97c0b3c7633d0e28ab4f44231679301a8d344e6c
[fio.git] / filehash.c
1 #include <stdlib.h>
2 #include <assert.h>
3
4 #include "fio.h"
5 #include "flist.h"
6 #include "crc/crc16.h"
7
8 #include "spinlock.h"
9
10 #define HASH_BUCKETS    512
11 #define HASH_MASK       (HASH_BUCKETS - 1)
12
13 unsigned int file_hash_size = HASH_BUCKETS * sizeof(struct flist_head);
14
15 static struct flist_head *file_hash;
16 static struct fio_spinlock *hash_lock;
17
18 static unsigned short hash(const char *name)
19 {
20         return crc16((const unsigned char *) name, strlen(name)) & HASH_MASK;
21 }
22
23 void remove_file_hash(struct fio_file *f)
24 {
25         fio_spin_lock(hash_lock);
26
27         if (f->flags & FIO_FILE_HASHED) {
28                 assert(!flist_empty(&f->hash_list));
29                 flist_del_init(&f->hash_list);
30                 f->flags &= ~FIO_FILE_HASHED;
31         }
32
33         fio_spin_unlock(hash_lock);
34 }
35
36 static struct fio_file *__lookup_file_hash(const char *name)
37 {
38         struct flist_head *bucket = &file_hash[hash(name)];
39         struct flist_head *n;
40
41         flist_for_each(n, bucket) {
42                 struct fio_file *f = flist_entry(n, struct fio_file, hash_list);
43
44                 if (!strcmp(f->file_name, name)) {
45                         assert(f->fd != -1);
46                         return f;
47                 }
48         }
49
50         return NULL;
51 }
52
53 struct fio_file *lookup_file_hash(const char *name)
54 {
55         struct fio_file *f;
56
57         fio_spin_lock(hash_lock);
58         f = __lookup_file_hash(name);
59         fio_spin_unlock(hash_lock);
60         return f;
61 }
62
63 struct fio_file *add_file_hash(struct fio_file *f)
64 {
65         struct fio_file *alias;
66
67         if (f->flags & FIO_FILE_HASHED)
68                 return NULL;
69
70         INIT_FLIST_HEAD(&f->hash_list);
71
72         fio_spin_lock(hash_lock);
73
74         alias = __lookup_file_hash(f->file_name);
75         if (!alias) {
76                 f->flags |= FIO_FILE_HASHED;
77                 flist_add_tail(&f->hash_list, &file_hash[hash(f->file_name)]);
78         }
79
80         fio_spin_unlock(hash_lock);
81         return alias;
82 }
83
84 void file_hash_exit(void)
85 {
86         unsigned int i, has_entries = 0;
87
88         fio_spin_lock(hash_lock);
89         for (i = 0; i < HASH_BUCKETS; i++)
90                 has_entries += !flist_empty(&file_hash[i]);
91
92         file_hash = NULL;
93         fio_spin_unlock(hash_lock);
94
95         if (has_entries)
96                 log_err("fio: file hash not empty on exit\n");
97
98         fio_spinlock_remove(hash_lock);
99         hash_lock = NULL;
100 }
101
102 void file_hash_init(void *ptr)
103 {
104         unsigned int i;
105
106         file_hash = ptr;
107         for (i = 0; i < HASH_BUCKETS; i++)
108                 INIT_FLIST_HEAD(&file_hash[i]);
109
110         hash_lock = fio_spinlock_init();
111 }