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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 15:49:25 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 15:49:25 +0000 |
commit | 464df1d5e5ab1322e2dd0a7796939fff1aeefa9a (patch) | |
tree | 6a403684e0978f0287d7f0ec0e5aab1fd31a59e1 /lib/support/dict.c | |
parent | Initial commit. (diff) | |
download | e2fsprogs-upstream.tar.xz e2fsprogs-upstream.zip |
Adding upstream version 1.47.0.upstream/1.47.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | lib/support/dict.c | 1542 |
1 files changed, 1542 insertions, 0 deletions
diff --git a/lib/support/dict.c b/lib/support/dict.c new file mode 100644 index 0000000..93fdd0b --- /dev/null +++ b/lib/support/dict.c @@ -0,0 +1,1542 @@ +/* + * Dictionary Abstract Data Type + * Copyright (C) 1997 Kaz Kylheku <kaz@ashi.footprints.net> + * + * Free Software License: + * + * All rights are reserved by the author, with the following exceptions: + * Permission is granted to freely reproduce and distribute this software, + * possibly in exchange for a fee, provided that this copyright notice appears + * intact. Permission is also granted to adapt this software to produce + * derivative works, as long as the modified versions carry this copyright + * notice and additional notices stating that the work has been modified. + * This source code may be translated into executable form and incorporated + * into proprietary software; there is no requirement for such software to + * contain a copyright notice related to this source. + * + * $Id: dict.c,v 1.40.2.7 2000/11/13 01:36:44 kaz Exp $ + * $Name: kazlib_1_20 $ + * The work has been modified. + */ + +#define DICT_NODEBUG + +#ifdef __GNUC__ +#define EXT2FS_ATTR(x) __attribute__(x) +#else +#define EXT2FS_ATTR(x) +#endif + +#include "config.h" +#include <stdlib.h> +#include <stddef.h> +#ifdef DICT_NODEBUG +#define dict_assert(x) +#else +#include <assert.h> +#define dict_assert(x) assert(x) +#endif +#define DICT_IMPLEMENTATION +#include "dict.h" + +#ifdef KAZLIB_RCSID +static const char rcsid[] = "$Id: dict.c,v 1.40.2.7 2000/11/13 01:36:44 kaz Exp $"; +#endif + +/* + * These macros provide short convenient names for structure members, + * which are embellished with dict_ prefixes so that they are + * properly confined to the documented namespace. It's legal for a + * program which uses dict to define, for instance, a macro called ``parent''. + * Such a macro would interfere with the dnode_t struct definition. + * In general, highly portable and reusable C modules which expose their + * structures need to confine structure member names to well-defined spaces. + * The resulting identifiers aren't necessarily convenient to use, nor + * readable, in the implementation, however! + */ + +#define left dict_left +#define right dict_right +#define parent dict_parent +#define color dict_color +#define key dict_key +#define data dict_data + +#define nilnode dict_nilnode +#define nodecount dict_nodecount +#define maxcount dict_maxcount +#define compare dict_compare +#define allocnode dict_allocnode +#define freenode dict_freenode +#define context dict_context +#define dupes dict_dupes + +#define dictptr dict_dictptr + +#define dict_root(D) ((D)->nilnode.left) +#define dict_nil(D) (&(D)->nilnode) +#define DICT_DEPTH_MAX 64 + +static dnode_t *dnode_alloc(void *context); +static void dnode_free(dnode_t *node, void *context); + +/* + * Perform a ``left rotation'' adjustment on the tree. The given node P and + * its right child C are rearranged so that the P instead becomes the left + * child of C. The left subtree of C is inherited as the new right subtree + * for P. The ordering of the keys within the tree is thus preserved. + */ + +static void rotate_left(dnode_t *upper) +{ + dnode_t *lower, *lowleft, *upparent; + + lower = upper->right; + upper->right = lowleft = lower->left; + lowleft->parent = upper; + + lower->parent = upparent = upper->parent; + + /* don't need to check for root node here because root->parent is + the sentinel nil node, and root->parent->left points back to root */ + + if (upper == upparent->left) { + upparent->left = lower; + } else { + dict_assert (upper == upparent->right); + upparent->right = lower; + } + + lower->left = upper; + upper->parent = lower; +} + +/* + * This operation is the ``mirror'' image of rotate_left. It is + * the same procedure, but with left and right interchanged. + */ + +static void rotate_right(dnode_t *upper) +{ + dnode_t *lower, *lowright, *upparent; + + lower = upper->left; + upper->left = lowright = lower->right; + lowright->parent = upper; + + lower->parent = upparent = upper->parent; + + if (upper == upparent->right) { + upparent->right = lower; + } else { + dict_assert (upper == upparent->left); + upparent->left = lower; + } + + lower->right = upper; + upper->parent = lower; +} + +/* + * Do a postorder traversal of the tree rooted at the specified + * node and free everything under it. Used by dict_free(). + */ + +static void free_nodes(dict_t *dict, dnode_t *node, dnode_t *nil) +{ + if (node == nil) + return; + free_nodes(dict, node->left, nil); + free_nodes(dict, node->right, nil); + dict->freenode(node, dict->context); +} + +/* + * This procedure performs a verification that the given subtree is a binary + * search tree. It performs an inorder traversal of the tree using the + * dict_next() successor function, verifying that the key of each node is + * strictly lower than that of its successor, if duplicates are not allowed, + * or lower or equal if duplicates are allowed. This function is used for + * debugging purposes. + */ +#ifndef DICT_NODEBUG +static int verify_bintree(dict_t *dict) +{ + dnode_t *first, *next; + + first = dict_first(dict); + + if (dict->dupes) { + while (first && (next = dict_next(dict, first))) { + if (dict->compare(first->key, next->key) > 0) + return 0; + first = next; + } + } else { + while (first && (next = dict_next(dict, first))) { + if (dict->compare(first->key, next->key) >= 0) + return 0; + first = next; + } + } + return 1; +} + +/* + * This function recursively verifies that the given binary subtree satisfies + * three of the red black properties. It checks that every red node has only + * black children. It makes sure that each node is either red or black. And it + * checks that every path has the same count of black nodes from root to leaf. + * It returns the blackheight of the given subtree; this allows blackheights to + * be computed recursively and compared for left and right siblings for + * mismatches. It does not check for every nil node being black, because there + * is only one sentinel nil node. The return value of this function is the + * black height of the subtree rooted at the node ``root'', or zero if the + * subtree is not red-black. + */ + +static unsigned int verify_redblack(dnode_t *nil, dnode_t *root) +{ + unsigned height_left, height_right; + + if (root != nil) { + height_left = verify_redblack(nil, root->left); + height_right = verify_redblack(nil, root->right); + if (height_left == 0 || height_right == 0) + return 0; + if (height_left != height_right) + return 0; + if (root->color == dnode_red) { + if (root->left->color != dnode_black) + return 0; + if (root->right->color != dnode_black) + return 0; + return height_left; + } + if (root->color != dnode_black) + return 0; + return height_left + 1; + } + return 1; +} + +/* + * Compute the actual count of nodes by traversing the tree and + * return it. This could be compared against the stored count to + * detect a mismatch. + */ + +static dictcount_t verify_node_count(dnode_t *nil, dnode_t *root) +{ + if (root == nil) + return 0; + else + return 1 + verify_node_count(nil, root->left) + + verify_node_count(nil, root->right); +} +#endif + +/* + * Verify that the tree contains the given node. This is done by + * traversing all of the nodes and comparing their pointers to the + * given pointer. Returns 1 if the node is found, otherwise + * returns zero. It is intended for debugging purposes. + */ + +static int verify_dict_has_node(dnode_t *nil, dnode_t *root, dnode_t *node) +{ + if (root != nil) { + return root == node + || verify_dict_has_node(nil, root->left, node) + || verify_dict_has_node(nil, root->right, node); + } + return 0; +} + + +#ifdef E2FSCK_NOTUSED +/* + * Dynamically allocate and initialize a dictionary object. + */ + +dict_t *dict_create(dictcount_t maxcount, dict_comp_t comp) +{ + dict_t *new = malloc(sizeof *new); + + if (new) { + new->compare = comp; + new->allocnode = dnode_alloc; + new->freenode = dnode_free; + new->context = NULL; + new->cmp_ctx = NULL; + new->nodecount = 0; + new->maxcount = maxcount; + new->nilnode.left = &new->nilnode; + new->nilnode.right = &new->nilnode; + new->nilnode.parent = &new->nilnode; + new->nilnode.color = dnode_black; + new->dupes = 0; + } + return new; +} +#endif /* E2FSCK_NOTUSED */ + +/* + * Select a different set of node allocator routines. + */ + +void dict_set_allocator(dict_t *dict, dnode_alloc_t al, + dnode_free_t fr, void *context) +{ + dict_assert (dict_count(dict) == 0); + dict_assert ((al == NULL && fr == NULL) || (al != NULL && fr != NULL)); + + dict->allocnode = al ? al : dnode_alloc; + dict->freenode = fr ? fr : dnode_free; + dict->context = context; +} + +void dict_set_cmp_context(dict_t *dict, const void *cmp_ctx) +{ + dict_assert (!dict->cmp_ctx); + dict_assert (dict_count(dict) == 0); + + dict->cmp_ctx = cmp_ctx; +} + +#ifdef E2FSCK_NOTUSED +/* + * Free a dynamically allocated dictionary object. Removing the nodes + * from the tree before deleting it is required. + */ + +void dict_destroy(dict_t *dict) +{ + dict_assert (dict_isempty(dict)); + free(dict); +} +#endif + +/* + * Free all the nodes in the dictionary by using the dictionary's + * installed free routine. The dictionary is emptied. + */ + +void dict_free_nodes(dict_t *dict) +{ + dnode_t *nil = dict_nil(dict), *root = dict_root(dict); + free_nodes(dict, root, nil); + dict->nodecount = 0; + dict->nilnode.left = &dict->nilnode; + dict->nilnode.right = &dict->nilnode; +} + +#ifdef E2FSCK_NOTUSED +/* + * Obsolescent function, equivalent to dict_free_nodes + */ +void dict_free(dict_t *dict) +{ +#ifdef KAZLIB_OBSOLESCENT_DEBUG + dict_assert ("call to obsolescent function dict_free()" && 0); +#endif + dict_free_nodes(dict); +} +#endif + +/* + * Initialize a user-supplied dictionary object. + */ + +dict_t *dict_init(dict_t *dict, dictcount_t maxcount, dict_comp_t comp) +{ + dict->compare = comp; + dict->allocnode = dnode_alloc; + dict->freenode = dnode_free; + dict->context = NULL; + dict->nodecount = 0; + dict->maxcount = maxcount; + dict->nilnode.left = &dict->nilnode; + dict->nilnode.right = &dict->nilnode; + dict->nilnode.parent = &dict->nilnode; + dict->nilnode.color = dnode_black; + dict->dupes = 0; + return dict; +} + +#ifdef E2FSCK_NOTUSED +/* + * Initialize a dictionary in the likeness of another dictionary + */ + +void dict_init_like(dict_t *dict, const dict_t *template) +{ + dict->compare = template->compare; + dict->allocnode = template->allocnode; + dict->freenode = template->freenode; + dict->context = template->context; + dict->nodecount = 0; + dict->maxcount = template->maxcount; + dict->nilnode.left = &dict->nilnode; + dict->nilnode.right = &dict->nilnode; + dict->nilnode.parent = &dict->nilnode; + dict->nilnode.color = dnode_black; + dict->dupes = template->dupes; + + dict_assert (dict_similar(dict, template)); +} + +/* + * Remove all nodes from the dictionary (without freeing them in any way). + */ + +static void dict_clear(dict_t *dict) +{ + dict->nodecount = 0; + dict->nilnode.left = &dict->nilnode; + dict->nilnode.right = &dict->nilnode; + dict->nilnode.parent = &dict->nilnode; + dict_assert (dict->nilnode.color == dnode_black); +} +#endif /* E2FSCK_NOTUSED */ + + +/* + * Verify the integrity of the dictionary structure. This is provided for + * debugging purposes, and should be placed in assert statements. Just because + * this function succeeds doesn't mean that the tree is not corrupt. Certain + * corruptions in the tree may simply cause undefined behavior. + */ +#ifndef DICT_NODEBUG +int dict_verify(dict_t *dict) +{ + dnode_t *nil = dict_nil(dict), *root = dict_root(dict); + + /* check that the sentinel node and root node are black */ + if (root->color != dnode_black) + return 0; + if (nil->color != dnode_black) + return 0; + if (nil->right != nil) + return 0; + /* nil->left is the root node; check that its parent pointer is nil */ + if (nil->left->parent != nil) + return 0; + /* perform a weak test that the tree is a binary search tree */ + if (!verify_bintree(dict)) + return 0; + /* verify that the tree is a red-black tree */ + if (!verify_redblack(nil, root)) + return 0; + if (verify_node_count(nil, root) != dict_count(dict)) + return 0; + return 1; +} +#endif /* DICT_NODEBUG */ + +#ifdef E2FSCK_NOTUSED +/* + * Determine whether two dictionaries are similar: have the same comparison and + * allocator functions, and same status as to whether duplicates are allowed. + */ +int dict_similar(const dict_t *left, const dict_t *right) +{ + if (left->compare != right->compare) + return 0; + + if (left->allocnode != right->allocnode) + return 0; + + if (left->freenode != right->freenode) + return 0; + + if (left->context != right->context) + return 0; + + if (left->dupes != right->dupes) + return 0; + + return 1; +} +#endif /* E2FSCK_NOTUSED */ + +/* + * Locate a node in the dictionary having the given key. + * If the node is not found, a null a pointer is returned (rather than + * a pointer that dictionary's nil sentinel node), otherwise a pointer to the + * located node is returned. + */ + +dnode_t *dict_lookup(dict_t *dict, const void *key) +{ + dnode_t *root = dict_root(dict); + dnode_t *nil = dict_nil(dict); + dnode_t *saved; + int result; + + /* simple binary search adapted for trees that contain duplicate keys */ + + while (root != nil) { + result = dict->compare(dict->cmp_ctx, key, root->key); + if (result < 0) + root = root->left; + else if (result > 0) + root = root->right; + else { + if (!dict->dupes) { /* no duplicates, return match */ + return root; + } else { /* could be dupes, find leftmost one */ + do { + saved = root; + root = root->left; + while (root != nil + && dict->compare(dict->cmp_ctx, key, root->key)) + root = root->right; + } while (root != nil); + return saved; + } + } + } + + return NULL; +} + +#ifdef E2FSCK_NOTUSED +/* + * Look for the node corresponding to the lowest key that is equal to or + * greater than the given key. If there is no such node, return null. + */ + +dnode_t *dict_lower_bound(dict_t *dict, const void *key) +{ + dnode_t *root = dict_root(dict); + dnode_t *nil = dict_nil(dict); + dnode_t *tentative = 0; + + while (root != nil) { + int result = dict->compare(dict->cmp_ctx, key, root->key); + + if (result > 0) { + root = root->right; + } else if (result < 0) { + tentative = root; + root = root->left; + } else { + if (!dict->dupes) { + return root; + } else { + tentative = root; + root = root->left; + } + } + } + + return tentative; +} + +/* + * Look for the node corresponding to the greatest key that is equal to or + * lower than the given key. If there is no such node, return null. + */ + +dnode_t *dict_upper_bound(dict_t *dict, const void *key) +{ + dnode_t *root = dict_root(dict); + dnode_t *nil = dict_nil(dict); + dnode_t *tentative = 0; + + while (root != nil) { + int result = dict->compare(dict->cmp_ctx, key, root->key); + + if (result < 0) { + root = root->left; + } else if (result > 0) { + tentative = root; + root = root->right; + } else { + if (!dict->dupes) { + return root; + } else { + tentative = root; + root = root->right; + } + } + } + + return tentative; +} +#endif + +/* + * Insert a node into the dictionary. The node should have been + * initialized with a data field. All other fields are ignored. + * The behavior is undefined if the user attempts to insert into + * a dictionary that is already full (for which the dict_isfull() + * function returns true). + */ + +void dict_insert(dict_t *dict, dnode_t *node, const void *key) +{ + dnode_t *where = dict_root(dict), *nil = dict_nil(dict); + dnode_t *parent = nil, *uncle, *grandpa; + int result = -1; + + node->key = key; + + dict_assert (!dict_isfull(dict)); + dict_assert (!dict_contains(dict, node)); + dict_assert (!dnode_is_in_a_dict(node)); + + /* basic binary tree insert */ + + while (where != nil) { + parent = where; + result = dict->compare(dict->cmp_ctx, key, where->key); + /* trap attempts at duplicate key insertion unless it's explicitly allowed */ + dict_assert (dict->dupes || result != 0); + if (result < 0) + where = where->left; + else + where = where->right; + } + + dict_assert (where == nil); + + if (result < 0) + parent->left = node; + else + parent->right = node; + + node->parent = parent; + node->left = nil; + node->right = nil; + + dict->nodecount++; + + /* red black adjustments */ + + node->color = dnode_red; + + while (parent->color == dnode_red) { + grandpa = parent->parent; + if (parent == grandpa->left) { + uncle = grandpa->right; + if (uncle->color == dnode_red) { /* red parent, red uncle */ + parent->color = dnode_black; + uncle->color = dnode_black; + grandpa->color = dnode_red; + node = grandpa; + parent = grandpa->parent; + } else { /* red parent, black uncle */ + if (node == parent->right) { + rotate_left(parent); + parent = node; + dict_assert (grandpa == parent->parent); + /* rotation between parent and child preserves grandpa */ + } + parent->color = dnode_black; + grandpa->color = dnode_red; + rotate_right(grandpa); + break; + } + } else { /* symmetric cases: parent == parent->parent->right */ + uncle = grandpa->left; + if (uncle->color == dnode_red) { + parent->color = dnode_black; + uncle->color = dnode_black; + grandpa->color = dnode_red; + node = grandpa; + parent = grandpa->parent; + } else { + if (node == parent->left) { + rotate_right(parent); + parent = node; + dict_assert (grandpa == parent->parent); + } + parent->color = dnode_black; + grandpa->color = dnode_red; + rotate_left(grandpa); + break; + } + } + } + + dict_root(dict)->color = dnode_black; + + dict_assert (dict_verify(dict)); +} + +#ifdef E2FSCK_NOTUSED +/* + * Delete the given node from the dictionary. If the given node does not belong + * to the given dictionary, undefined behavior results. A pointer to the + * deleted node is returned. + */ + +dnode_t *dict_delete(dict_t *dict, dnode_t *delete) +{ + dnode_t *nil = dict_nil(dict), *child, *delparent = delete->parent; + + /* basic deletion */ + + dict_assert (!dict_isempty(dict)); + dict_assert (dict_contains(dict, delete)); + + /* + * If the node being deleted has two children, then we replace it with its + * successor (i.e. the leftmost node in the right subtree.) By doing this, + * we avoid the traditional algorithm under which the successor's key and + * value *only* move to the deleted node and the successor is spliced out + * from the tree. We cannot use this approach because the user may hold + * pointers to the successor, or nodes may be inextricably tied to some + * other structures by way of embedding, etc. So we must splice out the + * node we are given, not some other node, and must not move contents from + * one node to another behind the user's back. + */ + + if (delete->left != nil && delete->right != nil) { + dnode_t *next = dict_next(dict, delete); + dnode_t *nextparent = next->parent; + dnode_color_t nextcolor = next->color; + + dict_assert (next != nil); + dict_assert (next->parent != nil); + dict_assert (next->left == nil); + + /* + * First, splice out the successor from the tree completely, by + * moving up its right child into its place. + */ + + child = next->right; + child->parent = nextparent; + + if (nextparent->left == next) { + nextparent->left = child; + } else { + dict_assert (nextparent->right == next); + nextparent->right = child; + } + + /* + * Now that the successor has been extricated from the tree, install it + * in place of the node that we want deleted. + */ + + next->parent = delparent; + next->left = delete->left; + next->right = delete->right; + next->left->parent = next; + next->right->parent = next; + next->color = delete->color; + delete->color = nextcolor; + + if (delparent->left == delete) { + delparent->left = next; + } else { + dict_assert (delparent->right == delete); + delparent->right = next; + } + + } else { + dict_assert (delete != nil); + dict_assert (delete->left == nil || delete->right == nil); + + child = (delete->left != nil) ? delete->left : delete->right; + + child->parent = delparent = delete->parent; + + if (delete == delparent->left) { + delparent->left = child; + } else { + dict_assert (delete == delparent->right); + delparent->right = child; + } + } + + delete->parent = NULL; + delete->right = NULL; + delete->left = NULL; + + dict->nodecount--; + + dict_assert (verify_bintree(dict)); + + /* red-black adjustments */ + + if (delete->color == dnode_black) { + dnode_t *parent, *sister; + + dict_root(dict)->color = dnode_red; + + while (child->color == dnode_black) { + parent = child->parent; + if (child == parent->left) { + sister = parent->right; + dict_assert (sister != nil); + if (sister->color == dnode_red) { + sister->color = dnode_black; + parent->color = dnode_red; + rotate_left(parent); + sister = parent->right; + dict_assert (sister != nil); + } + if (sister->left->color == dnode_black + && sister->right->color == dnode_black) { + sister->color = dnode_red; + child = parent; + } else { + if (sister->right->color == dnode_black) { + dict_assert (sister->left->color == dnode_red); + sister->left->color = dnode_black; + sister->color = dnode_red; + rotate_right(sister); + sister = parent->right; + dict_assert (sister != nil); + } + sister->color = parent->color; + sister->right->color = dnode_black; + parent->color = dnode_black; + rotate_left(parent); + break; + } + } else { /* symmetric case: child == child->parent->right */ + dict_assert (child == parent->right); + sister = parent->left; + dict_assert (sister != nil); + if (sister->color == dnode_red) { + sister->color = dnode_black; + parent->color = dnode_red; + rotate_right(parent); + sister = parent->left; + dict_assert (sister != nil); + } + if (sister->right->color == dnode_black + && sister->left->color == dnode_black) { + sister->color = dnode_red; + child = parent; + } else { + if (sister->left->color == dnode_black) { + dict_assert (sister->right->color == dnode_red); + sister->right->color = dnode_black; + sister->color = dnode_red; + rotate_left(sister); + sister = parent->left; + dict_assert (sister != nil); + } + sister->color = parent->color; + sister->left->color = dnode_black; + parent->color = dnode_black; + rotate_right(parent); + break; + } + } + } + + child->color = dnode_black; + dict_root(dict)->color = dnode_black; + } + + dict_assert (dict_verify(dict)); + + return delete; +} +#endif /* E2FSCK_NOTUSED */ + +/* + * Allocate a node using the dictionary's allocator routine, give it + * the data item. + */ + +int dict_alloc_insert(dict_t *dict, const void *key, void *data) +{ + dnode_t *node = dict->allocnode(dict->context); + + if (node) { + dnode_init(node, data); + dict_insert(dict, node, key); + return 1; + } + return 0; +} + +#ifdef E2FSCK_NOTUSED +void dict_delete_free(dict_t *dict, dnode_t *node) +{ + dict_delete(dict, node); + dict->freenode(node, dict->context); +} +#endif + +/* + * Return the node with the lowest (leftmost) key. If the dictionary is empty + * (that is, dict_isempty(dict) returns 1) a null pointer is returned. + */ + +dnode_t *dict_first(dict_t *dict) +{ + dnode_t *nil = dict_nil(dict), *root = dict_root(dict), *left; + + if (root != nil) + while ((left = root->left) != nil) + root = left; + + return (root == nil) ? NULL : root; +} + +/* + * Return the node with the highest (rightmost) key. If the dictionary is empty + * (that is, dict_isempty(dict) returns 1) a null pointer is returned. + */ + +dnode_t *dict_last(dict_t *dict) +{ + dnode_t *nil = dict_nil(dict), *root = dict_root(dict), *right; + + if (root != nil) + while ((right = root->right) != nil) + root = right; + + return (root == nil) ? NULL : root; +} + +/* + * Return the given node's successor node---the node which has the + * next key in the the left to right ordering. If the node has + * no successor, a null pointer is returned rather than a pointer to + * the nil node. + */ + +dnode_t *dict_next(dict_t *dict, dnode_t *curr) +{ + dnode_t *nil = dict_nil(dict), *parent, *left; + + if (curr->right != nil) { + curr = curr->right; + while ((left = curr->left) != nil) + curr = left; + return curr; + } + + parent = curr->parent; + + while (parent != nil && curr == parent->right) { + curr = parent; + parent = curr->parent; + } + + return (parent == nil) ? NULL : parent; +} + +/* + * Return the given node's predecessor, in the key order. + * The nil sentinel node is returned if there is no predecessor. + */ + +dnode_t *dict_prev(dict_t *dict, dnode_t *curr) +{ + dnode_t *nil = dict_nil(dict), *parent, *right; + + if (curr->left != nil) { + curr = curr->left; + while ((right = curr->right) != nil) + curr = right; + return curr; + } + + parent = curr->parent; + + while (parent != nil && curr == parent->left) { + curr = parent; + parent = curr->parent; + } + + return (parent == nil) ? NULL : parent; +} + +void dict_allow_dupes(dict_t *dict) +{ + dict->dupes = 1; +} + +#undef dict_count +#undef dict_isempty +#undef dict_isfull +#undef dnode_get +#undef dnode_put +#undef dnode_getkey + +dictcount_t dict_count(dict_t *dict) +{ + return dict->nodecount; +} + +int dict_isempty(dict_t *dict) +{ + return dict->nodecount == 0; +} + +int dict_isfull(dict_t *dict) +{ + return dict->nodecount == dict->maxcount; +} + +int dict_contains(dict_t *dict, dnode_t *node) +{ + return verify_dict_has_node(dict_nil(dict), dict_root(dict), node); +} + +static dnode_t *dnode_alloc(void *context EXT2FS_ATTR((unused))) +{ + return malloc(sizeof *dnode_alloc(NULL)); +} + +static void dnode_free(dnode_t *node, void *context EXT2FS_ATTR((unused))) +{ + free(node); +} + +dnode_t *dnode_create(void *data) +{ + dnode_t *new = malloc(sizeof *new); + if (new) { + new->data = data; + new->parent = NULL; + new->left = NULL; + new->right = NULL; + } + return new; +} + +dnode_t *dnode_init(dnode_t *dnode, void *data) +{ + dnode->data = data; + dnode->parent = NULL; + dnode->left = NULL; + dnode->right = NULL; + return dnode; +} + +void dnode_destroy(dnode_t *dnode) +{ + dict_assert (!dnode_is_in_a_dict(dnode)); + free(dnode); +} + +void *dnode_get(dnode_t *dnode) +{ + return dnode->data; +} + +const void *dnode_getkey(dnode_t *dnode) +{ + return dnode->key; +} + +#ifdef E2FSCK_NOTUSED +void dnode_put(dnode_t *dnode, void *data) +{ + dnode->data = data; +} +#endif + +#ifndef DICT_NODEBUG +int dnode_is_in_a_dict(dnode_t *dnode) +{ + return (dnode->parent && dnode->left && dnode->right); +} +#endif + +#ifdef E2FSCK_NOTUSED +void dict_process(dict_t *dict, void *context, dnode_process_t function) +{ + dnode_t *node = dict_first(dict), *next; + + while (node != NULL) { + /* check for callback function deleting */ + /* the next node from under us */ + dict_assert (dict_contains(dict, node)); + next = dict_next(dict, node); + function(dict, node, context); + node = next; + } +} + +static void load_begin_internal(dict_load_t *load, dict_t *dict) +{ + load->dictptr = dict; + load->nilnode.left = &load->nilnode; + load->nilnode.right = &load->nilnode; +} + +void dict_load_begin(dict_load_t *load, dict_t *dict) +{ + dict_assert (dict_isempty(dict)); + load_begin_internal(load, dict); +} + +void dict_load_next(dict_load_t *load, dnode_t *newnode, const void *key) +{ + dict_t *dict = load->dictptr; + dnode_t *nil = &load->nilnode; + + dict_assert (!dnode_is_in_a_dict(newnode)); + dict_assert (dict->nodecount < dict->maxcount); + +#ifndef DICT_NODEBUG + if (dict->nodecount > 0) { + if (dict->dupes) + dict_assert (dict->compare(nil->left->key, key) <= 0); + else + dict_assert (dict->compare(nil->left->key, key) < 0); + } +#endif + + newnode->key = key; + nil->right->left = newnode; + nil->right = newnode; + newnode->left = nil; + dict->nodecount++; +} + +void dict_load_end(dict_load_t *load) +{ + dict_t *dict = load->dictptr; + dnode_t *tree[DICT_DEPTH_MAX] = { 0 }; + dnode_t *curr, *dictnil = dict_nil(dict), *loadnil = &load->nilnode, *next; + dnode_t *complete = 0; + dictcount_t fullcount = DICTCOUNT_T_MAX, nodecount = dict->nodecount; + dictcount_t botrowcount; + unsigned baselevel = 0, level = 0, i; + + dict_assert (dnode_red == 0 && dnode_black == 1); + + while (fullcount >= nodecount && fullcount) + fullcount >>= 1; + + botrowcount = nodecount - fullcount; + + for (curr = loadnil->left; curr != loadnil; curr = next) { + next = curr->left; + + if (complete == NULL && botrowcount-- == 0) { + dict_assert (baselevel == 0); + dict_assert (level == 0); + baselevel = level = 1; + complete = tree[0]; + + if (complete != 0) { + tree[0] = 0; + complete->right = dictnil; + while (tree[level] != 0) { + tree[level]->right = complete; + complete->parent = tree[level]; + complete = tree[level]; + tree[level++] = 0; + } + } + } + + if (complete == NULL) { + curr->left = dictnil; + curr->right = dictnil; + curr->color = level % 2; + complete = curr; + + dict_assert (level == baselevel); + while (tree[level] != 0) { + tree[level]->right = complete; + complete->parent = tree[level]; + complete = tree[level]; + tree[level++] = 0; + } + } else { + curr->left = complete; + curr->color = (level + 1) % 2; + complete->parent = curr; + tree[level] = curr; + complete = 0; + level = baselevel; + } + } + + if (complete == NULL) + complete = dictnil; + + for (i = 0; i < DICT_DEPTH_MAX; i++) { + if (tree[i] != 0) { + tree[i]->right = complete; + complete->parent = tree[i]; + complete = tree[i]; + } + } + + dictnil->color = dnode_black; + dictnil->right = dictnil; + complete->parent = dictnil; + complete->color = dnode_black; + dict_root(dict) = complete; + + dict_assert (dict_verify(dict)); +} + +void dict_merge(dict_t *dest, dict_t *source) +{ + dict_load_t load; + dnode_t *leftnode = dict_first(dest), *rightnode = dict_first(source); + + dict_assert (dict_similar(dest, source)); + + if (source == dest) + return; + + dest->nodecount = 0; + load_begin_internal(&load, dest); + + for (;;) { + if (leftnode != NULL && rightnode != NULL) { + if (dest->compare(leftnode->key, rightnode->key) < 0) + goto copyleft; + else + goto copyright; + } else if (leftnode != NULL) { + goto copyleft; + } else if (rightnode != NULL) { + goto copyright; + } else { + dict_assert (leftnode == NULL && rightnode == NULL); + break; + } + + copyleft: + { + dnode_t *next = dict_next(dest, leftnode); +#ifndef DICT_NODEBUG + leftnode->left = NULL; /* suppress assertion in dict_load_next */ +#endif + dict_load_next(&load, leftnode, leftnode->key); + leftnode = next; + continue; + } + + copyright: + { + dnode_t *next = dict_next(source, rightnode); +#ifndef DICT_NODEBUG + rightnode->left = NULL; +#endif + dict_load_next(&load, rightnode, rightnode->key); + rightnode = next; + continue; + } + } + + dict_clear(source); + dict_load_end(&load); +} +#endif /* E2FSCK_NOTUSED */ + +#ifdef KAZLIB_TEST_MAIN + +#include <stdio.h> +#include <string.h> +#include <ctype.h> +#include <stdarg.h> + +typedef char input_t[256]; + +static int tokenize(char *string, ...) +{ + char **tokptr; + va_list arglist; + int tokcount = 0; + + va_start(arglist, string); + tokptr = va_arg(arglist, char **); + while (tokptr) { + while (*string && isspace((unsigned char) *string)) + string++; + if (!*string) + break; + *tokptr = string; + while (*string && !isspace((unsigned char) *string)) + string++; + tokptr = va_arg(arglist, char **); + tokcount++; + if (!*string) + break; + *string++ = 0; + } + va_end(arglist); + + return tokcount; +} + +static int comparef(const void *cmp_ctx, const void *key1, const void *key2) +{ + return strcmp(key1, key2); +} + +static char *dupstring(char *str) +{ + int sz = strlen(str) + 1; + char *new = malloc(sz); + if (new) + memcpy(new, str, sz); + return new; +} + +static dnode_t *new_node(void *c) +{ + static dnode_t few[5]; + static int count; + + if (count < 5) + return few + count++; + + return NULL; +} + +static void del_node(dnode_t *n, void *c) +{ +} + +static int prompt = 0; + +static void construct(dict_t *d) +{ + input_t in; + int done = 0; + dict_load_t dl; + dnode_t *dn; + char *tok1, *tok2, *val; + const char *key; + char *help = + "p turn prompt on\n" + "q finish construction\n" + "a <key> <val> add new entry\n"; + + if (!dict_isempty(d)) + puts("warning: dictionary not empty!"); + + dict_load_begin(&dl, d); + + while (!done) { + if (prompt) + putchar('>'); + fflush(stdout); + + if (!fgets(in, sizeof(input_t), stdin)) + break; + + switch (in[0]) { + case '?': + puts(help); + break; + case 'p': + prompt = 1; + break; + case 'q': + done = 1; + break; + case 'a': + if (tokenize(in+1, &tok1, &tok2, (char **) 0) != 2) { + puts("what?"); + break; + } + key = dupstring(tok1); + val = dupstring(tok2); + dn = dnode_create(val); + + if (!key || !val || !dn) { + puts("out of memory"); + free((void *) key); + free(val); + if (dn) + dnode_destroy(dn); + } + + dict_load_next(&dl, dn, key); + break; + default: + putchar('?'); + putchar('\n'); + break; + } + } + + dict_load_end(&dl); +} + +int main(void) +{ + input_t in; + dict_t darray[10]; + dict_t *d = &darray[0]; + dnode_t *dn; + int i; + char *tok1, *tok2, *val; + const char *key; + + char *help = + "a <key> <val> add value to dictionary\n" + "d <key> delete value from dictionary\n" + "l <key> lookup value in dictionary\n" + "( <key> lookup lower bound\n" + ") <key> lookup upper bound\n" + "# <num> switch to alternate dictionary (0-9)\n" + "j <num> <num> merge two dictionaries\n" + "f free the whole dictionary\n" + "k allow duplicate keys\n" + "c show number of entries\n" + "t dump whole dictionary in sort order\n" + "m make dictionary out of sorted items\n" + "p turn prompt on\n" + "s switch to non-functioning allocator\n" + "q quit"; + + for (i = 0; i < sizeof darray / sizeof *darray; i++) + dict_init(&darray[i], DICTCOUNT_T_MAX, comparef); + + for (;;) { + if (prompt) + putchar('>'); + fflush(stdout); + + if (!fgets(in, sizeof(input_t), stdin)) + break; + + switch(in[0]) { + case '?': + puts(help); + break; + case 'a': + if (tokenize(in+1, &tok1, &tok2, (char **) 0) != 2) { + puts("what?"); + break; + } + key = dupstring(tok1); + val = dupstring(tok2); + + if (!key || !val) { + puts("out of memory"); + free((void *) key); + free(val); + } + + if (!dict_alloc_insert(d, key, val)) { + puts("dict_alloc_insert failed"); + free((void *) key); + free(val); + break; + } + break; + case 'd': + if (tokenize(in+1, &tok1, (char **) 0) != 1) { + puts("what?"); + break; + } + dn = dict_lookup(d, tok1); + if (!dn) { + puts("dict_lookup failed"); + break; + } + val = dnode_get(dn); + key = dnode_getkey(dn); + dict_delete_free(d, dn); + + free(val); + free((void *) key); + break; + case 'f': + dict_free(d); + break; + case 'l': + case '(': + case ')': + if (tokenize(in+1, &tok1, (char **) 0) != 1) { + puts("what?"); + break; + } + dn = 0; + switch (in[0]) { + case 'l': + dn = dict_lookup(d, tok1); + break; + case '(': + dn = dict_lower_bound(d, tok1); + break; + case ')': + dn = dict_upper_bound(d, tok1); + break; + } + if (!dn) { + puts("lookup failed"); + break; + } + val = dnode_get(dn); + puts(val); + break; + case 'm': + construct(d); + break; + case 'k': + dict_allow_dupes(d); + break; + case 'c': + printf("%lu\n", (unsigned long) dict_count(d)); + break; + case 't': + for (dn = dict_first(d); dn; dn = dict_next(d, dn)) { + printf("%s\t%s\n", (char *) dnode_getkey(dn), + (char *) dnode_get(dn)); + } + break; + case 'q': + exit(0); + break; + case '\0': + break; + case 'p': + prompt = 1; + break; + case 's': + dict_set_allocator(d, new_node, del_node, NULL); + break; + case '#': + if (tokenize(in+1, &tok1, (char **) 0) != 1) { + puts("what?"); + break; + } else { + int dictnum = atoi(tok1); + if (dictnum < 0 || dictnum > 9) { + puts("invalid number"); + break; + } + d = &darray[dictnum]; + } + break; + case 'j': + if (tokenize(in+1, &tok1, &tok2, (char **) 0) != 2) { + puts("what?"); + break; + } else { + int dict1 = atoi(tok1), dict2 = atoi(tok2); + if (dict1 < 0 || dict1 > 9 || dict2 < 0 || dict2 > 9) { + puts("invalid number"); + break; + } + dict_merge(&darray[dict1], &darray[dict2]); + } + break; + default: + putchar('?'); + putchar('\n'); + break; + } + } + + return 0; +} + +#endif |