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      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_mutex *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_mutex_down(hash_lock);
     31 }
     32 
     33 void fio_file_hash_unlock(void)
     34 {
     35 	if (hash_lock)
     36 		fio_mutex_up(hash_lock);
     37 }
     38 
     39 void remove_file_hash(struct fio_file *f)
     40 {
     41 	fio_mutex_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_mutex_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_mutex_down(hash_lock);
     77 	f = __lookup_file_hash(name);
     78 	fio_mutex_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_mutex_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_mutex_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_mutex_down(hash_lock);
    113 	for (i = 0; i < HASH_BUCKETS; i++)
    114 		has_entries += !flist_empty(&file_hash[i]);
    115 	fio_mutex_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_mutex_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_mutex_init(FIO_MUTEX_UNLOCKED);
    138 	file_bloom = bloom_new(BLOOM_SIZE);
    139 }
    140