Instrumentation worker ffi (#27)

* Initial telemetry ffi implementation

* Add telemetry header generation to build script

* Using the nightly toolchain when running cbindgen to expand functions in macros

.github/workflows/test.yml

@@ -62,6 +62,9 @@ jobs:
           rust_version: ${{ matrix.rust_version }}
           build_profile: "release"
 
+      - name: Install nightly toolchain
+        run: rustup install nightly
+
       - name: Install Rust ${{ matrix.rust_version }}
         if: ${{ matrix.rust_version != '' }}
         run: rustup install ${{ matrix.rust_version }} && rustup default ${{ matrix.rust_version }}

Cargo.toml

@@ -8,6 +8,7 @@ members = [
     "ddcommon",
     "ddcommon-ffi",
     "ddtelemetry",
+    "ddtelemetry-ffi",
     "tools",
 ]
 # https://doc.rust-lang.org/cargo/reference/resolver.html#feature-resolver-version-2

build-profiling-ffi.sh

@@ -148,12 +148,15 @@ echo "Building tools"
 cargo build --package tools --bins
 
 echo "Generating $destdir/include/libdatadog headers..."
-cbindgen --crate ddcommon-ffi \
+rustup run nightly -- cbindgen --crate ddcommon-ffi \
     --config ddcommon-ffi/cbindgen.toml \
     --output "$destdir/include/datadog/common.h"
-cbindgen --crate "${datadog_profiling_ffi}" \
+rustup run nightly -- cbindgen --crate "${datadog_profiling_ffi}" \
     --config profiling-ffi/cbindgen.toml \
     --output "$destdir/include/datadog/profiling.h"
-./target/debug/dedup_headers "$destdir/include/datadog/common.h" "$destdir/include/datadog/profiling.h"
+rustup run nightly -- cbindgen --crate ddtelemetry-ffi \
+    --config ddtelemetry-ffi/cbindgen.toml \
+    --output "$destdir/include/datadog/telemetry.h"
+./target/debug/dedup_headers "$destdir/include/datadog/common.h" "$destdir/include/datadog/telemetry.h" "$destdir/include/datadog/profiling.h"
 
 echo "Done."

ddcommon-ffi/src/lib.rs

@@ -1,9 +1,11 @@
 // Unless explicitly stated otherwise all files in this repository are licensed under the Apache License Version 2.0.
 // This product includes software developed at Datadog (https://www.datadoghq.com/). Copyright 2021-Present Datadog, Inc.
 
+pub mod option;
 pub mod slice;
 pub mod tags;
 pub mod vec;
 
-pub use slice::Slice;
+pub use option::Option;
+pub use slice::{CharSlice, Slice};
 pub use vec::Vec;

ddcommon-ffi/src/option.rs

@@ -0,0 +1,24 @@
+// Unless explicitly stated otherwise all files in this repository are licensed under the Apache License Version 2.0.
+// This product includes software developed at Datadog (https://www.datadoghq.com/). Copyright 2021-Present Datadog, Inc.
+
+#[repr(C)]
+#[derive(Debug, PartialEq, Eq)]
+pub enum Option<T> {
+    Some(T),
+    None,
+}
+
+impl<T> Option<T> {
+    pub fn to_std(self) -> std::option::Option<T> {
+        self.into()
+    }
+}
+
+impl<T> From<Option<T>> for std::option::Option<T> {
+    fn from(o: Option<T>) -> Self {
+        match o {
+            Option::Some(s) => Some(s),
+            Option::None => None,
+        }
+    }
+}

ddcommon-ffi/src/vec.rs

@@ -13,13 +13,22 @@ use std::mem::ManuallyDrop;
 /// The names ptr and len were chosen to minimize conversion from a previous
 /// Buffer type which this has replaced to become more general.
 #[repr(C)]
+#[derive(Debug)]
 pub struct Vec<T: Sized> {
     ptr: *const T,
     len: usize,
     capacity: usize,
     _marker: PhantomData<T>,
 }
 
+impl<T: PartialEq> PartialEq for Vec<T> {
+    fn eq(&self, other: &Self) -> bool {
+        self.len() == other.len() && self.into_iter().zip(other.into_iter()).all(|(s, o)| s == o)
+    }
+}
+
+impl<T: Eq> Eq for Vec<T> {}
+
 impl<T> Drop for Vec<T> {
     fn drop(&mut self) {
         let vec =

ddtelemetry-ffi/Cargo.toml

@@ -0,0 +1,17 @@
+# Unless explicitly stated otherwise all files in this repository are licensed under the Apache License Version 2.0.
+# This product includes software developed at Datadog (https://www.datadoghq.com/). Copyright 2021-Present Datadog, Inc.
+
+[package]
+name = "ddtelemetry-ffi"
+version = "0.8.0"
+edition = "2021"
+
+[lib]
+# LTO is ignored if "lib" is added as crate type
+# cf. https://github.com/rust-lang/rust/issues/51009
+crate-type = ["staticlib", "cdylib"]
+
+[dependencies]
+ddtelemetry = { path = "../ddtelemetry", version = "0.8.0" }
+ddcommon-ffi = { path = "../ddcommon-ffi", version = "0.8.0" }
+paste = "1"

ddtelemetry-ffi/cbindgen.toml

@@ -0,0 +1,32 @@
+# Unless explicitly stated otherwise all files in this repository are licensed under the Apache License Version 2.0.
+# This product includes software developed at Datadog (https://www.datadoghq.com/). Copyright 2021-Present Datadog, Inc.
+
+language = "C"
+tab_width = 2
+header = """// Unless explicitly stated otherwise all files in this repository are licensed under the Apache License Version 2.0.
+// This product includes software developed at Datadog (https://www.datadoghq.com/). Copyright 2021-Present Datadog, Inc.
+"""
+include_guard = "DDOG_TELEMETRY_H"
+style = "both"
+
+no_includes = true
+sys_includes = ["stdbool.h", "stddef.h", "stdint.h"]
+includes = ["datadog/common.h"]
+
+[export]
+prefix = "ddog_"
+
+[export.mangle]
+rename_types="SnakeCase"
+
+[enum]
+prefix_with_name = true
+rename_variants = "ScreamingSnakeCase"
+
+[fn]
+must_use = "DDOG_CHECK_RETURN"
+
+[parse]
+expand = ["ddtelemetry-ffi"]
+parse_deps = true
+include = ["ddcommon", "ddtelemetry", "ddcommon-ffi"]