;;; -*- Mode: LISP;  Package: FS;  Base: 8 -*-
;;;	** (c) Copyright 1981 Massachusetts Institute of Technology **
;;; Chaosnet FILE JOB peek functions

(DECLARE-FLAVOR-INSTANCE-VARIABLES (FILE-HOST-MIXIN)
(DEFUN FILE-HOST-PEEK-FILE-SYSTEM (IGNORE)
  (TV:SCROLL-MAINTAIN-LIST
    `(LAMBDA () ',HOST-UNITS)
    #'PEEK-FILE-SYSTEM-HOST-UNIT)))

(DEFUN PEEK-FILE-SYSTEM-HOST-UNIT (UNIT &OPTIONAL (INDENT 2))
  "Generate a scroll item describing a host unit"
  (LIST ()
    (TV:SCROLL-PARSE-ITEM (FORMAT NIL "~VXHost unit ~A, control connection in " INDENT UNIT)
			  `(:FUNCTION ,#'(LAMBDA (UNIT)
					   (LET ((CONN (HOST-UNIT-CONTROL-CONNECTION UNIT)))
					     (IF CONN (GET-PNAME (CHAOS:STATE CONN))
						 "NONEXISTANT-STATE")))
				      (,UNIT)))
    (TV:SCROLL-MAINTAIN-LIST `(LAMBDA () (PEEK-FILE-SYSTEM-HOST-UNIT-NEXT-STREAM
					   (NCONS (HOST-UNIT-DATA-CONNECTIONS ',UNIT)) T))
			     `(LAMBDA (STREAM)
				(FUNCALL STREAM ':PEEK-FILE-SYSTEM (+ 2 ,INDENT)))
			     NIL
			     #'(LAMBDA (STATE &AUX NS STREAM)
				 (MULTIPLE-VALUE (NS STREAM)
				   (PEEK-FILE-SYSTEM-HOST-UNIT-NEXT-STREAM STATE))
				 (VALUES STREAM NS
					 (NULL (PEEK-FILE-SYSTEM-HOST-UNIT-NEXT-STREAM
						 NS T)))))))

(DEFUN PEEK-FILE-SYSTEM-HOST-UNIT-NEXT-STREAM (STATE &OPTIONAL DONT-STEP &AUX STREAM FLAG NS)
  "Returns new state and next stream.  If DONT-STEP is specified, returns the current
state if there is a stream available, else NIL"
  (SETQ FLAG (CDR STATE))
  (DO ((S (CAR STATE) (CDR S)))
      ((NULL S) (SETQ NS NIL))
    (SETQ NS S)
    (AND (NULL FLAG) (SETQ STREAM (DATA-STREAM (CAR S) ':INPUT))
	 (NEQ STREAM T) (RETURN (SETQ FLAG T)))
    (SETQ FLAG NIL)
    (AND (SETQ STREAM (DATA-STREAM (CAR S) ':OUTPUT))
	 (NEQ STREAM T) (RETURN (SETQ NS (CDR NS)))))
  (AND (NOT (SYMBOLP STREAM))
       (VALUES (IF DONT-STEP
		   STATE
		   (RPLACA STATE NS)
		   (RPLACD STATE FLAG))
	       STREAM)))