Amiga MA Magazine 1998 #6/amigamamagazinepolishissue1998.iso/coders/jËzyki_programowania/oberon/system/files.mod

Oberon Text | 1977-12-31 | 24KB | 773 lines

Syntax10.Scn.Fnt
ParcElems
Alloc
Syntax24b.Scn.Fnt
StampElems
Alloc
24 Dec 95
Syntax10b.Scn.Fnt
(* AMIGA *)
MODULE Files;  (* shml/cn 16.12.1992 Oberon files mapped onto AmigaDOS files,
    NOTE
        This module is built on the assumption, that it never holds
        an exclusive lock on any of its open files. Only temporary
        files used within a single procedure (like in rename) may
        be opend exclusively, but have to be closed before the
        procedure termination.
IMPORT
    SYSTEM,Amiga,Dos:=AmigaDos,I:=AmigaIntuition,Kernel;
CONST
    BigEndianSet=FALSE;    (* TRUE for HP,PowerOberon, FALSE for others (e.g. Amiga) *)
    BigEndianMachine=TRUE;    (* 680x0 is big endian, i386 is little endian *)
    nofbufs=4;
    bufsize=4096;
    fileTabSize=100;
    noDesc=0;
    (* file states *)
    open=0; create=1; close=2;
    (* error results *)
    noError=0; directoryNotFound=1; fileNotFound=2;
    FileName=ARRAY 104 OF CHAR;
    File*=POINTER TO Handle;
    Buffer=POINTER TO BufDesc;
    FileInfoBlockPtr=POINTER TO Dos.FileInfoBlock;
    workName: The name currently in use on the underlying file system.
    registerName: Name to enter in the directory, if the file is registered.
    fl: AmigaDos lock to the file.
    fd: AmigaDos file handle to the file.
    len: legth of the file.
    pos: Remebers the actual position in the underlying AmigaDos file.
    bufs: Buffers for the file.
    swapper: Number of the last swapped out buffer.
    state: see below.
    idx:
    When a file is opened with Old, its name is stored into workName,
    registerName is empty and state becomes open. fd and fl are valid
    handle and lock to the file.
    When a file is created with New, its name is stored into registerName,
    while workName stays empty and state becomes create. fd and fl are
    not set up, as no connection to an actual file is performed at this stage.
    Create will actually associate an AmigaDos file to the Oberon file when
    this is needed. If the state is create, then only a temporary file is associated
    to it. This follows the Oberon idea, that no directory entry is made unless
    Register is called. The state close indicates to Create, that we are registering
    a file which hasn't yet an association to an AmigaDos file. The register name
    is thus used. In any case the file changes state to open, as now an association
    is made.
    Handle=RECORD
        registerName:FileName;
        fl:Dos.FileLockPtr;
        fd:Dos.FileHandlePtr;
        len,pos:LONGINT;
        bufs:ARRAY nofbufs OF Buffer;
        swapper,state,idx:INTEGER
    END;
    f: File to which this buffer belongs.
    chg: TRUE if buffer content differs from the one stored in the file.
    org: The offset within the underlying file which corresponds to the first byte of the buffer.
    size: The numer of valid bytes in this buffer.
    data: buffer space.
    BufDesc=RECORD
        f:File;
        chg:BOOLEAN;
        org,size:LONGINT;
        data:ARRAY bufsize OF SYSTEM.BYTE
    END;
    Rider*=RECORD
        res*:LONGINT;
        eof*:BOOLEAN;
        buf:Buffer;
        org,offset:LONGINT
    END;
    CurrentDir-:ARRAY 256 OF CHAR;
    searchPath:ARRAY 256 OF CHAR;
    fileTab:ARRAY fileTabSize OF LONGINT;
    startTime:LONGINT;
    tempno:INTEGER;
PROCEDURE^ Finalize(obj:SYSTEM.PTR);
PROCEDURE isSeekError(oldPos,pos:LONGINT):BOOLEAN;
    Pre V39 seek doesn't correctly return -1 on a seek
    error. This procedure corrects for this.
BEGIN
    IF (oldPos=pos) & (Dos.dosVersion<39) THEN
        RETURN Dos.IoErr()#0
    ELSE
        RETURN oldPos<0
END isSeekError;
PROCEDURE SeekAndExtend(f:Dos.FileHandlePtr; newpos:LONGINT);
    Seek to the selected position in the file, extending it
    if necessary to reach this position.
    pos:LONGINT;
BEGIN
    pos:=Dos.Seek(f,newpos,Dos.beginning);
    IF isSeekError(pos,newpos) THEN
            Error in seek, probably because the file was too
            short. So extend the file and then seek again.
        pos:=Dos.SetFileSize(f,newpos,Dos.beginning);
        ASSERT(pos=newpos, 44);
        pos:=Dos.Seek(f,newpos,Dos.beginning);
        ASSERT(~isSeekError(pos,newpos), 45)
END SeekAndExtend;
PROCEDURE MakeFileName(dir,name:ARRAY OF CHAR; VAR dest:ARRAY OF CHAR);
BEGIN
    dest[0]:=0X;
    IF Dos.AddPart(dest,dir,LEN(dest)) THEN END;
    IF Dos.AddPart(dest,name,LEN(dest)) THEN END
END MakeFileName;
PROCEDURE GetTempName(VAR path:ARRAY OF CHAR);
    Generate a new temporary file name.
    n,i,c:LONGINT;
    name:FileName;
BEGIN
    INC(tempno);
    n:=tempno;
    COPY(".tmp.00000000.00000",name);
    i:=18;
    WHILE n>0 DO
        name[i]:=CHR(n MOD 10+ORD("0"));
        n:=n DIV 10;
        DEC(i)
    END;
    n:=startTime;
    i := 12;
    WHILE n>0 DO
        c:=n MOD 16;
        IF c>9 THEN INC(c,ORD("A")-ORD("9")-1) END;
        name[i]:=CHR(c+ORD("0"));
        n:=n DIV 16;
        DEC(i)
    END;
    MakeFileName(CurrentDir,name,path)
END GetTempName;
PROCEDURE CacheEntry(fl:Dos.FileLockPtr):File;
    Given an AmigaDos file lock search our open file
    table, whether the file was already opened.
    f:File;
    i:INTEGER;
BEGIN
    FOR i:=0 TO fileTabSize-1 DO
        f:=SYSTEM.VAL(File,fileTab[i]);
        IF (f#NIL) THEN
            IF Dos.SameLock(fl,f.fl)=Dos.same THEN
                RETURN f
            END
        END
    END;
    RETURN NIL
END CacheEntry;
PROCEDURE Rename*(old,new:ARRAY OF CHAR; VAR res:INTEGER);
    Rename a file. If necessary perform a copy/delete operation,
    to move the file across file systems.
CONST
    bufSize=4096;
    fdold,fdnew:Dos.FileHandlePtr;
    n,errno:LONGINT;
    lock:Dos.FileLockPtr;
    buf:ARRAY bufSize OF CHAR;
    tmp:ARRAY 104 OF CHAR;
    success:BOOLEAN;
BEGIN
        First locate the old file. Dos.Lock can only file, if the
        file doesn't exist, or if some other program than Oberon
        has it opened exclusively.
    lock:=Dos.Lock(old,Dos.sharedLock);
    IF lock=0 THEN
        res:=fileNotFound
    ELSE
            Delete any file already existing with the new name.
        IF ~Dos.DeleteFile(new) THEN res:=SHORT(Dos.IoErr()) ELSE res:=0 END;
        IF res=Dos.objectInUse THEN
            (*
                If the named file cannot be deleted, because it's
                opened, then rename it to some temporary name.
            *)
            GetTempName(tmp);
            success:=Dos.Rename(new,tmp);
            ASSERT(success,91)
        END;
            Now try to rename the old file to the
            new name.
        success:=Dos.Rename(old,new);
        Dos.UnLock(lock);
        IF ~success THEN
            errno:=Dos.IoErr();
            IF errno#Dos.renameAcrossDevices THEN
                (*
                    The rename failed because of some unexpected
                    reason, report this reason in res.
                *)
                res:=SHORT(errno);
                RETURN
            ELSE
                (*
                    The rename failed because the new name specifies a different file
                    systen than the old name. The files has to be moved by a copy
                    delete operation.
                    NOTE
                        The new files is opened exclusively, thus should guarantee its
                        closure as Oberon cannot handle exclusively locked files.
                *)
                fdold:=Dos.Open(old,Dos.oldFile);
                IF fdold=0 THEN errno:=Dos.IoErr(); HALT(92) END;
                fdnew:=Dos.Open(new,Dos.newFile);
                IF fdnew=0 THEN errno:=Dos.IoErr(); HALT(93) END;
                IF Dos.SetProtection(new,{Dos.protExecute}) THEN END; (* everything but excute *)
                n:=Dos.Read(fdold,buf,bufSize);
                WHILE n>0 DO
                    errno:=Dos.Write(fdnew,buf,n);
                    IF errno#n THEN
                        errno:=Dos.IoErr();
                        IF Dos.Close(fdold) THEN END;
                        IF Dos.Close(fdnew) THEN END;
                        HALT(94)
                    END;
                    n:=Dos.Read(fdold,buf,bufSize)
                END;
                IF Dos.Close(fdold) THEN END;
                IF Dos.Close(fdnew) THEN END;
                IF Dos.DeleteFile(old) THEN END;
                res:=0
            END
        END;
        res:=0
END Rename;
PROCEDURE Delete*(name:ARRAY OF CHAR; VAR res:INTEGER);
    Delete a file. If it is hold by Oberon, it is renamed to a
    temporary file.
    f:File;
    lock:Dos.FileLockPtr;
    tempName:FileName;
BEGIN
    lock:=Dos.Lock(name,Dos.sharedLock);
    IF lock=0 THEN
            If we can't lock it, it either doesn't exist, or is
            locked exclusively by another program.
        res:=fileNotFound
    ELSE
        f:=CacheEntry(lock);
        Dos.UnLock(lock);
        IF f=NIL THEN
            (*
                The file is not one of those opened by Oberon, so just delete it
                using Dos.DeleteFile.
            *)
            IF ~Dos.DeleteFile(name) THEN res:=SHORT(Dos.IoErr()) ELSE res:=0 END
        ELSE
            (*
                The file is opened by Oberon, thus we have to rename
                it to a temporary file, and not really delete it.
            *)
            IF ~Dos.NameFromLock(f.fl,f.registerName) THEN f.registerName:="" END;
            GetTempName(tempName);
            Rename(f.registerName,tempName,res);
            IF res#0 THEN HALT(117) END
        END
END Delete;
PROCEDURE Create(f:File);
    err:ARRAY 25 OF CHAR;
    errno:LONGINT;
    fl:Dos.FileLockPtr;
    i,res:INTEGER;
    newName:FileName;
    oldF:File;
    tmpName:FileName;
BEGIN
    IF f.fd=noDesc THEN
            We haven't yet associated an AmigaDos file to this
            Oberon file.
        IF f.state=create THEN
            (*
                The file was "just" created (Files.New), so assign a temporary
                name to it.
            *)
            GetTempName(newName)
        ELSIF f.state=close THEN
            (*
                We are already registering the file. Let's check, if
                try to use the name of an existing file which we already
                use. If we do, then the other file is "removed" from
                the directory, i.e. it gets a temporary name.
            *)
            fl:=Dos.Lock(f.registerName,Dos.sharedLock);
            IF fl#0 THEN
                oldF:=CacheEntry(fl);
                IF oldF#NIL THEN
                    IF ~Dos.NameFromLock(oldF.fl,oldF.registerName) THEN oldF.registerName:="" END;
                    GetTempName(tmpName);
                    Rename(oldF.registerName,tmpName,res);
                    IF res#0 THEN HALT(107) END
                END;
                Dos.UnLock(fl)
            END;
            newName:=f.registerName;
            f.registerName:=""
        END;
        IF Dos.DeleteFile(newName) THEN END;
        f.fd:=Dos.Open(newName,Dos.readWrite);
        IF f.fd=0 THEN errno:=Dos.IoErr(); err:="create not done"; HALT(95) END;
        f.fl:=0; f.idx:=-1;
        Kernel.RegisterObject(f,Finalize);
        IF Dos.SetProtection(newName,{Dos.protExecute}) THEN END; (* everything but excute *)
        i:=0;
        WHILE (i<fileTabSize) & (fileTab[i]#0) DO INC(i) END;
        IF i=fileTabSize THEN
            IF Dos.Close(f.fd) THEN END;
            f.fd:=0;
            err:="too many files open"; HALT(96)
        END;
        fileTab[i]:=SYSTEM.VAL(LONGINT,f); INC(Kernel.nofiles);
        f.state:=open; f.pos:=0; f.fl:=Dos.DupLockFromFH(f.fd); f.idx:=i
END Create;
PROCEDURE Flush(buf:Buffer);
    err:ARRAY 25 OF CHAR;
    errno:LONGINT;
    f:File;
    registerName,workName:FileName;
BEGIN
    IF buf.chg THEN
        f:=buf.f;
        Create(f);
        IF buf.org#f.pos THEN SeekAndExtend(f.fd,buf.org) END;
        errno:=Dos.Write(f.fd,buf.data,buf.size);
        IF errno#buf.size THEN
            errno:=Dos.IoErr();
            IF ~Dos.NameFromLock(f.fl,workName) THEN workName:="" END;
            registerName:=f.registerName;
            err:="error in writing file";
            HALT(97)
        END;
        f.pos:=buf.org+buf.size;
        buf.chg:=FALSE
END Flush;
PROCEDURE Close*(f:File);
    i:INTEGER;
BEGIN
    IF (f.state#create) OR (f.registerName#"") THEN
        Create(f);
        i:=0; WHILE (i<nofbufs) & (f.bufs[i]#NIL) DO Flush(f.bufs[i]); INC(i) END
END Close;
PROCEDURE Length*(f:File):LONGINT;
BEGIN
    RETURN f.len
END Length;
PROCEDURE New*(name:ARRAY OF CHAR):File;
    f:File;
BEGIN
    NEW(f); MakeFileName(CurrentDir,name,f.registerName);
    f.fd:=noDesc; f.state:=create; f.len:=0; f.pos:=0; f.swapper:=-1; (*all f.buf[i]=NIL*)
    RETURN f
END New;
PROCEDURE Old*(name:ARRAY OF CHAR):File;
    f:File;
    fd:Dos.FileHandlePtr;
    fl:Dos.FileLockPtr;
    err,path:ARRAY 256 OF CHAR;
    i:INTEGER;
BEGIN
    IF name="" THEN
        f:=NIL;    (* Can't open a file without a name. *)
    ELSE
        MakeFileName(CurrentDir,name,path);
            First search the file in the current directory. If it
            wasn't found, prepend the Oberon search path
            to it, and retry.
        fd:=Dos.Open(path,Dos.oldFile);
        IF (fd=0) & (name[0]#":") THEN
            MakeFileName(searchPath,name,path);
            fd:=Dos.Open(path,Dos.oldFile)
        END;
        IF fd=0 THEN
            f:=NIL;    (* couldn't locate the file. *)
        ELSE
            fl:=Dos.DupLockFromFH(fd);
            f:=CacheEntry(fl);
            IF f#NIL THEN
                (*
                    The file is already opened, so use the
                    existing file handle, and close the
                    AmigaDos file.
                *)
                Dos.UnLock(fl);
                IF Dos.Close(fd) THEN END
            ELSE
                (*
                    A new file. locate a free slot in the file table,
                    and enter the file.
                *)
                i:=0;
                WHILE (i<fileTabSize) & (fileTab[i]#0) DO INC(i) END;
                IF i=fileTabSize THEN
                    IF Dos.Close(fd) THEN END;
                    Dos.UnLock(fl);
                    err:="too many files open";
                    HALT(98)
                END;
                NEW(f); fileTab[i]:=SYSTEM.VAL(LONGINT,f); INC(Kernel.nofiles);
                f.len:=Dos.Seek(fd,0,Dos.end);
                f.len:=Dos.Seek(fd,f.len,Dos.beginning);
                f.fd:=fd; f.fl:= fl; f.idx:=i;
                Kernel.RegisterObject(f,Finalize);
                f.state:=open; f.pos:=0; f.swapper:=-1; (*all f.buf[i]=NIL*)
                f.registerName:=""
            END
        END
    END;
    RETURN f
END Old;
PROCEDURE Purge*(f:File);
    Reduce the files size to 0.
    i:INTEGER;
BEGIN
    FOR i:=0 TO nofbufs-1 DO
        IF f.bufs[i]#NIL THEN f.bufs[i].org:=-1; f.bufs[i]:=NIL END
    END;
    IF (f.fd#noDesc) & (Dos.SetFileSize(f.fd,0,Dos.beginning)=0) THEN END;
    f.pos:=0; f.len:=0; f.swapper:=-1
END Purge;
PROCEDURE GetDate*(f:File; VAR t,d:LONGINT);
    Get a files date.
    fib:FileInfoBlockPtr;
    sec,min,hour,days,mday,mon,year:LONGINT;
BEGIN
    Create(f); NEW(fib);
    IF Dos.Examine(f.fl,fib^) THEN
        sec:=fib.date.tick DIV Dos.ticksPerSecond;
        min:=fib.date.minute MOD 60;
        hour:=fib.date.minute DIV 60;
        t:=sec+ASH(min,6)+ASH(hour,12);
        days:=fib.date.days+28430; (* Days between 1.1.1978 and 1.3.1900 *)
        year:=(4*days+3) DIV 1461;
        DEC(days,1461*year DIV 4);
        mon:=(5*days+2) DIV 153;
        mday:=days-(153*days+2) DIV 5 +1;
        INC(mon,3);
        IF mon>12 THEN INC(year); DEC(mon,12) END;
        d:=mday+ASH(mon,5)+ASH(year MOD 100,9)
    ELSE
        t:=0; d:=0
END GetDate;
PROCEDURE Pos*(VAR r:Rider):LONGINT;
    Get the position of a rider.
BEGIN
    RETURN r.org+r.offset
END Pos;
PROCEDURE Set*(VAR r:Rider; f:File; pos:LONGINT);
    Set the rider to a specific position within the file.
    buf:Buffer;
    err:ARRAY 25 OF CHAR;
    org,offset,i,n,errno:LONGINT;
    workName,registerName:FileName;
BEGIN
    IF pos>f.len THEN pos:=f.len ELSIF pos<0 THEN pos:=0 END;
    offset:=pos MOD bufsize; org:=pos-offset; i:=0;
    WHILE (i<nofbufs) & (f.bufs[i]#NIL) & (org#f.bufs[i].org) DO INC(i) END;
    IF i<nofbufs THEN
        IF f.bufs[i]=NIL THEN NEW(buf); buf.chg:=FALSE; buf.org:=-1; buf.f:=f; f.bufs[i]:=buf; (* found empty buffer slot. *)
        ELSE buf:=f.bufs[i]; (* found buffer which contains position. *)
        END
    ELSE
            All slots used, but none containing the requested position.
            Swap out one of the buffers.
        f.swapper:=(f.swapper+1) MOD nofbufs;
        buf:=f.bufs[f.swapper];
        Flush(buf)
    END;
    IF buf.org#org THEN
            A new buffer was selected. If the selected position is at the
            end of the file, just an empty buffer is initialized. Otherwise,
            the buffer is loaded from the file.
        IF org=f.len THEN
            buf.size:=0
        ELSE
            Create(f);
            IF f.pos#org THEN n:=Dos.Seek(f.fd,org,Dos.beginning) END;
            n:=Dos.Read(f.fd,buf.data,bufsize);
            IF n<0 THEN errno:=Dos.IoErr();
                IF ~Dos.NameFromLock(f.fl,workName) THEN workName:="" END;
                registerName:=f.registerName;
                err:="read not done"; HALT(99)
            END;
            f.pos:=org+n;
            buf.size:=n
        END;
        buf.org:=org; buf.chg:=FALSE
    END;
    r.buf:=buf; r.org:=org; r.offset:=offset; r.eof:=FALSE; r.res:=0
END Set;
PROCEDURE Read*(VAR r:Rider; VAR x:SYSTEM.BYTE);
    buf:Buffer;
    offset:LONGINT;
BEGIN
    buf:=r.buf; offset:=r.offset;
    IF r.org#buf.org THEN Set(r,buf.f,r.org+offset); buf:=r.buf; offset:=r.offset END;
    IF (offset<buf.size) THEN
        x:=buf.data[offset]; r.offset:=offset+1
    ELSIF r.org+offset<buf.f.len THEN
        Set(r,r.buf.f,r.org+offset);
        x:=r.buf.data[0]; r.offset:=1
    ELSE
        x:=0X; r.eof:=TRUE
END Read;
PROCEDURE ReadBytes*(VAR r:Rider; VAR x:ARRAY OF SYSTEM.BYTE; n:LONGINT);
    buf:Buffer;
    xpos,min,restInBuf,offset:LONGINT;
BEGIN
    IF n>LEN(x) THEN HALT(43) END;
    xpos:=0; buf:=r.buf; offset:=r.offset;
    WHILE n>0 DO
        IF (r.org#buf.org) OR (offset>=bufsize) THEN
            Set(r,buf.f,r.org+offset);
            buf:=r.buf; offset:=r.offset
        END;
        restInBuf:=buf.size-offset;
        IF restInBuf=0 THEN r.res:=n; r.eof:=TRUE; RETURN
        ELSIF n>restInBuf THEN min:=restInBuf
        ELSE min:=n
        END;
        SYSTEM.MOVE(SYSTEM.ADR(buf.data)+offset,SYSTEM.ADR(x)+xpos,min);
        INC(offset,min); r.offset:=offset; INC(xpos,min); DEC(n,min)
    END;
    r.res:=0; r.eof:=FALSE
END ReadBytes;
PROCEDURE Base*(VAR r:Rider):File;
    Get the file on which this rider is based.
BEGIN
    RETURN r.buf.f
END Base;
PROCEDURE Write*(VAR r:Rider; x:SYSTEM.BYTE);
    buf:Buffer;
    offset:LONGINT;
BEGIN
    buf:=r.buf; offset:=r.offset;
    IF (r.org#buf.org) OR (offset>=bufsize) THEN
        Set(r,buf.f,r.org+offset);
        buf:=r.buf; offset:=r.offset
    END;
    buf.data[offset]:=x;
    buf.chg:=TRUE;
    IF offset=buf.size THEN
        INC(buf.size); INC(buf.f.len)
    END;
    r.offset:=offset+1; r.res:=0
END Write;
PROCEDURE WriteBytes*(VAR r:Rider; VAR x:ARRAY OF SYSTEM.BYTE; n:LONGINT);
    xpos,min,restInBuf,offset:LONGINT;
    buf:Buffer;
BEGIN
    IF n>LEN(x) THEN HALT(43) END;
    xpos:=0; buf:=r.buf; offset:=r.offset;
    WHILE n>0 DO
        IF (r.org#buf.org) OR (offset>=bufsize) THEN
            Set(r,buf.f,r.org+offset);
            buf:=r.buf; offset:=r.offset
        END;
        restInBuf:=bufsize-offset;
        IF n>restInBuf THEN min:=restInBuf ELSE min:=n END;
        SYSTEM.MOVE(SYSTEM.ADR(x)+xpos,SYSTEM.ADR(buf.data)+offset,min);
        INC(offset,min); r.offset:=offset;
        IF offset>buf.size THEN INC(buf.f.len,offset-buf.size); buf.size:=offset END;
        INC(xpos,min); DEC(n,min); buf.chg:=TRUE
    END;
    r.res:=0
END WriteBytes;
PROCEDURE Register*(f:File);
    errno:INTEGER;
    file:FileName;
BEGIN
    IF (f.state=create) & (f.registerName#"") THEN f.state:=close (* shortcut renaming *) END;
    Close(f);
    IF f.registerName#"" THEN
        IF ~Dos.NameFromLock(f.fl,file) THEN file:="" END;
        Rename(file,f.registerName,errno);
        IF errno#0 THEN COPY(f.registerName,file); HALT(100) END;
        f.registerName:=""
END Register;
PROCEDURE ChangeDirectory*(path:ARRAY OF CHAR; VAR res:INTEGER);
    lock,oldLock:Dos.FileLockPtr;
BEGIN
    lock:=Dos.Lock(path,Dos.sharedLock);
    IF lock#0 THEN
        oldLock:=Dos.CurrentDir(lock);
        Dos.UnLock(oldLock);
        IF Dos.NameFromLock(lock,CurrentDir) THEN END;
        res:=noError
    ELSE
        res:=directoryNotFound
END ChangeDirectory;
(*----------------- Files1 ----------------*)
    little endian,
    ORD({0})=1,
    false=0,true =1
    IEEE real format,
    null terminated strings,
    compact format according to M.Odersky
PROCEDURE FlipBytes(VAR src,dest:ARRAY OF SYSTEM.BYTE);
    i,j:LONGINT;
BEGIN
    j:=0;
    FOR i:=LEN(src)-1 TO 0 BY -1 DO dest[j]:=src[i]; INC(j) END
END FlipBytes;
PROCEDURE ReadBool*(VAR R:Rider; VAR x:BOOLEAN);
BEGIN
    Read(R,SYSTEM.VAL(CHAR,x))
END ReadBool;
PROCEDURE ReadInt*(VAR R:Rider; VAR x:INTEGER);
    b:ARRAY 2 OF CHAR;
BEGIN
    ReadBytes(R,b,2);
    x:=ORD(b[0])+ORD(b[1])*256
END ReadInt;
PROCEDURE ReadLInt*(VAR R:Rider; VAR x:LONGINT);
    b:ARRAY 4 OF CHAR;
BEGIN
    ReadBytes(R,b,4);
    x:=LONG(ORD(b[0]))+LONG(ORD(b[1]))*100H+LONG(ORD(b[2]))*10000H+LONG(ORD(b[3]))*1000000H
END ReadLInt;
PROCEDURE ReadSet*(VAR R:Rider; VAR x:SET);
    b:ARRAY 4 OF CHAR;
    s2,s3:SET;
    i:LONGINT;
BEGIN
    IF BigEndianSet THEN
        ReadBytes(R,b,4);
        s2:=SYSTEM.VAL(SET,LONG(ORD(b[0]))+LONG(ORD(b[1]))*100H +
        LONG(ORD(b[2]))*10000H +LONG(ORD(b[3]))*1000000H);
        s3:={};
        FOR i:=0 TO 31 DO
            IF i IN s2 THEN INCL(s3,31-i) END
        END;
        x:=s3
    ELSE
        IF BigEndianMachine THEN ReadBytes(R,b,4); FlipBytes(b,x)
        ELSE ReadBytes(R,x,4)
        END
END ReadSet;
PROCEDURE ReadReal*(VAR R:Rider; VAR x:REAL);
    b:ARRAY 4 OF CHAR;
BEGIN
    IF BigEndianMachine THEN ReadBytes(R,b,4); FlipBytes(b,x)
    ELSE ReadBytes(R,x,4)
END ReadReal;
PROCEDURE ReadLReal*(VAR R:Rider; VAR x:LONGREAL);
    b:ARRAY 8 OF CHAR;
BEGIN
    IF BigEndianMachine THEN ReadBytes(R,b,8); FlipBytes(b,x)
    ELSE ReadBytes(R,x,8)
END ReadLReal;
PROCEDURE ReadString*(VAR R:Rider; VAR x:ARRAY OF CHAR);
    i:INTEGER;
    ch:CHAR;
BEGIN
    i:=0; REPEAT Read(R,ch); x[i]:=ch; INC(i) UNTIL ch=0X
END ReadString;
PROCEDURE ReadNum*(VAR R:Rider; VAR x:LONGINT);
    ch:CHAR;
    n:LONGINT;
    s:SHORTINT;
BEGIN
    s:=0; n:=0; Read(R,ch);
    WHILE ORD(ch)>=128 DO INC(n,ASH(LONG(ORD(ch))-128,s) ); INC(s,7); Read(R,ch) END;
    x:=n+ASH(LONG(ORD(ch)) MOD 64-ORD(ch) DIV 64*64,s)
END ReadNum;
PROCEDURE WriteBool*(VAR R:Rider; x:BOOLEAN);
BEGIN
    Write(R,SYSTEM.VAL(CHAR,x))
END WriteBool;
PROCEDURE WriteInt*(VAR R:Rider; x:INTEGER);
    b:ARRAY 2 OF CHAR;
BEGIN
    b[0]:=CHR(x); b[1]:=CHR(x DIV 256);
    WriteBytes(R,b,2)
END WriteInt;
PROCEDURE WriteLInt*(VAR R:Rider; x:LONGINT);
    b:ARRAY 4 OF CHAR;
BEGIN
    b[0]:=CHR(x); b[1]:=CHR(x DIV 100H); b[2]:=CHR(x DIV 10000H); b[3]:=CHR(x DIV 1000000H);
    WriteBytes(R,b,4)
END WriteLInt;
PROCEDURE WriteSet*(VAR R:Rider; x:SET);
    b:ARRAY 4 OF CHAR; i:LONGINT; s2:SET;
BEGIN
    IF BigEndianSet THEN
        s2:={};
        FOR i:=0 TO 31 DO
            IF i IN x THEN INCL(s2,31-i) END
        END;
        i:=SYSTEM.VAL(LONGINT,s2);
        b[0]:=CHR(i); b[1]:=CHR(i DIV 100H); b[2]:=CHR(i DIV 10000H); b[3]:=CHR(i DIV 1000000H);
        WriteBytes(R,b,4)
    ELSE
        IF BigEndianMachine THEN FlipBytes(x,b); WriteBytes(R,b,4)
        ELSE WriteBytes(R,x,4)
        END
END WriteSet;
PROCEDURE WriteReal*(VAR R:Rider; x:REAL);
    b:ARRAY 4 OF CHAR;
BEGIN
    IF BigEndianMachine THEN FlipBytes(x,b); WriteBytes(R,b,4)
    ELSE WriteBytes(R,x,4)
END WriteReal;
PROCEDURE WriteLReal*(VAR R:Rider; x:LONGREAL);
    b:ARRAY 8 OF CHAR;
BEGIN
    IF BigEndianMachine THEN FlipBytes(x,b); WriteBytes(R,b,8)
    ELSE
        WriteBytes(R,x,8)
END WriteLReal;
PROCEDURE WriteString*(VAR R:Rider; x:ARRAY OF CHAR);
    i:INTEGER;
BEGIN
    i:=0; WHILE x[i]#0X DO INC(i) END;
    WriteBytes(R,x,i+1)
END WriteString;
PROCEDURE WriteNum*(VAR R:Rider; x:LONGINT);
BEGIN
    WHILE (x<-64) OR (x>63) DO Write(R,CHR(x MOD 128+128)); x:=x DIV 128 END;
    Write(R,CHR(x MOD 128))
END WriteNum;
PROCEDURE Finalize(obj:SYSTEM.PTR);
    file:File;
    pref:FileName;
    name:FileName;
BEGIN
    file:=SYSTEM.VAL(File,obj);
    ASSERT(file#NIL);
    IF ~Dos.NameFromLock(file.fl,name) THEN name:="" END;
    IF file.fl#0 THEN
        Dos.UnLock(file.fl);
        file.fl:=0
    END;
    IF file.fd#noDesc THEN
        SeekAndExtend(file.fd,file.len);
        IF Dos.Close(file.fd) THEN END;
        file.fd:=noDesc
    END;
    IF file.idx>=0 THEN
        DEC(Kernel.nofiles);
        fileTab[file.idx]:=0
    END;
        test for ".tmp." in first 5 chars and call Dos.Deletefile in
        this case.
    Dos.FilePart(name,pref);
    pref[5]:=0X;
    IF pref=".tmp." THEN
        IF ~Dos.DeleteFile(name) THEN
        END
END Finalize;
PROCEDURE Init;
    i:LONGINT;
    lock:Dos.FileLockPtr;
BEGIN
    I.CurrentTime(startTime,i);
    tempno:=-1;
    lock:=Dos.Lock("",Dos.sharedLock);
    IF ~Dos.NameFromLock(lock,CurrentDir) THEN CurrentDir:="" END;
    Dos.UnLock(lock);
    FOR i:=0 TO fileTabSize-1 DO fileTab[i]:=0 END;
    Kernel.nofiles:=0;
    Amiga.GetSearchPath(searchPath)
END Init;
BEGIN
    Init
END Files.