Availability:C-language interface function
void * PL_blob_data(atom_t
a, size_t *len, PL_blob_t **type)Get the data and type associated to a blob. This function is mainly used
from the callback functions described in section
12.4.10.1. Note that if the release()
hook is called from PL_cleanup(),
blobs are released regardless of whether or not they are referenced and
the order in which blobs are released is undefined (the order depends on
the ordering in the atom hash table). PL_blob_data()
may be called safely on a blob that has already been released. If this
happens during PL_cleanup()
the return value is guaranteed to be NULL. During normal
execution it may return the content of a newly allocated blob that
reuses the released handle.
