29     int tail;     /* where to put next byte into buf */  member
89     mb->tail = 0;  in memio_buffer_new()
100     mb->tail = 0;  in memio_buffer_destroy()
106     return (((mb->tail >= mb->head) ? mb->tail : mb->bufsize) - mb->head);  in memio_buffer_used_contiguous()
112     return (mb->tail >= mb->head) ? 0 : mb->tail;  in memio_buffer_wrapped_bytes()
118     if (mb->head > mb->tail) return mb->head - mb->tail - 1;  in memio_buffer_unused_contiguous()
119     return mb->bufsize - mb->tail - (mb->head == 0);  in memio_buffer_unused_contiguous()
132         memcpy(&mb->buf[mb->tail], buf, len);  in memio_buffer_put()
133         mb->tail += len;  in memio_buffer_put()
134         if (mb->tail == mb->bufsize)  in memio_buffer_put()
135             mb->tail = 0;  in memio_buffer_put()
144             memcpy(&mb->buf[mb->tail], buf, len);  in memio_buffer_put()
145             mb->tail += len;  in memio_buffer_put()
146             if (mb->tail == mb->bufsize)  in memio_buffer_put()
147                 mb->tail = 0;  in memio_buffer_put()
390     *buf = &mb->buf[mb->tail];  in memio_GetReadParams()
400         mb->tail += bytes_read;  in memio_PutReadResult()
401         if (mb->tail == mb->bufsize)  in memio_PutReadResult()
402             mb->tail = 0;  in memio_PutReadResult()