/*

    File:       QNetworkAdditions.m

    Contains:   Works around various NSNetService problems.

    Written by: DTS

    Copyright:  Copyright (c) 2012 Apple Inc. All Rights Reserved.

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                The Apple Software is provided by Apple on an "AS IS" basis. 

                APPLE MAKES NO WARRANTIES, EXPRESS OR IMPLIED, INCLUDING

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*/

#import "QNetworkAdditions.h"

@implementation NSNetService (QNetworkAdditions)

- (BOOL)qNetworkAdditions_getInputStream:(out NSInputStream **)inputStreamPtr 

    outputStream:(out NSOutputStream **)outputStreamPtr

    // The following works around three problems with -[NSNetService getInputStream:outputStream:]:

    //

    // o <rdar://problem/6868813> -- Currently the returns the streams with 

    //   +1 retain count, which is counter to Cocoa conventions and results in 

    //   leaks when you use it in ARC code.

    //

    // o <rdar://problem/9821932> -- If you create two pairs of streams from 

    //   one NSNetService and then attempt to open all the streams simultaneously, 

    //   some of the streams might fail to open.

    //

    // o <rdar://problem/9856751> -- If you create streams using 

    //   -[NSNetService getInputStream:outputStream:], start to open them, and 

    //   then release the last reference to the original NSNetService, the 

    //   streams never finish opening.  This problem is exacerbated under ARC 

    //   because ARC is better about keeping things out of the autorelease pool.

{

    BOOL                result;

    CFReadStreamRef     readStream;

    CFWriteStreamRef    writeStream;

    result = NO;

    readStream = NULL;

    writeStream = NULL;

    if ( (inputStreamPtr != NULL) || (outputStreamPtr != NULL) ) {

        CFNetServiceRef     netService;

        netService = CFNetServiceCreate(

            NULL, 

            (__bridge CFStringRef) [self domain], 

            (__bridge CFStringRef) [self type], 

            (__bridge CFStringRef) [self name], 

            0

        );

        if (netService != NULL) {

            CFStreamCreatePairWithSocketToNetService(

                NULL, 

                netService, 

                ((inputStreamPtr  != nil) ? &readStream  : NULL), 

                ((outputStreamPtr != nil) ? &writeStream : NULL)

            );

            CFRelease(netService);

        }

        // We have failed if the client requested an input stream and didn't 

        // get one, or requested an output stream and didn't get one.  We also 

        // fail if the client requested neither the input nor the output 

        // stream, but we don't get here in that case.

        result = ! ((( inputStreamPtr != NULL) && ( readStream == NULL)) || 

                    ((outputStreamPtr != NULL) && (writeStream == NULL)));

    }

    if (inputStreamPtr != NULL) {

        *inputStreamPtr  = CFBridgingRelease(readStream);

    }

    if (outputStreamPtr != NULL) {

        *outputStreamPtr = CFBridgingRelease(writeStream);

    }

    return result;

}

@end