bindgen implementation

crates/vdb-ffi/Cargo.toml

@@ -5,3 +5,6 @@ edition = "2021"
 
 [lib]
 path = "src/lib.rs"
+
+[build-dependencies]
+bindgen = "0.72"

crates/vdb-ffi/build.rs

@@ -0,0 +1,23 @@
+use std::{env, path::PathBuf};
+
+fn main() {
+    println!("cargo:rerun-if-changed=../../cpp/vector_engine_ffi.h");
+
+    let bindings = bindgen::Builder::default()
+        .header("../../cpp/vector_engine_ffi.h")
+        .clang_arg("-xc++")
+        .clang_arg("-std=c++17")
+        .clang_arg("-I../../cpp")
+        .allowlist_type("NativeVectorEngine")
+        .allowlist_type("NativeSearchResults")
+        .allowlist_function("native_.*")
+        .layout_tests(false)
+        .generate()
+        .expect("failed to generate FFI bindings with bindgen");
+
+    let out_dir = PathBuf::from(env::var("OUT_DIR").expect("OUT_DIR was not set"));
+
+    bindings
+        .write_to_file(out_dir.join("bindings.rs"))
+        .expect("failed to write generated bindings");
+}

crates/vdb-ffi/src/engine.rs

@@ -73,10 +73,8 @@ impl FfiSearchResults {
     pub fn id_at(&self, index: usize) -> String {
         let id_ptr = unsafe { native_search_results_id_at(self.handle, index) };
 
-        unsafe { CStr::from_ptr(id_ptr) }
-            .to_str()
-            .expect("native search result ID must be valid")
-            .to_string()
+        unsafe { CStr::from_ptr(id_ptr) }.to_str().expect("native search result ID must be valid").to_string()
+        // first converting pointer to rust CStr, then rust string
     }
 
     pub fn score_at(&self, index: usize) -> f32 {

crates/vdb-ffi/src/lib.rs

@@ -1,4 +1,8 @@
-mod bindings;
 mod engine;
 
+#[allow(non_camel_case_types, non_snake_case, non_upper_case_globals)]
+mod bindings {
+    include!(concat!(env!("OUT_DIR"), "/bindings.rs"));
+}
+
 pub use engine::{FfiSearchResults, FfiVectorEngine};