From fb060e112a372dca511d5f0dd26841493e73dfe2 Mon Sep 17 00:00:00 2001
From: Alan Liddell <aliddell@chanzuckerberg.com>
Date: Wed, 3 Apr 2024 11:59:20 -0400
Subject: [PATCH] Use `byte_offset` and `byte_offset_from` from the std library
 (#179)

Closes #159
---
 README.md      | 14 ++++++++++----
 src/runtime.rs | 16 +++-------------
 2 files changed, 13 insertions(+), 17 deletions(-)

diff --git a/README.md b/README.md
index 0d5a83d..4f7a3bb 100644
--- a/README.md
+++ b/README.md
@@ -9,7 +9,10 @@
 python -m pip install acquire-imaging
 ```
 
-Acquire ([`acquire-imaging` on PyPI](https://pypi.org/project/acquire-imaging/)) provides high-speed, multi-camera, video streaming for up to **2** cameras and image acquisition with a programming interface for streaming video data directly to Python, cloud-friendly file formats, and visualization platforms, such as [napari](https://napari.org/stable/).
+Acquire ([`acquire-imaging` on PyPI](https://pypi.org/project/acquire-imaging/)) provides high-speed, multi-camera,
+video streaming for up to **2** cameras and image acquisition with a programming interface for streaming video data
+directly to Python, cloud-friendly file formats, and visualization platforms, such
+as [napari](https://napari.org/stable/).
 
 > **Note** This is an early stage project. If you find it interesting, please
 > reach out!
@@ -33,9 +36,11 @@ For testing and demonstration purposes, Acquire provides a few simulated video s
 
 ## Usage
 
-Check out our documentation [here](https://acquire-project.github.io/acquire-docs/). 
+Check out our documentation [here](https://acquire-project.github.io/acquire-docs/).
 
-The provided [napari](https://napari.org/stable/) plugin ([code here](https://github.com/acquire-project/acquire-python/blob/main/python/acquire/__init__.py#L131)) is a good example of how to stream for visualization.
+The provided [napari](https://napari.org/stable/)
+plugin ([code here](https://github.com/acquire-project/acquire-python/blob/main/python/acquire/__init__.py#L131)) is a
+good example of how to stream for visualization.
 
 ## Development
 
@@ -50,7 +55,7 @@ Requires
   [chocolatey](https://community.chocolatey.org/packages/cmake))
 - A C++20 compiler (Microsoft Visual Studio Community [download
   page](https://visualstudio.microsoft.com/downloads/), or clang)
-- Rust (via rustup, see [install
+- Rust >= 1.75 (via rustup, see [install
   page](https://www.rust-lang.org/tools/install))
 - conda (optional; via
   [miniconda](https://docs.conda.io/en/latest/miniconda.html))
@@ -84,6 +89,7 @@ python -m build
 
 This package depends on a submodule ([acquire-common](https://github.com/acquire-project/acquire-common))
 and binaries from the following Acquire drivers:
+
 - [acquire-driver-hdcam](https://github.com/acquire-project/acquire-driver-hdcam)
 - [acquire-driver-egrabber](https://github.com/acquire-project/acquire-driver-egrabber)
 - [acquire-driver-zarr](https://github.com/acquire-project/acquire-driver-zarr)
diff --git a/src/runtime.rs b/src/runtime.rs
index 62a7ef5..c89802a 100644
--- a/src/runtime.rs
+++ b/src/runtime.rs
@@ -228,16 +228,6 @@ struct RawAvailableData {
 unsafe impl Send for RawAvailableData {}
 unsafe impl Sync for RawAvailableData {}
 
-// Can replace this if `pointer_byte_offsets` gets stabilized.
-unsafe fn byte_offset<T>(origin: *mut T, count: isize) -> *mut T {
-    (origin as *const u8).offset(count) as *mut T
-}
-
-// Can replace this if `pointer_byte_offsets` gets stabilized.
-unsafe fn byte_offset_from<T>(beg: *mut T, end: *mut T) -> isize {
-    (end as *const u8).offset_from(beg as *const u8)
-}
-
 impl RawAvailableData {
     fn get_frame_count(&self) -> usize {
         let mut count = 0;
@@ -253,7 +243,7 @@ impl RawAvailableData {
                     frame.bytes_of_frame
                 );
                 assert!(frame.bytes_of_frame > 0);
-                cur = byte_offset(cur, frame.bytes_of_frame as _);
+                cur = cur.byte_offset(frame.bytes_of_frame as _);
                 count += 1;
             }
         }
@@ -265,7 +255,7 @@ impl Drop for RawAvailableData {
     fn drop(&mut self) {
         let consumed_bytes = self
             .consumed_bytes
-            .unwrap_or(unsafe { byte_offset_from(self.beg.as_ptr(), self.end.as_ptr()) } as usize);
+            .unwrap_or(unsafe { self.end.as_ptr().byte_offset_from(self.beg.as_ptr()) } as usize);
         log::debug!(
             "[stream {}] DROP read region: {:p}-{:p}:{}",
             self.stream_id,
@@ -341,7 +331,7 @@ impl AvailableDataContext {
         let nbytes = if beg.is_null() || end.is_null() {
             0
         } else {
-            unsafe { byte_offset_from(beg, end) }
+            unsafe { end.byte_offset_from(beg) }
         };
 
         log::trace!(