Jens Axboe | 380065a | 2008-03-01 18:56:24 +0100 | [diff] [blame^] | 1 | #include <stdlib.h> |
| 2 | #include <assert.h> |
| 3 | |
| 4 | #include "fio.h" |
| 5 | #include "list.h" |
| 6 | #include "crc/crc16.h" |
| 7 | |
| 8 | #define HASH_BUCKETS 512 |
| 9 | #define HASH_MASK (HASH_BUCKETS - 1) |
| 10 | |
| 11 | unsigned int file_hash_size = HASH_BUCKETS * sizeof(struct list_head); |
| 12 | |
| 13 | static struct list_head *file_hash; |
| 14 | static struct fio_mutex *hash_lock; |
| 15 | |
| 16 | static void dump_hash(void) |
| 17 | { |
| 18 | struct list_head *n; |
| 19 | unsigned int i; |
| 20 | |
| 21 | for (i = 0; i < HASH_BUCKETS; i++) { |
| 22 | list_for_each(n, &file_hash[i]) { |
| 23 | struct fio_file *f; |
| 24 | |
| 25 | f = list_entry(n, struct fio_file, hash_list); |
| 26 | printf("%d: %s\n", i, f->file_name); |
| 27 | } |
| 28 | } |
| 29 | } |
| 30 | |
| 31 | static unsigned short hash(const char *name) |
| 32 | { |
| 33 | return crc16((const unsigned char *) name, strlen(name)) & HASH_MASK; |
| 34 | } |
| 35 | |
| 36 | void remove_file_hash(struct fio_file *f) |
| 37 | { |
| 38 | fio_mutex_down(hash_lock); |
| 39 | |
| 40 | if (f->flags & FIO_FILE_HASHED) { |
| 41 | assert(!list_empty(&f->hash_list)); |
| 42 | list_del_init(&f->hash_list); |
| 43 | f->flags &= ~FIO_FILE_HASHED; |
| 44 | } |
| 45 | |
| 46 | fio_mutex_up(hash_lock); |
| 47 | } |
| 48 | |
| 49 | static struct fio_file *__lookup_file_hash(const char *name) |
| 50 | { |
| 51 | struct list_head *bucket = &file_hash[hash(name)]; |
| 52 | struct list_head *n; |
| 53 | |
| 54 | list_for_each(n, bucket) { |
| 55 | struct fio_file *f = list_entry(n, struct fio_file, hash_list); |
| 56 | |
| 57 | if (!strcmp(f->file_name, name)) { |
| 58 | assert(f->fd != -1); |
| 59 | return f; |
| 60 | } |
| 61 | } |
| 62 | |
| 63 | dump_hash(); |
| 64 | return NULL; |
| 65 | } |
| 66 | |
| 67 | struct fio_file *lookup_file_hash(const char *name) |
| 68 | { |
| 69 | struct fio_file *f; |
| 70 | |
| 71 | fio_mutex_down(hash_lock); |
| 72 | f = __lookup_file_hash(name); |
| 73 | fio_mutex_up(hash_lock); |
| 74 | return f; |
| 75 | } |
| 76 | |
| 77 | struct fio_file *add_file_hash(struct fio_file *f) |
| 78 | { |
| 79 | struct fio_file *alias; |
| 80 | |
| 81 | if (f->flags & FIO_FILE_HASHED) |
| 82 | return NULL; |
| 83 | |
| 84 | INIT_LIST_HEAD(&f->hash_list); |
| 85 | |
| 86 | fio_mutex_down(hash_lock); |
| 87 | |
| 88 | alias = __lookup_file_hash(f->file_name); |
| 89 | if (!alias) { |
| 90 | f->flags |= FIO_FILE_HASHED; |
| 91 | list_add_tail(&f->hash_list, &file_hash[hash(f->file_name)]); |
| 92 | } |
| 93 | |
| 94 | fio_mutex_up(hash_lock); |
| 95 | return alias; |
| 96 | } |
| 97 | |
| 98 | void file_hash_init(void *ptr) |
| 99 | { |
| 100 | unsigned int i; |
| 101 | |
| 102 | file_hash = ptr; |
| 103 | for (i = 0; i < HASH_BUCKETS; i++) |
| 104 | INIT_LIST_HEAD(&file_hash[i]); |
| 105 | |
| 106 | hash_lock = fio_mutex_init(1); |
| 107 | } |