200 lines
3.4 KiB
Plaintext
200 lines
3.4 KiB
Plaintext
(*
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BSD 2-Clause License
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Copyright (c) 2018-2022, Anton Krotov
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All rights reserved.
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*)
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MODULE FILES;
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IMPORT UTILS, C := COLLECTIONS;
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TYPE
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FILE* = POINTER TO RECORD (C.ITEM)
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ptr: INTEGER;
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buffer: ARRAY 64*1024 OF BYTE;
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count: INTEGER
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END;
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VAR
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files: C.COLLECTION;
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PROCEDURE copy (src: ARRAY OF BYTE; src_idx: INTEGER; VAR dst: ARRAY OF BYTE; dst_idx: INTEGER; bytes: INTEGER);
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BEGIN
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WHILE bytes > 0 DO
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dst[dst_idx] := src[src_idx];
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INC(dst_idx);
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INC(src_idx);
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DEC(bytes)
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END
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END copy;
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PROCEDURE flush (file: FILE): INTEGER;
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VAR
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res: INTEGER;
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BEGIN
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IF file # NIL THEN
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res := UTILS.FileWrite(file.ptr, file.buffer, file.count);
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IF res < 0 THEN
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res := 0
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END
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ELSE
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res := 0
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END
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RETURN res
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END flush;
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PROCEDURE NewFile (): FILE;
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VAR
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file: FILE;
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citem: C.ITEM;
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BEGIN
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citem := C.pop(files);
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IF citem = NIL THEN
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NEW(file)
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ELSE
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file := citem(FILE)
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END
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RETURN file
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END NewFile;
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PROCEDURE create* (name: ARRAY OF CHAR): FILE;
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VAR
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file: FILE;
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ptr: INTEGER;
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BEGIN
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ptr := UTILS.FileCreate(name);
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IF ptr > 0 THEN
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file := NewFile();
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file.ptr := ptr;
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file.count := 0
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ELSE
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file := NIL
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END
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RETURN file
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END create;
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PROCEDURE open* (name: ARRAY OF CHAR): FILE;
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VAR
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file: FILE;
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ptr: INTEGER;
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BEGIN
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ptr := UTILS.FileOpen(name);
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IF ptr > 0 THEN
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file := NewFile();
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file.ptr := ptr;
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file.count := -1
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ELSE
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file := NIL
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END
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RETURN file
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END open;
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PROCEDURE close* (VAR file: FILE);
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VAR
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n: INTEGER;
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BEGIN
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IF file # NIL THEN
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IF file.count > 0 THEN
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n := flush(file)
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END;
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file.count := -1;
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UTILS.FileClose(file.ptr);
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file.ptr := 0;
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C.push(files, file);
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file := NIL
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END
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END close;
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PROCEDURE read* (file: FILE; VAR chunk: ARRAY OF CHAR; bytes: INTEGER): INTEGER;
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VAR
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res: INTEGER;
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BEGIN
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IF file # NIL THEN
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res := UTILS.FileRead(file.ptr, chunk, MAX(MIN(bytes, LEN(chunk)), 0));
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IF res < 0 THEN
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res := 0
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END
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ELSE
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res := 0
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END
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RETURN res
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END read;
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PROCEDURE write* (file: FILE; chunk: ARRAY OF BYTE; bytes: INTEGER): INTEGER;
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VAR
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free, n, idx: INTEGER;
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BEGIN
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idx := 0;
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IF (file # NIL) & (file.count >= 0) THEN
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free := LEN(file.buffer) - file.count;
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WHILE bytes > 0 DO
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n := MIN(free, bytes);
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copy(chunk, idx, file.buffer, file.count, n);
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DEC(free, n);
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DEC(bytes, n);
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INC(idx, n);
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INC(file.count, n);
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IF free = 0 THEN
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IF flush(file) # LEN(file.buffer) THEN
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bytes := 0;
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DEC(idx, n)
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ELSE
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file.count := 0;
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free := LEN(file.buffer)
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END
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END
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END
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END
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RETURN idx
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END write;
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PROCEDURE WriteByte* (file: FILE; byte: BYTE): BOOLEAN;
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VAR
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arr: ARRAY 1 OF BYTE;
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BEGIN
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arr[0] := byte
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RETURN write(file, arr, 1) = 1
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END WriteByte;
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BEGIN
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files := C.create()
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END FILES. |