rust: ffi POC

rust/.gitignore

+*.lock
+target

rust/Cargo.toml

+[package]
+name = "opendht"
+version = "0.1.0"
+authors = ["Sébastien Blin <sebastien.blin@savoirfairelinux.com>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+libc="0.2.0"
\ No newline at end of file

rust/README.md

+# Rust bindings for opendht
+
+## Build
+
+Install rust on your system (https://rustup.rs/ is the recommanded way). Once done:
+
+```
+cargo build
+```
+
+## Run tests
+
+```
+cargo test
+```
\ No newline at end of file

rust/src/lib.rs

+extern crate libc;
+use std::ffi::CString;
+use libc::c_char;
+
+#[repr(C)]
+struct InfoHash {}
+
+#[link(name = "opendht-c")]
+extern {
+    fn dht_infohash_print(h: *const InfoHash) -> *mut c_char;
+    fn dht_infohash_random(h: *mut InfoHash) -> ();
+}
+
+impl InfoHash {
+    pub fn new() -> Box<InfoHash> {
+        let mut h = Box::new(InfoHash {});
+        unsafe {
+            dht_infohash_random(&mut *h);
+        }
+        h
+    }
+    pub fn print(&self) -> CString{
+        unsafe {
+            CString::from_raw(dht_infohash_print(&*self))
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+
+    use super::*;
+
+    #[test]
+    fn print_random_infohash() {
+        println!("{:?}", InfoHash::print(&*InfoHash::new()));
+    }
+}