DIRECTORYDisk USING[ Channel, PageCount, PageNumber ],File USING[ RC, Volume, VolumeFile, VolumeID ],Rope USING[ ROPE ];PhysicalVolume: CEDAR DEFINITIONS =BEGINPhysical: TYPE = REF PhysicalObject;PhysicalObject: TYPE;NextPhysical: PROC[prev: Physical, wait: BOOL _ FALSE] RETURNS[Physical];GetPhysical: PROC[volume: File.Volume, page: LogicalPage _ [0]] RETURNS[ Physical ];PhysicalRC: TYPE = File.RC[ok..hardware];PhysicalInfo: PROC[Physical] RETURNS[channel: Disk.Channel,rootStatus: PhysicalRC,id: File.VolumeID,name: Rope.ROPE,size: Disk.PageCount,free: Disk.PageCount,timeValid: BOOL,time: TimeParameters];TimeParameters: TYPE[2];SetPhysicalRoot: PROC[volume: File.Volume, root: File.VolumeFile];WriteTimeParameters: PROC[physical: Physical, timeValid: BOOL, time: TimeParameters] RETURNS[ PhysicalRC ];Credentials: TYPE = --VM-page-aligned-- LONG POINTER TO CredentialsObject;CredentialsObject: TYPE;ReadCredentials: UNSAFE PROC[physical: Physical, credentials: Credentials] RETURNS[ PhysicalRC ];WriteCredentials: PROC[physical: Physical, credentials: Credentials] RETURNS[ PhysicalRC ];LogicalPage: TYPE = RECORD[INT];LogicalPageCount: TYPE = INT;GetSubVolumes: PROC[physical: PhysicalVolume.Physical] RETURNS[ SubVolumes ];SubVolumes: TYPE = REF SubVolumesObject;SubVolumesObject: TYPE = RECORD[subVolumes: SEQUENCE count: CARDINAL OF SubVolumeDetailsObject];SubVolumeDetails: TYPE = REF READONLY SubVolumeDetailsObject;SubVolumeDetailsObject: TYPE = RECORD[ -- immutable information about the sub-volume --id: File.VolumeID, -- logical volume of which this is a fragment --start: LogicalPage, -- logical page number of this fragment of logical volume --size: LogicalPageCount,physical: Physical,channel: Disk.Channel,address: Disk.PageNumber -- physical page number of this subvolume --];END.   ø  Cedar Nucleus (Files):  management of physical volumesPhysicalVolume.mesaAndrew Birrell  September 20, 1983 2:11 pmThe world consists of online packs, each mounted on a drive.  Each interesting pack contains precisely one physical volume.  Each physical volume contains some number of sub-volumes.  Each sub-volume is a part of some logical volume.  A logical volume consists of its constituent sub-volumes.  Sub-volumes may be added to a physical volume, but once added their layout may not be changed without erasing the entire physical volume.Standard enumerator.  No errors.Returns the physical volume containing the specified page of the logical volume.  No errors.The following results are defined only if rootStatus = okNo errors.Opaque at this level.  Concrete type is only interesting to Time software.! File.Error[wentOffline, nonCedarVolume, inconsistent, software, hardware]Assumes "credentials" is VM-page-aligned and occupies File.wordsPerPage words;  the memory belongs to the caller.  No errors.Assumes "credentials" is VM-page-aligned and occupies File.wordsPerPage words;  the memory belongs to the caller.  No errors.Page number relative to a logical volume! File.Error[wentOffline, nonCedarVolume, inconsistent, software, hardware] Êä  ˜ Jšœ6™6Jšœ™Jšœ*™*J˜ šÏk	˜	Jšœœ#˜-Jšœœœ!˜/Jšœœœ˜—J˜ Jšœœœ˜#J˜ Jš˜J˜ Jšœ¯™¯J˜ Jšœ
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