note description: "SToraGe Mode flags" legal: "See notice at end of class." info: "Priority mode not supported" status: "See notice at end of class." date: "$Date$" revision: "$Revision$" class ECOM_STGM feature -- Access Stgm_create: INTEGER -- Stgm_create indicates an existing IStorage or IStream object -- should be removed before the new one replaces it. A new object -- is created when this flag is specified only if the existing -- IStorage or IStream has been successfully removed. external "C [macro ]" alias "STGM_CREATE" end Stgm_convert: INTEGER -- This flag is applicable only to the creation of IStorage objects. -- Stgm_convert allows the creation to proceed while preserving -- existing data. The old data is saved to a stream named CONTENTS -- containing the same data that was in the old IStorage or IStream -- instance. In the IStorage case, the data is flattened to a -- stream regardless of whether the existing file currently contains -- a layered storage object. external "C [macro ]" alias "STGM_CONVERT" end Stgm_failifthere: INTEGER -- Stgm_failifthere causes the create operation to fail if an -- existing object with the specified name exists. In this case, -- Stg_e_filealreadyexists is returned. Stgm_failifthere -- applies to both IStorage and IStream objects. external "C [macro ]" alias "STGM_FAILIFTHERE" end Stgm_deleteonrelease: INTEGER -- The Stgm_deleteonrelease flag indicates that the underlying -- file is to be automatically destroyed when the root IStorage -- object is released. This capability is most useful for -- creating temporary files. external "C [macro ]" alias "STGM_DELETEONRELEASE" end Stgm_direct: INTEGER -- Stgm_DIrect is always specified for IStream objects. -- Stgm_transacted is not supported in the compound file -- implementation of IStream. Other implementations can choose -- to support it. external "C [macro ]" alias "STGM_DIRECT" end Stgm_transacted: INTEGER -- The transaction for each open object is nested in the transaction -- for its parent storage object. Therefore, committing changes at the -- child level is dependent on committing changes in the parent and -- a commit of the root storage object (top-level parent) is necessary -- before changes to an object are actually written to disk. -- The changes percolate upward: inner objects publish changes to the -- transaction of the next object outwards. Outermost objects publish -- changes permanently into the file system. Transacted mode is not -- required on the parent storage object in order to use transacted -- mode on a contained object.The scope of changes that are buffered -- in transacted mode is very broad. A storage or stream object can -- be opened, have arbitrary changes made to it, and then have the -- changes reverted, preserving the object as it was when it was -- first opened. The creation and destruction of elements within a -- storage object are scoped by its transaction. external "C [macro ]" alias "STGM_TRANSACTED" end Stgm_read: INTEGER -- When applied to an IStream object, Stgm_READ enables -- applications to successfully call IStream.Read. If Stgm_read -- is omitted, IStream.Read will return an error. When applied to an -- IStorage, Stgm_READ allows the enumeration of the storage -- object's elements and enables applications to open these elements -- in read mode. Parents of storage objects to be opened in read mode -- must also have been opened in read mode otherwise, an error is -- returned. external "C [macro ]" alias "STGM_READ" end Stgm_write: INTEGER -- Stgm_write lets an object commit changes to the storage. -- Specifically, unless this flag has been given, IStorage.Commit -- and IStream.Commit will fail. An open object whose changes cannot -- be committed can save its changes by copying the storage or stream -- with IStorage.CopyTo or IStream.CopyTo. In direct mode, -- changes are committed after every change operation. Thus, write -- permissions are needed to call any function that causes a change. -- On streams, this includes IStream.Write and IStream.SetSize. -- If a parent storage is opened in direct mode without write -- permission, any attempt to open a child stream within it in direct -- mode with write permission will fail, because it causes an implicit -- commit to be made on the storage. Similarly, trying to create or -- destroy a contained element in this storage object also causes an -- implicit commit, resulting in an error. external "C [macro ]" alias "STGM_WRITE" end Stgm_readwrite: INTEGER -- Stgm_readwrite is the logical combination of the -- Stgm_read and Stgm_write. However, the defined value -- of Stgm_readwrite is not equal to -- (Stgm_read or Stgm_write). external "C [macro ]" alias "STGM_READWRITE" end Stgm_share_deny_none: INTEGER -- 0x00000040L -- Stgm_SHARE_DENY_NONE indicates that neither read access nor -- write access should be denied to subsequent openings. This is the -- default sharing mode and if no Stgm_SHARE_* flag is explicitly -- given, Stgm_SHARE_DENY_NONE is implied. external "C [macro ]" alias "STGM_SHARE_DENY_NONE" end Stgm_share_deny_read: INTEGER -- 0x00000030L -- When successfully applied to a root IStorage, the -- Stgm_SHARE_DENY_READ flag prevents others from opening the -- object in read mode. The open call fails and returns an error if -- the object is presently open in deny-read mode. -- Stgm_SHARE_DENY_READ is most useful when opening root storage -- objects. Deny modes on inner elements are still useful if some -- component is coordinating the opening of these inner elements, as -- might happen in a Copy/Paste operation. However, inner elements -- always require Stgm_SHARE_EXCLUSIVE. Opening a parent storage -- object with Stgm_SHARE_DENY_READ applies only to that opening, -- not the network-wide set of openings of the parent. external "C [macro ]" alias "STGM_SHARE_DENY_READ" end Stgm_share_deny_write: INTEGER -- When successfully applied the Stgm_share_deny_write flag -- prevents subsequent openings of either a storage or a stream from -- specifying write mode. The open call fails and returns an error -- if the storage or stream is presently open in write mode. -- For information about the interaction of this flag with nested -- openings, see the earlier discussion about Stgm_share_deny_read. external "C [macro ]" alias "STGM_SHARE_DENY_WRITE" end Stgm_share_exclusive: INTEGER -- The compound files implementation requires that all inner elements -- be opened Stgm_share_exclusive. It is the logical combination -- of the Stgm_share_deny_read and Stgm_share_deny_write. -- All root storage objects, as well as child storage and stream -- objects must be opened with Stgm_share_exclusive. external "C [macro ]" alias "STGM_SHARE_EXCLUSIVE" end Stgm_priority: INTEGER -- The Stgm_priority flag allows an IStorage object to be opened -- so that a subsequent copy operation can be done at reduced cost. -- Stgm_priority allows an application to read certain streams -- from storage before opening the storage object in a mode that would -- require a snapshot copy to be made. Priority mode has exclusive -- access to the committed version of the IStorage object. -- While a compound file is open in priority mode, no other opening -- of the compound file can commit changes even one that was opened -- before the priority mode opening. Therefore, applications should -- keep IStorage objects open in priority mode for as short a time -- as possible. external "C [macro ]" alias "STGM_PRIORITY" end is_valid_stgm (stgm: INTEGER): BOOLEAN -- Is `stgm' a valid storage mode flag? do Result := stgm = Stgm_create or stgm = Stgm_convert or stgm = Stgm_failifthere or stgm = Stgm_deleteonrelease or stgm = Stgm_direct or stgm = Stgm_transacted or stgm = Stgm_read or stgm = Stgm_write or stgm = Stgm_readwrite or stgm = Stgm_share_deny_none or stgm = Stgm_share_deny_read or stgm = Stgm_share_deny_write or stgm = Stgm_share_exclusive -- or -- stgm = Stgm_priority end note copyright: "Copyright (c) 1984-2006, Eiffel Software and others" license: "Eiffel Forum License v2 (see http://www.eiffel.com/licensing/forum.txt)" source: "[ Eiffel Software 356 Storke Road, Goleta, CA 93117 USA Telephone 805-685-1006, Fax 805-685-6869 Website http://www.eiffel.com Customer support http://support.eiffel.com ]" end -- class STGM