Feature/599 add rust bindings

misc/experimental/rust/CMakeLists.txt

@@ -25,8 +25,16 @@ if (CELIX_RUST_EXPERIMENTAL)
     )
     FetchContent_MakeAvailable(Corrosion)
 
+    #Prepare a list of include paths needed to generating bindings for the Apache Celix C API
+    file(GENERATE
+            OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/include_paths.txt"
+            CONTENT "$<TARGET_PROPERTY:framework,INTERFACE_INCLUDE_DIRECTORIES>;$<TARGET_PROPERTY:utils,INTERFACE_INCLUDE_DIRECTORIES>"
+    )
+
     corrosion_import_crate(MANIFEST_PATH Cargo.toml)
-    corrosion_add_target_local_rustflags(rust_bundle_activator  "-Cprefer-dynamic")
+
+    corrosion_add_target_local_rustflags(rust_bundle_activator "-Cprefer-dynamic")
+    corrosion_link_libraries(rust_bundle_activator Celix::framework)
 
     #Note corrosion_import_crate import creates a rust_bundle_activator CMake target, but this is a INTERFACE target.
     #Using the INTERFACE_LINK_LIBRARIES property we can get the actual target.
@@ -41,5 +49,4 @@ if (CELIX_RUST_EXPERIMENTAL)
             Celix::shell_tui
             rust_bundle
     )
-
 endif ()

misc/experimental/rust/Cargo.toml

@@ -17,5 +17,6 @@
 
 [workspace]
 members = [
+    "celix_bindings",
     "hello_world_activator",
 ]

misc/experimental/rust/README.md

@@ -26,3 +26,26 @@ and is not intended to be used in production.
 
 Ideally Rust support is done by adding a Rust API for Apache Celix and use that API for Rust bundles, the current
 implementation only shows that is possible to write a bundle in Rust that gets called by Apache Celix framework. 
+
+# Building
+
+To build rust source the Corrosion cmake module is used. This module will be automatically downloaded when building 
+using `FetchContent_Declare`.
+
+To actual build the rust source files both the rust compiler and cargo are required. For ubuntu this can be installed
+using apt:
+```bash
+sudo apt install rustc cargo
+```
+It is possible to define C bindings in rust manually, but this is a lot of work and error prone. Rust has a tool called
+bindgen which can generate C bindings from a C header file. This is used to generate the C bindings for Apache Celix.
+bindgen is used in the build.rs of the rust package `celix_bindings`.
+
+It is also possible to run bindgen manually, for example:
+```bash
+cargo install bindgen # install bindgen, only needed once
+PATH=$PATH:$HOME/.cargo/bin # add cargo bin to path
+
+cd misc/experimental/rust/celix_bindings
+bindgen -o src/celix_bindings.rs celix_bindings.h -- -I<celix_framework_include_dir> -I<celix_utils_include_dir>
+```

misc/experimental/rust/celix_bindings/Cargo.toml

@@ -0,0 +1,28 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+[package]
+name = "celix_bindings"
+version = "0.0.1"
+
+[build-dependencies]
+bindgen = "0.66.1"
+
+[lib]
+name = "celix_bindings"
+path = "src/lib.rs"
+crate-type = ["rlib"]

misc/experimental/rust/celix_bindings/build.rs

@@ -0,0 +1,65 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ *  KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+extern crate bindgen;
+
+use std::error::Error;
+use std::path::PathBuf;
+use std::fs::File;
+use std::io::{self, BufRead};
+use std::env;
+
+fn print_include_paths() -> Result<Vec<String>, Box<dyn Error>> {
+    let build_dir = PathBuf::from(env::var("CORROSION_BUILD_DIR").unwrap());
+    let include_path_file = build_dir.join("include_paths.txt");
+
+    //let include_path_file = Path::new("include_paths.txt");
+    let file = File::open(&include_path_file)?;
+    let reader = io::BufReader::new(file);
+    let mut include_paths = Vec::new();
+    let line = reader.lines().next().ok_or("Expected at least one line")??;
+    for path in line.split(';') {
+        include_paths.push(path.to_string());
+    }
+    Ok(include_paths)
+}
+
+fn main() {
+    println!("cargo:info=Start build.rs for celix_bindings");
+    let include_paths = print_include_paths().unwrap();
+
+    let mut builder = bindgen::Builder::default()
+        .header("src/celix_bindings.h");
+
+    // Add framework and utils include paths
+    for path in &include_paths {
+        builder = builder.clang_arg(format!("-I{}", path));
+    }
+
+    // Gen bindings
+    let bindings = builder
+        .generate()
+        .expect("Unable to generate bindings");
+
+
+    let out_path = PathBuf::from(env::var("OUT_DIR").unwrap());
+    bindings
+        .write_to_file(out_path.join("celix_bindings.rs"))
+        .expect("Couldn't write Apache Celix bindings!");
+}

misc/experimental/rust/celix_bindings/src/celix_bindings.h

@@ -0,0 +1,32 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ *  KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+/**
+ * @file celix_bindings.h
+ * @brief A header files that includes all Apache Celix headers used to create bindings.
+*/
+
+#include "celix_errno.h"
+#include "celix_properties.h"
+#include "celix_filter.h"
+
+#include "celix_bundle_context.h"
+#include "celix_framework.h"
+#include "celix_framework_factory.h"
+#include "celix_framework_utils.h"

misc/experimental/rust/celix_bindings/src/lib.rs

@@ -0,0 +1,41 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ *  KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+#[allow(non_camel_case_types, non_snake_case, non_upper_case_globals, dead_code)]
+ mod bindings {
+      include!(concat!(env!("OUT_DIR"), "/celix_bindings.rs"));
+ }
+pub use bindings::*;
+
+//Note C #defines (compile-time constants) are not all generated in the bindings.
+pub const CELIX_SUCCESS: celix_status_t = 0;
+pub const CELIX_BUNDLE_EXCEPTION: celix_status_t = 70001;
+
+// Move to celix_api lib
+pub mod celix {
+
+    #[warn(unused_imports)]
+    pub enum LogLevel {
+        Trace = ::bindings::celix_log_level_CELIX_LOG_LEVEL_TRACE as isize,
+        Debug = ::bindings::celix_log_level_CELIX_LOG_LEVEL_DEBUG as isize,
+        Info = ::bindings::celix_log_level_CELIX_LOG_LEVEL_INFO as isize,
+        Warn = ::bindings::celix_log_level_CELIX_LOG_LEVEL_WARNING as isize,
+        Error = ::bindings::celix_log_level_CELIX_LOG_LEVEL_ERROR as isize,
+    }
+}

misc/experimental/rust/hello_world_activator/Cargo.toml

@@ -17,8 +17,12 @@
 
 [package]
 name = "rust_bundle_activator"
-version = "0.1.0"
+version = "0.0.1"
+
+[dependencies]
+celix_bindings = { path = "../celix_bindings" }
 
 [lib]
 name = "rust_bundle_activator"
+path = "src/lib.rs"
 crate-type = ["cdylib"]

misc/experimental/rust/hello_world_activator/src/lib.rs

@@ -17,16 +17,91 @@
  * under the License.
  */
 
+extern crate celix_bindings;
+
+use std::error::Error;
 use std::os::raw::c_void;
+use std::ffi::CString;
+use std::ffi::NulError;
+use celix_bindings::*; //Add all Apache Celix C bindings to the namespace (i.e. celix_bundleContext_log, etc.)
+
+struct RustBundle {
+    name: String,
+    ctx: *mut celix_bundle_context_t,
+}
+
+impl RustBundle {
+
+    unsafe fn new(name: String, ctx: *mut celix_bundle_context_t) -> Result<RustBundle, NulError> {
+        let result = RustBundle {
+            name,
+            ctx,
+        };
+        result.log_lifecycle("created")?;
+        Ok(result)
+    }
+
+    unsafe fn log_lifecycle(&self, event: &str) -> Result<(), NulError> {
+        let id = celix_bundleContext_getBundleId(self.ctx);
+        let c_string = CString::new(format!("Rust Bundle '{}' with id {} {}!", self.name, id, event))?;
+        celix_bundleContext_log(self.ctx, celix_log_level_CELIX_LOG_LEVEL_INFO, c_string.as_ptr());
+        Ok(())
+    }
+
+    unsafe fn start(&self) -> Result<(), NulError> {
+        self.log_lifecycle("started")
+    }
+
+    unsafe fn stop(&self) -> Result<(), NulError> {
+        self.log_lifecycle("stopped")
+    }
+}
+
+impl Drop for RustBundle {
+    fn drop(&mut self) {
+        unsafe {
+            let result = self.log_lifecycle("destroyed");
+            match result {
+                Ok(()) => (),
+                Err(e) => println!("Error while logging: {}", e),
+            }
+        }
+    }
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn celix_bundleActivator_create(ctx: *mut celix_bundle_context_t, data: *mut *mut c_void) -> celix_status_t {
+    let rust_bundle = RustBundle::new("Hello World".to_string(), ctx);
+    if rust_bundle.is_err() {
+        return CELIX_BUNDLE_EXCEPTION;
+    }
+    *data = Box::into_raw(Box::new(rust_bundle.unwrap())) as *mut c_void;
+    CELIX_SUCCESS
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn celix_bundleActivator_start(data: *mut c_void, _ctx: *mut celix_bundle_context_t) -> celix_status_t {
+    let rust_bundle = &*(data as *mut RustBundle);
+    let result = rust_bundle.start();
+    match result {
+        Ok(()) => CELIX_SUCCESS,
+        Err(_) => CELIX_BUNDLE_EXCEPTION,
+    }
+}
 
 #[no_mangle]
-pub unsafe extern "C" fn celix_bundleActivator_start(_data: *mut c_void, _context: *mut c_void) -> i32 {
-    println!("Rust Bundle started!");
-    0
+pub unsafe extern "C" fn celix_bundleActivator_stop(data: *mut c_void, _ctx: *mut celix_bundle_context_t) -> celix_status_t {
+    let rust_bundle = &*(data as *mut RustBundle);
+    let result = rust_bundle.stop();
+    match result {
+        Ok(()) => CELIX_SUCCESS,
+        Err(_) => CELIX_BUNDLE_EXCEPTION,
+    }
 }
 
 #[no_mangle]
-pub unsafe extern "C" fn celix_bundleActivator_stop(_data: *mut c_void, _context: *mut c_void) -> i32 {
-    println!("Rust Bundle stopped!");
-    0
+pub unsafe extern "C" fn celix_bundleActivator_destroy(data: *mut c_void, _ctx: *mut celix_bundle_context_t) -> celix_status_t {
+    let rust_bundle = Box::from_raw(data as *mut RustBundle);
+    drop(rust_bundle);
+    CELIX_SUCCESS
 }