The deflateBound() function shall estimate the size
of buffer required to compress sourceLen
bytes of data. If successful, the value returned shall be an upper
bound for the size of buffer required to compress
sourceLen bytes of data, using the
parameters stored in stream,
in a single
call to deflate() with flush set to
On entry, stream should have been initialized via a call to deflateInit_() or deflateInit2_().
The deflateBound() shall return a value
representing the upper bound of an array to allocate to hold
the compressed data in a single call to deflate().
If the stream is not correctly initialized,
NULL, then deflateBound()
may return a conservative value that may be larger than