DIRECTORYDBCommon USING[CacheHandle, TID],DBStorage USING[TupleHandle, FieldHandle],DBStoragePage USING[TupleBody];DBStorageGroup: CEDAR DEFINITIONS = BEGIN OPEN DBCommon;TIDFieldBody: TYPE = MACHINE DEPENDENT RECORD[headTID: TID,prevTID: TID,nextTID: TID];--TIDFieldBodyTIDFieldPart: TYPE = {headTID, prevTID, nextTID};GroupList: TYPE = ARRAY [0..0) OF GroupListEntry;GroupListEntry: TYPE = MACHINE DEPENDENT RECORD[groupID: TID,firstTID: TID,lastTID: TID];--GroupListEntryHeadFieldPart: TYPE = {firstTID, lastTID};GroupListFromTuple: PROC[DBStorage.TupleHandle] RETURNS[LONG DESCRIPTOR FOR GroupList, DBCommon.CacheHandle];ReadGroupField: PROC[ x: DBStorage.TupleHandle, f: DBStorage.FieldHandle, part: TIDFieldPart] RETURNS[DBStorage.TupleHandle];WriteGroupField: PROC[ x: DBStorage.TupleHandle, f: DBStorage.FieldHandle, part: TIDFieldPart, val: DBStorage.TupleHandle];ReadHeadField: PROC[ x: DBStorage.TupleHandle, f: DBStorage.FieldHandle, part: HeadFieldPart] RETURNS[DBStorage.TupleHandle];WriteHeadField: PROC[ x: DBStorage.TupleHandle, f: DBStorage.FieldHandle, part: HeadFieldPart, val: DBStorage.TupleHandle];CreateHeadEntry: PROC[x: DBStorage.TupleHandle, f: DBStorage.FieldHandle];DestroyHeadEntry: PROC[x: DBStorage.TupleHandle, f: DBStorage.FieldHandle];GroupListFromTupleBase: PROC[LONG POINTER TO DBStoragePage.TupleBody]RETURNS[LONG DESCRIPTOR FOR GroupList];END.--DBStorageGroupCHANGE LOGCreated by MBrown on June 17, 1980  10:15 AMChanged by MBrown on June 18, 1980  8:16 PMChanged by MBrown on August 13, 1980  11:56 AMChanged by Willie-Sue on February 15, 1985  `  File DBStorageGroup.mesaCopyright c 1985 by Xerox Corporation.  All rights reserved.Last edited by MBrown on August 13, 1980  11:55 AMWillie-Sue, February 15, 1985 11:17:17 am PSTDonahue, May 23, 1986 9:55:06 am PDTThis interface contains the internal storage level definitions that relate to therepresentation of groups.TypesAllows parts of a TIDFieldBody to be addressed (see ReadGroupField below).Allows parts of a GroupListEntry to be addressed (see ReadHeadField below).ProcsReturns the BASE and LENGTH of the tuple's GroupList.  The BASE is a LONG POINTER to a locked readonly cache page, and the second result is the cache handle to be used for unlocking it.Returns the indicated part of x's group field f.Writes val into the indicated part of x's group field f.returns the indicated part of x's GroupListEntry for group field f.error if no such entry.  result is never NIL.writes val's tid into the indicated part of x's GroupListEntry for group field f.error if no such entry.  val is never NIL.creates a group list entry in tuple x for group field f.error if already such an entryremoves the group list entry in tuple x for group field f.error if no such entryReturns the BASE and LENGTH of the tuple's GroupList, given a LONG POINTERto the tuple's body (presumably in a cache page).Moved here from DBStoragePrivateB.  This allows the implementation of group scans to be split fromthe implementation of group field reading/writing.Added GroupListFromTupleBase, to satisfy StoragePrintImpl.DBStoragePrivateB.TupleBody became DBStorageExtTuple.TupleBody.made cedar, added tioga formatting Ê  ˜ šœ™Jšœ
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