Bonjour communication wrapper for Objective-C? - objective-c

I've been using MYNetwork by the venerable Jens Alfke for an app of mine that allows devices to connect and share info over the network, it's actually a mission-critical part of the app. I tried writing my own wrapper for all of the C-level stuff you have to do for Bonjour, but it didn't work out so well, so I moved to MYNetwork.
It's been great so far, but the fact it's essentially opaque to me is causing trouble, as is that I want to move over to ARC once we can submit apps with it (there's a lot of Objective-C object references in structs, which ARC hates).
Can anyone recommend a similar wrapper, ideally that allows easy message passing between a client and a server over Bonjour as well as service discovery?

Just a thought- Would using ZeroMQ advertised and discovered by the stock NSNetService suffice? Separating the service pub/sub from the actual communication would allow you to use other bonjour libraries like Avahi on linux too. ZeroMQ is sufficiently simple to make wrapping trivial, yet powerful enough to cope with complex network topologies, fast.
I have experience with both technologies in isolation but not together although I see no reason why it wouldn't work. The only caveat right now is the limited body of collective experience of ZeroMQ use on iOS but I'd expect that to change over time.

You know you can disable ARC for specific files? So, you can just disable ARC for the library, and keep it on for your other files.
Disable Automatic Reference Counting for Some Files

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Applying Non-Standard Power Assertions & Creating Virtual HIDs

I've got a big ask here, but I am hoping someone might be able to help me. If there's another site you think this should be posted on, please let me know.
I'm the developer of the free app Amphetamine for macOS and I'm hoping to add a new feature to the app - keeping a Mac awake while in closed-display (clamshell) mode while not having a keyboard/mouse/power adapter/display connected to the Mac. I get requests to add this feature on an almost daily basis.
I've been working on a solution (and it's mostly ready) which uses a non-App Store helper app that must be download and installed separately. I could still go with that solution, but I want to explore one more option before pushing the separate app solution out to the world.
An Amphetamine user tipped me off that another app, AntiSleep can keep a Mac awake while in closed-display mode, while not meeting Apple's requirements. I've tested this claim, and it's true. After doing a bit of digging into how AntiSleep might be accomplishing this, I've come up with 2 possible theories so far (though there may be more to it):
In addition to the standard power assertion types, it looks like AntiSleep is using (a) private framework(s) to apply non-standard power assertions. The following non-standard power assertion types are active when AntiSleep is keeping a Mac awake: DenySystemSleep, UserIsActive, RequiresDisplayAudio, & InternalPreventDisplaySleep. I haven't been able to find much information on these power assertion types beyond what appears in IOPMLibPrivate.h. I'm not familiar at all with using private frameworks, but I assume I could theoretically add the IOPMLibPrivate header file to a project and then create these power assertion types. I understand that would likely result in an App Store review rejection for Amphetamine, of course. What about non-App Store apps? Would Apple notarize an app using this? Beyond that, could someone help me confirm that the only way to apply these non-standard power assertions is to use a private framework?
I suspect that AntiSleep may also be creating a virtual keyboard and mouse. Certainly, the idea of creating a virtual keyboard and mouse to get around Apple's requirement of having a keyboard and mouse connected to the Mac when using closed-display mode is an intriguing idea. After doing some searching, I found foohid. However, I ran into all kinds of errors trying to add and use the foohid files in a test project. Would someone be willing to take a look at the foohid project and help me understand whether it is theoretically possible to include this functionality in an App Store compatible app? I'm not asking for code help with that (yet). I'd just like some help determining whether it might be possible to do.
Thank you in advance for taking a look.
Would Apple notarize an app using this?
I haven't seen any issues with notarising code that uses private APIs. Currently, Apple only seems to use notarisation for scanning for inclusion of known malware.
Would someone be willing to take a look at the foohid project and help me understand whether it is theoretically possible to include this functionality in an App Store compatible app?
Taking a quick glance at the code of that project, it's clear it implements a kernel extension (kext). Those are not allowed on the App Store.
However, since macOS 10.15 Catalina, there's a new way to write HID drivers, using DriverKit. The idea is that the APIs are very similar to the kernel APIs, although I suspect it'll be a rewrite of the kext as a DriverKit driver, rather than a simple port.
DriverKit drivers are permitted to be included in App Store apps.
I don't know if a DriverKit based HID driver will solve your specific power management issue.
If you go with a DriverKit solution, this will only work on 10.15+.
I suspect that AntiSleep may also be creating a virtual keyboard and mouse.
I haven't looked at AntiSleep, but I do know that in addition to writing an outright HID driver, it's possible to generate HID events using user space APIs such as IOHIDPostEvent(). I don't know if those are allowed on the App Store, but as far as I'm aware, IOKitLib is generally fine.
It's possible you might be able to implement your virtual input device using those.

Passing data between 32 and 64bit cocoa applications

I have a 64 bit cocoa project that needs to use a 32-bit rendering library, which I cannot port to 64-bit.
I decided to separate it to a rendering service, which will be compiled in 32-bit and will provide an interface for the library, and the main project, which will be compiled in 64-bit and will access the rendering service.
I am wondering what is the best way to do the interprocess communication. I am looking for a solution that will provide fast communication and easy api.
It seems that XPC (and specifically, NSXPCConnection) is the recommended solution nowadays. However, I'm not sure - is it implemented for 32-bit applications?
In addition, I need to pass a fairly large quantity of data (max ~5MB), and so I worry about the performance and speed of the XPC. Is shared memory mapping is possible/recommended in this situation? can it work in conjunction with xpc?
For 32-to-64-bit APIs, Apple does use XPC services in their own apps, like Pages, to migrate old data to a more recent API.
Although I have yet to get it to work using NSXPCConnection, and Apple's own apps use the functions found in xpc/xpc.h.

Protobuf vs binary plists for network trafficking in a iOS game

I'm developing experimental multiplayer roguelike for iOS. Players will be connected via GameKit API and they'll be put in one dungeon. There is various actions that players can perform, so I want to make one device be a host, and to implement some sort of RPC for sending/receiving of this actions (and pretty complicated state of dungeon when game starts)
I need some compact and fast serialization. I'm choosing between protobuf and binary plists. Binary plists looks pretty simple to use for objc objects serialization/deserialization (this is important point, cause its experimental non commercial project), but it looks inefficient. Protobuf looks efficient, but totally alien. Any alternatives?
Edit: just found http://msgpack.org/. Looks like a way to go
Protocol buffer serialization should be faster than binary plist.
Also, if you want to make the game again on android or any other platform then protocol buffers will be your friend. (platform independence)
Working with protocol buffers on ios can be a pain in the beginning. Just setting up the project with XCode takes up a lot of time.
Initially i tried to work with objective c version of protobuf, but i had to drop it completely because of some limitations in the library.
I have now added the google source code directly on Xcode, ands its working perfectly. check out this answer. Through this you'll be able to start working with protobufs in your project easily.

How to encrypt or obfuscate objective c code? [duplicate]

This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
iPhone/iPad App Code Obfuscation - Is it Possible? Worth it?
I have spent a lot of time on this and I couldn't able to find a perfect answer. That's why I decided to put my question here. I have an iPhone application and want to encrypt the code to prevent from class-dump or otool utilities. (Tools used to dump out the headers from executable). I would like to know is there any way to encrypt the source code or obfuscate the source code?
It's a lot more complicated than it might seem initially. Any tool that mangles method names has the potential to fudge up:
KVC compliance
The use of dynamically generated selectors
Nib file compatibility
Protocol conformance
Method inheritance
Obfuscation is just another layer to deal with; often obfuscation is easily reversed. It is not really possible to “encrypt” your classes because the Objective-C runtime and Cocoa framework won't know how to decrypt it. Anyone determined enough will eventually figure out how your program works.
Actually you can provide some obfuscation and tamper protection with specialist 3rd party tools. There are 2 companies, I know of, that provide tools or services to do this : Arxan and irDato.
Neither are cheap or accessible to small developers but if you are developing for a large corporation then you should consider them.
Obfuscation is done by mangling code paths and adding redundant instructions so as to confuse anybody trying to reverse engineer the code. Tamper protection is done by adding checksums to the code and embedding checksum checks within functions. You can create a network of interdependent checksums that makes it extremely difficult to bypass them. There are a few other things that can be done but you really need to talk to specialists in this area.
Further to the earlier answer, Apple does not encrypt the binaries but just signs them. It is fairly easy to reverse engineer and modify app binaries on a jailbroken device.
Apparently, according to this answer Apple encrypts iPhone binaries as a matter of course for all iPhone apps.
I'd stop worrying about it.

Applescript Inside of a Cocoa Application

For the application I am writing, I need to access some other applications' items, for which Applescript seems the best way to go. I have been using the Appscript framework, which worked well, because it allowed me to thread it and not make my app lock up when an Applescript was taking a while. However, now I am attempting to make my application 64 bit compatible, and it seems like the Appscript framework does not support 64 bit. Is there a "good" way to use Applescript in Cocoa that will not lock up my application, but still give me the full control I need?
--firen
It seems like SBApplication should work, but I haven't used it before.
According to #cocoadevcentral:
SBApplication: use to make cross-application scripting calls with Objective-C instead of AppleScript. Ex: get current iTunes track.
Here is is the excerpt from the documentation:
The SBApplication class provides a mechanism enabling an Objective-C program to send Apple events to a scriptable application and receive Apple events in response. It thereby makes it possible for that program to control the application and exchange data with it. Scripting Bridge works by bridging data types between Apple event descriptors and Cocoa objects.
Although SBApplication includes methods that manually send and process Apple events, you should never have to call these methods directly. Instead, subclasses of SBApplication implement application-specific methods that handle the sending of Apple events automatically.
For example, if you wanted to get the current iTunes track, you can simply use the currentTrack method of the dynamically defined subclass for the iTunes application—which handles the details of sending the Apple event for you—rather than figuring out the more complicated, low-level alternative:
[iTunes propertyWithCode:'pTrk'];
If you do need to send Apple events manually, consider using the NSAppleEventDescriptor class.
Hope that helps!
As Blaenk mentioned Scripting Bridge may well be the way to go, although it can prove somewhat inefficient if you have to iterating through large arrays etc.
The simplest way to run an Applescript in Cocoa is using NSAppleScript.
Apple has some pretty good examples, which I found useful when I needed to do something similar. There are three articles you might want to take a look at. They all contain some sample code, which I always find very useful.
A Few Examples of using Scripting Bridge
Performance & Optimisation with Scripting Bridge
NSAppleScript Technote/Example
I created a gist with the full URLs as I can't post more than one link, what with being a newbie and all.
http://gist.github.com/130146
it seems like the Appscript framework does not support 64 bit.
Should work. Make sure you set the correct architectures and SDK (64-bit requires 10.5) in the Xcode project. File a bug report if you have a specific problem.