remove byteorder dependency from git-commitgraph (#293)

This is now sufficiently well implemented in the standard library.

Author: Byron

Cargo.lock

@@ -21,7 +21,6 @@ git-hash = { version ="^0.8.0", path = "../git-hash" }
 git-chunk = { version ="^0.2.0", path = "../git-chunk" }
 
 bstr = { version = "0.2.13", default-features = false, features = ["std"] }
-byteorder = "1.2.3"
 memmap2 = "0.5.0"
 serde = { version = "1.0.114", optional = true, default-features = false, features = ["derive"] }
 thiserror = "1.0.26"

git-commitgraph/Cargo.toml

@@ -5,8 +5,6 @@ use std::{
     slice::Chunks,
 };
 
-use byteorder::{BigEndian, ByteOrder};
-
 use crate::{
     file::{self, File, EXTENDED_EDGES_MASK, LAST_EXTENDED_EDGE_MASK, NO_PARENT},
     graph,
@@ -38,17 +36,23 @@ pub struct Commit<'a> {
     root_tree_id: &'a git_hash::oid,
 }
 
+#[inline]
+fn read_u32(b: &[u8]) -> u32 {
+    u32::from_be_bytes(b.try_into().unwrap())
+}
+
 impl<'a> Commit<'a> {
     pub(crate) fn new(file: &'a File, pos: file::Position) -> Self {
         let bytes = file.commit_data_bytes(pos);
         Commit {
             file,
             pos,
             root_tree_id: git_hash::oid::from_bytes_unchecked(&bytes[..file.hash_len]),
-            parent1: ParentEdge::from_raw(BigEndian::read_u32(&bytes[file.hash_len..][..4])),
-            parent2: ParentEdge::from_raw(BigEndian::read_u32(&bytes[file.hash_len + 4..][..4])),
-            generation: BigEndian::read_u32(&bytes[file.hash_len + 8..][..4]) >> 2,
-            commit_timestamp: BigEndian::read_u64(&bytes[file.hash_len + 8..][..8]) & 0x0003_ffff_ffff,
+            parent1: ParentEdge::from_raw(read_u32(&bytes[file.hash_len..][..4])),
+            parent2: ParentEdge::from_raw(read_u32(&bytes[file.hash_len + 4..][..4])),
+            generation: read_u32(&bytes[file.hash_len + 8..][..4]) >> 2,
+            commit_timestamp: u64::from_be_bytes(bytes[file.hash_len + 8..][..8].try_into().unwrap())
+                & 0x0003_ffff_ffff,
         }
     }
 
@@ -173,7 +177,7 @@ impl<'a> Iterator for ParentIterator<'a> {
             },
             ParentIteratorState::Extra(mut chunks) => {
                 if let Some(chunk) = chunks.next() {
-                    let extra_edge = BigEndian::read_u32(chunk);
+                    let extra_edge = read_u32(chunk);
                     match ExtraEdge::from_raw(extra_edge) {
                         ExtraEdge::Internal(pos) => {
                             self.state = ParentIteratorState::Extra(chunks);

git-commitgraph/src/file/commit.rs

@@ -4,7 +4,6 @@ use std::{
 };
 
 use bstr::ByteSlice;
-use byteorder::{BigEndian, ByteOrder};
 use memmap2::Mmap;
 
 use crate::file::{
@@ -249,7 +248,7 @@ impl TryFrom<&Path> for File {
 fn read_fan(d: &[u8]) -> ([u32; FAN_LEN], usize) {
     let mut fan = [0; FAN_LEN];
     for (c, f) in d.chunks(4).zip(fan.iter_mut()) {
-        *f = BigEndian::read_u32(c);
+        *f = u32::from_be_bytes(c.try_into().unwrap());
     }
     (fan, FAN_LEN * 4)
 }