内核中rbtree的API简单使用备忘:一个rbtree根,向其中插入结点,遍历之,删除节点,再遍历之。
系统环境:ubuntu-10.04/linux-2.6.32-38-generic
代码:
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/rbtree.h>
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("zl");
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MODULE_DESCRIPTION("rbtree test");
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struct mytype {
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struct rb_node node;
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char *keystring;
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};
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struct rb_root mytree = RB_ROOT;
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/** Same as binary sort tree**/
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struct mytype *my_search(struct rb_root *root, char *string)
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{
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struct rb_node *node = root->rb_node;
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while (node) {
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struct mytype *data = container_of(node, struct mytype, node);
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int result;
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result = strcmp(string, data->keystring);
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if (result < 0)
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node = node->rb_left;
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else if (result > 0)
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node = node->rb_right;
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else
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return data;
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}
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return NULL;
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}
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int my_insert(struct rb_root *root, struct mytype *data)
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{
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struct rb_node **new = &(root->rb_node), *parent = NULL;
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/* Figure out where to put new node */
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while (*new) {
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struct mytype *this = container_of(*new, struct mytype, node);
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int result = strcmp(data->keystring, this->keystring);
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parent = *new;
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if (result < 0)
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new = &((*new)->rb_left);
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else if (result > 0)
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new = &((*new)->rb_right);
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else
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return 0;
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}
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/* Add new node and rebalance tree. */
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rb_link_node(&(data->node), parent, new);
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#if 1
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rb_insert_color(&(data->node), root);
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#endif
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return 1;
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}
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#if 0
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/** remove **/
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struct mytype *data = mysearch(mytree, "walrus");
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if (data) {
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rb_erase(data->node, mytree);
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myfree(data);
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}
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#endif
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#if 0
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void rb_replace_node(struct rb_node *old, struct rb_node *new,
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struct rb_root *tree);
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#endif
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#if 0
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struct rb_node *rb_first(struct rb_root *tree);
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struct rb_node *rb_last(struct rb_root *tree);
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struct rb_node *rb_next(struct rb_node *node);
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struct rb_node *rb_prev(struct rb_node *node);
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#endif
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char *array[] = {
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"aaaaa",
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"bbb",
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"333",
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"c",
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"dddd",
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"111",
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"eeeeeeeee",
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"ffffghi",
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"222",
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"gggabcd",
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"12345"
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"abcdefg"
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};
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#define TAB_SIZE(array) (sizeof(array)/sizeof(array[0]))
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static int __init rbtree_init(void)
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{
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struct rb_node *node;
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struct mytype *mynode;
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int i;
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for(i = 0; i < TAB_SIZE(array); i++)
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{
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mynode = kmalloc(sizeof(struct mytype), GFP_KERNEL);
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mynode->keystring = (char *)array[i];
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printk("kerstring is %s\n", mynode->keystring);
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my_insert(&mytree, mynode);
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}
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printk("*********** 升序 ****************************\n");
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i = 0;
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for(node = rb_first(&mytree); node; node = rb_next(node))
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{
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printk("i = %d, key = %s\n", i, (rb_entry(node, struct mytype, node))->keystring);
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i++;
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}
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printk("------------降序---------------------------\n");
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i = 0;
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for(node = rb_last(&mytree); node; node = rb_prev(node))
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{
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printk("i = %d, key = %s\n", i, (rb_entry(node, struct mytype, node))->keystring);
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i++;
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}
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printk("------------删除后升序---------------------------\n");
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mynode = my_search(&mytree, "eeeeeeeee");
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if(mynode)
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{
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rb_erase(&(mynode->node), &mytree);
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kfree(mynode);
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printk("Erased eeeeeeeee node !\n");
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}
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for(node = rb_first(&mytree); node; node = rb_next(node))
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{
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printk("i = %d, key = %s\n", i, (rb_entry(node, struct mytype, node))->keystring);
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i++;
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}
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return 0;
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}
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static void __exit rbtree_exit(void)
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{
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printk("exit !\n");
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}
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module_init(rbtree_init);
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module_exit(rbtree_exit);
Makefile:
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obj-m = myrbtree.o
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#KERNELS = /media/STUDY/linux/kernel/my2440-2.6.36
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KERNELS = /lib/modules/$(shell uname -r)/build/
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default:
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make -C $(KERNELS) M=$(shell pwd) modules
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.PHONY:clean
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clean:
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make -C $(KERNELS) M=$(shell pwd) clean
编译,运行,及查看运行结果:符合预期
make clean;make;sudo rmmod myrbtree;sudo insmod myrbtree.ko ;dmesg
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