There are two secp256k1 implementations that are related to Bitcoin-Core:
bitcoin-core/secp256k1
bitcoin/src/secp256k1
What is the more authoritative implementation?
What secp256k1 library should be used?
As far as I'm concerned, that's the same thing. The most recent version is here bitcoin-core/secp256k1 and from time to time is pulled by developers in bitcoin/src/secp256k1
Related
While writing my code I thought of having a common implementation for all POSIX OSes as opposed to separate implementation for each OS. One of the POSIX API I use is posix_fallocate() and while testing I found it not being supported by MacOS.
Had I known this earlier I would have not used this API or have had separate implementations for each OS.
So my question is - what is an easy way to find support for a particular posix call in different OSes? Do people always have to search documentation for each target OS?
Thanks.
Looking at the documentation is a good start, but it often won't tell you when a particular function has been implemented, which is also important. For obscure platforms, it may be difficult to tell which older versions are still relevant, which makes it even harder to decide whether a dependency on a particular POSIX feature is acceptable.
The other question is whether a feature is implemented, but with substandard quality. posix_fallocate is an interesting corner case in this regard. The glibc implementation uses emulation if the file system lacks support for an actual low-level fallocate operation (such as NFS until recently):
https://www.gnu.org/software/libc/manual/html_node/Storage-Allocation.html
Depending on what your application does, this behavior might not be acceptable. Just checking header files and documentation might not reveal this (the Note part in the documentation above was added only recently, for example).
In the end, there isn't a good substitute for building and testing as early as possible on all relevant targets, but I understand that this is increasingly difficult for non-Linux targets.
Hoping to hear from some more experienced developers (completely new to protobufs as of yesterday). I've been researching how to get protobufs to work with iOS given that Google doesn't have a homegrown library for objective C.
Experimenting a bit, it seems there are two general approaches:
Use a third-party library - Booyah's objective C compiler - (https://github.com/booyah/protobuf-objc).
The issue is that it won't compile with protobuf 2.5.0, and requires 2.4.1. Does anyone see a compelling reason NOT to use this method and use the older version of protobufs?
Use C++ generated protobuf classes with some tweaking - (http://www.kotancode.com/2012/10/14/using-google-protocol-buffers-in-objective-c-on-ios-and-the-mac/)
This doesn't seem like a very clean approach and C++ bleeding into objective-C code doesn't sound like fun.
On a related note, I can't find any documentation on cleanly uninstalling 2.5.0 if I opted for the former approach. What's the easiest way to do this?
Thanks.
Looking for some fast, simple and stable RPC library I stumbled upon MessagePack project which seems to be very good. It is also under active development.
If you used it in any way, could you please share your experience?
P.S. I think this question should be community wiki
Well, after some time I found that MessagePack is not well-documented (there was even non-working tutorial in Wiki for Java), there are like 7 outstanding bugs several months old without any replies. Code even is not JavaDoc'ed so that you can take and learn it quickly...
But it seems developer activity there is quite high despite of some outstanding pull requests from the community, that are several months old.
So, well, if GPL suits you, go for ICE. If not... don't know yet. Still looking.
I'm also looking into a fast, cross-platform, cross-language, non-GPL-licensed RPC library.
From looking at the C++ source of MessagePack it seems that it doesn't work on Win32 though, which is a requirement for myself.
Except for that that single item it is on top of my list of serialization/RPC libraries.
http://msgpack.org/ - Win32 missing
http://avro.apache.org/
http://thrift.apache.org/ - Win32 missing
http://bert-rpc.org/
http://www.xmlrpc.com/
http://json-rpc.org/ - GPL license
http://code.google.com/p/protobuf/ - RPC missing
Where can I find the source code for the Objective-C language? Is it open-source or is there an open-sourced implementation of it available?
It really depends on what you mean by Objective-C, there are compilers, runtimes and libraries for it.
http://opensource.apple.com/ Contains much of Apple's source code for OS X and iOS.
you can also see http://clang.llvm.org/ for a compiler.
GNUstep is an open source implementation of OpenStep (Cocoa).
I think you are asking for Cocoa - and this is not open source. All you have are the header and reverse engineering tools.
Looking around, I've found several copies of Objective-C's source code. Apple maintains it at http://opensource.apple.com/source/objc4/, which is up to date as of OS X 10.9.x Mavericks at version 551.1, but I have also found several repositories GitHub that are copies of this main repository which people have made at various points in time, so they may or may not be as up to date as Apple's main repository. These include the GitHub repositories "opensource-apple/objc4" at version 532.2; "bavarious/objc4," which is up to date at version 551.1; "macmade/OBJC4-437.1-Runtime," which obviously includes just the Objective-C runtime at version 437.1; "Apple-FOSS-Mirror/objc4" at version 532.2; "aosm," which is up to date at version 551.1; "robertvojta/objc4," which is up to date at version 551.1; "j4n0/objc4-532," which is obviously at version 532.0; and "chenniaoc/objc4-551.1," which is obviously up to date at version 551.1. Personally, it seems to me that robertvojta/objc4 is the best repository from which you could possibly fork code due to the fact that it's got every single release from Apple's Open Source website so far copied over to it.
There is no one source code. There would be as many different versions as there are compilers for the language. They would likely be written in a low-level language such as assembly or C, and be vastly complicated. For whichever compiler you are interested in, you will need to confirm that it is open-source, which I find unlikely. Even then, it may be difficult.
I'm getting ready to deploy the first release of our software, version 1.0. Once it's out to our customer, inevitably, some bugs will be found. When I fix those bugs though, I'm not sure what "best practice" is for versioning it. When I release the fixes, would that be an entirely new version (in maven), such as 1.01 (or whatever the increment is, 1.1 for example)? Or would it still be 1.0 with some sort of classifier (maybe a date tag)?
Thanks,
Jeff
Wikipedia has a surprisingly thorough discussion of software versioning. It covers all the major points and discusses most of the approaches I've seen.
(In your specific case I'd go with 1.0.1 which would generally be regarded as "an update to 1.0 with no significant feature additions")
You have to change the number in order for maven clients to recognize a newer version in the repository. The change is up to you. I'm sure there's a best practice document somewhere but my company dictates the numbers we use so I've never looked for one.