Add Rust wrapper around AHardwareBuffer_Desc.

Bug: 359100544
Test: atest libnativewindow_rs-internal_test
Test: atest libbufferstreams-internal_test
Change-Id: I9065ca34cebde50a97b1e5331e293347bc42f563

3 files changed, 146 insertions, 110 deletions

diff --git a/libs/bufferstreams/rust/src/stream_config.rs b/libs/bufferstreams/rust/src/stream_config.rs
index 454bdf144e..8288f9f3cf 100644
--- a/libs/bufferstreams/rust/src/stream_config.rs
+++ b/libs/bufferstreams/rust/src/stream_config.rs
@@ -32,10 +32,23 @@ pub struct StreamConfig {
     pub stride: u32,
 }
 
+impl From<StreamConfig> for HardwareBufferDescription {
+    fn from(config: StreamConfig) -> Self {
+        HardwareBufferDescription::new(
+            config.width,
+            config.height,
+            config.layers,
+            config.format,
+            config.usage,
+            config.stride,
+        )
+    }
+}
+
 impl StreamConfig {
     /// Tries to create a new HardwareBuffer from settings in a [StreamConfig].
     pub fn create_hardware_buffer(&self) -> Option<HardwareBuffer> {
-        HardwareBuffer::new(self.width, self.height, self.layers, self.format, self.usage)
+        HardwareBuffer::new(&(*self).into())
     }
 }
 
@@ -59,9 +72,10 @@ mod test {
         assert!(maybe_buffer.is_some());
 
         let buffer = maybe_buffer.unwrap();
-        assert_eq!(config.width, buffer.width());
-        assert_eq!(config.height, buffer.height());
-        assert_eq!(config.format, buffer.format());
-        assert_eq!(config.usage, buffer.usage());
+        let description = buffer.description();
+        assert_eq!(config.width, description.width());
+        assert_eq!(config.height, description.height());
+        assert_eq!(config.format, description.format());
+        assert_eq!(config.usage, description.usage());
     }
 }
diff --git a/libs/nativewindow/rust/src/lib.rs b/libs/nativewindow/rust/src/lib.rs
index 54dad04071..931c311e65 100644
--- a/libs/nativewindow/rust/src/lib.rs
+++ b/libs/nativewindow/rust/src/lib.rs
@@ -30,31 +30,29 @@ use binder::{
     unstable_api::{status_result, AsNative},
     StatusCode,
 };
-use ffi::{AHardwareBuffer, AHardwareBuffer_readFromParcel, AHardwareBuffer_writeToParcel};
+use ffi::{
+    AHardwareBuffer, AHardwareBuffer_Desc, AHardwareBuffer_readFromParcel,
+    AHardwareBuffer_writeToParcel,
+};
 use std::fmt::{self, Debug, Formatter};
 use std::mem::ManuallyDrop;
 use std::ptr::{self, null_mut, NonNull};
 
-/// Wrapper around an opaque C `AHardwareBuffer`.
-#[derive(PartialEq, Eq)]
-pub struct HardwareBuffer(NonNull<AHardwareBuffer>);
+/// Wrapper around a C `AHardwareBuffer_Desc`.
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct HardwareBufferDescription(AHardwareBuffer_Desc);
 
-impl HardwareBuffer {
-    /// Test whether the given format and usage flag combination is allocatable.  If this function
-    /// returns true, it means that a buffer with the given description can be allocated on this
-    /// implementation, unless resource exhaustion occurs. If this function returns false, it means
-    /// that the allocation of the given description will never succeed.
-    ///
-    /// Available since API 29
-    pub fn is_supported(
+impl HardwareBufferDescription {
+    /// Creates a new `HardwareBufferDescription` with the given parameters.
+    pub fn new(
         width: u32,
         height: u32,
         layers: u32,
         format: AHardwareBuffer_Format::Type,
         usage: AHardwareBuffer_UsageFlags,
         stride: u32,
-    ) -> bool {
-        let buffer_desc = ffi::AHardwareBuffer_Desc {
+    ) -> Self {
+        Self(AHardwareBuffer_Desc {
             width,
             height,
             layers,
@@ -63,9 +61,69 @@ impl HardwareBuffer {
             stride,
             rfu0: 0,
             rfu1: 0,
-        };
-        // SAFETY: *buffer_desc will never be null.
-        let status = unsafe { ffi::AHardwareBuffer_isSupported(&buffer_desc) };
+        })
+    }
+
+    /// Returns the width from the buffer description.
+    pub fn width(&self) -> u32 {
+        self.0.width
+    }
+
+    /// Returns the height from the buffer description.
+    pub fn height(&self) -> u32 {
+        self.0.height
+    }
+
+    /// Returns the number from layers from the buffer description.
+    pub fn layers(&self) -> u32 {
+        self.0.layers
+    }
+
+    /// Returns the format from the buffer description.
+    pub fn format(&self) -> AHardwareBuffer_Format::Type {
+        self.0.format
+    }
+
+    /// Returns the usage bitvector from the buffer description.
+    pub fn usage(&self) -> AHardwareBuffer_UsageFlags {
+        AHardwareBuffer_UsageFlags(self.0.usage)
+    }
+
+    /// Returns the stride from the buffer description.
+    pub fn stride(&self) -> u32 {
+        self.0.stride
+    }
+}
+
+impl Default for HardwareBufferDescription {
+    fn default() -> Self {
+        Self(AHardwareBuffer_Desc {
+            width: 0,
+            height: 0,
+            layers: 0,
+            format: 0,
+            usage: 0,
+            stride: 0,
+            rfu0: 0,
+            rfu1: 0,
+        })
+    }
+}
+
+/// Wrapper around an opaque C `AHardwareBuffer`.
+#[derive(PartialEq, Eq)]
+pub struct HardwareBuffer(NonNull<AHardwareBuffer>);
+
+impl HardwareBuffer {
+    /// Test whether the given format and usage flag combination is allocatable.  If this function
+    /// returns true, it means that a buffer with the given description can be allocated on this
+    /// implementation, unless resource exhaustion occurs. If this function returns false, it means
+    /// that the allocation of the given description will never succeed.
+    ///
+    /// Available since API 29
+    pub fn is_supported(buffer_description: &HardwareBufferDescription) -> bool {
+        // SAFETY: The pointer comes from a reference so must be valid.
+        let status = unsafe { ffi::AHardwareBuffer_isSupported(&buffer_description.0) };
 
         status == 1
     }
@@ -77,27 +135,11 @@ impl HardwareBuffer {
     ///
     /// Available since API level 26.
     #[inline]
-    pub fn new(
-        width: u32,
-        height: u32,
-        layers: u32,
-        format: AHardwareBuffer_Format::Type,
-        usage: AHardwareBuffer_UsageFlags,
-    ) -> Option<Self> {
-        let buffer_desc = ffi::AHardwareBuffer_Desc {
-            width,
-            height,
-            layers,
-            format,
-            usage: usage.0,
-            stride: 0,
-            rfu0: 0,
-            rfu1: 0,
-        };
+    pub fn new(buffer_description: &HardwareBufferDescription) -> Option<Self> {
         let mut ptr = ptr::null_mut();
         // SAFETY: The returned pointer is valid until we drop/deallocate it. The function may fail
         // and return a status, but we check it later.
-        let status = unsafe { ffi::AHardwareBuffer_allocate(&buffer_desc, &mut ptr) };
+        let status = unsafe { ffi::AHardwareBuffer_allocate(&buffer_description.0, &mut ptr) };
 
         if status == 0 {
             Some(Self(NonNull::new(ptr).expect("Allocated AHardwareBuffer was null")))
@@ -112,7 +154,7 @@ impl HardwareBuffer {
     /// in.
     pub fn create_from_handle(
         handle: &NativeHandle,
-        buffer_desc: &ffi::AHardwareBuffer_Desc,
+        buffer_description: &HardwareBufferDescription,
     ) -> Result<Self, StatusCode> {
         let mut buffer = ptr::null_mut();
         // SAFETY: The caller guarantees that `handle` is valid, and the buffer pointer is valid
@@ -121,7 +163,7 @@ impl HardwareBuffer {
         // it.
         let status = unsafe {
             ffi::AHardwareBuffer_createFromHandle(
-                buffer_desc,
+                &buffer_description.0,
                 handle.as_raw().as_ptr(),
                 ffi::CreateFromHandleMethod_AHARDWAREBUFFER_CREATE_FROM_HANDLE_METHOD_CLONE
                     .try_into()
@@ -202,37 +244,8 @@ impl HardwareBuffer {
         out_id
     }
 
-    /// Get the width of this buffer
-    pub fn width(&self) -> u32 {
-        self.description().width
-    }
-
-    /// Get the height of this buffer
-    pub fn height(&self) -> u32 {
-        self.description().height
-    }
-
-    /// Get the number of layers of this buffer
-    pub fn layers(&self) -> u32 {
-        self.description().layers
-    }
-
-    /// Get the format of this buffer
-    pub fn format(&self) -> AHardwareBuffer_Format::Type {
-        self.description().format
-    }
-
-    /// Get the usage bitvector of this buffer
-    pub fn usage(&self) -> AHardwareBuffer_UsageFlags {
-        AHardwareBuffer_UsageFlags(self.description().usage)
-    }
-
-    /// Get the stride of this buffer
-    pub fn stride(&self) -> u32 {
-        self.description().stride
-    }
-
-    fn description(&self) -> ffi::AHardwareBuffer_Desc {
+    /// Returns the description of this buffer.
+    pub fn description(&self) -> HardwareBufferDescription {
         let mut buffer_desc = ffi::AHardwareBuffer_Desc {
             width: 0,
             height: 0,
@@ -245,7 +258,7 @@ impl HardwareBuffer {
         };
         // SAFETY: neither the buffer nor AHardwareBuffer_Desc pointers will be null.
         unsafe { ffi::AHardwareBuffer_describe(self.0.as_ref(), &mut buffer_desc) };
-        buffer_desc
+        HardwareBufferDescription(buffer_desc)
     }
 }
 
@@ -328,19 +341,27 @@ mod test {
 
     #[test]
     fn create_valid_buffer_returns_ok() {
-        let buffer = HardwareBuffer::new(
+        let buffer = HardwareBuffer::new(&HardwareBufferDescription::new(
             512,
             512,
             1,
             AHardwareBuffer_Format::AHARDWAREBUFFER_FORMAT_R8G8B8A8_UNORM,
             AHardwareBuffer_UsageFlags::AHARDWAREBUFFER_USAGE_CPU_READ_OFTEN,
-        );
+            0,
+        ));
         assert!(buffer.is_some());
     }
 
     #[test]
     fn create_invalid_buffer_returns_err() {
-        let buffer = HardwareBuffer::new(512, 512, 1, 0, AHardwareBuffer_UsageFlags(0));
+        let buffer = HardwareBuffer::new(&HardwareBufferDescription::new(
+            512,
+            512,
+            1,
+            0,
+            AHardwareBuffer_UsageFlags(0),
+            0,
+        ));
         assert!(buffer.is_none());
     }
 
@@ -366,39 +387,45 @@ mod test {
         // SAFETY: The pointer must be valid because it was just allocated successfully, and we
         // don't use it after calling this.
         let buffer = unsafe { HardwareBuffer::from_raw(NonNull::new(raw_buffer_ptr).unwrap()) };
-        assert_eq!(buffer.width(), 1024);
+        assert_eq!(buffer.description().width(), 1024);
     }
 
     #[test]
     fn basic_getters() {
-        let buffer = HardwareBuffer::new(
+        let buffer = HardwareBuffer::new(&HardwareBufferDescription::new(
             1024,
             512,
             1,
             AHardwareBuffer_Format::AHARDWAREBUFFER_FORMAT_R8G8B8A8_UNORM,
             AHardwareBuffer_UsageFlags::AHARDWAREBUFFER_USAGE_CPU_READ_OFTEN,
-        )
+            0,
+        ))
         .expect("Buffer with some basic parameters was not created successfully");
 
-        assert_eq!(buffer.width(), 1024);
-        assert_eq!(buffer.height(), 512);
-        assert_eq!(buffer.layers(), 1);
-        assert_eq!(buffer.format(), AHardwareBuffer_Format::AHARDWAREBUFFER_FORMAT_R8G8B8A8_UNORM);
+        let description = buffer.description();
+        assert_eq!(description.width(), 1024);
+        assert_eq!(description.height(), 512);
+        assert_eq!(description.layers(), 1);
         assert_eq!(
-            buffer.usage(),
+            description.format(),
+            AHardwareBuffer_Format::AHARDWAREBUFFER_FORMAT_R8G8B8A8_UNORM
+        );
+        assert_eq!(
+            description.usage(),
             AHardwareBuffer_UsageFlags::AHARDWAREBUFFER_USAGE_CPU_READ_OFTEN
         );
     }
 
     #[test]
     fn id_getter() {
-        let buffer = HardwareBuffer::new(
+        let buffer = HardwareBuffer::new(&HardwareBufferDescription::new(
             1024,
             512,
             1,
             AHardwareBuffer_Format::AHARDWAREBUFFER_FORMAT_R8G8B8A8_UNORM,
             AHardwareBuffer_UsageFlags::AHARDWAREBUFFER_USAGE_CPU_READ_OFTEN,
-        )
+            0,
+        ))
         .expect("Buffer with some basic parameters was not created successfully");
 
         assert_ne!(0, buffer.id());
@@ -406,13 +433,14 @@ mod test {
 
     #[test]
     fn clone() {
-        let buffer = HardwareBuffer::new(
+        let buffer = HardwareBuffer::new(&HardwareBufferDescription::new(
             1024,
             512,
             1,
             AHardwareBuffer_Format::AHARDWAREBUFFER_FORMAT_R8G8B8A8_UNORM,
             AHardwareBuffer_UsageFlags::AHARDWAREBUFFER_USAGE_CPU_READ_OFTEN,
-        )
+            0,
+        ))
         .expect("Buffer with some basic parameters was not created successfully");
         let buffer2 = buffer.clone();
 
@@ -421,13 +449,14 @@ mod test {
 
     #[test]
     fn into_raw() {
-        let buffer = HardwareBuffer::new(
+        let buffer = HardwareBuffer::new(&HardwareBufferDescription::new(
             1024,
             512,
             1,
             AHardwareBuffer_Format::AHARDWAREBUFFER_FORMAT_R8G8B8A8_UNORM,
             AHardwareBuffer_UsageFlags::AHARDWAREBUFFER_USAGE_CPU_READ_OFTEN,
-        )
+            0,
+        ))
         .expect("Buffer with some basic parameters was not created successfully");
         let buffer2 = buffer.clone();
 
@@ -440,31 +469,23 @@ mod test {
 
     #[test]
     fn native_handle_and_back() {
-        let buffer = HardwareBuffer::new(
+        let buffer_description = HardwareBufferDescription::new(
             1024,
             512,
             1,
             AHardwareBuffer_Format::AHARDWAREBUFFER_FORMAT_R8G8B8A8_UNORM,
             AHardwareBuffer_UsageFlags::AHARDWAREBUFFER_USAGE_CPU_READ_OFTEN,
-        )
-        .expect("Buffer with some basic parameters was not created successfully");
+            1024,
+        );
+        let buffer = HardwareBuffer::new(&buffer_description)
+            .expect("Buffer with some basic parameters was not created successfully");
 
         let native_handle =
             buffer.cloned_native_handle().expect("Failed to get native handle for buffer");
-        let buffer_desc = ffi::AHardwareBuffer_Desc {
-            width: 1024,
-            height: 512,
-            layers: 1,
-            format: AHardwareBuffer_Format::AHARDWAREBUFFER_FORMAT_R8G8B8A8_UNORM,
-            usage: AHardwareBuffer_UsageFlags::AHARDWAREBUFFER_USAGE_CPU_READ_OFTEN.0,
-            stride: 1024,
-            rfu0: 0,
-            rfu1: 0,
-        };
-        let buffer2 = HardwareBuffer::create_from_handle(&native_handle, &buffer_desc)
+        let buffer2 = HardwareBuffer::create_from_handle(&native_handle, &buffer_description)
             .expect("Failed to create buffer from native handle");
 
-        assert_eq!(buffer.description(), buffer_desc);
-        assert_eq!(buffer2.description(), buffer_desc);
+        assert_eq!(buffer.description(), buffer_description);
+        assert_eq!(buffer2.description(), buffer_description);
     }
 }
diff --git a/libs/nativewindow/tests/benchmark/buffer_benchmarks.rs b/libs/nativewindow/tests/benchmark/buffer_benchmarks.rs
index 876f6c8e26..73a7e95149 100644
--- a/libs/nativewindow/tests/benchmark/buffer_benchmarks.rs
+++ b/libs/nativewindow/tests/benchmark/buffer_benchmarks.rs
@@ -22,13 +22,14 @@ use nativewindow::*;
 
 #[inline]
 fn create_720p_buffer() -> HardwareBuffer {
-    HardwareBuffer::new(
+    HardwareBuffer::new(&HardwareBufferDescription::new(
         1280,
         720,
         1,
         AHardwareBuffer_Format::AHARDWAREBUFFER_FORMAT_R8G8B8A8_UNORM,
         AHardwareBuffer_UsageFlags::AHARDWAREBUFFER_USAGE_CPU_READ_OFTEN,
-    )
+        0,
+    ))
     .unwrap()
 }
 
@@ -51,7 +52,7 @@ fn criterion_benchmark(c: &mut Criterion) {
     // underlying call to AHardwareBuffer_describe.
     c.bench_with_input(BenchmarkId::new("desc", "buffer"), &buffer, |b, buffer| {
         b.iter(|| {
-            buffer.width();
+            buffer.description().width();
         })
     });
 }