From 94a140092ed01c1944a0d08819657de405cd288b Mon Sep 17 00:00:00 2001
From: Marijn Suijten <marijns95@gmail.com>
Date: Sat, 11 Jun 2022 12:02:23 +0200
Subject: [PATCH] ndk: Replace `posix` module with
 `std::io::Error::from_raw_os_error`

Platform specific - i.e. POSIX - error codes can be wrapped in humand
readable form by Rust's `std` through [`Error::from_raw_os_error()`].
Certain NDK interfaces use these codes directly from `errno.h` through
[`Errors.h`].

[`Error::from_raw_os_error()`]: https://doc.rust-lang.org/std/io/struct.Error.html#method.from_raw_os_error
[`Errors.h`]: https://cs.android.com/android/platform/superproject/+/master:system/core/libutils/include/utils/Errors.h
---
 ndk/src/lib.rs             |  1 -
 ndk/src/posix.rs           | 10 --------
 ndk/src/surface_texture.rs | 50 +++++++++++++++++++++++---------------
 3 files changed, 30 insertions(+), 31 deletions(-)
 delete mode 100644 ndk/src/posix.rs

diff --git a/ndk/src/lib.rs b/ndk/src/lib.rs
index 29f267ea..8b6ec33f 100644
--- a/ndk/src/lib.rs
+++ b/ndk/src/lib.rs
@@ -27,6 +27,5 @@ pub mod looper;
 pub mod media;
 pub mod native_activity;
 pub mod native_window;
-pub mod posix;
 pub mod surface_texture;
 pub mod trace;
diff --git a/ndk/src/posix.rs b/ndk/src/posix.rs
deleted file mode 100644
index c0f81817..00000000
--- a/ndk/src/posix.rs
+++ /dev/null
@@ -1,10 +0,0 @@
-use thiserror::Error;
-
-#[derive(Debug, Error)]
-pub struct PosixError(pub i32);
-
-impl std::fmt::Display for PosixError {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
-        write!(f, "Posix Error: {}", self.0)
-    }
-}
diff --git a/ndk/src/surface_texture.rs b/ndk/src/surface_texture.rs
index 2d79bd77..60c68502 100644
--- a/ndk/src/surface_texture.rs
+++ b/ndk/src/surface_texture.rs
@@ -6,10 +6,14 @@
 //! [`ASurfaceTexture`]: https://developer.android.com/ndk/reference/group/surface-texture
 #![cfg(feature = "api-level-28")]
 
-use super::posix::PosixError;
 use crate::native_window::NativeWindow;
 use jni_sys::{jobject, JNIEnv};
-use std::{convert::TryInto, ptr::NonNull, time::Duration};
+use std::{
+    convert::TryInto,
+    io::{Error, Result},
+    ptr::NonNull,
+    time::Duration,
+};
 
 /// An opaque type to manage [`android.graphics.SurfaceTexture`] from native code
 ///
@@ -83,12 +87,14 @@ impl SurfaceTexture {
     /// This can be used to access the [`SurfaceTexture`] image contents from multiple OpenGL ES
     /// contexts. Note, however, that the image contents are only accessible from one OpenGL ES
     /// context at a time.
-    pub fn attach_to_gl_context(&self, tex_name: u32) -> Result<(), PosixError> {
-        let r = unsafe { ffi::ASurfaceTexture_attachToGLContext(self.ptr.as_ptr(), tex_name) };
-        if r == 0 {
-            Ok(())
-        } else {
-            Err(PosixError(r))
+    pub fn attach_to_gl_context(&self, tex_name: u32) -> Result<()> {
+        match unsafe { ffi::ASurfaceTexture_attachToGLContext(self.ptr.as_ptr(), tex_name) } {
+            0 => Ok(()),
+            r if r < 0 => Err(Error::from_raw_os_error(-r)),
+            r => unreachable!(
+                "ASurfaceTexture_attachToGLContext returned positive integer {}",
+                r
+            ),
         }
     }
 
@@ -103,12 +109,14 @@ impl SurfaceTexture {
     /// This can be used to access the [`SurfaceTexture`] image contents from multiple OpenGL ES
     /// contexts. Note, however, that the image contents are only accessible from one OpenGL ES
     /// context at a time.
-    pub fn detach_from_gl_context(&self) -> Result<(), PosixError> {
-        let r = unsafe { ffi::ASurfaceTexture_detachFromGLContext(self.ptr.as_ptr()) };
-        if r == 0 {
-            Ok(())
-        } else {
-            Err(PosixError(r))
+    pub fn detach_from_gl_context(&self) -> Result<()> {
+        match unsafe { ffi::ASurfaceTexture_detachFromGLContext(self.ptr.as_ptr()) } {
+            0 => Ok(()),
+            r if r < 0 => Err(Error::from_raw_os_error(-r)),
+            r => unreachable!(
+                "ASurfaceTexture_detachFromGLContext returned positive integer {}",
+                r
+            ),
         }
     }
 
@@ -161,12 +169,14 @@ impl SurfaceTexture {
     /// This may only be called while the OpenGL ES context that owns the texture is current on the
     /// calling thread. It will implicitly bind its texture to the `GL_TEXTURE_EXTERNAL_OES`
     /// texture target.
-    pub fn update_tex_image(&self) -> Result<(), PosixError> {
-        let r = unsafe { ffi::ASurfaceTexture_updateTexImage(self.ptr.as_ptr()) };
-        if r == 0 {
-            Ok(())
-        } else {
-            Err(PosixError(r))
+    pub fn update_tex_image(&self) -> Result<()> {
+        match unsafe { ffi::ASurfaceTexture_updateTexImage(self.ptr.as_ptr()) } {
+            0 => Ok(()),
+            r if r < 0 => Err(Error::from_raw_os_error(-r)),
+            r => unreachable!(
+                "ASurfaceTexture_updateTexImage returned positive integer {}",
+                r
+            ),
         }
     }
 }