1. 抽象对象和对象集
抽象对象：操作目标是一个对象，且对象类型不确定。
对象集：操作目标是一组对象，且同对象集类型相同，但类型不确定。
对于抽象对象的实现，可以使用 ADT，也可以使用 typedef 和 宏，
对于大多数应用，ADT太多繁琐，且效率相对低，所以更倾向于使用 typedef 宏
如
typedef int Item
#define eq(A, B) (A == B)
typedef char *Item
#define eq(A, B) (strcmp(A, B) == 0)
若抽象对象很复杂，则应该考虑ADT。
集合对象，他有多个通用操作：
- 向集合插入一个新对象
- 从集合删除一个对象
为了方便，通常还包含 - 初始化
- 统计
- 销毁
- 复制
集合对象的实现 和 链表，数组，
链表，数组，树，是集合对象的实现基础，由于他们插入，遍历等操作效率不同，
所以对不同特征的集合对象的实现的效率不同。
ADT：抽象数据类型，指 只通过接口进行访问的数据类型，使用ADT的程序为客户，
ADT定义程序为实现。
#ifndef _LIST_HEAD_H
#define _LIST_HEAD_H
#include <stdlib.h>
#include <stddef.h>
#include "container.h"
/*
* These are non-NULL pointers that will result in page faults
* under normal circumstances, used to verify that nobody uses
* non-initialized list entries.
*/
#define LIST_POISON1 ((void *) 0x00100100)
#define LIST_POISON2 ((void *) 0x00200200)
/*
* Simple doubly linked list implementation.
*
* Some of the internal functions ("__xxx") are useful when
* manipulating whole lists rather than single entries, as
* sometimes we already know the next/prev entries and we can
* generate better code by using them directly rather than
* using the generic single-entry routines.
*/
typedef struct list_head {
struct list_head *next, *prev;
} list_head_t;
/* Simple initializer */
#define LIST_HEAD_INITIALIZER(name) { &(name), &(name) }
#define LIST_HEAD_INITIALIZE(name) \
list_head_t name = LIST_HEAD_INITIALIZER(name)
#define INIT_LIST_HEAD(ptr) do { \
(ptr)->next = (ptr); (ptr)->prev = (ptr); \
} while (0)
/*
* Insert a new entry between two known consecutive entries.
*
* This is only for internal list manipulation where we know
* the prev/next entries already!
*/
static inline void __list_add(struct list_head *new,
struct list_head *prev,
struct list_head *next)
{
next->prev = new;
new->next = next;
new->prev = prev;
prev->next = new;
}
/**
* list_head_add - add a new entry
* @new: new entry to be added
* @head: list head to add it after
*
* Insert a new entry after the specified head.
* This is good for implementing stacks.
*/
static inline void list_head_add(struct list_head *new, struct list_head *head)
{
__list_add(new, head, head->next);
}
// list_head_add_tail
/**
* list_add_tail - add a new entry
* @new: new entry to be added
* @head: list head to add it before
*
* Insert a new entry before the specified head.
* This is useful for implementing queues.
*/
static inline void list_add_tail(struct list_head *new, struct list_head *head)
{
__list_add(new, head->prev, head);
}
/*
* Delete a list entry by making the prev/next entries
* point to each other.
*
* This is only for internal list manipulation where we know
* the prev/next entries already!
*/
static inline void __list_del(struct list_head * prev, struct list_head * next)
{
next->prev = prev;
prev->next = next;
}
/**
* list_del - deletes entry from list.
* @entry: the element to delete from the list.
* Note: list_empty on entry does not return true after this, the entry is
* in an undefined state.
*/
static inline void list_head_del(struct list_head *entry)
{
__list_del(entry->prev, entry->next);
entry->next = LIST_POISON1;
entry->prev = LIST_POISON2;
}
/**
* list_del_init - deletes entry from list and reinitialize it.
* @entry: the element to delete from the list.
*/
static inline void list_del_init(struct list_head *entry)
{
__list_del(entry->prev, entry->next);
INIT_LIST_HEAD(entry);
}
/**
* list_move - delete from one list and add as another's head
* @lst: the entry to move
* @head: the head that will precede our entry
*/
static inline void list_move(struct list_head *lst, struct list_head *head)
{
__list_del(lst->prev, lst->next);
list_head_add(lst, head);
}
/**
* list_move_tail - delete from one list and add as another's tail
* @lst: the entry to move
* @head: the head that will follow our entry
*/
static inline void list_move_tail(struct list_head *lst,
struct list_head *head)
{
__list_del(lst->prev, lst->next);
list_add_tail(lst, head);
}
/**
* list_is_first - tests whether @list is the first entry in list @head
* @lst: the entry to test
* @head: the head of the list
*/
static inline int list_is_first(const struct list_head *lst,
const struct list_head *head)
{
return lst->prev == head;
}
/**
* list_is_last - tests whether @list is the last entry in list @head
* @lst: the entry to test
* @head: the head of the list
*/
static inline int list_is_last(const struct list_head *lst,
const struct list_head *head)
{
return lst->next == head;
}
/**
* list_empty - tests whether a list is empty
* @head: the list to test.
*/
static inline int list_empty(const struct list_head *head)
{
return head->next == head;
}
/**
* list_copy - copy one list to another
* @dst: the destination list
* @src: the source list
*/
static inline void list_copy(struct list_head *dst, struct list_head *src)
{
if (list_empty(src))
INIT_LIST_HEAD(dst);
else {
*dst = *src;
dst->next->prev = dst;
dst->prev->next = dst;
}
}
static inline void __list_splice(struct list_head *lst,
struct list_head *head)
{
struct list_head *first = lst->next;
struct list_head *last = lst->prev;
struct list_head *at = head->next;
first->prev = head;
head->next = first;
last->next = at;
at->prev = last;
}
/**
* list_splice - join two lists
* @lst: the new list to add.
* @head: the place to add it in the first list.
*/
static inline void list_splice(struct list_head *lst, struct list_head *head)
{
if (!list_empty(lst))
__list_splice(lst, head);
}
/**
* list_splice_init - join two lists and reinitialise the emptied list.
* @list: the new list to add.
* @head: the place to add it in the first list.
*
* The list at @list is reinitialised
*/
static inline void list_splice_init(struct list_head *lst,
struct list_head *head)
{
if (!list_empty(lst)) {
__list_splice(lst, head);
INIT_LIST_HEAD(lst);
}
}
/**
* list_sort - merge sort elements of a list.
* @head: the head of the list.
* @cmp: the function used to compare to list nodes.
*/
void list_sort(struct list_head *head,
int (*cmp)(struct list_head *a, struct list_head *b));
/**
* list_entry - get the struct for this entry
* @ptr: the &struct list_head pointer.
* @type: the type of the struct this is embedded in.
* @member: the name of the list_struct within the struct.
*/
#define list_entry(ptr, type, member) \
container_of(ptr, type, member)
/**
* list_first_entry - get the first element from a list
* @ptr: the list head to take the element from.
* @type: the type of the struct this is embedded in.
* @member: the name of the list_struct within the struct.
*
* Note, that list is expected to be not empty.
*/
#define list_first_entry(ptr, type, member) \
list_entry((ptr)->next, type, member)
/**
* list_last_entry - get the last element from a list
* @ptr: the list head to take the element from.
* @type: the type of the struct this is embedded in.
* @member: the name of the list_struct within the struct.
*
* Note, that list is expected to be not empty.
*/
#define list_last_entry(ptr, type, member) \
list_entry((ptr)->prev, type, member)
/**
* list_for_each - iterate over a list
* @pos: the &struct list_head to use as a loop counter.
* @head: the head for your list.
*/
#define list_for_each(pos, head) \
for (pos = (head)->next; pos != (head); \
pos = pos->next)
// __list_for_each isn't different
/**
* __list_for_each - iterate over a list
* @pos: the &struct list_head to use as a loop counter.
* @head: the head for your list.
*
* This variant differs from list_for_each() in that it's the
* simplest possible list iteration code, no prefetching is done.
* Use this for code that knows the list to be very short (empty
* or 1 entry) most of the time.
*/
#define __list_for_each(pos, head) \
for (pos = (head)->next; pos != (head); pos = pos->next)
/**
* list_for_each_prev - iterate over a list backwards
* @pos: the &struct list_head to use as a loop counter.
* @head: the head for your list.
*/
#define list_for_each_prev(pos, head) \
for (pos = (head)->prev; pos != (head); \
pos = pos->prev)
/**
* list_for_each_safe - iterate over a list safe against removal of list entry
* @pos: the &struct list_head to use as a loop counter.
* @n: another &struct list_head to use as temporary storage
* @head: the head for your list.
*/
#define list_for_each_safe(pos, n, head) \
for (pos = (head)->next, n = pos->next; pos != (head); \
pos = n, n = pos->next)
/**
* list_for_each_entry - iterate over list of given type
* @pos: the type * to use as a loop counter.
* @head: the head for your list.
* @member: the name of the list_struct within the struct.
*/
#define list_for_each_entry(pos, head, member) \
for (pos = list_entry((head)->next, typeof(*pos), member); \
&pos->member != (head); \
pos = list_entry(pos->member.next, typeof(*pos), member))
/**
* list_for_each_entry_reverse - iterate backwards over list of given type.
* @pos: the type * to use as a loop counter.
* @head: the head for your list.
* @member: the name of the list_struct within the struct.
*/
#define list_for_each_entry_reverse(pos, head, member) \
for (pos = list_entry((head)->prev, typeof(*pos), member); \
&pos->member != (head); \
pos = list_entry(pos->member.prev, typeof(*pos), member))
/**
* list_for_each_entry_continue - iterate over list of given type
* continuing after existing point
* @pos: the type * to use as a loop counter.
* @head: the head for your list.
* @member: the name of the list_struct within the struct.
*/
#define list_for_each_entry_continue(pos, head, member) \
for (pos = list_entry(pos->member.next, typeof(*pos), member); \
&pos->member != (head); \
pos = list_entry(pos->member.next, typeof(*pos), member))
/**
* list_for_each_entry_continue_reverse - iterate backwards from the given point
* @pos: the type * to use as a loop cursor.
* @head: the head for your list.
* @member: the name of the list_struct within the struct.
*
* Start to iterate over list of given type backwards, continuing after
* the current position.
*/
#define list_for_each_entry_continue_reverse(pos, head, member) \
for (pos = list_entry(pos->member.prev, typeof(*pos), member); \
&pos->member != (head); \
pos = list_entry(pos->member.prev, typeof(*pos), member))
/**
* list_for_each_entry_from - iterate over list of given type from the current point
* @pos: the type * to use as a loop cursor.
* @head: the head for your list.
* @member: the name of the list_struct within the struct.
*
* Iterate over list of given type, continuing from current position.
*/
#define list_for_each_entry_from(pos, head, member) \
for (; &pos->member != (head); \
pos = list_entry(pos->member.next, typeof(*pos), member))
/**
* list_for_each_entry_from - iterate over list of given type from the current point
* @pos: the type * to use as a loop cursor.
* @head: the head for your list.
* @member: the name of the list_struct within the struct.
*
* Iterate over list of given type, continuing from current position.
*/
#define list_for_each_entry_from_reverse(pos, head, member) \
for (; &pos->member != (head); \
pos = list_entry(pos->member.prev, typeof(*pos), member))
/**
* list_for_each_entry_safe - iterate over list of given type safe against removal of list entry
* @pos: the type * to use as a loop counter.
* @n: another type * to use as temporary storage
* @head: the head for your list.
* @member: the name of the list_struct within the struct.
*/
// Try the alternative
#define list_for_each_entry_safe(pos, n, head, member) \
for (pos = list_entry((head)->next, typeof(*pos), member), \
n = list_entry(pos->member.next, typeof(*pos), member); \
&pos->member != (head); \
pos = n, n = list_entry(n->member.next, typeof(*n), member))
/*
* Double linked lists with a single pointer list head.
* Mostly useful for hash tables where the two pointer list head is
* too wasteful.
* You lose the ability to access the tail in O(1).
*/
typedef struct hlist_head {
struct hlist_node *first;
} hlist_head_t;
typedef struct hlist_node {
struct hlist_node *next, **pprev;
} hlist_node_t;
#define HLIST_HEAD_INITIALIZER { .first = NULL }
#define HLIST_HEAD_INITIALIZE(name) \
hlist_head_t name = { .first = NULL }
#define INIT_HLIST_HEAD(ptr) ((ptr)->first = NULL)
#define INIT_HLIST_NODE(ptr) ((ptr)->next = NULL, (ptr)->pprev = NULL)
static __inline__ int hlist_unhashed(const struct hlist_node *h)
{
return !h->pprev;
}
static __inline__ int hlist_empty(const struct hlist_head *h)
{
return !h->first;
}
static __inline__ void __hlist_del(struct hlist_node *n)
{
struct hlist_node *next = n->next;
struct hlist_node **pprev = n->pprev;
*pprev = next;
if (next)
next->pprev = pprev;
}
static __inline__ void hlist_del(struct hlist_node *n)
{
__hlist_del(n);
n->next = LIST_POISON1;
n->pprev = LIST_POISON2;
}
static __inline__ void hlist_del_init(struct hlist_node *n)
{
if (n->pprev) {
__hlist_del(n);
INIT_HLIST_NODE(n);
}
}
static __inline__ void hlist_add_head(struct hlist_node *n, struct hlist_head *h)
{
struct hlist_node *first = h->first;
n->next = first;
if (first)
first->pprev = &n->next;
h->first = n;
n->pprev = &h->first;
}
static __inline__ void hlist_add_before(struct hlist_node *n, struct hlist_node *next)
{
n->pprev = next->pprev;
n->next = next;
next->pprev = &n->next;
*(n->pprev) = n;
}
static __inline__ void hlist_add_after(struct hlist_node *n,
struct hlist_node *next)
{
next->next = n->next;
n->next = next;
next->pprev = &n->next;
if (next->next)
next->next->pprev = &next->next;
}
#define hlist_entry(ptr, type, member) container_of(ptr,type,member)
#define hlist_for_each(pos, head) \
for (pos = (head)->first; pos; pos = pos->next)
#define hlist_for_each_safe(pos, n, head) \
for (pos = (head)->first; n = pos ? pos->next : 0, pos; \
pos = n)
/**
* hlist_for_each_entry - iterate over list of given type
* @tpos: the type * to use as a loop counter.
* @pos: the &struct hlist_node to use as a loop counter.
* @head: the head for your list.
* @member: the name of the hlist_node within the struct.
*/
#define hlist_for_each_entry(tpos, pos, head, member) \
for (pos = (head)->first; \
pos && \
({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
pos = pos->next)
/**
* hlist_for_each_entry_continue - iterate over a hlist continuing after existing point
* @tpos: the type * to use as a loop counter.
* @pos: the &struct hlist_node to use as a loop counter.
* @member: the name of the hlist_node within the struct.
*/
#define hlist_for_each_entry_continue(tpos, pos, member) \
for (pos = (pos)->next; \
pos && \
({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
pos = pos->next)
/**
* hlist_for_each_entry_from - iterate over a hlist continuing from existing point
* @tpos: the type * to use as a loop counter.
* @pos: the &struct hlist_node to use as a loop counter.
* @member: the name of the hlist_node within the struct.
*/
#define hlist_for_each_entry_from(tpos, pos, member) \
for (; pos && \
({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
pos = pos->next)
/**
* hlist_for_each_entry_safe - iterate over list of given type safe against removal of list entry
* @tpos: the type * to use as a loop counter.
* @pos: the &struct hlist_node to use as a loop counter.
* @n: another &struct hlist_node to use as temporary storage
* @head: the head for your list.
* @member: the name of the hlist_node within the struct.
*/
#define hlist_for_each_entry_safe(tpos, pos, n, head, member) \
for (pos = (head)->first; \
pos && ({ n = pos->next; 1; }) && \
({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
pos = n)
#define hlist_insert_sorted(tpos, ntpos, pos, head, smember, hmember, res) \
res = 0; \
tpos = NULL; \
hlist_for_each_entry(tpos, pos, (head), hmember) \
if (ntpos->smember <= tpos->smember) \
break; \
if (tpos) { \
if (ntpos->smember < tpos->smember) \
hlist_add_before(&ntpos->hmember, &tpos->hmember); \
else if (ntpos->smember > tpos->smember) \
hlist_add_after(&tpos->hmember, &ntpos->hmember); \
else \
res = 1; \
} else \
hlist_add_head(&ntpos->hmember, (head));
#endif /* ! _LIST_HEAD_H */
#ifndef _CONTAINER_H
#define _CONTAINER_H
//#include "align.h"
/* Copy from linux kernel 2.6 source (kernel.h, stddef.h) */
#ifndef offsetof
# define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
#endif
/*
* container_of - cast a member of a structure out to the containing structure
*
* @ptr: the pointer to the member.
* @type: the type of the container struct this is embedded in.
* @member: the name of the member within the struct.
*
*/
#ifndef container_of
# define container_of(ptr, type, member) ({ \
typeof( ((type *)0)->member ) *__mptr = (ptr); \
PTR_CAST(type, (char *)__mptr - offsetof(type,member) );})
#endif
#ifndef container_of_const
# define container_of_const(ptr, type, member) ({ \
const typeof( ((type *)0)->member ) *__mptr = (ptr); \
PTR_CAST_CONST(type, (const char *)__mptr - offsetof(type,member) );})
#endif
#endif
#include "list_head.h"
void list_sort(struct list_head *head,
int (*cmp)(struct list_head *a, struct list_head *b))
{
struct list_head *p, *q, *e, *list, *tail, *oldhead;
unsigned insize, nmerges, psize, qsize, i;
list = head->next;
list_head_del(head);
insize = 1;
while (1) {
p = oldhead = list;
list = tail = NULL;
nmerges = 0;
while (p) {
nmerges++;
q = p;
psize = 0;
for (i = 0; i < insize; i++) {
psize++;
q = q->next == oldhead ? NULL : q->next;
if (!q)
break;
}
qsize = insize;
while (psize > 0 || (qsize > 0 && q)) {
if (!psize) {
e = q;
q = q->next;
qsize--;
if (q == oldhead)
q = NULL;
} else if (!qsize || !q) {
e = p;
p = p->next;
psize--;
} else if (cmp(p, q) <= 0) {
e = p;
p = p->next;
psize--;
} else {
e = q;
q = q->next;
qsize--;
if (q == oldhead)
q = NULL;
}
if (tail)
tail->next = e;
else
list = e;
e->prev = tail;
tail = e;
}
p = q;
}
tail->next = list;
list->prev = tail;
if (nmerges <= 1)
break;
insize *= 2;
}
head->next = list;
head->prev = list->prev;
list->prev->next = head;
list->prev = head;
}
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