filehash.c

   1 #include <stdlib.h>
   2 #include <assert.h>
   3
   4 #include "fio.h"
   5 #include "flist.h"
   6 #include "hash.h"
   7 #include "filehash.h"
   8 #include "smalloc.h"
   9 #include "lib/bloom.h"
  10
  11 #define HASH_BUCKETS    512
  12 #define HASH_MASK       (HASH_BUCKETS - 1)
  13
  14 #define BLOOM_SIZE      16*1024*1024
  15
  16 static unsigned int file_hash_size = HASH_BUCKETS * sizeof(struct flist_head);
  17
  18 static struct flist_head *file_hash;
  19 static struct fio_sem *hash_lock;
  20 static struct bloom *file_bloom;
  21
  22 static unsigned short hash(const char *name)
  23 {
  24         return jhash(name, strlen(name), 0) & HASH_MASK;
  25 }
  26
  27 void fio_file_hash_lock(void)
  28 {
  29         if (hash_lock)
  30                 fio_sem_down(hash_lock);
  31 }
  32
  33 void fio_file_hash_unlock(void)
  34 {
  35         if (hash_lock)
  36                 fio_sem_up(hash_lock);
  37 }
  38
  39 void remove_file_hash(struct fio_file *f)
  40 {
  41         fio_sem_down(hash_lock);
  42
  43         if (fio_file_hashed(f)) {
  44                 assert(!flist_empty(&f->hash_list));
  45                 flist_del_init(&f->hash_list);
  46                 fio_file_clear_hashed(f);
  47         }
  48
  49         fio_sem_up(hash_lock);
  50 }
  51
  52 static struct fio_file *__lookup_file_hash(const char *name)
  53 {
  54         struct flist_head *bucket = &file_hash[hash(name)];
  55         struct flist_head *n;
  56
  57         flist_for_each(n, bucket) {
  58                 struct fio_file *f = flist_entry(n, struct fio_file, hash_list);
  59
  60                 if (!f->file_name)
  61                         continue;
  62
  63                 if (!strcmp(f->file_name, name)) {
  64                         assert(f->fd != -1);
  65                         return f;
  66                 }
  67         }
  68
  69         return NULL;
  70 }
  71
  72 struct fio_file *lookup_file_hash(const char *name)
  73 {
  74         struct fio_file *f;
  75
  76         fio_sem_down(hash_lock);
  77         f = __lookup_file_hash(name);
  78         fio_sem_up(hash_lock);
  79         return f;
  80 }
  81
  82 struct fio_file *add_file_hash(struct fio_file *f)
  83 {
  84         struct fio_file *alias;
  85
  86         if (fio_file_hashed(f))
  87                 return NULL;
  88
  89         INIT_FLIST_HEAD(&f->hash_list);
  90
  91         fio_sem_down(hash_lock);
  92
  93         alias = __lookup_file_hash(f->file_name);
  94         if (!alias) {
  95                 fio_file_set_hashed(f);
  96                 flist_add_tail(&f->hash_list, &file_hash[hash(f->file_name)]);
  97         }
  98
  99         fio_sem_up(hash_lock);
 100         return alias;
 101 }
 102
 103 bool file_bloom_exists(const char *fname, bool set)
 104 {
 105         return bloom_string(file_bloom, fname, strlen(fname), set);
 106 }
 107
 108 void file_hash_exit(void)
 109 {
 110         unsigned int i, has_entries = 0;
 111
 112         fio_sem_down(hash_lock);
 113         for (i = 0; i < HASH_BUCKETS; i++)
 114                 has_entries += !flist_empty(&file_hash[i]);
 115         fio_sem_up(hash_lock);
 116
 117         if (has_entries)
 118                 log_err("fio: file hash not empty on exit\n");
 119
 120         sfree(file_hash);
 121         file_hash = NULL;
 122         fio_sem_remove(hash_lock);
 123         hash_lock = NULL;
 124         bloom_free(file_bloom);
 125         file_bloom = NULL;
 126 }
 127
 128 void file_hash_init(void)
 129 {
 130         unsigned int i;
 131
 132         file_hash = smalloc(file_hash_size);
 133
 134         for (i = 0; i < HASH_BUCKETS; i++)
 135                 INIT_FLIST_HEAD(&file_hash[i]);
 136
 137         hash_lock = fio_sem_init(FIO_SEM_UNLOCKED);
 138         file_bloom = bloom_new(BLOOM_SIZE);
 139 }