From 4705eb35d25a513c2b22fcd910fdcc765ad472e4 Mon Sep 17 00:00:00 2001
From: Marijn Suijten <marijn@traverseresearch.nl>
Date: Mon, 18 Mar 2024 15:13:09 +0100
Subject: [PATCH] Binder and parcel for `HardwareBuffer`

---
 ndk-sys/CHANGELOG.md       |  1 +
 ndk-sys/Cargo.toml         |  4 ++++
 ndk-sys/src/lib.rs         |  8 ++++++++
 ndk-sys/wrapper.h          |  2 ++
 ndk/Cargo.toml             |  5 ++++-
 ndk/src/hardware_buffer.rs | 30 ++++++++++++++++++++++++++++++
 6 files changed, 49 insertions(+), 1 deletion(-)

diff --git a/ndk-sys/CHANGELOG.md b/ndk-sys/CHANGELOG.md
index 4ff63c02..b1848503 100644
--- a/ndk-sys/CHANGELOG.md
+++ b/ndk-sys/CHANGELOG.md
@@ -4,6 +4,7 @@
 
 - Generate against upstream NDK build `11769913`. (#471)
 - Add `nativewindow` feature to link against `libnativewindow`. (#465)
+- Add `AIBinder` and `Parcel`
 
 # 0.5.0 (2023-10-15)
 
diff --git a/ndk-sys/Cargo.toml b/ndk-sys/Cargo.toml
index a17bae36..1b857f9e 100644
--- a/ndk-sys/Cargo.toml
+++ b/ndk-sys/Cargo.toml
@@ -15,10 +15,14 @@ categories = ["os", "os::android-apis", "external-ffi-bindings"]
 
 [dependencies]
 jni-sys = "0.3.0"
+# Official crate from https://cs.android.com/android/platform/superproject/main/+/main:frameworks/native/libs/binder/rust/sys/
+android-binder-ndk-sys = { version = "0.1.0", optional = true }
 
 [features]
 test = []
+
 audio = []
+binder = ["android-binder-ndk-sys"]
 bitmap = []
 media = []
 nativewindow = []
diff --git a/ndk-sys/src/lib.rs b/ndk-sys/src/lib.rs
index 14138af1..679b5304 100644
--- a/ndk-sys/src/lib.rs
+++ b/ndk-sys/src/lib.rs
@@ -45,6 +45,11 @@ extern "C" {}
 #[link(name = "mediandk")]
 extern "C" {}
 
+// TODO: Delete. Taken care of in android-binder-ndk-sys
+// #[cfg(all(feature = "binder", target_os = "android"))]
+// #[link(name = "binder_ndk")]
+// extern "C" {}
+
 #[cfg(all(feature = "bitmap", target_os = "android"))]
 #[link(name = "jnigraphics")]
 extern "C" {}
@@ -56,3 +61,6 @@ extern "C" {}
 #[cfg(all(feature = "sync", target_os = "android"))]
 #[link(name = "sync")]
 extern "C" {}
+
+#[cfg(all(feature = "binder", target_os = "android"))]
+pub use android_binder_ndk_sys::*;
diff --git a/ndk-sys/wrapper.h b/ndk-sys/wrapper.h
index 670f2640..ee5b679f 100644
--- a/ndk-sys/wrapper.h
+++ b/ndk-sys/wrapper.h
@@ -1,6 +1,8 @@
 #include <android/api-level.h>
 #include <android/asset_manager.h>
 #include <android/asset_manager_jni.h>
+// XXX: Binder APIs are included/reexported/forwarded to official crate:
+// https://cs.android.com/android/platform/superproject/main/+/main:frameworks/native/libs/binder/rust/sys/
 // #include <android/binder_auto_utils.h>
 // #include <android/binder_enums.h>
 // #include <android/binder_ibinder.h>
diff --git a/ndk/Cargo.toml b/ndk/Cargo.toml
index 8378f6a0..0db66242 100644
--- a/ndk/Cargo.toml
+++ b/ndk/Cargo.toml
@@ -15,9 +15,10 @@ categories = ["os", "os::android-apis", "api-bindings"]
 
 [features]
 default = ["rwh_06"]
-all = ["audio", "bitmap", "media", "nativewindow", "sync", "api-level-34", "rwh_04", "rwh_05", "rwh_06"]
+all = ["audio", "binder", "bitmap", "media", "nativewindow", "sync", "api-level-34", "rwh_04", "rwh_05", "rwh_06"]
 
 audio = ["ffi/audio", "api-level-26"]
+binder = ["ffi/binder", "dep:android-binder"]
 bitmap = ["ffi/bitmap"]
 media = ["ffi/media"]
 nativewindow = ["ffi/nativewindow"]
@@ -47,6 +48,8 @@ rwh_04 = { package = "raw-window-handle", version = "0.4", optional = true }
 rwh_05 = { package = "raw-window-handle", version = "0.5", optional = true }
 rwh_06 = { package = "raw-window-handle", version = "0.6", optional = true }
 thiserror = "1.0.23"
+# Official crate from https://cs.android.com/android/platform/superproject/main/+/main:frameworks/native/libs/binder/rust/
+android-binder = { version = "0.1.0", optional = true }
 
 [dependencies.jni]
 version = "0.21"
diff --git a/ndk/src/hardware_buffer.rs b/ndk/src/hardware_buffer.rs
index e5d4e3e3..0243310e 100644
--- a/ndk/src/hardware_buffer.rs
+++ b/ndk/src/hardware_buffer.rs
@@ -527,6 +527,36 @@ impl HardwareBuffer {
             HardwareBufferRef::from_ptr(self.inner)
         }
     }
+
+    #[cfg(all(feature = "binder", feature = "api-level-34"))]
+    pub fn read_from_parcel(
+        parcel: android_binder::binder_impl::BorrowedParcel<'_>,
+    ) -> std::result::Result<HardwareBufferRef, android_binder::StatusCode> {
+        use android_binder::unstable_api::AsNative;
+
+        let mut out = MaybeUninit::uninit();
+        let status =
+            unsafe { ffi::AHardwareBuffer_readFromParcel(parcel.as_native(), out.as_mut_ptr()) };
+        android_binder::unstable_api::status_result(status)
+            .and_then(|()| {
+                NonNull::new(unsafe { out.assume_init() })
+                    .ok_or(android_binder::StatusCode::UNEXPECTED_NULL)
+            })
+            .map(|p| unsafe { HardwareBufferRef::from_ptr(p) })
+    }
+
+    #[cfg(all(feature = "binder", feature = "api-level-34"))]
+    pub fn write_to_parcel(
+        &self,
+        // TODO: mut parcel borrows? This API seems to allow writing either way.
+        mut parcel: android_binder::binder_impl::BorrowedParcel<'_>,
+    ) -> std::result::Result<(), android_binder::StatusCode> {
+        use android_binder::unstable_api::AsNative;
+
+        let status =
+            unsafe { ffi::AHardwareBuffer_writeToParcel(self.as_ptr(), parcel.as_native_mut()) };
+        android_binder::unstable_api::status_result(status)
+    }
 }
 
 /// A [`HardwareBuffer`] with an owned reference, that is released when dropped.