H5F_GET_MDC_SIZE queries the metadata cache of the target file for the desired size information, and returns this information in the locations indicated by the pointer parameters. If any pointer parameter is NULL, the associated data is not returned.
If the API call fails, the values returned via the pointer parameters are undefined.
If adaptive cache resizing is enabled, the cache maximum size and minimum clean size may change at the end of each epoch. Current size and current number of entries can change on each cache access.
Current size can exceed maximum size under certain conditions. See the overview of the metadata cache in the special topics section of the user manual for a discussion of this.