 'lib/libc/stdlib/rb.h')
| -rw-r--r-- | lib/libc/stdlib/rb.h | 776 |
1 files changed, 776 insertions, 0 deletions
diff --git a/lib/libc/stdlib/rb.h b/lib/libc/stdlib/rb.h new file mode 100644 index 000000000000..7978534def43 --- /dev/null +++ b/lib/libc/stdlib/rb.h @@ -0,0 +1,776 @@ +/****************************************************************************** + * + * Copyright (C) 2008 Jason Evans <jasone@FreeBSD.org>. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice(s), this list of conditions and the following disclaimer + * unmodified other than the allowable addition of one or more + * copyright notices. + * 2. Redistributions in binary form must reproduce the above copyright + * notice(s), this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``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 HOLDER(S) 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. + * + ****************************************************************************** + * + * cpp macro implementation of left-leaning red-black trees. All operations + * are done non-recursively. Parent pointers are not used, and color bits are + * stored in the least significant bit of right-child pointers, thus making + * node linkage as compact as is possible for red-black trees. + * + * Some macros use a comparison function pointer, which is expected to have the + * following prototype: + * + * int (a_cmp *)(a_type *a_node, a_type *a_other); + * ^^^^^^ + * or a_key + * + * Interpretation of comparision function return values: + * + * -1 : a_node < a_other + * 0 : a_node == a_other + * 1 : a_node > a_other + * + * In all cases, the a_node or a_key macro argument is the first argument to the + * comparison function, which makes it possible to write comparison functions + * that treat the first argument specially. + * + ******************************************************************************/ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +/* To disable assertions, #define NDEBUG before #include'ing rb.h. */ +#include <assert.h> + +/* Node structure. */ +#define rb_node(a_type) \ +struct { \ + a_type *rbn_left; \ + a_type *rbn_right_red; \ +} + +/* Root structure. */ +#define rb_tree(a_type) \ +struct { \ + a_type *rbt_root; \ + a_type rbt_nil; \ +} + +/* Left accessors. */ +#define rbp_left_get(a_type, a_field, a_node) \ + ((a_node)->a_field.rbn_left) +#define rbp_left_set(a_type, a_field, a_node, a_left) do { \ + (a_node)->a_field.rbn_left = a_left; \ +} while (0) + +/* Right accessors. */ +#define rbp_right_get(a_type, a_field, a_node) \ + ((a_type *) (((intptr_t) (a_node)->a_field.rbn_right_red) \ + & ((ssize_t)-2))) +#define rbp_right_set(a_type, a_field, a_node, a_right) do { \ + (a_node)->a_field.rbn_right_red = (a_type *) (((uintptr_t) a_right) \ + | (((uintptr_t) (a_node)->a_field.rbn_right_red) & ((size_t)1))); \ +} while (0) + +/* Color accessors. */ +#define rbp_red_get(a_type, a_field, a_node) \ + ((bool) (((uintptr_t) (a_node)->a_field.rbn_right_red) \ + & ((size_t)1))) +#define rbp_color_set(a_type, a_field, a_node, a_red) do { \ + (a_node)->a_field.rbn_right_red = (a_type *) ((((intptr_t) \ + (a_node)->a_field.rbn_right_red) & ((ssize_t)-2)) \ + | ((ssize_t)a_red)); \ +} while (0) +#define rbp_red_set(a_type, a_field, a_node) do { \ + (a_node)->a_field.rbn_right_red = (a_type *) (((uintptr_t) \ + (a_node)->a_field.rbn_right_red) | ((size_t)1)); \ +} while (0) +#define rbp_black_set(a_type, a_field, a_node) do { \ + (a_node)->a_field.rbn_right_red = (a_type *) (((intptr_t) \ + (a_node)->a_field.rbn_right_red) & ((ssize_t)-2)); \ +} while (0) + +/* Node initializer. */ +#define rbp_node_new(a_type, a_field, a_tree, a_node) do { \ + rbp_left_set(a_type, a_field, (a_node), &(a_tree)->rbt_nil); \ + rbp_right_set(a_type, a_field, (a_node), &(a_tree)->rbt_nil); \ + rbp_red_set(a_type, a_field, (a_node)); \ +} while (0) + +/* Tree initializer. */ +#define rb_tree_new(a_type, a_field, a_tree) do { \ + (a_tree)->rbt_root = &(a_tree)->rbt_nil; \ + rbp_node_new(a_type, a_field, a_tree, &(a_tree)->rbt_nil); \ + rbp_black_set(a_type, a_field, &(a_tree)->rbt_nil); \ +} while (0) + +/* Tree operations. */ +#define rbp_black_height(a_type, a_field, a_tree, r_height) do { \ + a_type *rbp_bh_t; \ + for (rbp_bh_t = (a_tree)->rbt_root, (r_height) = 0; \ + rbp_bh_t != &(a_tree)->rbt_nil; \ + rbp_bh_t = rbp_left_get(a_type, a_field, rbp_bh_t)) { \ + if (rbp_red_get(a_type, a_field, rbp_bh_t) == false) { \ + (r_height)++; \ + } \ + } \ +} while (0) + +#define rbp_first(a_type, a_field, a_tree, a_root, r_node) do { \ + for ((r_node) = (a_root); \ + rbp_left_get(a_type, a_field, (r_node)) != &(a_tree)->rbt_nil; \ + (r_node) = rbp_left_get(a_type, a_field, (r_node))) { \ + } \ +} while (0) + +#define rbp_last(a_type, a_field, a_tree, a_root, r_node) do { \ + for ((r_node) = (a_root); \ + rbp_right_get(a_type, a_field, (r_node)) != &(a_tree)->rbt_nil; \ + (r_node) = rbp_right_get(a_type, a_field, (r_node))) { \ + } \ +} while (0) + +#define rbp_next(a_type, a_field, a_cmp, a_tree, a_node, r_node) do { \ + if (rbp_right_get(a_type, a_field, (a_node)) \ + != &(a_tree)->rbt_nil) { \ + rbp_first(a_type, a_field, a_tree, rbp_right_get(a_type, \ + a_field, (a_node)), (r_node)); \ + } else { \ + a_type *rbp_n_t = (a_tree)->rbt_root; \ + assert(rbp_n_t != &(a_tree)->rbt_nil); \ + (r_node) = &(a_tree)->rbt_nil; \ + while (true) { \ + int rbp_n_cmp = (a_cmp)((a_node), rbp_n_t); \ + if (rbp_n_cmp < 0) { \ + (r_node) = rbp_n_t; \ + rbp_n_t = rbp_left_get(a_type, a_field, rbp_n_t); \ + } else if (rbp_n_cmp > 0) { \ + rbp_n_t = rbp_right_get(a_type, a_field, rbp_n_t); \ + } else { \ + break; \ + } \ + assert(rbp_n_t != &(a_tree)->rbt_nil); \ + } \ + } \ +} while (0) + +#define rbp_prev(a_type, a_field, a_cmp, a_tree, a_node, r_node) do { \ + if (rbp_left_get(a_type, a_field, (a_node)) != &(a_tree)->rbt_nil) {\ + rbp_last(a_type, a_field, a_tree, rbp_left_get(a_type, \ + a_field, (a_node)), (r_node)); \ + } else { \ + a_type *rbp_p_t = (a_tree)->rbt_root; \ + assert(rbp_p_t != &(a_tree)->rbt_nil); \ + (r_node) = &(a_tree)->rbt_nil; \ + while (true) { \ + int rbp_p_cmp = (a_cmp)((a_node), rbp_p_t); \ + if (rbp_p_cmp < 0) { \ + rbp_p_t = rbp_left_get(a_type, a_field, rbp_p_t); \ + } else if (rbp_p_cmp > 0) { \ + (r_node) = rbp_p_t; \ + rbp_p_t = rbp_right_get(a_type, a_field, rbp_p_t); \ + } else { \ + break; \ + } \ + assert(rbp_p_t != &(a_tree)->rbt_nil); \ + } \ + } \ +} while (0) + +#define rb_first(a_type, a_field, a_tree, r_node) do { \ + rbp_first(a_type, a_field, a_tree, (a_tree)->rbt_root, (r_node)); \ + if ((r_node) == &(a_tree)->rbt_nil) { \ + (r_node) = NULL; \ + } \ +} while (0) + +#define rb_last(a_type, a_field, a_tree, r_node) do { \ + rbp_last(a_type, a_field, a_tree, (a_tree)->rbt_root, r_node); \ + if ((r_node) == &(a_tree)->rbt_nil) { \ + (r_node) = NULL; \ + } \ +} while (0) + +#define rb_next(a_type, a_field, a_cmp, a_tree, a_node, r_node) do { \ + rbp_next(a_type, a_field, a_cmp, a_tree, (a_node), (r_node)); \ + if ((r_node) == &(a_tree)->rbt_nil) { \ + (r_node) = NULL; \ + } \ +} while (0) + +#define rb_prev(a_type, a_field, a_cmp, a_tree, a_node, r_node) do { \ + rbp_prev(a_type, a_field, a_cmp, a_tree, (a_node), (r_node)); \ + if ((r_node) == &(a_tree)->rbt_nil) { \ + (r_node) = NULL; \ + } \ +} while (0) + +#define rb_search(a_type, a_field, a_cmp, a_tree, a_key, r_node) do { \ + int rbp_se_cmp; \ + (r_node) = (a_tree)->rbt_root; \ + while ((r_node) != &(a_tree)->rbt_nil \ + && (rbp_se_cmp = (a_cmp)((a_key), (r_node))) != 0) { \ + if (rbp_se_cmp < 0) { \ + (r_node) = rbp_left_get(a_type, a_field, (r_node)); \ + } else { \ + (r_node) = rbp_right_get(a_type, a_field, (r_node)); \ + } \ + } \ + if ((r_node) == &(a_tree)->rbt_nil) { \ + (r_node) = NULL; \ + } \ +} while (0) + +/* + * Find a match if it exists. Otherwise, find the next greater node, if one + * exists. + */ +#define rb_nsearch(a_type, a_field, a_cmp, a_tree, a_key, r_node) do { \ + a_type *rbp_ns_t = (a_tree)->rbt_root; \ + (r_node) = NULL; \ + while (rbp_ns_t != &(a_tree)->rbt_nil) { \ + int rbp_ns_cmp = (a_cmp)((a_key), rbp_ns_t); \ + if (rbp_ns_cmp < 0) { \ + (r_node) = rbp_ns_t; \ + rbp_ns_t = rbp_left_get(a_type, a_field, rbp_ns_t); \ + } else if (rbp_ns_cmp > 0) { \ + rbp_ns_t = rbp_right_get(a_type, a_field, rbp_ns_t); \ + } else { \ + (r_node) = rbp_ns_t; \ + break; \ + } \ + } \ +} while (0) + +/* + * Find a match if it exists. Otherwise, find the previous lesser node, if one + * exists. + */ +#define rb_psearch(a_type, a_field, a_cmp, a_tree, a_key, r_node) do { \ + a_type *rbp_ps_t = (a_tree)->rbt_root; \ + (r_node) = NULL; \ + while (rbp_ps_t != &(a_tree)->rbt_nil) { \ + int rbp_ps_cmp = (a_cmp)((a_key), rbp_ps_t); \ + if (rbp_ps_cmp < 0) { \ + rbp_ps_t = rbp_left_get(a_type, a_field, rbp_ps_t); \ + } else if (rbp_ps_cmp > 0) { \ + (r_node) = rbp_ps_t; \ + rbp_ps_t = rbp_right_get(a_type, a_field, rbp_ps_t); \ + } else { \ + (r_node) = rbp_ps_t; \ + break; \ + } \ + } \ +} while (0) + +#define rbp_rotate_left(a_type, a_field, a_node, r_node) do { \ + (r_node) = rbp_right_get(a_type, a_field, (a_node)); \ + rbp_right_set(a_type, a_field, (a_node), \ + rbp_left_get(a_type, a_field, (r_node))); \ + rbp_left_set(a_type, a_field, (r_node), (a_node)); \ +} while (0) + +#define rbp_rotate_right(a_type, a_field, a_node, r_node) do { \ + (r_node) = rbp_left_get(a_type, a_field, (a_node)); \ + rbp_left_set(a_type, a_field, (a_node), \ + rbp_right_get(a_type, a_field, (r_node))); \ + rbp_right_set(a_type, a_field, (r_node), (a_node)); \ +} while (0) + +#define rbp_lean_left(a_type, a_field, a_node, r_node) do { \ + bool rbp_ll_red; \ + rbp_rotate_left(a_type, a_field, (a_node), (r_node)); \ + rbp_ll_red = rbp_red_get(a_type, a_field, (a_node)); \ + rbp_color_set(a_type, a_field, (r_node), rbp_ll_red); \ + rbp_red_set(a_type, a_field, (a_node)); \ +} while (0) + +#define rbp_lean_right(a_type, a_field, a_node, r_node) do { \ + bool rbp_lr_red; \ + rbp_rotate_right(a_type, a_field, (a_node), (r_node)); \ + rbp_lr_red = rbp_red_get(a_type, a_field, (a_node)); \ + rbp_color_set(a_type, a_field, (r_node), rbp_lr_red); \ + rbp_red_set(a_type, a_field, (a_node)); \ +} while (0) + +#define rbp_move_red_left(a_type, a_field, a_node, r_node) do { \ + a_type *rbp_mrl_t, *rbp_mrl_u; \ + rbp_mrl_t = rbp_left_get(a_type, a_field, (a_node)); \ + rbp_red_set(a_type, a_field, rbp_mrl_t); \ + rbp_mrl_t = rbp_right_get(a_type, a_field, (a_node)); \ + rbp_mrl_u = rbp_left_get(a_type, a_field, rbp_mrl_t); \ + if (rbp_red_get(a_type, a_field, rbp_mrl_u)) { \ + rbp_rotate_right(a_type, a_field, rbp_mrl_t, rbp_mrl_u); \ + rbp_right_set(a_type, a_field, (a_node), rbp_mrl_u); \ + rbp_rotate_left(a_type, a_field, (a_node), (r_node)); \ + rbp_mrl_t = rbp_right_get(a_type, a_field, (a_node)); \ + if (rbp_red_get(a_type, a_field, rbp_mrl_t)) { \ + rbp_black_set(a_type, a_field, rbp_mrl_t); \ + rbp_red_set(a_type, a_field, (a_node)); \ + rbp_rotate_left(a_type, a_field, (a_node), rbp_mrl_t); \ + rbp_left_set(a_type, a_field, (r_node), rbp_mrl_t); \ + } else { \ + rbp_black_set(a_type, a_field, (a_node)); \ + } \ + } else { \ + rbp_red_set(a_type, a_field, (a_node)); \ + rbp_rotate_left(a_type, a_field, (a_node), (r_node)); \ + } \ +} while (0) + +#define rbp_move_red_right(a_type, a_field, a_node, r_node) do { \ + a_type *rbp_mrr_t; \ + rbp_mrr_t = rbp_left_get(a_type, a_field, (a_node)); \ + if (rbp_red_get(a_type, a_field, rbp_mrr_t)) { \ + a_type *rbp_mrr_u, *rbp_mrr_v; \ + rbp_mrr_u = rbp_right_get(a_type, a_field, rbp_mrr_t); \ + rbp_mrr_v = rbp_left_get(a_type, a_field, rbp_mrr_u); \ + if (rbp_red_get(a_type, a_field, rbp_mrr_v)) { \ + rbp_color_set(a_type, a_field, rbp_mrr_u, \ + rbp_red_get(a_type, a_field, (a_node))); \ + rbp_black_set(a_type, a_field, rbp_mrr_v); \ + rbp_rotate_left(a_type, a_field, rbp_mrr_t, rbp_mrr_u); \ + rbp_left_set(a_type, a_field, (a_node), rbp_mrr_u); \ + rbp_rotate_right(a_type, a_field, (a_node), (r_node)); \ + rbp_rotate_left(a_type, a_field, (a_node), rbp_mrr_t); \ + rbp_right_set(a_type, a_field, (r_node), rbp_mrr_t); \ + } else { \ + rbp_color_set(a_type, a_field, rbp_mrr_t, \ + rbp_red_get(a_type, a_field, (a_node))); \ + rbp_red_set(a_type, a_field, rbp_mrr_u); \ + rbp_rotate_right(a_type, a_field, (a_node), (r_node)); \ + rbp_rotate_left(a_type, a_field, (a_node), rbp_mrr_t); \ + rbp_right_set(a_type, a_field, (r_node), rbp_mrr_t); \ + } \ + rbp_red_set(a_type, a_field, (a_node)); \ + } else { \ + rbp_red_set(a_type, a_field, rbp_mrr_t); \ + rbp_mrr_t = rbp_left_get(a_type, a_field, rbp_mrr_t); \ + if (rbp_red_get(a_type, a_field, rbp_mrr_t)) { \ + rbp_black_set(a_type, a_field, rbp_mrr_t); \ + rbp_rotate_right(a_type, a_field, (a_node), (r_node)); \ + rbp_rotate_left(a_type, a_field, (a_node), rbp_mrr_t); \ + rbp_right_set(a_type, a_field, (r_node), rbp_mrr_t); \ + } else { \ + rbp_rotate_left(a_type, a_field, (a_node), (r_node)); \ + } \ + } \ +} while (0) + +#define rb_insert(a_type, a_field, a_cmp, a_tree, a_node) do { \ + a_type rbp_i_s; \ + a_type *rbp_i_g, *rbp_i_p, *rbp_i_c, *rbp_i_t, *rbp_i_u; \ + int rbp_i_cmp = 0; \ + rbp_i_g = &(a_tree)->rbt_nil; \ + rbp_left_set(a_type, a_field, &rbp_i_s, (a_tree)->rbt_root); \ + rbp_right_set(a_type, a_field, &rbp_i_s, &(a_tree)->rbt_nil); \ + rbp_black_set(a_type, a_field, &rbp_i_s); \ + rbp_i_p = &rbp_i_s; \ + rbp_i_c = (a_tree)->rbt_root; \ + /* Iteratively search down the tree for the insertion point, */\ + /* splitting 4-nodes as they are encountered. At the end of each */\ + /* iteration, rbp_i_g->rbp_i_p->rbp_i_c is a 3-level path down */\ + /* the tree, assuming a sufficiently deep tree. */\ + while (rbp_i_c != &(a_tree)->rbt_nil) { \ + rbp_i_t = rbp_left_get(a_type, a_field, rbp_i_c); \ + rbp_i_u = rbp_left_get(a_type, a_field, rbp_i_t); \ + if (rbp_red_get(a_type, a_field, rbp_i_t) \ + && rbp_red_get(a_type, a_field, rbp_i_u)) { \ + /* rbp_i_c is the top of a logical 4-node, so split it. */\ + /* This iteration does not move down the tree, due to the */\ + /* disruptiveness of node splitting. */\ + /* */\ + /* Rotate right. */\ + rbp_rotate_right(a_type, a_field, rbp_i_c, rbp_i_t); \ + /* Pass red links up one level. */\ + rbp_i_u = rbp_left_get(a_type, a_field, rbp_i_t); \ + rbp_black_set(a_type, a_field, rbp_i_u); \ + if (rbp_left_get(a_type, a_field, rbp_i_p) == rbp_i_c) { \ + rbp_left_set(a_type, a_field, rbp_i_p, rbp_i_t); \ + rbp_i_c = rbp_i_t; \ + } else { \ + /* rbp_i_c was the right child of rbp_i_p, so rotate */\ + /* left in order to maintain the left-leaning */\ + /* invariant. */\ + assert(rbp_right_get(a_type, a_field, rbp_i_p) \ + == rbp_i_c); \ + rbp_right_set(a_type, a_field, rbp_i_p, rbp_i_t); \ + rbp_lean_left(a_type, a_field, rbp_i_p, rbp_i_u); \ + if (rbp_left_get(a_type, a_field, rbp_i_g) == rbp_i_p) {\ + rbp_left_set(a_type, a_field, rbp_i_g, rbp_i_u); \ + } else { \ + assert(rbp_right_get(a_type, a_field, rbp_i_g) \ + == rbp_i_p); \ + rbp_right_set(a_type, a_field, rbp_i_g, rbp_i_u); \ + } \ + rbp_i_p = rbp_i_u; \ + rbp_i_cmp = (a_cmp)((a_node), rbp_i_p); \ + if (rbp_i_cmp < 0) { \ + rbp_i_c = rbp_left_get(a_type, a_field, rbp_i_p); \ + } else { \ + assert(rbp_i_cmp > 0); \ + rbp_i_c = rbp_right_get(a_type, a_field, rbp_i_p); \ + } \ + continue; \ + } \ + } \ + rbp_i_g = rbp_i_p; \ + rbp_i_p = rbp_i_c; \ + rbp_i_cmp = (a_cmp)((a_node), rbp_i_c); \ + if (rbp_i_cmp < 0) { \ + rbp_i_c = rbp_left_get(a_type, a_field, rbp_i_c); \ + } else { \ + assert(rbp_i_cmp > 0); \ + rbp_i_c = rbp_right_get(a_type, a_field, rbp_i_c); \ + } \ + } \ + /* rbp_i_p now refers to the node under which to insert. */\ + rbp_node_new(a_type, a_field, a_tree, (a_node)); \ + if (rbp_i_cmp > 0) { \ + rbp_right_set(a_type, a_field, rbp_i_p, (a_node)); \ + rbp_lean_left(a_type, a_field, rbp_i_p, rbp_i_t); \ + if (rbp_left_get(a_type, a_field, rbp_i_g) == rbp_i_p) { \ + rbp_left_set(a_type, a_field, rbp_i_g, rbp_i_t); \ + } else if (rbp_right_get(a_type, a_field, rbp_i_g) == rbp_i_p) {\ + rbp_right_set(a_type, a_field, rbp_i_g, rbp_i_t); \ + } \ + } else { \ + rbp_left_set(a_type, a_field, rbp_i_p, (a_node)); \ + } \ + /* Update the root and make sure that it is black. */\ + (a_tree)->rbt_root = rbp_left_get(a_type, a_field, &rbp_i_s); \ + rbp_black_set(a_type, a_field, (a_tree)->rbt_root); \ +} while (0) + +#define rb_remove(a_type, a_field, a_cmp, a_tree, a_node) do { \ + a_type rbp_r_s; \ + a_type *rbp_r_p, *rbp_r_c, *rbp_r_xp, *rbp_r_t, *rbp_r_u; \ + int rbp_r_cmp; \ + rbp_left_set(a_type, a_field, &rbp_r_s, (a_tree)->rbt_root); \ + rbp_right_set(a_type, a_field, &rbp_r_s, &(a_tree)->rbt_nil); \ + rbp_black_set(a_type, a_field, &rbp_r_s); \ + rbp_r_p = &rbp_r_s; \ + rbp_r_c = (a_tree)->rbt_root; \ + rbp_r_xp = &(a_tree)->rbt_nil; \ + /* Iterate down the tree, but always transform 2-nodes to 3- or */\ + /* 4-nodes in order to maintain the invariant that the current */\ + /* node is not a 2-node. This allows simple deletion once a leaf */\ + /* is reached. Handle the root specially though, since there may */\ + /* be no way to convert it from a 2-node to a 3-node. */\ + rbp_r_cmp = (a_cmp)((a_node), rbp_r_c); \ + if (rbp_r_cmp < 0) { \ + rbp_r_t = rbp_left_get(a_type, a_field, rbp_r_c); \ + rbp_r_u = rbp_left_get(a_type, a_field, rbp_r_t); \ + if (rbp_red_get(a_type, a_field, rbp_r_t) == false \ + && rbp_red_get(a_type, a_field, rbp_r_u) == false) { \ + /* Apply standard transform to prepare for left move. */\ + rbp_move_red_left(a_type, a_field, rbp_r_c, rbp_r_t); \ + rbp_black_set(a_type, a_field, rbp_r_t); \ + rbp_left_set(a_type, a_field, rbp_r_p, rbp_r_t); \ + rbp_r_c = rbp_r_t; \ + } else { \ + /* Move left. */\ + rbp_r_p = rbp_r_c; \ + rbp_r_c = rbp_left_get(a_type, a_field, rbp_r_c); \ + } \ + } else { \ + if (rbp_r_cmp == 0) { \ + assert((a_node) == rbp_r_c); \ + if (rbp_right_get(a_type, a_field, rbp_r_c) \ + == &(a_tree)->rbt_nil) { \ + /* Delete root node (which is also a leaf node). */\ + if (rbp_left_get(a_type, a_field, rbp_r_c) \ + != &(a_tree)->rbt_nil) { \ + rbp_lean_right(a_type, a_field, rbp_r_c, rbp_r_t); \ + rbp_right_set(a_type, a_field, rbp_r_t, \ + &(a_tree)->rbt_nil); \ + } else { \ + rbp_r_t = &(a_tree)->rbt_nil; \ + } \ + rbp_left_set(a_type, a_field, rbp_r_p, rbp_r_t); \ + } else { \ + /* This is the node we want to delete, but we will */\ + /* instead swap it with its successor and delete the */\ + /* successor. Record enough information to do the */\ + /* swap later. rbp_r_xp is the a_node's parent. */\ + rbp_r_xp = rbp_r_p; \ + rbp_r_cmp = 1; /* Note that deletion is incomplete. */\ + } \ + } \ + if (rbp_r_cmp == 1) { \ + if (rbp_red_get(a_type, a_field, rbp_left_get(a_type, \ + a_field, rbp_right_get(a_type, a_field, rbp_r_c))) \ + == false) { \ + rbp_r_t = rbp_left_get(a_type, a_field, rbp_r_c); \ + if (rbp_red_get(a_type, a_field, rbp_r_t)) { \ + /* Standard transform. */\ + rbp_move_red_right(a_type, a_field, rbp_r_c, \ + rbp_r_t); \ + } else { \ + /* Root-specific transform. */\ + rbp_red_set(a_type, a_field, rbp_r_c); \ + rbp_r_u = rbp_left_get(a_type, a_field, rbp_r_t); \ + if (rbp_red_get(a_type, a_field, rbp_r_u)) { \ + rbp_black_set(a_type, a_field, rbp_r_u); \ + rbp_rotate_right(a_type, a_field, rbp_r_c, \ + rbp_r_t); \ + rbp_rotate_left(a_type, a_field, rbp_r_c, \ + rbp_r_u); \ + rbp_right_set(a_type, a_field, rbp_r_t, \ + rbp_r_u); \ + } else { \ + rbp_red_set(a_type, a_field, rbp_r_t); \ + rbp_rotate_left(a_type, a_field, rbp_r_c, \ + rbp_r_t); \ + } \ + } \ + rbp_left_set(a_type, a_field, rbp_r_p, rbp_r_t); \ + rbp_r_c = rbp_r_t; \ + } else { \ + /* Move right. */\ + rbp_r_p = rbp_r_c; \ + rbp_r_c = rbp_right_get(a_type, a_field, rbp_r_c); \ + } \ + } \ + } \ + if (rbp_r_cmp != 0) { \ + while (true) { \ + assert(rbp_r_p != &(a_tree)->rbt_nil); \ + rbp_r_cmp = (a_cmp)((a_node), rbp_r_c); \ + if (rbp_r_cmp < 0) { \ + rbp_r_t = rbp_left_get(a_type, a_field, rbp_r_c); \ + if (rbp_r_t == &(a_tree)->rbt_nil) { \ + /* rbp_r_c now refers to the successor node to */\ + /* relocate, and rbp_r_xp/a_node refer to the */\ + /* context for the relocation. */\ + if (rbp_left_get(a_type, a_field, rbp_r_xp) \ + == (a_node)) { \ + rbp_left_set(a_type, a_field, rbp_r_xp, \ + rbp_r_c); \ + } else { \ + assert(rbp_right_get(a_type, a_field, \ + rbp_r_xp) == (a_node)); \ + rbp_right_set(a_type, a_field, rbp_r_xp, \ + rbp_r_c); \ + } \ + rbp_left_set(a_type, a_field, rbp_r_c, \ + rbp_left_get(a_type, a_field, (a_node))); \ + rbp_right_set(a_type, a_field, rbp_r_c, \ + rbp_right_get(a_type, a_field, (a_node))); \ + rbp_color_set(a_type, a_field, rbp_r_c, \ + rbp_red_get(a_type, a_field, (a_node))); \ + if (rbp_left_get(a_type, a_field, rbp_r_p) \ + == rbp_r_c) { \ + rbp_left_set(a_type, a_field, rbp_r_p, \ + &(a_tree)->rbt_nil); \ + } else { \ + assert(rbp_right_get(a_type, a_field, rbp_r_p) \ + == rbp_r_c); \ + rbp_right_set(a_type, a_field, rbp_r_p, \ + &(a_tree)->rbt_nil); \ + } \ + break; \ + } \ + rbp_r_u = rbp_left_get(a_type, a_field, rbp_r_t); \ + if (rbp_red_get(a_type, a_field, rbp_r_t) == false \ + && rbp_red_get(a_type, a_field, rbp_r_u) == false) { \ + rbp_move_red_left(a_type, a_field, rbp_r_c, \ + rbp_r_t); \ + if (rbp_left_get(a_type, a_field, rbp_r_p) \ + == rbp_r_c) { \ + rbp_left_set(a_type, a_field, rbp_r_p, rbp_r_t);\ + } else { \ + rbp_right_set(a_type, a_field, rbp_r_p, \ + rbp_r_t); \ + } \ + rbp_r_c = rbp_r_t; \ + } else { \ + rbp_r_p = rbp_r_c; \ + rbp_r_c = rbp_left_get(a_type, a_field, rbp_r_c); \ + } \ + } else { \ + /* Check whether to delete this node (it has to be */\ + /* the correct node and a leaf node). */\ + if (rbp_r_cmp == 0) { \ + assert((a_node) == rbp_r_c); \ + if (rbp_right_get(a_type, a_field, rbp_r_c) \ + == &(a_tree)->rbt_nil) { \ + /* Delete leaf node. */\ + if (rbp_left_get(a_type, a_field, rbp_r_c) \ + != &(a_tree)->rbt_nil) { \ + rbp_lean_right(a_type, a_field, rbp_r_c, \ + rbp_r_t); \ + rbp_right_set(a_type, a_field, rbp_r_t, \ + &(a_tree)->rbt_nil); \ + } else { \ + rbp_r_t = &(a_tree)->rbt_nil; \ + } \ + if (rbp_left_get(a_type, a_field, rbp_r_p) \ + == rbp_r_c) { \ + rbp_left_set(a_type, a_field, rbp_r_p, \ + rbp_r_t); \ + } else { \ + rbp_right_set(a_type, a_field, rbp_r_p, \ + rbp_r_t); \ + } \ + break; \ + } else { \ + /* This is the node we want to delete, but we */\ + /* will instead swap it with its successor */\ + /* and delete the successor. Record enough */\ + /* information to do the swap later. */\ + /* rbp_r_xp is a_node's parent. */\ + rbp_r_xp = rbp_r_p; \ + } \ + } \ + rbp_r_t = rbp_right_get(a_type, a_field, rbp_r_c); \ + rbp_r_u = rbp_left_get(a_type, a_field, rbp_r_t); \ + if (rbp_red_get(a_type, a_field, rbp_r_u) == false) { \ + rbp_move_red_right(a_type, a_field, rbp_r_c, \ + rbp_r_t); \ + if (rbp_left_get(a_type, a_field, rbp_r_p) \ + == rbp_r_c) { \ + rbp_left_set(a_type, a_field, rbp_r_p, rbp_r_t);\ + } else { \ + rbp_right_set(a_type, a_field, rbp_r_p, \ + rbp_r_t); \ + } \ + rbp_r_c = rbp_r_t; \ + } else { \ + rbp_r_p = rbp_r_c; \ + rbp_r_c = rbp_right_get(a_type, a_field, rbp_r_c); \ + } \ + } \ + } \ + } \ + /* Update root. */\ + (a_tree)->rbt_root = rbp_left_get(a_type, a_field, &rbp_r_s); \ +} while (0) + +/* + * The iterators simulate recursion via an array of pointers that store the + * current path. This is critical to performance, since a series of calls to + * rb_{next,prev}() would require time proportional to (n lg n), whereas this + * implementation only requires time proportional to (n). + */ + +#define rb_foreach_begin(a_type, a_field, a_tree, a_var) { \ + /* Compute the maximum possible tree depth (3X the black height). */\ + unsigned rbp_f_height; \ + rbp_black_height(a_type, a_field, a_tree, rbp_f_height); \ + rbp_f_height *= 3; \ + { \ + /* Initialize the path to contain the left spine. */\ + a_type *rbp_f_path[rbp_f_height]; \ + a_type *rbp_f_node; \ + unsigned rbp_f_depth = 0; \ + if ((a_tree)->rbt_root != &(a_tree)->rbt_nil) { \ + rbp_f_path[rbp_f_depth] = (a_tree)->rbt_root; \ + rbp_f_depth++; \ + while ((rbp_f_node = rbp_left_get(a_type, a_field, \ + rbp_f_path[rbp_f_depth-1])) != &(a_tree)->rbt_nil) { \ + rbp_f_path[rbp_f_depth] = rbp_f_node; \ + rbp_f_depth++; \ + } \ + } \ + /* While the path is non-empty, iterate. */\ + while (rbp_f_depth > 0) { \ + (a_var) = rbp_f_path[rbp_f_depth-1]; + +#define rb_foreach_end(a_type, a_field, a_tree, a_var) \ + /* Find the successor. */\ + if ((rbp_f_node = rbp_right_get(a_type, a_field, \ + rbp_f_path[rbp_f_depth-1])) != &(a_tree)->rbt_nil) { \ + /* The successor is the left-most node in the right */\ + /* subtree. */\ + rbp_f_path[rbp_f_depth] = rbp_f_node; \ + rbp_f_depth++; \ + while ((rbp_f_node = rbp_left_get(a_type, a_field, \ + rbp_f_path[rbp_f_depth-1])) != &(a_tree)->rbt_nil) { \ + rbp_f_path[rbp_f_depth] = rbp_f_node; \ + rbp_f_depth++; \ + } \ + } else { \ + /* The successor is above the current node. Unwind */\ + /* until a left-leaning edge is removed from the */\ + /* path, or the path is empty. */\ + for (rbp_f_depth--; rbp_f_depth > 0; rbp_f_depth--) { \ + if (rbp_left_get(a_type, a_field, \ + rbp_f_path[rbp_f_depth-1]) \ + == rbp_f_path[rbp_f_depth]) { \ + break; \ + } \ + } \ + } \ + } \ + } \ +} + +#define rb_foreach_reverse_begin(a_type, a_field, a_tree, a_var) { \ + /* Compute the maximum possible tree depth (3X the black height). */\ + unsigned rbp_fr_height; \ + rbp_black_height(a_type, a_field, a_tree, rbp_fr_height); \ + rbp_fr_height *= 3; \ + { \ + /* Initialize the path to contain the right spine. */\ + a_type *rbp_fr_path[rbp_fr_height]; \ + a_type *rbp_fr_node; \ + unsigned rbp_fr_depth = 0; \ + if ((a_tree)->rbt_root != &(a_tree)->rbt_nil) { \ + rbp_fr_path[rbp_fr_depth] = (a_tree)->rbt_root; \ + rbp_fr_depth++; \ + while ((rbp_fr_node = rbp_right_get(a_type, a_field, \ + rbp_fr_path[rbp_fr_depth-1])) != &(a_tree)->rbt_nil) { \ + rbp_fr_path[rbp_fr_depth] = rbp_fr_node; \ + rbp_fr_depth++; \ + } \ + } \ + /* While the path is non-empty, iterate. */\ + while (rbp_fr_depth > 0) { \ + (a_var) = rbp_fr_path[rbp_fr_depth-1]; + +#define rb_foreach_reverse_end(a_type, a_field, a_tree, a_var) \ + /* Find the predecessor. */\ + if ((rbp_fr_node = rbp_left_get(a_type, a_field, \ + rbp_fr_path[rbp_fr_depth-1])) != &(a_tree)->rbt_nil) { \ + /* The predecessor is the right-most node in the left */\ + /* subtree. */\ + rbp_fr_path[rbp_fr_depth] = rbp_fr_node; \ + rbp_fr_depth++; \ + while ((rbp_fr_node = rbp_right_get(a_type, a_field, \ + rbp_fr_path[rbp_fr_depth-1])) != &(a_tree)->rbt_nil) {\ + rbp_fr_path[rbp_fr_depth] = rbp_fr_node; \ + rbp_fr_depth++; \ + } \ + } else { \ + /* The predecessor is above the current node. Unwind */\ + /* until a right-leaning edge is removed from the */\ + /* path, or the path is empty. */\ + for (rbp_fr_depth--; rbp_fr_depth > 0; rbp_fr_depth--) {\ + if (rbp_right_get(a_type, a_field, \ + rbp_fr_path[rbp_fr_depth-1]) \ + == rbp_fr_path[rbp_fr_depth]) { \ + break; \ + } \ + } \ + } \ + } \ + } \ +} |