1 LDK Java and TypeScript Bindings
2 ================================
4 This repo contains an autogeneration system to generate LDK bindings for garbage-collected languages, currently including Java and TypeScript. See below for the current status of the bindings.
6 The auto-generated code contains copies of the Rust documentation, which can also be viewed at
7 [docs.rs/lightning](https://docs.rs/lightning). High-level documentation of the API can be found at
8 [lightningdevkit.org](https://lightningdevkit.org).
13 A release build of the Java bindings library for Linux is available in git. Thus, the bindings should work as long as the `LD_LIBRARY_PATH` includes the top-level directory of this repository.
15 To build the bindings locally, the bindings require some additional work which is still making its
16 way upstream, for now it should be built against the
17 [rust-lightning 2022-07-109-java-bindings branch on git.bitcoin.ninja](https://git.bitcoin.ninja/?p=rust-lightning;a=shortlog;h=refs/heads/2022-07-109-java-bindings).
18 Check that branch out locally as well as [ldk-c-bindings](https://github.com/lightningdevkit/ldk-c-bindings)
19 and run the `genbindings.sh` script in ldk-c-bindings to build the required binaries. Thereafter,
20 in this repo, run the `genbindings.sh` script with the first argument pointing to the ldk-c-bindings
21 directory, the second the relevant JNI CFLAGS, the third argument set to `true` or `false` to
22 indicate whether building in debug mode, and the third set to true or false to indicate if the
23 bindings should be built with workarounds required for Android. JNI CFLAGS on debian are likely
24 "-I/usr/lib/jvm/java-11-openjdk-amd64/include/ -I/usr/lib/jvm/java-11-openjdk-amd64/include/linux/".
25 When running a program linking against the library in debug mode, LD_PRELOAD should likely include
26 the relevant `libclang_rt.asan-platform.so` path.
28 Note that building with address sanitizer is only supported on MacOS with upstream clang (ie where
29 the LLVM version in use matches the LLVM version against which rustc was built), not with Apple clang.
30 Builds with Apple clang will work fine, but largely only be useful in a release context.
31 To build on Mac with address sanitizer, you will need to run `ldk-c-bindings`' `genbindings.sh`
32 script with upstream clang in your PATH and likely replace your $JAVA_HOME/bin/java with a simple
33 wrapper which calls java after an export like:
34 `export DYLD_INSERT_LIBRARIES=/path/to/upstream/llvm/lib/clang/12.0.0/lib/darwin/libclang_rt.asan_osx_dynamic.dylib`
36 To build for Apple M1 (ie aarch64-apple-darwin), you probably want something like
37 `CC="clang --target=aarch64-apple-darwin" LDK_TARGET=aarch64-apple-darwin LDK_TARGET_CPU=generic ./genbindings.sh ...`
44 While the underlying library and C bindings are relatively mature, the Java bindings should be
45 considered beta quality and some issues may still appear. Specifically, because the Java bindings
46 map between two very different memory models - Rust's strict ownership model and Java's reference
47 cloning and garbage collection - a lot of work occurs in the background to keep the Java GC
48 informed of Rust ownership semantics.
50 The debug-mode build includes memory leak tracking and will print all loose objects when the
51 program exists, though without calls to `System.gc(); System.runFinalization();` immediately before
52 exit there will likely be many false positives. While it will require some complicated usage, there
53 are likely some use-after-free or unkonwn-free bugs remaining. The debug-mode build links LLVM
54 address sanitizer and will print diagnostic information in case of such issues.
58 The TypeScript bindings are functionally complete, but should be considered early alpha quality.
59 Some functions may error spuriously due to oversights or missing implementations.
61 The TypeScript bindings require modern web standards, including support for `FinalizationRegistry`
62 and `WeakRef` (Chrome 84, Firefox 79, Safari 14.1/iOS 14.5 and Node 14.6) and WASM BigInt support
63 (Chrome 85, Firefox 78, Safari 14.1/iOS 14.5, and Node 15.0).
65 For users of Node.JS environments you may wish to use the `lightningdevkit-node-net` package as
66 well to implement the required network handling to bridge the `lightningdevkit` package's
67 `SocketDescriptor` interface to Node.JS TCP Sockets. For those wishing to run a lightning node in
68 the browser you will need to provide your own bridge from `SocketDescriptor` to a WebSocket proxy.
72 The only known issue resulting in a use-after-free bug requires custom a custom ChannelKeys instance
73 created as a part of a new channel. After the channel is created, the ChannelKeys object will not
74 be freed while the parent ChannelManager exists, however if the ChannelManager is garbage collected
75 while a ChannelMonitor object which is associated with the same channel exists, a use-after-free bug
76 may occur. This issue should be relatively rare as uses where a ChannelManager is removed while
77 associated ChannelMonitors exist is not anticipated.