[Linux]学习笔记系列 -- hashtable

---

title: hashtable
categories:

• linux
• include
  tags:
• linux
• include
  abbrlink: 14dfa8ed
  date: 2025-10-03 09:01:49

---

https://github.com/wdfk-prog/linux-study

文章目录

• include/linux/hashtable.h
• • DEFINE_HASHTABLE 定义哈希表
  • hlist_for_each_entry 遍历哈希表
  • hash_add 将一个对象添加到哈希表

include/linux/hashtable.h

DEFINE_HASHTABLE 定义哈希表

#defineDEFINE_HASHTABLE(name,bits)\structhlist_headname[1<<(bits)]=\{[0...((1<<(bits))-1)]=HLIST_HEAD_INIT}

hlist_for_each_entry 遍历哈希表

#definehlist_entry(ptr,type,member)container_of(ptr,type,member)#definehlist_for_each(pos,head)\for(pos=(head)->first;pos;pos=pos->next)#definehlist_for_each_safe(pos,n,head)\for(pos=(head)->first;pos&&({n=pos->next;1;});\pos=n)#definehlist_entry_safe(ptr,type,member)\({typeof(ptr)____ptr=(ptr);\____ptr?hlist_entry(____ptr,type,member):NULL;\})/** * hlist_for_each_entry - 遍历给定类型的列表 * @pos: 用作循环游标的类型 *。 * @head: 您列表的开头。 * @member: 结构体内 hlist_node 的名称。 */#definehlist_for_each_entry(pos,head,member)\for(pos=hlist_entry_safe((head)->first,typeof(*(pos)),member);\pos;\pos=hlist_entry_safe((pos)->member.next,typeof(*(pos)),member))/** * hash_for_each_possible - 遍历所有可能哈希到同一桶的对象 * @name: 要遍历的哈希表 * @obj: 用作每个条目的循环游标的类型* * @member: 结构体内 hlist_node 的名称 * @key: 要遍历的对象的键 */#definehash_for_each_possible(name,obj,member,key)\hlist_for_each_entry(obj,&name[hash_min(key,HASH_BITS(name))],member)

hash_add 将一个对象添加到哈希表

/** * hlist_add_head - add a new entry at the beginning of the hlist * @n: new entry to be added * @h: hlist head to add it after * * Insert a new entry after the specified head. * This is good for implementing stacks. */staticinlinevoidhlist_add_head(structhlist_node*n,structhlist_head*h){structhlist_node*first=h->first;WRITE_ONCE(n->next,first);if(first)WRITE_ONCE(first->pprev,&n->next);WRITE_ONCE(h->first,n);WRITE_ONCE(n->pprev,&h->first);}/** * hash_add - 将一个对象添加到哈希表 * @hashtable: 要添加到的哈希表 * @node: 要添加的对象的 &struct hlist_node * @key: 要添加的对象的键 */#definehash_add(hashtable,node,key)\hlist_add_head(node,&hashtable[hash_min(key,HASH_BITS(hashtable))])