GetHandleSize
returns the size of the data area (a 32-bit value)
GetHandleSize returns the size, in bytes of a relocatable block of memory. theHandle is a Handle, leading to a relocatable block of memory. Returns: the size of the data led to by a Handle (a 32-bit long), 0 may indicate an error occurred. The MemError function may return an noErr (0) No error
nilHandleErr (-109) Illegal operation on empty handle
memWZErr (-111) Illegal operation on a free block
Notes: You can use GetHandleSize to determine the size of objects (such as pictures) that may exceed the 64K or 32K maximum value of their
historically- defined size.
The returned value is the size of the allocated area available for data
storage. The actual memory used by a Handle includes a block header and up to 12 bytes of filler.