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Diffstat (limited to 'Utilities/cmlibarchive/libarchive/archive_rb.c')
| -rw-r--r-- | Utilities/cmlibarchive/libarchive/archive_rb.c | 701 |
1 files changed, 701 insertions, 0 deletions
diff --git a/Utilities/cmlibarchive/libarchive/archive_rb.c b/Utilities/cmlibarchive/libarchive/archive_rb.c new file mode 100644 index 0000000..f8035d9 --- /dev/null +++ b/Utilities/cmlibarchive/libarchive/archive_rb.c @@ -0,0 +1,701 @@ +/*- + * Copyright (c) 2001 The NetBSD Foundation, Inc. + * All rights reserved. + * + * This code is derived from software contributed to The NetBSD Foundation + * by Matt Thomas <matt@3am-software.com>. + * + * 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, this list of conditions and the following disclaimer. + * 2. 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. + * + * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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. + * + * Based on: NetBSD: rb.c,v 1.6 2010/04/30 13:58:09 joerg Exp + */ + +#include "archive_platform.h" + +#include <stddef.h> + +#include "archive_rb.h" + +/* Keep in sync with archive_rb.h */ +#define RB_DIR_LEFT 0 +#define RB_DIR_RIGHT 1 +#define RB_DIR_OTHER 1 +#define rb_left rb_nodes[RB_DIR_LEFT] +#define rb_right rb_nodes[RB_DIR_RIGHT] + +#define RB_FLAG_POSITION 0x2 +#define RB_FLAG_RED 0x1 +#define RB_FLAG_MASK (RB_FLAG_POSITION|RB_FLAG_RED) +#define RB_FATHER(rb) \ + ((struct archive_rb_node *)((rb)->rb_info & ~RB_FLAG_MASK)) +#define RB_SET_FATHER(rb, father) \ + ((void)((rb)->rb_info = (uintptr_t)(father)|((rb)->rb_info & RB_FLAG_MASK))) + +#define RB_SENTINEL_P(rb) ((rb) == NULL) +#define RB_LEFT_SENTINEL_P(rb) RB_SENTINEL_P((rb)->rb_left) +#define RB_RIGHT_SENTINEL_P(rb) RB_SENTINEL_P((rb)->rb_right) +#define RB_FATHER_SENTINEL_P(rb) RB_SENTINEL_P(RB_FATHER((rb))) +#define RB_CHILDLESS_P(rb) \ + (RB_SENTINEL_P(rb) || (RB_LEFT_SENTINEL_P(rb) && RB_RIGHT_SENTINEL_P(rb))) +#define RB_TWOCHILDREN_P(rb) \ + (!RB_SENTINEL_P(rb) && !RB_LEFT_SENTINEL_P(rb) && !RB_RIGHT_SENTINEL_P(rb)) + +#define RB_POSITION(rb) \ + (((rb)->rb_info & RB_FLAG_POSITION) ? RB_DIR_RIGHT : RB_DIR_LEFT) +#define RB_RIGHT_P(rb) (RB_POSITION(rb) == RB_DIR_RIGHT) +#define RB_LEFT_P(rb) (RB_POSITION(rb) == RB_DIR_LEFT) +#define RB_RED_P(rb) (!RB_SENTINEL_P(rb) && ((rb)->rb_info & RB_FLAG_RED) != 0) +#define RB_BLACK_P(rb) (RB_SENTINEL_P(rb) || ((rb)->rb_info & RB_FLAG_RED) == 0) +#define RB_MARK_RED(rb) ((void)((rb)->rb_info |= RB_FLAG_RED)) +#define RB_MARK_BLACK(rb) ((void)((rb)->rb_info &= ~RB_FLAG_RED)) +#define RB_INVERT_COLOR(rb) ((void)((rb)->rb_info ^= RB_FLAG_RED)) +#define RB_ROOT_P(rbt, rb) ((rbt)->rbt_root == (rb)) +#define RB_SET_POSITION(rb, position) \ + ((void)((position) ? ((rb)->rb_info |= RB_FLAG_POSITION) : \ + ((rb)->rb_info &= ~RB_FLAG_POSITION))) +#define RB_ZERO_PROPERTIES(rb) ((void)((rb)->rb_info &= ~RB_FLAG_MASK)) +#define RB_COPY_PROPERTIES(dst, src) \ + ((void)((dst)->rb_info ^= ((dst)->rb_info ^ (src)->rb_info) & RB_FLAG_MASK)) +#define RB_SWAP_PROPERTIES(a, b) do { \ + uintptr_t xorinfo = ((a)->rb_info ^ (b)->rb_info) & RB_FLAG_MASK; \ + (a)->rb_info ^= xorinfo; \ + (b)->rb_info ^= xorinfo; \ + } while (/*CONSTCOND*/ 0) + +static void __archive_rb_tree_insert_rebalance(struct archive_rb_tree *, + struct archive_rb_node *); +static void __archive_rb_tree_removal_rebalance(struct archive_rb_tree *, + struct archive_rb_node *, unsigned int); + +#define RB_SENTINEL_NODE NULL + +#define T 1 +#define F 0 + +void +__archive_rb_tree_init(struct archive_rb_tree *rbt, + const struct archive_rb_tree_ops *ops) +{ + rbt->rbt_ops = ops; + *((const struct archive_rb_node **)&rbt->rbt_root) = RB_SENTINEL_NODE; +} + +struct archive_rb_node * +__archive_rb_tree_find_node(struct archive_rb_tree *rbt, const void *key) +{ + archive_rbto_compare_key_fn compare_key = rbt->rbt_ops->rbto_compare_key; + struct archive_rb_node *parent = rbt->rbt_root; + + while (!RB_SENTINEL_P(parent)) { + const signed int diff = (*compare_key)(parent, key); + if (diff == 0) + return parent; + parent = parent->rb_nodes[diff > 0]; + } + + return NULL; +} + +struct archive_rb_node * +__archive_rb_tree_find_node_geq(struct archive_rb_tree *rbt, const void *key) +{ + archive_rbto_compare_key_fn compare_key = rbt->rbt_ops->rbto_compare_key; + struct archive_rb_node *parent = rbt->rbt_root; + struct archive_rb_node *last = NULL; + + while (!RB_SENTINEL_P(parent)) { + const signed int diff = (*compare_key)(parent, key); + if (diff == 0) + return parent; + if (diff < 0) + last = parent; + parent = parent->rb_nodes[diff > 0]; + } + + return last; +} + +struct archive_rb_node * +__archive_rb_tree_find_node_leq(struct archive_rb_tree *rbt, const void *key) +{ + archive_rbto_compare_key_fn compare_key = rbt->rbt_ops->rbto_compare_key; + struct archive_rb_node *parent = rbt->rbt_root; + struct archive_rb_node *last = NULL; + + while (!RB_SENTINEL_P(parent)) { + const signed int diff = (*compare_key)(parent, key); + if (diff == 0) + return parent; + if (diff > 0) + last = parent; + parent = parent->rb_nodes[diff > 0]; + } + + return last; +} + +int +__archive_rb_tree_insert_node(struct archive_rb_tree *rbt, + struct archive_rb_node *self) +{ + archive_rbto_compare_nodes_fn compare_nodes = rbt->rbt_ops->rbto_compare_nodes; + struct archive_rb_node *parent, *tmp; + unsigned int position; + int rebalance; + + tmp = rbt->rbt_root; + /* + * This is a hack. Because rbt->rbt_root is just a + * struct archive_rb_node *, just like rb_node->rb_nodes[RB_DIR_LEFT], + * we can use this fact to avoid a lot of tests for root and know + * that even at root, updating + * RB_FATHER(rb_node)->rb_nodes[RB_POSITION(rb_node)] will + * update rbt->rbt_root. + */ + parent = (struct archive_rb_node *)(void *)&rbt->rbt_root; + position = RB_DIR_LEFT; + + /* + * Find out where to place this new leaf. + */ + while (!RB_SENTINEL_P(tmp)) { + const signed int diff = (*compare_nodes)(tmp, self); + if (diff == 0) { + /* + * Node already exists; don't insert. + */ + return F; + } + parent = tmp; + position = (diff > 0); + tmp = parent->rb_nodes[position]; + } + + /* + * Initialize the node and insert as a leaf into the tree. + */ + RB_SET_FATHER(self, parent); + RB_SET_POSITION(self, position); + if (parent == (struct archive_rb_node *)(void *)&rbt->rbt_root) { + RB_MARK_BLACK(self); /* root is always black */ + rebalance = F; + } else { + /* + * All new nodes are colored red. We only need to rebalance + * if our parent is also red. + */ + RB_MARK_RED(self); + rebalance = RB_RED_P(parent); + } + self->rb_left = parent->rb_nodes[position]; + self->rb_right = parent->rb_nodes[position]; + parent->rb_nodes[position] = self; + + /* + * Rebalance tree after insertion + */ + if (rebalance) + __archive_rb_tree_insert_rebalance(rbt, self); + + return T; +} + +/* + * Swap the location and colors of 'self' and its child @ which. The child + * can not be a sentinel node. This is our rotation function. However, + * since it preserves coloring, it great simplifies both insertion and + * removal since rotation almost always involves the exchanging of colors + * as a separate step. + */ +/*ARGSUSED*/ +static void +__archive_rb_tree_reparent_nodes( + struct archive_rb_node *old_father, const unsigned int which) +{ + const unsigned int other = which ^ RB_DIR_OTHER; + struct archive_rb_node * const grandpa = RB_FATHER(old_father); + struct archive_rb_node * const old_child = old_father->rb_nodes[which]; + struct archive_rb_node * const new_father = old_child; + struct archive_rb_node * const new_child = old_father; + + /* + * Exchange descendant linkages. + */ + grandpa->rb_nodes[RB_POSITION(old_father)] = new_father; + new_child->rb_nodes[which] = old_child->rb_nodes[other]; + new_father->rb_nodes[other] = new_child; + + /* + * Update ancestor linkages + */ + RB_SET_FATHER(new_father, grandpa); + RB_SET_FATHER(new_child, new_father); + + /* + * Exchange properties between new_father and new_child. The only + * change is that new_child's position is now on the other side. + */ + RB_SWAP_PROPERTIES(new_father, new_child); + RB_SET_POSITION(new_child, other); + + /* + * Make sure to reparent the new child to ourself. + */ + if (!RB_SENTINEL_P(new_child->rb_nodes[which])) { + RB_SET_FATHER(new_child->rb_nodes[which], new_child); + RB_SET_POSITION(new_child->rb_nodes[which], which); + } + +} + +static void +__archive_rb_tree_insert_rebalance(struct archive_rb_tree *rbt, + struct archive_rb_node *self) +{ + struct archive_rb_node * father = RB_FATHER(self); + struct archive_rb_node * grandpa; + struct archive_rb_node * uncle; + unsigned int which; + unsigned int other; + + for (;;) { + /* + * We are red and our parent is red, therefore we must have a + * grandfather and he must be black. + */ + grandpa = RB_FATHER(father); + which = (father == grandpa->rb_right); + other = which ^ RB_DIR_OTHER; + uncle = grandpa->rb_nodes[other]; + + if (RB_BLACK_P(uncle)) + break; + + /* + * Case 1: our uncle is red + * Simply invert the colors of our parent and + * uncle and make our grandparent red. And + * then solve the problem up at his level. + */ + RB_MARK_BLACK(uncle); + RB_MARK_BLACK(father); + if (RB_ROOT_P(rbt, grandpa)) { + /* + * If our grandpa is root, don't bother + * setting him to red, just return. + */ + return; + } + RB_MARK_RED(grandpa); + self = grandpa; + father = RB_FATHER(self); + if (RB_BLACK_P(father)) { + /* + * If our greatgrandpa is black, we're done. + */ + return; + } + } + + /* + * Case 2&3: our uncle is black. + */ + if (self == father->rb_nodes[other]) { + /* + * Case 2: we are on the same side as our uncle + * Swap ourselves with our parent so this case + * becomes case 3. Basically our parent becomes our + * child. + */ + __archive_rb_tree_reparent_nodes(father, other); + } + /* + * Case 3: we are opposite a child of a black uncle. + * Swap our parent and grandparent. Since our grandfather + * is black, our father will become black and our new sibling + * (former grandparent) will become red. + */ + __archive_rb_tree_reparent_nodes(grandpa, which); + + /* + * Final step: Set the root to black. + */ + RB_MARK_BLACK(rbt->rbt_root); +} + +static void +__archive_rb_tree_prune_node(struct archive_rb_tree *rbt, + struct archive_rb_node *self, int rebalance) +{ + const unsigned int which = RB_POSITION(self); + struct archive_rb_node *father = RB_FATHER(self); + + /* + * Since we are childless, we know that self->rb_left is pointing + * to the sentinel node. + */ + father->rb_nodes[which] = self->rb_left; + + /* + * Rebalance if requested. + */ + if (rebalance) + __archive_rb_tree_removal_rebalance(rbt, father, which); +} + +/* + * When deleting an interior node + */ +static void +__archive_rb_tree_swap_prune_and_rebalance(struct archive_rb_tree *rbt, + struct archive_rb_node *self, struct archive_rb_node *standin) +{ + const unsigned int standin_which = RB_POSITION(standin); + unsigned int standin_other = standin_which ^ RB_DIR_OTHER; + struct archive_rb_node *standin_son; + struct archive_rb_node *standin_father = RB_FATHER(standin); + int rebalance = RB_BLACK_P(standin); + + if (standin_father == self) { + /* + * As a child of self, any childen would be opposite of + * our parent. + */ + standin_son = standin->rb_nodes[standin_which]; + } else { + /* + * Since we aren't a child of self, any childen would be + * on the same side as our parent. + */ + standin_son = standin->rb_nodes[standin_other]; + } + + if (RB_RED_P(standin_son)) { + /* + * We know we have a red child so if we flip it to black + * we don't have to rebalance. + */ + RB_MARK_BLACK(standin_son); + rebalance = F; + + if (standin_father != self) { + /* + * Change the son's parentage to point to his grandpa. + */ + RB_SET_FATHER(standin_son, standin_father); + RB_SET_POSITION(standin_son, standin_which); + } + } + + if (standin_father == self) { + /* + * If we are about to delete the standin's father, then when + * we call rebalance, we need to use ourselves as our father. + * Otherwise remember our original father. Also, sincef we are + * our standin's father we only need to reparent the standin's + * brother. + * + * | R --> S | + * | Q S --> Q T | + * | t --> | + * + * Have our son/standin adopt his brother as his new son. + */ + standin_father = standin; + } else { + /* + * | R --> S . | + * | / \ | T --> / \ | / | + * | ..... | S --> ..... | T | + * + * Sever standin's connection to his father. + */ + standin_father->rb_nodes[standin_which] = standin_son; + /* + * Adopt the far son. + */ + standin->rb_nodes[standin_other] = self->rb_nodes[standin_other]; + RB_SET_FATHER(standin->rb_nodes[standin_other], standin); + /* + * Use standin_other because we need to preserve standin_which + * for the removal_rebalance. + */ + standin_other = standin_which; + } + + /* + * Move the only remaining son to our standin. If our standin is our + * son, this will be the only son needed to be moved. + */ + standin->rb_nodes[standin_other] = self->rb_nodes[standin_other]; + RB_SET_FATHER(standin->rb_nodes[standin_other], standin); + + /* + * Now copy the result of self to standin and then replace + * self with standin in the tree. + */ + RB_COPY_PROPERTIES(standin, self); + RB_SET_FATHER(standin, RB_FATHER(self)); + RB_FATHER(standin)->rb_nodes[RB_POSITION(standin)] = standin; + + if (rebalance) + __archive_rb_tree_removal_rebalance(rbt, standin_father, standin_which); +} + +/* + * We could do this by doing + * __archive_rb_tree_node_swap(rbt, self, which); + * __archive_rb_tree_prune_node(rbt, self, F); + * + * But it's more efficient to just evalate and recolor the child. + */ +static void +__archive_rb_tree_prune_blackred_branch( + struct archive_rb_node *self, unsigned int which) +{ + struct archive_rb_node *father = RB_FATHER(self); + struct archive_rb_node *son = self->rb_nodes[which]; + + /* + * Remove ourselves from the tree and give our former child our + * properties (position, color, root). + */ + RB_COPY_PROPERTIES(son, self); + father->rb_nodes[RB_POSITION(son)] = son; + RB_SET_FATHER(son, father); +} +/* + * + */ +void +__archive_rb_tree_remove_node(struct archive_rb_tree *rbt, + struct archive_rb_node *self) +{ + struct archive_rb_node *standin; + unsigned int which; + + /* + * In the following diagrams, we (the node to be removed) are S. Red + * nodes are lowercase. T could be either red or black. + * + * Remember the major axiom of the red-black tree: the number of + * black nodes from the root to each leaf is constant across all + * leaves, only the number of red nodes varies. + * + * Thus removing a red leaf doesn't require any other changes to a + * red-black tree. So if we must remove a node, attempt to rearrange + * the tree so we can remove a red node. + * + * The simpliest case is a childless red node or a childless root node: + * + * | T --> T | or | R --> * | + * | s --> * | + */ + if (RB_CHILDLESS_P(self)) { + const int rebalance = RB_BLACK_P(self) && !RB_ROOT_P(rbt, self); + __archive_rb_tree_prune_node(rbt, self, rebalance); + return; + } + if (!RB_TWOCHILDREN_P(self)) { + /* + * The next simpliest case is the node we are deleting is + * black and has one red child. + * + * | T --> T --> T | + * | S --> R --> R | + * | r --> s --> * | + */ + which = RB_LEFT_SENTINEL_P(self) ? RB_DIR_RIGHT : RB_DIR_LEFT; + __archive_rb_tree_prune_blackred_branch(self, which); + return; + } + + /* + * We invert these because we prefer to remove from the inside of + * the tree. + */ + which = RB_POSITION(self) ^ RB_DIR_OTHER; + + /* + * Let's find the node closes to us opposite of our parent + * Now swap it with ourself, "prune" it, and rebalance, if needed. + */ + standin = __archive_rb_tree_iterate(rbt, self, which); + __archive_rb_tree_swap_prune_and_rebalance(rbt, self, standin); +} + +static void +__archive_rb_tree_removal_rebalance(struct archive_rb_tree *rbt, + struct archive_rb_node *parent, unsigned int which) +{ + + while (RB_BLACK_P(parent->rb_nodes[which])) { + unsigned int other = which ^ RB_DIR_OTHER; + struct archive_rb_node *brother = parent->rb_nodes[other]; + + /* + * For cases 1, 2a, and 2b, our brother's children must + * be black and our father must be black + */ + if (RB_BLACK_P(parent) + && RB_BLACK_P(brother->rb_left) + && RB_BLACK_P(brother->rb_right)) { + if (RB_RED_P(brother)) { + /* + * Case 1: Our brother is red, swap its + * position (and colors) with our parent. + * This should now be case 2b (unless C or E + * has a red child which is case 3; thus no + * explicit branch to case 2b). + * + * B -> D + * A d -> b E + * C E -> A C + */ + __archive_rb_tree_reparent_nodes(parent, other); + brother = parent->rb_nodes[other]; + } else { + /* + * Both our parent and brother are black. + * Change our brother to red, advance up rank + * and go through the loop again. + * + * B -> *B + * *A D -> A d + * C E -> C E + */ + RB_MARK_RED(brother); + if (RB_ROOT_P(rbt, parent)) + return; /* root == parent == black */ + which = RB_POSITION(parent); + parent = RB_FATHER(parent); + continue; + } + } + /* + * Avoid an else here so that case 2a above can hit either + * case 2b, 3, or 4. + */ + if (RB_RED_P(parent) + && RB_BLACK_P(brother) + && RB_BLACK_P(brother->rb_left) + && RB_BLACK_P(brother->rb_right)) { + /* + * We are black, our father is red, our brother and + * both nephews are black. Simply invert/exchange the + * colors of our father and brother (to black and red + * respectively). + * + * | f --> F | + * | * B --> * b | + * | N N --> N N | + */ + RB_MARK_BLACK(parent); + RB_MARK_RED(brother); + break; /* We're done! */ + } else { + /* + * Our brother must be black and have at least one + * red child (it may have two). + */ + if (RB_BLACK_P(brother->rb_nodes[other])) { + /* + * Case 3: our brother is black, our near + * nephew is red, and our far nephew is black. + * Swap our brother with our near nephew. + * This result in a tree that matches case 4. + * (Our father could be red or black). + * + * | F --> F | + * | x B --> x B | + * | n --> n | + */ + __archive_rb_tree_reparent_nodes(brother, which); + brother = parent->rb_nodes[other]; + } + /* + * Case 4: our brother is black and our far nephew + * is red. Swap our father and brother locations and + * change our far nephew to black. (these can be + * done in either order so we change the color first). + * The result is a valid red-black tree and is a + * terminal case. (again we don't care about the + * father's color) + * + * If the father is red, we will get a red-black-black + * tree: + * | f -> f --> b | + * | B -> B --> F N | + * | n -> N --> | + * + * If the father is black, we will get an all black + * tree: + * | F -> F --> B | + * | B -> B --> F N | + * | n -> N --> | + * + * If we had two red nephews, then after the swap, + * our former father would have a red grandson. + */ + RB_MARK_BLACK(brother->rb_nodes[other]); + __archive_rb_tree_reparent_nodes(parent, other); + break; /* We're done! */ + } + } +} + +struct archive_rb_node * +__archive_rb_tree_iterate(struct archive_rb_tree *rbt, + struct archive_rb_node *self, const unsigned int direction) +{ + const unsigned int other = direction ^ RB_DIR_OTHER; + + if (self == NULL) { + self = rbt->rbt_root; + if (RB_SENTINEL_P(self)) + return NULL; + while (!RB_SENTINEL_P(self->rb_nodes[direction])) + self = self->rb_nodes[direction]; + return self; + } + /* + * We can't go any further in this direction. We proceed up in the + * opposite direction until our parent is in direction we want to go. + */ + if (RB_SENTINEL_P(self->rb_nodes[direction])) { + while (!RB_ROOT_P(rbt, self)) { + if (other == RB_POSITION(self)) + return RB_FATHER(self); + self = RB_FATHER(self); + } + return NULL; + } + + /* + * Advance down one in current direction and go down as far as possible + * in the opposite direction. + */ + self = self->rb_nodes[direction]; + while (!RB_SENTINEL_P(self->rb_nodes[other])) + self = self->rb_nodes[other]; + return self; +} |