common/utils/human-size.h

   1 /* nbd client library in userspace
   2  * Copyright Red Hat
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  17  */
  18
  19 #ifndef LIBNBD_HUMAN_SIZE_H
  20 #define LIBNBD_HUMAN_SIZE_H
  21
  22 #include <stdbool.h>
  23 #include <stdint.h>
  24
  25 /* If you allocate a buffer of at least this length in bytes and pass
  26  * it as the first parameter to human_size, then it will not overrun.
  27  */
  28 #define HUMAN_SIZE_LONGEST 64
  29
  30 /* Convert bytes to a human-readable string.
  31  *
  32  * This is roughly the opposite of nbdkit_parse_size.  It will convert
  33  * multiples of powers of 1024 to the appropriate human size with the
  34  * right extension like 'M' or 'G'.  Anything that cannot be converted
  35  * is returned as bytes.  The *human flag is set to true if the output
  36  * was abbreviated to a human-readable size, or false if it is just
  37  * bytes.
  38  *
  39  * If buf == NULL, a buffer is allocated and returned.  In this case
  40  * the returned buffer must be freed.
  41  *
  42  * buf may also be allocated by the caller, in which case it must be
  43  * at least HUMAN_SIZE_LONGEST bytes.
  44  *
  45  * On error the function returns an error and sets errno.
  46  */
  47 extern char *human_size (char *buf, uint64_t bytes, bool *human);
  48
  49 #endif /* LIBNBD_HUMAN_SIZE_H */