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Sourcecode: fio version File versions

filehash.c

#include <stdlib.h>
#include <assert.h>

#include "fio.h"
#include "flist.h"
#include "crc/crc16.h"

#define HASH_BUCKETS    512
#define HASH_MASK (HASH_BUCKETS - 1)

unsigned int file_hash_size = HASH_BUCKETS * sizeof(struct flist_head);

static struct flist_head *file_hash;
static struct fio_mutex *hash_lock;

static unsigned short hash(const char *name)
{
      return crc16((const unsigned char *) name, strlen(name)) & HASH_MASK;
}

void remove_file_hash(struct fio_file *f)
{
      fio_mutex_down(hash_lock);

      if (fio_file_hashed(f)) {
            assert(!flist_empty(&f->hash_list));
            flist_del_init(&f->hash_list);
            fio_file_clear_hashed(f);
      }

      fio_mutex_up(hash_lock);
}

static struct fio_file *__lookup_file_hash(const char *name)
{
      struct flist_head *bucket = &file_hash[hash(name)];
      struct flist_head *n;

      flist_for_each(n, bucket) {
            struct fio_file *f = flist_entry(n, struct fio_file, hash_list);

            if (!f->file_name)
                  continue;

            if (!strcmp(f->file_name, name)) {
                  assert(f->fd != -1);
                  return f;
            }
      }

      return NULL;
}

struct fio_file *lookup_file_hash(const char *name)
{
      struct fio_file *f;

      fio_mutex_down(hash_lock);
      f = __lookup_file_hash(name);
      fio_mutex_up(hash_lock);
      return f;
}

struct fio_file *add_file_hash(struct fio_file *f)
{
      struct fio_file *alias;

      if (fio_file_hashed(f))
            return NULL;

      INIT_FLIST_HEAD(&f->hash_list);

      fio_mutex_down(hash_lock);

      alias = __lookup_file_hash(f->file_name);
      if (!alias) {
            fio_file_set_hashed(f);
            flist_add_tail(&f->hash_list, &file_hash[hash(f->file_name)]);
      }

      fio_mutex_up(hash_lock);
      return alias;
}

void file_hash_exit(void)
{
      unsigned int i, has_entries = 0;

      fio_mutex_down(hash_lock);
      for (i = 0; i < HASH_BUCKETS; i++)
            has_entries += !flist_empty(&file_hash[i]);
      fio_mutex_up(hash_lock);

      if (has_entries)
            log_err("fio: file hash not empty on exit\n");

      file_hash = NULL;
      fio_mutex_remove(hash_lock);
      hash_lock = NULL;
}

void file_hash_init(void *ptr)
{
      unsigned int i;

      file_hash = ptr;
      for (i = 0; i < HASH_BUCKETS; i++)
            INIT_FLIST_HEAD(&file_hash[i]);

      hash_lock = fio_mutex_init(1);
}

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