-- OpenFileMap.mesa
-- Last edited by
--   Taft on October 25, 1982 11:06 am
--   MBrown on 12-Feb-82 17:31:47
--   Kolling on November 12, 1982 4:35 pm


DIRECTORY
   AlpineEnvironment
      USING [AccessRights, Conversation, FileID, LockOption, OpenFileID, RecoveryOption,
         ReferencePattern, VolumeID],
   AlpineInternal
      USING[FileHandle, FileInstanceHandle, OpenFileHandle, TransHandle];


OpenFileMap: CEDAR DEFINITIONS =

BEGIN


Handle: TYPE = AlpineInternal.OpenFileHandle;


-- Errors:

BadConversation: --CALLING OR PROGRAMMING-- ERROR;  -- from GetAndCheckHandle.
HandleNotFound: --CALLING OR PROGRAMMING-- ERROR;  -- from GetAndCheckHandle.
OpenFileIDNotFound: --CALLING OR PROGRAMMING-- ERROR;  -- from GetAndCheckHandle.



Initialize: PROCEDURE[numHashSlotsDesired: NAT];
 -- errors defined in this interface: none.

-- 

Register: PROCEDURE [conversation: AlpineEnvironment.Conversation, trans:
  AlpineInternal.TransHandle, volumeID: AlpineEnvironment.VolumeID, fileID:
  AlpineEnvironment.FileID] RETURNS [handle: Handle, openFileID:
  AlpineEnvironment.OpenFileID];
-- errors defined in this interface:  none.

Unregister: PROCEDURE [handle: Handle];
-- errors defined in this interface:  HandleNotFound.



-- Check validity of conversation and openFileID.

GetAndCheckHandle: PROCEDURE [conversation: AlpineEnvironment.Conversation, openFileID:
 AlpineEnvironment.OpenFileID] RETURNS [handle: Handle];
-- errors defined in this interface:  BadConversation, OpenFileIDNotFound.
-- Raises OpenFileIDNotFound if invalid openFileID;  raises BadConversation if conversation does not match the one in the OpenFileMap data structure for this openFileID.
-- Returned Handle is guaranteed valid as long as caller holds onto it.



ChangeTransaction: PROCEDURE [handle: Handle, trans: AlpineInternal.TransHandle];
-- errors defined in this interface:  none.
-- Causes the existing OpenFileObject to be registered with a new transaction trans, including the suitable unregistration/registration calls on FileInstance and FileMap.



-- Access to attributes that can change, but aren't exactly "read/write."

GetTransHandle: PROCEDURE [handle: Handle] RETURNS [trans: AlpineInternal.TransHandle];
-- errors defined in this interface:  none.

GetFileInstanceHandle: PROCEDURE [handle: Handle] RETURNS [fileHandle:
 AlpineInternal.FileInstanceHandle];
-- errors defined in this interface:  none.

GetFileHandle: PROCEDURE [handle: Handle] RETURNS [fileHandle: AlpineInternal.FileHandle];
-- errors defined in this interface:  none.



-- Access to immutable attributes.

GetVolumeID: PROCEDURE [handle: Handle] RETURNS [volumeID:
 AlpineEnvironment.VolumeID];
-- errors defined in this interface:  none.

GetFileID: PROCEDURE [handle: Handle] RETURNS [fileID: AlpineEnvironment.FileID];
-- errors defined in this interface:  none.

GetVolumeIDAndFileID: PROCEDURE [handle: Handle] RETURNS [volumeID:
 AlpineEnvironment.VolumeID, fileID: AlpineEnvironment.FileID];
-- errors defined in this interface: none.

GetConversation: PROCEDURE [handle: Handle] RETURNS [conversation:
 AlpineEnvironment.Conversation];
-- errors defined in this interface:  none.



-- Access to read/write attributes.

GetAccessRights: PROCEDURE [handle: Handle] RETURNS [access:
 AlpineEnvironment.AccessRights];
-- errors defined in this interface:  none.

SetAccessRights: PROCEDURE [handle: Handle, access: AlpineEnvironment.AccessRights];
-- errors defined in this interface:  none.

GetLockOption: PROCEDURE [handle: Handle] RETURNS [lock: AlpineEnvironment.LockOption];
-- errors defined in this interface:  none.
-- reads ifConflict from the OpenFileObject and LockMode from the FileInstanceObject.

SetLockOption: PROCEDURE [handle: Handle, lock: AlpineEnvironment.LockOption];
-- errors defined in this interface:  none.
-- sets ifConflict in the OpenFileObject and LockMode in the FileInstanceObject.

GetRecoveryOption: PROCEDURE [handle: Handle] RETURNS [recovery:
 AlpineEnvironment.RecoveryOption];
-- errors defined in this interface:  none.

SetRecoveryOption: PROCEDURE [handle: Handle, recovery:
 AlpineEnvironment.RecoveryOption];
-- errors defined in this interface:  none.

GetReferencePattern: PROCEDURE [handle: Handle] RETURNS [referencePattern:
 AlpineEnvironment.ReferencePattern];
-- errors defined in this interface:  none.

SetReferencePattern: PROCEDURE [handle: Handle, referencePattern: AlpineEnvironment.ReferencePattern];
-- errors defined in this interface:  none.



-- Enumeration.

GetNextHandleForTrans: PROCEDURE [trans: AlpineInternal.TransHandle, handle: Handle _
 NIL] RETURNS [nextHandle: Handle];
-- errors defined in this interface:  none.
-- handle = NIL starts a new enumeration, and nextHandle = NIL is returned
-- when the enumeration is exhausted.  The only guaranteed property of the enumeration is
-- that all Handles in existence during the entire enumeration will be visited at least once; 
-- some handles may be seen more than once.




END.