Developer CD Series 1994 June: Reference Library/Dev.CD Jun 94.toast/Periodicals/develop/develop Issue 11/develop 11 code/The NetWork Project/Examples (Sources)/TrivialLookUp.p

Text File | 1992-07-15 | 4.3 KB | 194 lines | [TEXT/MPS ]

{file TrivialLookUp. This is a sample implementation for a trivial look-up system.
Include a reference to this file and unit in your "uses" clause, compile and link
to TrivialLookUp.p.o before linking to NetWorkLib.o.

Trivial solutions:
    Register:     we do not register at all. Hence we can only be addressed, if a local NetWork
                processor knows us.
    SetSearch:     we only default search allowed.
    Active:        always claim true.
    Random:        return broadcast address
    Next:        return local address
    }

{     © Copyright 1991 The NetWork Project, StatLab Heidelberg.   }
{     © Copyright 1991 G. Sawitzki, Heidelberg.   }

unit NetWorkLookup;

interface

{ The compile time variables NlServer and NlClient are only included to make
comparisons with full implementations easier}
{ use "pascal -d NlServer=false" if you don´t want to register your own names }

{$IFC Undefined NlServer}
{$SETC NlServer:=true}
{$ENDC}

{ use "pascal -d NlClient=false" if you don´t want to look for other programs }

{$IFC Undefined NlClient}
{$SETC NlClient:=true}
{$ENDC}

uses    Types,
        Errors,
        NetWork;


{$IFC UNDEFINED UsingAppletalk}
type Str32 = String [32];
{$ENDC}

{    =============================================================    }

{    name lookup - identication of possible partners }

const
    nlVersion    = -31100;    { -- no appletalk version 48 or higher, could be removed }
    nlTaskErr    = -31103;     { -- routines called in wrong order }
    nlNotFound    = -31104;     { -- used internally }
    nlDupReg    = -31105;     { -- called NlRegister twice }
    nlNoReg        = -31106;     { -- called NlDeregister without NlRegister }
    nlAtkOffErr = -31108;    { -- appletalk off, cannot use function }


    nlLocal        = 0;    { can be used instead of local to denote this machine }
    nlBroadcast    = -1;    { bradcast address, all of this cable }

function NlNode : longint;

{$IFC NlClient}


function NlSetSearch (NlName, NlType, NlZone : Str32) : OSErr;

{    start/stop of NL task }

function NlStart : OSErr;
function NlStop : OSErr;

function NlCount : integer;    { or OSErr, if error, NlCount returns the number of partners found. }
function NLActive (who:longint) : boolean;    { is who still on the list ? }
function NLRandom : longint; { any partner. returns 0 on error.}
function NLNext(after:longint) : longint;    { next partner. NLNext(0) retrurns first. returns 0 on error. }
function NlTask : OSErr;        { call this function periodically }
function NlGetSleep : longint;        { time that may elapse until next call to NlTask  }

{$ENDC}

{$IFC NlServer}

{    register a server, pass '' to use choosername, only one entity can be registered }

function NlRegister (NlName, NlType : Str32) : OSErr;
function NlDeregister : OSErr;

{$ENDC}

function NlInit : OSErr;

{ this function is obsolete and should no longer be used.
function NlExit : OSErr;
}

implementation


{    =============================================================    }

{    name lookup - identication of possible partners }

{ this function returns 0 if appletalk is down or driver/appletalk transport not installed }

function NlNode : longint;
begin
    NlNode := 0;
end;

{$IFC NlServer}

function NlRegister : OSErr;
begin
    NlRegister:=noErr;
end;

function NlDeregister : OSErr;
begin
    NlDeregister:=noErr;
end;
{$ENDC}

{$IFC NlClient}
function NlSetSearch (NlName, NlType, NlZone : Str32) : OSErr;
{trivial implementation checks whether parameters correspond to defaults =
'=:Network Processor@*' }
begin
    if (NlName<>'=') | (NlType<> 'Network Processor') | (NlZone <>'*')
    then {not default search target}
        NlSetSearch := nlNotFound {error code recycled}
    else
        NlSetSearch := noErr;
end;


function NlStart : OSErr;
begin
     NlStart := noErr;
end;

function NlStop : OSErr;
begin
    NlStop := noErr;
end;

function NlCount : integer;
begin
    NlCount := 0;
end;

function NLActive(who:longint):boolean;
begin
    NlActive:=true
end;

function NLRandom:longint;
begin
        NLRandom:=nlBroadcast;
end;

function NLNext(after:longint):longint;
var scr,NrOthers:integer;
begin
        NLNext:= 0;
end;

function NlTask : OSErr;        { call this function periodically }
begin
    NlTask:=NoErr;
end;

function NlGetSleep : longint;        { time that may elapse until next call to NlTask  }
begin
    NlGetSleep:=maxlongint;
end;

{$ENDC}

{    =============================================================    }


function NlInit : OSErr;
begin
    NlInit:=NoErr;
end;

function NlExit : OSErr;
begin
    NlExit:=NoErr;
end;


end.