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(******************************************************************************)
(* Copyright (c) 1988 by GMD Karlruhe, Germany *)
(* Gesellschaft fuer Mathematik und Datenverarbeitung *)
(* (German National Research Center for Computer Science) *)
(* Forschungsstelle fuer Programmstrukturen an Universitaet Karlsruhe *)
(* All rights reserved. *)
(******************************************************************************)
IMPLEMENTATION MODULE ByteIO;
FROM SYSTEM IMPORT
ADR, ADDRESS, BYTE;
FROM SysLib IMPORT
access, unlink;
IMPORT BasicIO;
IMPORT Storage;
CONST
MAXFILE = 50;
BUFFSIZE = 1024;
VAR
ENDOFFILE : ARRAY [0..MAXFILE] OF BOOLEAN;
ISOUTPUT : ARRAY [0..MAXFILE] OF BOOLEAN;
BFIRST, BPOS, BLAST : ARRAY [0..MAXFILE] OF ADDRESS;
(* For Input: *)
(* BFIRST .... BPOS ... BLAST *)
(* [processed] [unprocessed ] *)
(* For Output: *)
(* BFIRST ... BPOS ... BLAST *)
(* [filled ] [free ] *)
(*=== Open/Close ===*)
PROCEDURE OpenInput (VAR file : File; VAR name : ARRAY OF CHAR);
BEGIN
BasicIO.OpenInput (file, name);
IF file < 0 THEN
BasicIO.DONE := FALSE;
ELSE
Storage.ALLOCATE (BFIRST[file], BUFFSIZE);
BPOS[file] := BFIRST[file]+1;
BLAST[file] := BFIRST[file];
ISOUTPUT[file] := FALSE;
BasicIO.DONE := TRUE;
END;
END OpenInput;
PROCEDURE OpenOutput (VAR file : File; VAR name : ARRAY OF CHAR);
BEGIN
BasicIO.OpenOutput (file, name);
IF file < 0 THEN
BasicIO.DONE := FALSE;
ELSE
Storage.ALLOCATE (BFIRST[file], BUFFSIZE);
BPOS[file] := BFIRST[file];
BLAST[file] := BFIRST[file] + BUFFSIZE - 1;
ISOUTPUT[file] := TRUE;
BasicIO.DONE := TRUE;
END;
END OpenOutput;
PROCEDURE Close (file: File);
BEGIN
IF ISOUTPUT[file] THEN PutBf(file) END;
BasicIO.Close (file);
BasicIO.DONE := TRUE; (*;;*)
(* ++ jv ++ *)
Storage.DEALLOCATE (BFIRST[file], BUFFSIZE);
(* -- jv -- *)
END Close;
(*=== Byte IO ===*)
PROCEDURE GetByte (file : File; VAR x : BYTE);
BEGIN
IF BPOS[file] > BLAST[file] THEN
FillBuffer(file);
IF NOT BasicIO.DONE THEN RETURN END;
END;
x := BPOS[file]^;
INC(BPOS[file]);
BasicIO.DONE := TRUE;
END GetByte;
PROCEDURE UndoGetByte (file: File);
BEGIN
DEC(BPOS[file]);
BasicIO.DONE := TRUE;
END UndoGetByte;
PROCEDURE GetBytes (file : File; VAR x : ARRAY OF BYTE; len : CARDINAL);
VAR i: CARDINAL;
BEGIN
i := 0;
WHILE i <> len DO
IF BPOS[file] > BLAST[file] THEN
FillBuffer(file);
IF NOT BasicIO.DONE THEN RETURN END;
END;
x[i] := BPOS[file]^;
INC(BPOS[file]);
INC(i);
END;
BasicIO.DONE := TRUE;
END GetBytes;
PROCEDURE GetItem (file : File; VAR x : ARRAY OF BYTE);
VAR i, len: CARDINAL; n: INTEGER;
BEGIN
i := 0;
len := HIGH(x) + 1;
WHILE i <> len DO
IF BPOS[file] > BLAST[file] THEN
FillBuffer(file);
IF NOT BasicIO.DONE THEN RETURN END;
END;
x[i] := BPOS[file]^;
INC(BPOS[file]);
INC(i);
END;
BasicIO.DONE := TRUE;
END GetItem;
PROCEDURE PutByte (file : File; x : BYTE);
BEGIN
IF BPOS[file] > BLAST[file] THEN
EmitBuffer(file);
IF NOT BasicIO.DONE THEN RETURN END;
END;
BPOS[file]^ := x;
INC(BPOS[file]);
BasicIO.DONE := TRUE;
END PutByte;
PROCEDURE PutBytes (file : File; VAR x : ARRAY OF BYTE; len : CARDINAL);
VAR i: CARDINAL;
BEGIN
i := 0;
WHILE i <> len DO
IF BPOS[file] > BLAST[file] THEN
EmitBuffer(file);
IF NOT BasicIO.DONE THEN RETURN END;
END;
BPOS[file]^ := x[i];
INC(BPOS[file]);
INC(i);
END;
BasicIO.DONE := TRUE;
END PutBytes;
PROCEDURE PutItem (file : File; VAR x : ARRAY OF BYTE);
VAR i, len: CARDINAL;
BEGIN
i := 0;
len := HIGH(x) + 1;
WHILE i <> len DO
IF BPOS[file] > BLAST[file] THEN
EmitBuffer(file);
IF NOT BasicIO.DONE THEN RETURN END;
END;
BPOS[file]^ := x[i];
INC(BPOS[file]);
INC(i);
END;
BasicIO.DONE := TRUE;
END PutItem;
(*=== Misc. ===*)
PROCEDURE PutBf (file: File);
BEGIN
IF BPOS[file] <> BFIRST[file] THEN EmitBuffer(file) END;
END PutBf;
PROCEDURE Done () : BOOLEAN;
BEGIN
RETURN BasicIO.DONE;
END Done;
PROCEDURE EOF (file : File) : BOOLEAN;
BEGIN;
IF ISOUTPUT[file] THEN RETURN TRUE END;
IF BPOS[file] > BLAST[file] THEN
FillBuffer(file);
RETURN (ENDOFFILE[file]);
END;
RETURN FALSE
END EOF;
PROCEDURE Accessible (VAR name : ARRAY OF CHAR;
ForWriting : BOOLEAN) : BOOLEAN;
BEGIN
RETURN BasicIO.Accessible (name, ForWriting);
END Accessible;
PROCEDURE Erase (VAR name : ARRAY OF CHAR; VAR ok : BOOLEAN);
BEGIN
BasicIO.Erase (name, ok);
END Erase;
(*=== Private ===*)
PROCEDURE EmitBuffer (file : File);
BEGIN
BasicIO.Write (file, BFIRST[file], INTEGER(BPOS[file] - BFIRST[file]));
BPOS[file] := BFIRST[file];
BasicIO.DONE := TRUE;
END EmitBuffer;
PROCEDURE FillBuffer (file : File);
VAR n: INTEGER;
BEGIN
BasicIO.Read (file, BFIRST[file], BUFFSIZE, n);
IF n > 0 THEN
BPOS[file] := BFIRST[file];
BLAST[file] := BFIRST[file] + CARDINAL(n) - 1;
BasicIO.DONE := TRUE;
ENDOFFILE[file] := FALSE;
ELSE
BPOS[file] := BFIRST[file];
BLAST[file] := BFIRST[file] - 1;
BasicIO.DONE := FALSE;
ENDOFFILE[file] := n = 0;
END;
END FillBuffer;
END ByteIO.
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