opendht/rust/BUILD.md

Building and Testing the Rust Crate

The opendht crate links to the native OpenDHT C library. Cargo does not build or bundle that library. Install Rust and the native dependencies described in the OpenDHT build guide.

Install the Native Library

From the root of an OpenDHT source checkout, enable the C bindings:

cmake -S . -B build-bindings -DOPENDHT_C=ON -DBUILD_TESTING=ON
cmake --build build-bindings
ctest --test-dir build-bindings -R test_c --output-on-failure
cmake --install build-bindings

Installation may require administrator privileges, depending on the install prefix. Set CMAKE_INSTALL_PREFIX when configuring to choose another location. The linker and runtime loader must be able to find the installed libraries. Applications can then depend on opendht from crates.io as shown in the README.

Use an Uninstalled Native Build

You can use the native build directly by setting its library search paths. For example, from the repository root on macOS:

export LIBRARY_PATH="$PWD/build-bindings${LIBRARY_PATH:+:$LIBRARY_PATH}"
export DYLD_LIBRARY_PATH="$PWD/build-bindings${DYLD_LIBRARY_PATH:+:$DYLD_LIBRARY_PATH}"
export RUSTFLAGS="-L native=$PWD/build-bindings"
cargo test --manifest-path rust/Cargo.toml --all-targets

On Linux use LD_LIBRARY_PATH instead of DYLD_LIBRARY_PATH; on Windows add the native DLL directory to PATH. For an application outside this checkout, use absolute paths to the native build and run Cargo in the application directory.

When linking an AddressSanitizer native build, use the same compiler runtime. For example, with Clang:

export RUSTFLAGS="-L native=$PWD/build-bindings -C linker=clang -C link-arg=-fsanitize=address"

Build and Test the Crate

With the native library available, run from the rust directory:

cargo build --all-targets
cargo test --all-targets
cargo test --doc
cargo test --all-features --all-targets
cargo test --all-features --doc

Run the Examples

From the rust directory:

cargo run --example dhtnode
cargo run --features async --example dhtnode_async
cargo run --features serde --example dhtnode_async

The callback example contacts a public bootstrap server. The async example uses two loopback nodes; enabling serde also demonstrates typed MessagePack records.