// TfsCreate.bcpl -- procedures to create and delete files // Copyright Xerox Corporation 1979 // Last modified November 8, 1979 6:28 PM by Taft get "Altofilesys.d" get "Disks.d" get "Tfs.d" external [ //outgoing procedures TFSCreateFile TFSDeletePages TFSReleaseDiskPage //incoming procedures ActOnDiskPages WriteDiskPages DeleteDiskPages ReleaseDiskPage TFSIncrement ReadDDPage LockDD UnlockDD MoveBlock SetBlock Zero DefaultArgs ReadCalendar Dvec // statics defined elsewhere freePageFp oneBits ] //---------------------------------------------------------------------------- let TFSCreateFile(disk, name, filePtr, dirFp, word1, useOldFp, pageBuf; numargs na) be //---------------------------------------------------------------------------- // See CreateDiskFile description in BFS section of O.S. manual. // Create a file by writing a leader page and page 1. // If useOldFp, there was an existing file; re-use it, but change the FP. // If pageBuf supplied, it is used as a page buffer and the initial contents // of the last 3/4 of the page are written onto the leader page. [ DefaultArgs(lv na, -3, 0, 0, false, 0) if pageBuf eq 0 then [ pageBuf = TFSwordsPerPage; Dvec(TFSCreateFile, lv pageBuf) ] let oldFp = vec lFP MoveBlock(oldFp, filePtr, lFP) // Generate a new FP: Zero(filePtr, lFP) filePtr>>FP.version = 1 TFSIncrement(lv disk>>TFSDSK.lastSn) MoveBlock(lv filePtr>>FP.serialNumber, lv disk>>TFSDSK.lastSn, lSN) filePtr>>FP.serialNumber.word1 = filePtr>>FP.serialNumber.word1 % word1 let DAs = vec 4 MoveBlock(DAs, table [ eofDA; fillInDA; fillInDA; eofDA ], 4) DAs = DAs+1 // If there was an existing file, "rename" it: if useOldFp then [ let da = oldFp>>FP.leaderVirtualDa DeleteDiskPages(disk, pageBuf, da, oldFp, 0, filePtr) DAs!0 = da ] // Set up the leader page Zero(pageBuf, 256) ReadCalendar(lv pageBuf>>LD.created) MoveBlock(lv pageBuf>>LD.name, name, size LD.name/16) if dirFp ne 0 then MoveBlock(lv pageBuf>>LD.dirFp, dirFp, lFP) pageBuf>>LD.propertyBegin = offset LD.leaderProps/16 pageBuf>>LD.propertyLength = size LD.leaderProps/16 // Actually write out the leader page and the first data page (useOldFp? ActOnDiskPages, WriteDiskPages)(disk, 0, DAs, filePtr, 0, 1, DCwriteD, 0, 0, pageBuf) filePtr>>FP.leaderVirtualDa = DAs!0 ] //---------------------------------------------------------------------------- and TFSDeletePages(disk, CA, firstDA, fp, firstPage, newFp, hintLastPage; numargs na) be //---------------------------------------------------------------------------- // See DeleteDiskPages description in BFS section of O.S. manual. // Delete pages starting at firstDA and continuing to the end of // the file. CA is a page-size buffer which is clobbered. // Optional 6th argument is the "new" FP to install (used by TFSCreateFile). [ DefaultArgs(lv na, -5, freePageFp, 0) manifest biteSize = 100 while firstDA ne eofDA do [ let DAs = vec biteSize+1 SetBlock(DAs, fillInDA, biteSize+2) // Reason for extra 1 is that DAs!(firstpage-1) is referenced by // the default cleanup routine. DAs = DAs+1-firstPage DAs!firstPage = firstDA // Collect disk addresses of pages in file let lastNumChars = nil let lastPageFound = ActOnDiskPages(disk, 0, DAs, fp, firstPage, firstPage+biteSize-1, DCreadnD, lv lastNumChars, 0, CA, 0, 0, 0, hintLastPage) // Write newFp in all the labels. // The data must be zeroed in the case that we are 'renaming' // an existing file. Zero(CA, TFSwordsPerPage) WriteDiskPages(disk, 0, DAs, newFp, firstPage, lastPageFound, -1, 0, lastNumChars, CA) // If deleting (rather than renaming), mark pages free in bit table if newFp eq freePageFp then for i = firstPage to lastPageFound do ReleaseDiskPage(disk, DAs!i) firstPage = lastPageFound+1 firstDA = DAs!firstPage ] ] //---------------------------------------------------------------------------- and TFSReleaseDiskPage(disk, vda) be //---------------------------------------------------------------------------- // See ReleaseDiskPage description in BFS section of O.S. manual. [ let ddMgr = disk>>TFSDSK.ddMgr LockDD(ddMgr, disk) // Make sure appropriate BT page is in mem let buf = ReadDDPage(ddMgr, disk, vda<>TFSDSK.freePages = disk>>TFSDSK.freePages+1 ] ifnot TFSIncrement(lv disk>>TFSDSK.nBTErrors) // Note dirty BT UnlockDD(ddMgr, disk, true) ]