int xdl_emit_diffrec(char const *rec, long size, char const *pre, long psize,
xdemitcb_t *ecb);
int xdl_cha_init(chastore_t *cha, long isize, long icount);
int xdl_emit_diffrec(char const *rec, long size, char const *pre, long psize,
xdemitcb_t *ecb);
int xdl_cha_init(chastore_t *cha, long isize, long icount);