-- AccessControlFile.mesa
 -- Last edited by
 -- Kolling on May 27, 1983 4:22 pm

DIRECTORY

      AccessControlPrivate
         USING[PntrDataRec, PntrHeaderRec, RecNumber],
      AlpineEnvironment
         USING[LockMode, OpenFileID, OwnerName, PageCount, PageRun, ReferencePattern,
            TransID, UniversalFile];


AccessControlFile: CEDAR DEFINITIONS =

BEGIN


RecNumber: TYPE = AccessControlPrivate.RecNumber; -- we really own the def of this, but it has to live in AccessControlPrivate to 
avoid circularity.

FirstDataRecNum: RecNumber;
PagesPerRec: CARDINAL;
WordsPerRec: CARDINAL;

LockConflict: ERROR [lockItem: LockItem];  -- signalled by various read routines.
LockItem: TYPE = RECORD[
   mode: AlpineEnvironment.LockMode,
   whatToLock: SELECT what: {file, pageRun} FROM
                     file => [transID: AlpineEnvironment.TransID, universalFile:
                                 AlpineEnvironment.UniversalFile,
                                 refPattern: AlpineEnvironment.ReferencePattern],
                     pageRun => [openFileID: AlpineEnvironment.OpenFileID, pageRun:
                                 AlpineEnvironment.PageRun],
                     ENDCASE];


--- read the header record.

ReadHeaderRec: PROCEDURE[ownerOpenFileID: AlpineEnvironment.OpenFileID,
 recLockMode: AlpineEnvironment.LockMode, pntrHeaderRec:
 AccessControlPrivate.PntrHeaderRec];
  -- non system-fatal errors: ACF.LockConflict, AC.Unknown[openFileID, transID].

-- read an owner record, given an owner name.

ReadDataRec: PROCEDURE[ownerOpenFileID: AlpineEnvironment.OpenFileID, ownerName:
 AlpineEnvironment.OwnerName, desiredState: WantOwnerOrEmpty, recLockMode:
 AlpineEnvironment.LockMode,  pntrDataRec: AccessControlPrivate.PntrDataRec,
 lastDataRecNum: RecNumber] RETURNS [dataRecNum: RecNumber, reclaimedRec: BOOLEAN];
  -- non system-fatal errors: ACF.LockConflict, AC.OperationFailed[duplicateOwner, ownerDatabaseFull], AC.StaticallyInvalid 
(badLengthName), AC.Unknown[openFileID, owner, transID].
  WantOwnerOrEmpty: TYPE = {wantEmpty, wantOwner};


-- read an owner record, given a logical record number.
--    (Used at phase one (write mode) and enumeration (read mode).)

ReadDataRecViaRecNum: PROCEDURE[ownerOpenFileID: AlpineEnvironment.OpenFileID,
 dataRecNum: RecNumber, recLockMode: AlpineEnvironment.LockMode, pntrDataRec:
 AccessControlPrivate.PntrDataRec, lastDataRecNum: RecNumber];
  -- non system-fatal errors: OutOfRecNumRange, ACF.LockConflict, AC.Unknown[openFileID, transID].
    OutOfRecNumRange: ERROR;



-- unlock a data record.

UnlockDataRecViaRecNum: PROCEDURE[ownerOpenFileID: AlpineEnvironment.OpenFileID,
 dataRecNum: RecNumber, lastDataRecNum: RecNumber];
  -- non system-fatal errors: non system-fatal errors: OutOfRecNumRange, AC.Unknown[openFileID, transID].


-- lock a file or a page run.

LockFileOrPageRun: PROCEDURE[lockItem: LockItem];
  -- non system-fatal errors: AC.LockFailed[timeout], AC.Unknown[transID].



-- write the header record.

WriteHeaderRec: PROCEDURE[ownerOpenFileID: AlpineEnvironment.OpenFileID,
 pntrHeaderRec: AccessControlPrivate.PntrHeaderRec];
  -- non system-fatal errors: AC.Unknown[openFileID, transID].


-- write an owner record.

WriteDataRec: PROCEDURE[ownerOpenFileID: AlpineEnvironment.OpenFileID,
 dataRecNum: RecNumber, pntrDataRec: AccessControlPrivate.PntrDataRec];
  -- non system-fatal errors: AC.Unknown[openFileID, transID].



-- given a logical record number, return the "next" logical record number.

GetNextDataRecNumber: PROCEDURE[prevDataRecNum, lastDataRecNum: RecNumber,
 whatToDo: StopOrWrap, wrapDataRecNumber: RecNumber] RETURNS [nextDataRecNum:
 RecNumber];
  -- non system-fatal errors: non system-fatal errors: ACF.Stopped, ACF.Wrapped.
   StopOrWrap: TYPE = {stopOnEof, wrapOnEof};
   Stopped: ERROR;
   Wrapped: ERROR;



-- for use only by the "heavies" like InitAndRegisterVolumeGroup or ReorganizeVolumeGroup; not needed by normal routines.

ComputeLastDataRecNumberFromFileLength: PROCEDURE [length:
 AlpineEnvironment.PageCount] RETURNS [lastDataRecNum: RecNumber];
  -- non system-fatal errors: none.


LengthToSetOwnerFile: PROCEDURE[totalEntries: CARDINAL] RETURNS [length:
 AlpineEnvironment.PageCount];
  -- non system-fatal errors: none.



StartAccessControlFile: PROCEDURE;



END.

                    Edit Log

Initial: Kolling: 29-Oct-81 13:21:18: defs file private to AccessControl; interface to the owner files.