<> <> <> <> DIRECTORY AlpineEnvironment USING[FileID, LockMode, PageCount, VolumeID], AlpineInternal USING[FileHandle, TransHandle], FileInstance, FileMap USING[GetFileID, GetVolumeID, GetVolumeIDAndFileID, Register], TransactionMap USING[GetFileInstanceList, SetFileInstanceList]; FileInstanceImpl: CEDAR MONITOR IMPORTS FileMap, TM: TransactionMap EXPORTS AlpineInternal, FileInstance = BEGIN OPEN AE: AlpineEnvironment, AI: AlpineInternal; Handle: TYPE = REF FileInstanceObject; FileInstanceObject: PUBLIC TYPE = RECORD[ trans: AI.TransHandle, fileHandle: AI.FileHandle, useCount: CARDINAL, deltaVersion: LONG INTEGER, highWaterMark: AE.PageCount, lockMode: AE.LockMode, nextForTrans: Handle]; <> InUse: --CALLING-- ERROR = CODE; OldHandleNotFound: --CALLING-- ERROR = CODE; UseCountAlreadyZero: --CALLING-- ERROR = CODE; <> Register: PUBLIC ENTRY PROCEDURE [trans: AI.TransHandle, volumeID: AE.VolumeID, fileID: AE.FileID] RETURNS [handle: Handle] = BEGIN -- errors defined in FileInstance: none. ENABLE UNWIND => NULL; firstInsHandle: Handle; TRUSTED BEGIN firstInsHandle _ TM.GetFileInstanceList[trans]; END; FOR handle _ firstInsHandle, handle.nextForTrans UNTIL handle = NIL DO IF FileMap.GetVolumeIDAndFileID[handle.fileHandle] = [volumeID, fileID] THEN GOTO found; REPEAT found => handle.useCount _ handle.useCount + 1; FINISHED => BEGIN handle _ NEW[FileInstanceObject _ [trans: trans, fileHandle: FileMap.Register[volumeID, fileID], useCount: 1, deltaVersion: 0, highWaterMark: LAST[AE.PageCount], lockMode: none, nextForTrans: firstInsHandle]]; TRUSTED BEGIN TM.SetFileInstanceList[trans, handle]; END; END; ENDLOOP; END; <> Unregister: PUBLIC ENTRY PROCEDURE [handle: Handle] = BEGIN -- errors defined in FileInstance: none. ENABLE UNWIND => NULL; IF handle.useCount = 0 THEN RETURN WITH ERROR UseCountAlreadyZero; IF (((handle.useCount _ handle.useCount - 1) = 0) AND (handle.deltaVersion = 0)) THEN TRUSTED BEGIN prevInsHandle: Handle _ FindHandle[handle.fileHandle, TM.GetFileInstanceList[handle.trans]]; IF prevInsHandle = NIL THEN TM.SetFileInstanceList[handle.trans, handle.nextForTrans] ELSE prevInsHandle.nextForTrans _ handle.nextForTrans; END; END; <> FlushTransState: PUBLIC ENTRY PROCEDURE [trans: AI.TransHandle] = TRUSTED BEGIN -- errors defined in FileInstance: none. ENABLE UNWIND => NULL; FOR insHandle: Handle _ TM.GetFileInstanceList[trans], insHandle.nextForTrans UNTIL insHandle = NIL DO IF ((insHandle.useCount # 0) OR (insHandle.deltaVersion = 0)) THEN RETURN WITH ERROR InUse; ENDLOOP; TM.SetFileInstanceList[trans, NIL]; END; <> GetFileHandle: PUBLIC PROCEDURE [handle: Handle] RETURNS [fileHandle: AI.FileHandle] = BEGIN -- errors defined in FileInstance: none. RETURN[handle.fileHandle]; END; GetTransHandle: PUBLIC PROCEDURE [handle: Handle] RETURNS [trans: AI.TransHandle] = BEGIN -- errors defined in FileInstance: none. RETURN[handle.trans]; END; GetVolumeID: PUBLIC PROCEDURE [handle: Handle] RETURNS [volumeID: AE.VolumeID] = BEGIN -- errors defined in FileInstance: none. RETURN[FileMap.GetVolumeID[handle.fileHandle]]; END; GetFileID: PUBLIC PROCEDURE [handle: Handle] RETURNS [fileID: AE.FileID] = BEGIN -- errors defined in FileInstance: none. RETURN[FileMap.GetFileID[handle.fileHandle]]; END; GetVolumeIDAndFileID: PUBLIC PROCEDURE [handle: Handle] RETURNS [volumeID: AE.VolumeID, fileID: AE.FileID] = BEGIN -- errors defined in FileInstance: none. [volumeID, fileID] _ FileMap.GetVolumeIDAndFileID[handle.fileHandle]; END; <> GetDeltaVersion: PUBLIC ENTRY PROCEDURE [handle: Handle] RETURNS [delta: LONG INTEGER] = BEGIN -- errors defined in FileInstance: none. ENABLE UNWIND => NULL; RETURN[handle.deltaVersion]; END; <> SetMaxDeltaVersion: PUBLIC ENTRY PROCEDURE [handle: Handle, increment: LONG INTEGER] = BEGIN -- errors defined in FileInstance: none. ENABLE UNWIND => NULL; handle.deltaVersion _ MAX[handle.deltaVersion, increment]; END; <> GetHighWaterMark: PUBLIC ENTRY PROCEDURE [handle: Handle] RETURNS [highWaterMark: AE.PageCount] = BEGIN -- errors defined in FileInstance: none. ENABLE UNWIND => NULL; RETURN[handle.highWaterMark]; END; SetHighWaterMark: PUBLIC ENTRY PROCEDURE [handle: Handle, highWaterMark: AE.PageCount] RETURNS [oldHighWaterMark: AE.PageCount] = BEGIN -- errors defined in FileInstance: none. ENABLE UNWIND => NULL; oldHighWaterMark _ handle.highWaterMark; handle.highWaterMark _ highWaterMark; END; GetLockMode: PUBLIC ENTRY PROCEDURE [handle: Handle] RETURNS [lock: AE.LockMode] = BEGIN -- errors defined in FileInstance: none. ENABLE UNWIND => NULL; RETURN[handle.lockMode]; END; SetLockMode: PUBLIC ENTRY PROCEDURE [handle: Handle, lock: AE.LockMode] = BEGIN -- errors defined in FileInstance: none. ENABLE UNWIND => NULL; handle.lockMode _ lock; END; <> <> <> <> GetNextHandleForTrans: PUBLIC ENTRY PROCEDURE [trans: AI.TransHandle, handle: Handle] RETURNS [nextHandle: Handle] = BEGIN -- errors defined in FileInstance: none. ENABLE UNWIND => NULL; firstInsHandle: Handle; TRUSTED BEGIN firstInsHandle _ TM.GetFileInstanceList[trans]; END; IF handle = NIL THEN RETURN[firstInsHandle]; [] _ FindHandle[handle.fileHandle, firstInsHandle]; RETURN[handle.nextForTrans]; END; FindHandle: INTERNAL PROCEDURE [fileHandle: AI.FileHandle, firstInsHandle: Handle] RETURNS [prevHandle: Handle] = BEGIN -- errors defined in FileInstance: none. volumeID: AE.VolumeID; fileID: AE.FileID; [volumeID, fileID] _ FileMap.GetVolumeIDAndFileID[fileHandle]; prevHandle _ NIL; FOR foundHandle: Handle _ firstInsHandle, foundHandle.nextForTrans UNTIL foundHandle = NIL DO IF FileMap.GetVolumeIDAndFileID[foundHandle.fileHandle] = [volumeID, fileID] THEN EXIT; prevHandle _ foundHandle; REPEAT FINISHED => ERROR OldHandleNotFound; ENDLOOP; END; <

> END. Edit Log Initial: Kolling: October 21, 1982 2:22 pm: an impl module for FileInstance. <> <> <<>>