From 88ae928ca3f950fa0ecb8b8e0aff118b7360a9d7 Mon Sep 17 00:00:00 2001 From: Joe Thornber Date: Fri, 8 Jun 2018 11:24:18 +0100 Subject: base: Move list to base/data-struct --- base/Makefile | 1 + base/data-struct/list.c | 170 +++++++++++++++++++++++++++++++++++++++ base/data-struct/list.h | 209 ++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 380 insertions(+) create mode 100644 base/data-struct/list.c create mode 100644 base/data-struct/list.h (limited to 'base') diff --git a/base/Makefile b/base/Makefile index 27f539f64..4dcb6b6e6 100644 --- a/base/Makefile +++ b/base/Makefile @@ -12,6 +12,7 @@ BASE_SOURCE=\ base/data-struct/radix-tree.c \ + base/data-struct/list.c BASE_DEPENDS=$(addprefix $(top_builddir)/,$(subst .c,.d,$(BASE_SOURCE))) BASE_OBJECTS=$(addprefix $(top_builddir)/,$(subst .c,.o,$(BASE_SOURCE))) diff --git a/base/data-struct/list.c b/base/data-struct/list.c new file mode 100644 index 000000000..894e273b4 --- /dev/null +++ b/base/data-struct/list.c @@ -0,0 +1,170 @@ +/* + * Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved. + * Copyright (C) 2004-2010 Red Hat, Inc. All rights reserved. + * + * This file is part of LVM2. + * + * This copyrighted material is made available to anyone wishing to use, + * modify, copy, or redistribute it subject to the terms and conditions + * of the GNU Lesser General Public License v.2.1. + * + * You should have received a copy of the GNU Lesser General Public License + * along with this program; if not, write to the Free Software Foundation, + * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include "list.h" + +#include +#include + +/* + * Initialise a list before use. + * The list head's next and previous pointers point back to itself. + */ +void dm_list_init(struct dm_list *head) +{ + head->n = head->p = head; +} + +/* + * Insert an element before 'head'. + * If 'head' is the list head, this adds an element to the end of the list. + */ +void dm_list_add(struct dm_list *head, struct dm_list *elem) +{ + assert(head->n); + + elem->n = head; + elem->p = head->p; + + head->p->n = elem; + head->p = elem; +} + +/* + * Insert an element after 'head'. + * If 'head' is the list head, this adds an element to the front of the list. + */ +void dm_list_add_h(struct dm_list *head, struct dm_list *elem) +{ + assert(head->n); + + elem->n = head->n; + elem->p = head; + + head->n->p = elem; + head->n = elem; +} + +/* + * Delete an element from its list. + * Note that this doesn't change the element itself - it may still be safe + * to follow its pointers. + */ +void dm_list_del(struct dm_list *elem) +{ + elem->n->p = elem->p; + elem->p->n = elem->n; +} + +/* + * Remove an element from existing list and insert before 'head'. + */ +void dm_list_move(struct dm_list *head, struct dm_list *elem) +{ + dm_list_del(elem); + dm_list_add(head, elem); +} + +/* + * Is the list empty? + */ +int dm_list_empty(const struct dm_list *head) +{ + return head->n == head; +} + +/* + * Is this the first element of the list? + */ +int dm_list_start(const struct dm_list *head, const struct dm_list *elem) +{ + return elem->p == head; +} + +/* + * Is this the last element of the list? + */ +int dm_list_end(const struct dm_list *head, const struct dm_list *elem) +{ + return elem->n == head; +} + +/* + * Return first element of the list or NULL if empty + */ +struct dm_list *dm_list_first(const struct dm_list *head) +{ + return (dm_list_empty(head) ? NULL : head->n); +} + +/* + * Return last element of the list or NULL if empty + */ +struct dm_list *dm_list_last(const struct dm_list *head) +{ + return (dm_list_empty(head) ? NULL : head->p); +} + +/* + * Return the previous element of the list, or NULL if we've reached the start. + */ +struct dm_list *dm_list_prev(const struct dm_list *head, const struct dm_list *elem) +{ + return (dm_list_start(head, elem) ? NULL : elem->p); +} + +/* + * Return the next element of the list, or NULL if we've reached the end. + */ +struct dm_list *dm_list_next(const struct dm_list *head, const struct dm_list *elem) +{ + return (dm_list_end(head, elem) ? NULL : elem->n); +} + +/* + * Return the number of elements in a list by walking it. + */ +unsigned int dm_list_size(const struct dm_list *head) +{ + unsigned int s = 0; + const struct dm_list *v; + + dm_list_iterate(v, head) + s++; + + return s; +} + +/* + * Join two lists together. + * This moves all the elements of the list 'head1' to the end of the list + * 'head', leaving 'head1' empty. + */ +void dm_list_splice(struct dm_list *head, struct dm_list *head1) +{ + assert(head->n); + assert(head1->n); + + if (dm_list_empty(head1)) + return; + + head1->p->n = head; + head1->n->p = head->p; + + head->p->n = head1->n; + head->p = head1->p; + + dm_list_init(head1); +} diff --git a/base/data-struct/list.h b/base/data-struct/list.h new file mode 100644 index 000000000..1a107d180 --- /dev/null +++ b/base/data-struct/list.h @@ -0,0 +1,209 @@ +#ifndef BASE_DATA_STRUCT_LIST_H +#define BASE_DATA_STRUCT_LIST_H + +//---------------------------------------------------------------- + +/* + * A list consists of a list head plus elements. + * Each element has 'next' and 'previous' pointers. + * The list head's pointers point to the first and the last element. + */ + +struct dm_list { + struct dm_list *n, *p; +}; + +/* + * String list. + */ +struct dm_str_list { + struct dm_list list; + const char *str; +}; + +/* + * Initialise a list before use. + * The list head's next and previous pointers point back to itself. + */ +#define DM_LIST_HEAD_INIT(name) { &(name), &(name) } +#define DM_LIST_INIT(name) struct dm_list name = DM_LIST_HEAD_INIT(name) +void dm_list_init(struct dm_list *head); + +/* + * Insert an element before 'head'. + * If 'head' is the list head, this adds an element to the end of the list. + */ +void dm_list_add(struct dm_list *head, struct dm_list *elem); + +/* + * Insert an element after 'head'. + * If 'head' is the list head, this adds an element to the front of the list. + */ +void dm_list_add_h(struct dm_list *head, struct dm_list *elem); + +/* + * Delete an element from its list. + * Note that this doesn't change the element itself - it may still be safe + * to follow its pointers. + */ +void dm_list_del(struct dm_list *elem); + +/* + * Remove an element from existing list and insert before 'head'. + */ +void dm_list_move(struct dm_list *head, struct dm_list *elem); + +/* + * Join 'head1' to the end of 'head'. + */ +void dm_list_splice(struct dm_list *head, struct dm_list *head1); + +/* + * Is the list empty? + */ +int dm_list_empty(const struct dm_list *head); + +/* + * Is this the first element of the list? + */ +int dm_list_start(const struct dm_list *head, const struct dm_list *elem); + +/* + * Is this the last element of the list? + */ +int dm_list_end(const struct dm_list *head, const struct dm_list *elem); + +/* + * Return first element of the list or NULL if empty + */ +struct dm_list *dm_list_first(const struct dm_list *head); + +/* + * Return last element of the list or NULL if empty + */ +struct dm_list *dm_list_last(const struct dm_list *head); + +/* + * Return the previous element of the list, or NULL if we've reached the start. + */ +struct dm_list *dm_list_prev(const struct dm_list *head, const struct dm_list *elem); + +/* + * Return the next element of the list, or NULL if we've reached the end. + */ +struct dm_list *dm_list_next(const struct dm_list *head, const struct dm_list *elem); + +/* + * Given the address v of an instance of 'struct dm_list' called 'head' + * contained in a structure of type t, return the containing structure. + */ +#define dm_list_struct_base(v, t, head) \ + ((t *)((const char *)(v) - (const char *)&((t *) 0)->head)) + +/* + * Given the address v of an instance of 'struct dm_list list' contained in + * a structure of type t, return the containing structure. + */ +#define dm_list_item(v, t) dm_list_struct_base((v), t, list) + +/* + * Given the address v of one known element e in a known structure of type t, + * return another element f. + */ +#define dm_struct_field(v, t, e, f) \ + (((t *)((uintptr_t)(v) - (uintptr_t)&((t *) 0)->e))->f) + +/* + * Given the address v of a known element e in a known structure of type t, + * return the list head 'list' + */ +#define dm_list_head(v, t, e) dm_struct_field(v, t, e, list) + +/* + * Set v to each element of a list in turn. + */ +#define dm_list_iterate(v, head) \ + for (v = (head)->n; v != head; v = v->n) + +/* + * Set v to each element in a list in turn, starting from the element + * in front of 'start'. + * You can use this to 'unwind' a list_iterate and back out actions on + * already-processed elements. + * If 'start' is 'head' it walks the list backwards. + */ +#define dm_list_uniterate(v, head, start) \ + for (v = (start)->p; v != head; v = v->p) + +/* + * A safe way to walk a list and delete and free some elements along + * the way. + * t must be defined as a temporary variable of the same type as v. + */ +#define dm_list_iterate_safe(v, t, head) \ + for (v = (head)->n, t = v->n; v != head; v = t, t = v->n) + +/* + * Walk a list, setting 'v' in turn to the containing structure of each item. + * The containing structure should be the same type as 'v'. + * The 'struct dm_list' variable within the containing structure is 'field'. + */ +#define dm_list_iterate_items_gen(v, head, field) \ + for (v = dm_list_struct_base((head)->n, __typeof__(*v), field); \ + &v->field != (head); \ + v = dm_list_struct_base(v->field.n, __typeof__(*v), field)) + +/* + * Walk a list, setting 'v' in turn to the containing structure of each item. + * The containing structure should be the same type as 'v'. + * The list should be 'struct dm_list list' within the containing structure. + */ +#define dm_list_iterate_items(v, head) dm_list_iterate_items_gen(v, (head), list) + +/* + * Walk a list, setting 'v' in turn to the containing structure of each item. + * The containing structure should be the same type as 'v'. + * The 'struct dm_list' variable within the containing structure is 'field'. + * t must be defined as a temporary variable of the same type as v. + */ +#define dm_list_iterate_items_gen_safe(v, t, head, field) \ + for (v = dm_list_struct_base((head)->n, __typeof__(*v), field), \ + t = dm_list_struct_base(v->field.n, __typeof__(*v), field); \ + &v->field != (head); \ + v = t, t = dm_list_struct_base(v->field.n, __typeof__(*v), field)) +/* + * Walk a list, setting 'v' in turn to the containing structure of each item. + * The containing structure should be the same type as 'v'. + * The list should be 'struct dm_list list' within the containing structure. + * t must be defined as a temporary variable of the same type as v. + */ +#define dm_list_iterate_items_safe(v, t, head) \ + dm_list_iterate_items_gen_safe(v, t, (head), list) + +/* + * Walk a list backwards, setting 'v' in turn to the containing structure + * of each item. + * The containing structure should be the same type as 'v'. + * The 'struct dm_list' variable within the containing structure is 'field'. + */ +#define dm_list_iterate_back_items_gen(v, head, field) \ + for (v = dm_list_struct_base((head)->p, __typeof__(*v), field); \ + &v->field != (head); \ + v = dm_list_struct_base(v->field.p, __typeof__(*v), field)) + +/* + * Walk a list backwards, setting 'v' in turn to the containing structure + * of each item. + * The containing structure should be the same type as 'v'. + * The list should be 'struct dm_list list' within the containing structure. + */ +#define dm_list_iterate_back_items(v, head) dm_list_iterate_back_items_gen(v, (head), list) + +/* + * Return the number of elements in a list by walking it. + */ +unsigned int dm_list_size(const struct dm_list *head); + +//---------------------------------------------------------------- + +#endif -- cgit v1.2.1