Celestin Apprentice 2/Apprentice-Release2.iso/Source Code/Libraries/TurboTCP 2.0.1/TurboTCP source/UTurboTCP.cp

Text File | 1994-07-11 | 4.5 KB | 186 lines | [TEXT/MPCC]

/*
** UTurboTCP.cp
**
**    TurboTCP support library
**    Utility functions
**
**    Copyright © 1993-94, FrostByte Design / Eric Scouten
**
*/

#include "UTurboTCP.h"

#include "CTCPDriver.h"
#include "CTCPResolverCall.h"


extern Boolean            gInBackground;        // TCL global: in background under MultiFinder


//    —— opening/closing TCP services ——

/*______________________________________________________________________
**
** InitTCP (static method)
**
**    Create a TCP driver object and initialize it. Should be called once at application startup.
**    In a future version of TurboTCP, this routine will check for MacTCP and/or Open Transport
**    and open the appropriate object.
**
*/

void UTurboTCP::InitTCP()

{
    if (!CTCPDriver::gTCPDriver)
        new CTCPDriver;
}


/*______________________________________________________________________
**
** CloseTCP (static method)
**
**    Close the TCP driver object and destroy it. Should be called once at application
**    shut-down time.
**
*/

void UTurboTCP::CloseTCP()

{
    if (CTCPDriver::gTCPDriver)
        (CTCPDriver::gTCPDriver)->Dispose();
}


//    —— processing network events ——

/*______________________________________________________________________
**
** ProcessNetEvents (static method)
**
**    Call once at every event-loop (or frequent non-interrupt-level) to handle processing
**    of TCP completions and notifications.
**
**        maxEventsToProcess (short):    maximum number of TCP events to process this time
**        maxTicks (long):            maximum ticks to spend in this loop
**                                    positive values:    use value “as is”
**                                    zero:            use intelligent default
**                                    negative value:        use value with compensation
**                                                        for background activities
*/

void UTurboTCP::ProcessNetEvents(short maxEventsToProcess, long maxTicks)

{
    static long        lastTickCount = 0;            // tick count last time through routine
    long            stopTickCount;                // tick count to stop processing events
    long            defaultNetTicks;            // how long are we typically in net event loop
    long            defaultNetWait;                // how long to delay before each net event loop


    // if no TCP driver, quit now

    if (!CTCPDriver::gTCPDriver)
        return;


    // decide how long we can go through net event loop

    if (maxEventsToProcess < 1)
        maxEventsToProcess = 100;
    if (lastTickCount == 0)
        lastTickCount = LMGetTicks();

    if (!gInBackground) {
        defaultNetTicks = 45;                            // spend up to 3/4 second on net events
        defaultNetWait = 0;                                //    if in foreground
    }
    else {
        defaultNetTicks = 40;                            // consume less time in background
        defaultNetWait = 3;                                //    and give other apps more chance to
                                                    //    do meaningful work
    }


    // adjust time in net event loop to other CPU activity

    if (maxTicks < 1) {
        long elapsedTicks = LMGetTicks() - lastTickCount;        // long time, no see?

        if (elapsedTicks < defaultNetWait)                    // ensure that other apps can do meaningful
            return;                                    //    stuff before we hog the CPU again

        if (maxTicks < 0)                                // negative maxTicks values will override
            defaultNetTicks = -maxTicks;                    //    earlier decision of how much time

        maxTicks = defaultNetTicks - elapsedTicks;            // reduce time if CPU is otherwise busy

        if (maxTicks < 2)                                // make sure we get at least a little time
            maxTicks = 2;
        if (maxTicks > defaultNetTicks)                        // not sure how this would happen, but …
            maxTicks = defaultNetTicks;
    }


    // record the current time

    lastTickCount = LMGetTicks();
    stopTickCount = lastTickCount + maxTicks;


    // loop through async event queue (until queue is empty or time is up)

    while ((maxEventsToProcess-- > 0) && (LMGetTicks() < stopTickCount)) {
        if (!(CTCPDriver::gTCPDriver)->ProcessOneNetEvent())
            break;                        // no more events to process
    }


    // rerecord current time (in case net event processing was incredibly slow)

    lastTickCount = LMGetTicks();

}


//    —— IP address utilities ——

/*______________________________________________________________________
**
** GetLocalIPAddr (static method)
**
**    Get the local machine’s IP address.
**
**        return (unsigned long):    the local IP address
**
*/

unsigned long UTurboTCP::GetLocalIPAddr()

{
    if (CTCPDriver::gTCPDriver)
        return (CTCPDriver::gTCPDriver)->GetIPAddr();
    else
        return 0L;
}


/*______________________________________________________________________
**
** DoAddrToStr (static method)
**
**    Convert an IP address to dotted decimal format.
**
**        theIPaddr (unsigned long):    the IP address to convert
**        theString (char*):        pointer to a buffer for the string (16 chars)
**
*/

void UTurboTCP::DoAddrToStr(unsigned long theIPaddr, char* theString)

{
    CTCPResolverCall::DoAddrToStr((ip_addr) theIPaddr, theString);
}