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                         return f;
  65         }
  66
  67         return NULL;
  68 }
  69
  70 struct fio_file *lookup_file_hash(const char *name)
  71 {
  72         struct fio_file *f;
  73
  74         fio_sem_down(hash_lock);
  75         f = __lookup_file_hash(name);
  76         fio_sem_up(hash_lock);
  77         return f;
  78 }
  79
  80 struct fio_file *add_file_hash(struct fio_file *f)
  81 {
  82         struct fio_file *alias;
  83
  84         if (fio_file_hashed(f))
  85                 return NULL;
  86
  87         INIT_FLIST_HEAD(&f->hash_list);
  88
  89         fio_sem_down(hash_lock);
  90
  91         alias = __lookup_file_hash(f->file_name);
  92         if (!alias) {
  93                 fio_file_set_hashed(f);
  94                 flist_add_tail(&f->hash_list, &file_hash[hash(f->file_name)]);
  95         }
  96
  97         fio_sem_up(hash_lock);
  98         return alias;
  99 }
 100
 101 bool file_bloom_exists(const char *fname, bool set)
 102 {
 103         return bloom_string(file_bloom, fname, strlen(fname), set);
 104 }
 105
 106 void file_hash_exit(void)
 107 {
 108         unsigned int i, has_entries = 0;
 109
 110         fio_sem_down(hash_lock);
 111         for (i = 0; i < HASH_BUCKETS; i++)
 112                 has_entries += !flist_empty(&file_hash[i]);
 113         fio_sem_up(hash_lock);
 114
 115         if (has_entries)
 116                 log_err("fio: file hash not empty on exit\n");
 117
 118         sfree(file_hash);
 119         file_hash = NULL;
 120         fio_sem_remove(hash_lock);
 121         hash_lock = NULL;
 122         bloom_free(file_bloom);
 123         file_bloom = NULL;
 124 }
 125
 126 void file_hash_init(void)
 127 {
 128         unsigned int i;
 129
 130         file_hash = smalloc(file_hash_size);
 131
 132         for (i = 0; i < HASH_BUCKETS; i++)
 133                 INIT_FLIST_HEAD(&file_hash[i]);
 134
 135         hash_lock = fio_sem_init(FIO_SEM_UNLOCKED);
 136         file_bloom = bloom_new(BLOOM_SIZE);
 137 }