(FILECREATED " 4-Jul-85 18:31:16" {ERIS}<LISPCORE>LOCALFILE>SCAVENGEDSKDIRECTORY.;1
 6523   

      changes to:  (VARS SCAVENGEDSKDIRECTORYCOMS)
		   (FNS SCAVENGEVOLUME)

      previous date: " 4-Mar-85 17:28:56" {DSK}SCAVENGEDSKDIRECTORY.;1)


(* Copyright (c) 1985 by Xerox Corporation. All rights reserved.)

(PRETTYCOMPRINT SCAVENGEDSKDIRECTORYCOMS)

(RPAQQ SCAVENGEDSKDIRECTORYCOMS
 ((DECLARE: EVAL@COMPILE DONTCOPY (FILES (LOADCOMP)
									LFDIRECTORY LFFILEMAP)
					   (FILES DECL))
				 (DECLARE: (LOCALVARS . T)
					   (IGNOREDECL))
				 (* * Directory (LFDIRECTORY)
				    level stuff)
				 (FNS SCAVENGEDSKDIRECTORY SCAVENGEVOLUME \LFScavFileName 
				      \LFScavVersion)
				 (GLOBALVARS \LFtopMonitor)
				 (* * Volume file map (LFFILEMAP)
				    level stuff)
				 (FNS \VFMGenerateFileIDs)))
(DECLARE: EVAL@COMPILE DONTCOPY 
(FILESLOAD (LOADCOMP)
	   LFDIRECTORY LFFILEMAP)

(FILESLOAD DECL)
)
(DECLARE: 
(DECLARE: DOEVAL@COMPILE DONTCOPY

(LOCALVARS . T)
)

(DECLARE: DOEVAL@COMPILE DONTEVAL@LOAD DONTCOPY 
(RESETSAVE COMPILEIGNOREDECL (QUOTE NIL))
)
)
(* * Directory (LFDIRECTORY) level stuff)


(DEFINEQ

(SCAVENGEDSKDIRECTORY

  [DLAMBDA ((volName (ONEOF ATOM STRINGP))
            (RETURNS (ONEOF NIL STRINGP)))
                                                             (* hts: " 4-Mar-85 17:26")


          (* If your BTree is intact but your directory is smashed, this routine will scavenge your volume by building a new 

	  directory which associates all fileIDs in the BTree with a gensym filename)



    [WITH.MONITOR \LFtopMonitor
		  (
PROG
 ((vol (
\LFEntryPoint
 volName))
			 DIRECTORY LISPDIRECTORY LISPFILES)
		        (if
 (
NOT
 (
\PFPilotVolumeP
 vol))
			    then
 (
ERROR
 "Non-pilot volume"))

          (* * Find the file ID's of the Lisp directory and all the Lisp files on the specified volume.)



		        (
SETQ
 LISPDIRECTORY (\VFMGenerateFileIDs
 vol tLispDirectory))
		        (
SETQ
 LISPFILES (\VFMGenerateFileIDs
 vol tLispFile))

          (* * If there are no Lisp files of any sort on the volume, abort)



		        (if
 (
AND
 (
NULL
 LISPDIRECTORY)
				 (
NULL
 LISPFILES))
			    then
 (
RETURN
 NIL))

          (* * This block throws away the old directory and builds a new one. It must be atomic.)



		        (UNINTERRUPTABLY

          (* * If there is an old directory, get rid of it.)



			    (
\LFPurgeDirectory
 vol)

          (* * Create a fresh directory)



			    (
\LFMakeVolumeDirectory
 vol)

          (* * For each file in volume file map, enter this fileID into the new directory)



			    [for
 fileID in
 LISPFILES
			       do
 (
PROG
 ((stream (
\LFOpenOldFile
 (create
 FileDescriptor
									 fileID ← fileID
									 volNum ←(
\PFVolumeNumber

									   vol)
									 type ← tLispFile)
								 NIL NIL))
					 NAME&VERSION)
				        (
SETQ
 NAME&VERSION (fetch
 (LeaderPage fileName)
							      of
 (fetch
 (DLIONSTREAM LEADERPAGE)
								    of
 stream)))
				        (
\LFMakeDirEntry
 stream (create
 ExpandedName
									VOLNUM ←(
\PFVolumeNumber

									  vol)
									CHARLIST ←(\LFScavFileName

									  NAME&VERSION)
									VERSION ←(\LFScavVersion

									  NAME&VERSION fileID))
							 (
\LFGetDirectory
 vol])

          (* * Return the name of the new directory)



		        (
RETURN
 (
PACKFILENAME.STRING
 (
QUOTE
 HOST)
						     (
QUOTE
 DSK)
						     (
QUOTE
 DIRECTORY)
						     (
U-CASE
 (fetch
 (LogicalVolumeDescriptor LVlabel)
								of
 vol]])

(SCAVENGEVOLUME

  [LAMBDA (volName)                                          (* hts: " 4-Jul-85 18:30")


          (* * for backward compatibility)



    (SCAVENGEDSKDIRECTORY
 volName])

(\LFScavFileName

  [DLAMBDA ((NAME&VERSION (ONEOF ATOM STRINGP))
            (RETURNS (
LISTP
 OF SMALLP)))
                                                             (* mjs "28-Feb-85 20:15")


          (* * Extract the filename part of NAME&VERSION (ignore version number) and return it as a list of charcode)



    (
PROG
 ((NAME (for
 C instring
 (
MKSTRING
 NAME&VERSION) until
 (
EQ
 C (
CHARCODE
 ;)) collect
 C)))
          (
RETURN
 (if
 (
OR
 (
NULL
 NAME)
			  (for
 C in
 NAME thereis
 (
EQ
 (
\LFCASEARRAYFETCH
 C)
						     0)))
		      then
 

          (* * If there is an illegal char in the filename, or the filename is the empty string, gin up a random filename)



			   (
CHCON
 (
GENSYM
 (
QUOTE
 TRASHEDFILENAME)))
		    else
 

          (* * Otherwise return the filename found)



			 NAME)))])

(\LFScavVersion

  [DLAMBDA ((NAME&VERSION (ONEOF ATOM STRINGP))
            (FILEID FIXP)
            (RETURNS SMALLP))
                                                             (* hts: " 4-Mar-85 17:27")


          (* * Fetch the version number from NAME&VERSION. If it's garbled (ie, isn't a fixp) use the fileID as a version 

	  number instead (the fileID will at least give the file a unique version number and so avoid version number clashes))



    (
OR
 (
SMALLP
 (
FILENAMEFIELD
 NAME&VERSION (
QUOTE
 VERSION)))
	(
SMALLP
 FILEID)
	(
RAND
 1 MAX.SMALLP))])
)
(DECLARE: DOEVAL@COMPILE DONTCOPY

(GLOBALVARS \LFtopMonitor)
)
(* * Volume file map (LFFILEMAP) level stuff)


(DEFINEQ

(\VFMGenerateFileIDs

  [DLAMBDA ((vol LogicalVolumeDescriptor)
            (desiredType SMALLP)
            (RETURNS (LST OF FIXP)))
                                                             (* hts: "16-Feb-85 21:40")


          (* * Returns a list of the fileIDs of all the keys in the BTree with type = desiredType)



    [WITH.MONITOR \VFMmonitor (UNINTERRUPTABLY
                                  (
\VFMContextSet
 vol)
				  (bind
 (currentKey ←(create
 Key))
				     until
 (
PROGN
 (replace
 (Key filePage) of
 currentKey with
 MAX.FIXP)
						  (MESASETQ currentKey (fetch
 (Interval nextKey)
									  of
 (
\VFMGet
 currentKey 0))
							    Key)
						  (
EQP
 (fetch
 (Key fileID) of
 currentKey)
						       \VFMmaxID))
				     when
 (
EQ
 (fetch
 (Key type) of
 currentKey)
					      desiredType)
				     collect
 (fetch
 (Key fileID) of
 currentKey)))]])
)
(PUTPROPS SCAVENGEDSKDIRECTORY COPYRIGHT ("Xerox Corporation" 1985))
(DECLARE: DONTCOPY
  (FILEMAP (NIL (1133 5355 (SCAVENGEDSKDIRECTORY 1143 . 3653) (SCAVENGEVOLUME 3655 . 3856) (
\LFScavFileName 3858 . 4755) (\LFScavVersion 4757 . 5353)) (5472 6432 (\VFMGenerateFileIDs 5482 . 6430
)))))
STOP