[Oberon] FPGA - Files.ReadBytes(), Files.WriteBytes()

[Jörg]

Hi Tomas

If you look at the base code of ReadByte() you see that it does some checks, if needed writes and reloads file buffers and copies only one byte.  x := r.buf.data[r.bpos]; or x := r.buf.data[0]; 

Instead of repeatingly call ReadByte() and doing the whole checks again and again, one could improve the performance of ReadBytes() by:
- taking over the base code of ReadByte
- modify it to handle multiple bytes at once
- improve the performance of copying the buffer over to parameter "x" by using SYSTEM.COPY

This effort was not spent yet.

br
Jörg


Am 20.08.18, 11:17 schrieb "Oberon im Auftrag von Tomas Kral" <oberon-bounces at lists.inf.ethz.ch im Auftrag von thomas.kral at email.cz>:

    Hi,
    
    Files.Mod has procedures for reading/writing a block of bytes, bytewise.
    
      PROCEDURE ReadBytes*(VAR r: Rider; VAR x: ARRAY OF BYTE; n: INTEGER);
        VAR i: INTEGER;
      BEGIN i := 0;  (*this implementation is to be improved*)
        WHILE i < n DO ReadByte(r, x[i]); INC(i) END
      END ReadBytes;
    
      PROCEDURE WriteBytes*(VAR r: Rider; x: ARRAY OF BYTE; n: INTEGER);
        VAR i: INTEGER;
      BEGIN i := 0; (*this implementation is to be improed*)
        WHILE i < n DO WriteByte(r, x[i]); INC(i) END
      END WriteBytes;
    
    The comment suggests improving the code further. Any hints to improve
    the code?
    Thanks
    
    -- 
    Tomas Kral <thomas.kral at email.cz>
    --
    Oberon at lists.inf.ethz.ch mailing list for ETH Oberon and related systems
    https://lists.inf.ethz.ch/mailman/listinfo/oberon