
    <<RCMapOps.mesa>>
        <<Copyright © 1985 by Xerox Corporation.  All rights reserved.>>
        <<Rovner On September 19, 1983 9:31 pm>>
    <<Russ Atkinson (RRA) January 31, 1985 1:11:22 pm PST>>
        <<Satterthwaite April 23, 1986 11:34:52 am PST>>

    DIRECTORY
        RCMap: TYPE USING[Base, Index],
        SymbolTable: TYPE USING[Base],
        Symbols: TYPE USING[Type, MDIndex];

    RCMapOps: DEFINITIONS = { 

    <<TYPEs>>

        RCMapTable: TYPE;
        RCMT: TYPE = LONG POINTER TO RCMapTable;

        OuterProc: TYPE =
            PROC[stb: SymbolTable.Base, mdi: Symbols.MDIndex, inner: PROC[base: SymbolTable.Base]];

        MapMap: TYPE = LONG POINTER TO MapMapObj;  -- built by Include
        MapMapObj: TYPE = RECORD[SEQUENCE length: CARDINAL OF MapMapItem];
        MapMapItem: TYPE = RECORD[old, new: RCMap.Index];

    <<OPERATIONs>>

            <<Create an RCMapTable object>>
            <<ASSUME ptr was allocated by VM.Allocate>>
            <<Note that access to this object is not monitored>>
        Create: PROC[
              zone: UNCOUNTED ZONE,
              ptr: RCMap.Base, nPages: CARDINAL, outerProc: OuterProc_NIL,
              expansionOK: BOOL_FALSE] 
            RETURNS[RCMT];

        Destroy: PROC[rcmt: RCMT] RETURNS[RCMT];

            <<Retrieve info about the RCMap.Base>>
        GetSpan: PROC[rcmt: RCMT] RETURNS[base: RCMap.Base, size: CARDINAL];

            <<Returns the RCMap.Index of the RCMap for the specified type.>>
            <<Makes an entry if necessary.>>
        Acquire: PROC[rcmt: RCMT, stb: SymbolTable.Base, type: Symbols.Type]
            RETURNS[RCMap.Index];

            <<Merges the specified RCMap.Base into the table object.>>
            <<If zone # NIL, allocates and returns a MapMap >>
        Include: PROC[
              rcmt: RCMT, rcmb: RCMap.Base, size: CARDINAL, zone: UNCOUNTED ZONE_NIL]
            RETURNS[MapMap];

            <<Does a MapMap lookup: returns the index in the current RCMap.Base that corresponds>>
            <<to the specified index in the RCMap.Base that Include processed.>>
        FindMapMapEntry: PROC[mapMap: MapMap, oldIndex: RCMap.Index]
            RETURNS[RCMap.Index];

        Enumerate: PROC[
              base: RCMap.Base,
              limit: CARDINAL,
              proc: PROC[RCMap.Index] RETURNS[stop: BOOL]]
            RETURNS[stopped: BOOLEAN];

        }.

    <<BEWARE: If you allow expansion of the RCMap Base, you must be careful about concurrent access to the existing Base. In current 
    Cedar, for performance reasons (all accesses to the Base would have to be protected by a monitor), the Cedar runtime does not 
    allow expansion (ERROR if RCMap Base overflows).>>


