89 lines
1.4 KiB
C
89 lines
1.4 KiB
C
#include <stddef.h>
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#include <initrd.h>
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#include <kmalloc.h>
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#include <random.h>
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#include <string.h>
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#define nullnode ((file_node_t *)0)
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void _init_node(file_node_t *node) {
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node->l = nullnode;
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node->r = nullnode;
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node->rand = random();
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node->node_size = 1;
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}
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void _pull_from(file_node_t *to, file_node_t *from)
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{
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if (!from)
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return;
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to->node_size += from->node_size;
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}
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void _pull(file_node_t *node)
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{
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node->node_size = 1;
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_pull_from(node, node->l);
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_pull_from(node, node->r);
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}
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file_node_t *_merge(file_node_t *a, file_node_t *b)
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{
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if (!a || !b)
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return a ?: b;
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if (a->rand < b->rand) {
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a->r = _merge(a->r, b);
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_pull(a);
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return a;
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}
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b->l = _merge(a, b->l);
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_pull(b);
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return b;
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}
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void _split(file_node_t *rt, const char *s, file_node_t **a, file_node_t **b)
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{
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if (!rt) {
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*a = *b = nullnode;
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return;
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}
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if (strcmp(s, rt->filename) < 0) {
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*a = rt;
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_split((*a)->r, s, &(*a)->r, b);
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_pull(*a);
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} else {
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*b = rt;
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_split((*b)->l, s, a, &(*b)->l);
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_pull(*b);
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}
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}
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file_node_t *initrd_init(void)
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{
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// TODO
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return nullnode;
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}
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file_node_t *_node_bs(file_node_t *cur, const char *s)
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{
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if (!cur)
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return nullnode;
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int cmp = strcmp(s, cur->filename);
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if (cmp < 0)
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return _node_bs(cur->r, s);
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if (cmp > 0)
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return _node_bs(cur->l, s);
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return cur; // cmp == 0
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}
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file_node_t *initrd_get(file_node_t *root, const char *filename)
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{
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return _node_bs(root, filename);
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}
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