fix android get raw data (#8171)

If `std::ptr::copy_nonoverlapping` is not in `take`, it's not protected by the lock.

Signed-off-by: 21pages <sunboeasy@gmail.com>

libs/scrap/src/android/ffi.rs

@@ -65,7 +65,7 @@ impl FrameRaw {
 
     // take inner data as slice
     // release when success
-    fn take<'a>(&mut self) -> Option<&'a [u8]> {
+    fn take<'a>(&mut self, dst: &mut Vec<u8>, last: &mut Vec<u8>) -> Option<()> {
         if self.enable.not() {
             return None;
         }
@@ -79,7 +79,14 @@ impl FrameRaw {
             }
             let slice = unsafe { std::slice::from_raw_parts(ptr, self.len) };
             self.release();
-            Some(slice)
+            if last.len() == slice.len() && crate::would_block_if_equal(last, slice).is_err() {
+                return None;
+            }
+            dst.resize(slice.len(), 0);
+            unsafe {
+                std::ptr::copy_nonoverlapping(slice.as_ptr(), dst.as_mut_ptr(), slice.len());
+            }
+            Some(())
         }
     }
 
@@ -89,12 +96,12 @@ impl FrameRaw {
     }
 }
 
-pub fn get_video_raw<'a>() -> Option<&'a [u8]> {
-    VIDEO_RAW.lock().ok()?.take()
+pub fn get_video_raw<'a>(dst: &mut Vec<u8>, last: &mut Vec<u8>) -> Option<()> {
+    VIDEO_RAW.lock().ok()?.take(dst, last)
 }
 
-pub fn get_audio_raw<'a>() -> Option<&'a [u8]> {
-    AUDIO_RAW.lock().ok()?.take()
+pub fn get_audio_raw<'a>(dst: &mut Vec<u8>, last: &mut Vec<u8>) -> Option<()> {
+    AUDIO_RAW.lock().ok()?.take(dst, last)
 }
 
 #[no_mangle]

libs/scrap/src/common/android.rs

@@ -36,13 +36,7 @@ impl Capturer {
 
 impl crate::TraitCapturer for Capturer {
     fn frame<'a>(&'a mut self, _timeout: Duration) -> io::Result<Frame<'a>> {
-        if let Some(buf) = get_video_raw() {
-            crate::would_block_if_equal(&mut self.saved_raw_data, buf)?;
-            // Is it safe to directly return buf without copy?
-            self.rgba.resize(buf.len(), 0);
-            unsafe {
-                std::ptr::copy_nonoverlapping(buf.as_ptr(), self.rgba.as_mut_ptr(), buf.len())
-            };
+        if get_video_raw(&mut self.rgba, &mut self.saved_raw_data).is_some() {
             Ok(Frame::PixelBuffer(PixelBuffer::new(
                 &self.rgba,
                 self.width(),

src/server/audio_service.rs

@@ -68,6 +68,8 @@ mod pa_impl {
         );
         #[cfg(target_os = "linux")]
         let zero_audio_frame: Vec<f32> = vec![0.; AUDIO_DATA_SIZE_U8 / 4];
+        #[cfg(target_os = "android")]
+        let mut android_data = vec![];
         while sp.ok() && !RESTARTING.load(Ordering::SeqCst) {
             sp.snapshot(|sps| {
                 sps.send(create_format_msg(crate::platform::PA_SAMPLE_RATE, 2));
@@ -88,9 +90,12 @@ mod pa_impl {
                 send_f32(data, &mut encoder, &sp);
             }
             #[cfg(target_os = "android")]
-            if let Some(data) = scrap::android::ffi::get_audio_raw() {
+            if scrap::android::ffi::get_audio_raw(&mut android_data, &mut vec![]).is_some() {
                 let data = unsafe {
-                    std::slice::from_raw_parts::<f32>(data.as_ptr() as _, data.len() / 4)
+                    std::slice::from_raw_parts::<f32>(
+                        android_data.as_ptr() as _,
+                        android_data.len() / 4,
+                    )
                 };
                 send_f32(data, &mut encoder, &sp);
             } else {