From ee87aebc7912d3e439fa059362952f2517c7bae7 Mon Sep 17 00:00:00 2001
From: Jordan Rose <jrose@signal.org>
Date: Fri, 13 Sep 2024 12:33:18 -0700
Subject: [PATCH] Update MSRV to 1.75

---
 .github/workflows/build_and_test.yml |  2 +-
 rust/protocol/src/sealed_sender.rs   |  5 +---
 rust/protocol/src/utils.rs           | 45 ----------------------------
 rust/svr3/src/lib.rs                 |  6 ++--
 4 files changed, 4 insertions(+), 54 deletions(-)

diff --git a/.github/workflows/build_and_test.yml b/.github/workflows/build_and_test.yml
index 2b83943a..d3a8fe24 100644
--- a/.github/workflows/build_and_test.yml
+++ b/.github/workflows/build_and_test.yml
@@ -9,7 +9,7 @@ env:
   CARGO_TERM_COLOR: always
   NDK_VERSION: 27.0.12077973
   RUST_BACKTRACE: 1
-  LIBSIGNAL_MINIMUM_SUPPORTED_RUST_VERSION: 1.72
+  LIBSIGNAL_MINIMUM_SUPPORTED_RUST_VERSION: 1.75
   # For dev builds, include limited debug info in the output. See
   # https://doc.rust-lang.org/cargo/reference/profiles.html#debug
   CARGO_PROFILE_DEV_DEBUG: limited
diff --git a/rust/protocol/src/sealed_sender.rs b/rust/protocol/src/sealed_sender.rs
index 2cba494f..f6b97ff5 100644
--- a/rust/protocol/src/sealed_sender.rs
+++ b/rust/protocol/src/sealed_sender.rs
@@ -1451,10 +1451,7 @@ where
     let parallelism = std::thread::available_parallelism()
         .map(usize::from)
         .unwrap_or(1);
-    let chunk_size = std::cmp::max(
-        6,
-        crate::utils::div_ceil(identity_keys_and_ranges.len(), parallelism),
-    );
+    let chunk_size = std::cmp::max(6, identity_keys_and_ranges.len().div_ceil(parallelism));
 
     if parallelism == 1 || chunk_size >= identity_keys_and_ranges.len() {
         process_chunk(&mut serialized, &identity_keys_and_ranges)?;
diff --git a/rust/protocol/src/utils.rs b/rust/protocol/src/utils.rs
index 62bbfeb2..67a108c8 100644
--- a/rust/protocol/src/utils.rs
+++ b/rust/protocol/src/utils.rs
@@ -4,7 +4,6 @@
 //
 
 use std::cmp::Ordering;
-use std::ops::{Add, Div, Rem};
 
 fn expand_top_bit(a: u8) -> u8 {
     //if (a >> 7) == 1 { 0xFF } else { 0 }
@@ -82,24 +81,6 @@ pub(crate) fn constant_time_cmp(x: &[u8], y: &[u8]) -> Ordering {
     }
 }
 
-// To be replaced by 1.73's div_ceil when we update our MSRV.
-#[inline]
-pub(crate) fn div_ceil<
-    T: Copy + Div<Output = T> + Rem<Output = T> + Add<Output = T> + Ord + From<u8>,
->(
-    dividend: T,
-    divisor: T,
-) -> T {
-    // From the std implementation of div_ceil.
-    let q = dividend / divisor;
-    let r = dividend % divisor;
-    if (r > 0u8.into() && divisor > 0u8.into()) || (r < 0u8.into() && divisor < 0u8.into()) {
-        q + 1u8.into()
-    } else {
-        q
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -157,30 +138,4 @@ mod tests {
             }
         }
     }
-
-    #[test]
-    fn test_div_ceil() {
-        assert_eq!(div_ceil(0_usize, 4), 0);
-        assert_eq!(div_ceil(7_usize, 4), 2);
-        assert_eq!(div_ceil(8_usize, 4), 2);
-        assert_eq!(div_ceil(9_usize, 4), 3);
-    }
-
-    #[test]
-    #[should_panic]
-    fn test_div_ceil_panic() {
-        _ = div_ceil(4_usize, 0);
-    }
-
-    // From https://doc.rust-lang.org/std/primitive.isize.html#method.div_ceil
-    #[test]
-    fn test_div_ceil_isize() {
-        let a: isize = 8;
-        let b = 3;
-
-        assert_eq!(div_ceil(a, b), 3);
-        assert_eq!(div_ceil(a, -b), -2);
-        assert_eq!(div_ceil(-a, b), -2);
-        assert_eq!(div_ceil(-a, -b), 3);
-    }
 }
diff --git a/rust/svr3/src/lib.rs b/rust/svr3/src/lib.rs
index 1e5d3151..12e36a08 100644
--- a/rust/svr3/src/lib.rs
+++ b/rust/svr3/src/lib.rs
@@ -52,8 +52,7 @@ fn arr_xor(from: &[u8], into: &mut [u8]) {
 pub struct Query4 {}
 
 impl Query4 {
-    // Using `impl Iterator<...>` makes libsignal-net fail to build in Rust 1.72
-    pub fn requests() -> std::iter::Repeat<Vec<u8>> {
+    pub fn requests() -> impl Iterator<Item = Vec<u8>> {
         std::iter::repeat(
             svr4::Request4 {
                 inner: Some(svr4::request4::Inner::Query(svr4::request4::Query {})),
@@ -85,8 +84,7 @@ impl Query4 {
 pub struct Remove4 {}
 
 impl Remove4 {
-    // Using `impl Iterator<...>` makes libsignal-net fail to build in Rust 1.72
-    pub fn requests() -> std::iter::Repeat<Vec<u8>> {
+    pub fn requests() -> impl Iterator<Item = Vec<u8>> {
         std::iter::repeat(
             svr4::Request4 {
                 inner: Some(svr4::request4::Inner::Remove(svr4::request4::Remove {})),