From 9de6273e10bc03e17ee09e0a44136ae528e6646f Mon Sep 17 00:00:00 2001
From: Yuya Nishihara <yuya@tcha.org>
Date: Fri, 22 Dec 2023 09:06:40 +0900
Subject: [PATCH] index, stacked_table: inline read_u32::<LittleEndian>()

There aren't many callers of ReadBytesExt::read_u32().
---
 lib/src/default_index/readonly.rs | 17 +++++++++++++----
 lib/src/stacked_table.rs          | 10 +++++++---
 2 files changed, 20 insertions(+), 7 deletions(-)

diff --git a/lib/src/default_index/readonly.rs b/lib/src/default_index/readonly.rs
index eafb4070a..0c3b08b71 100644
--- a/lib/src/default_index/readonly.rs
+++ b/lib/src/default_index/readonly.rs
@@ -23,7 +23,6 @@ use std::io::Read;
 use std::path::Path;
 use std::sync::Arc;
 
-use byteorder::{LittleEndian, ReadBytesExt};
 use smallvec::SmallVec;
 use thiserror::Error;
 
@@ -216,7 +215,12 @@ impl ReadonlyIndexSegment {
         change_id_length: usize,
     ) -> Result<Arc<ReadonlyIndexSegment>, ReadonlyIndexLoadError> {
         let from_io_err = |err| ReadonlyIndexLoadError::from_io_err(&name, err);
-        let parent_filename_len = file.read_u32::<LittleEndian>().map_err(from_io_err)?;
+        let read_u32 = |file: &mut dyn Read| {
+            let mut buf = [0; 4];
+            file.read_exact(&mut buf).map_err(from_io_err)?;
+            Ok(u32::from_le_bytes(buf))
+        };
+        let parent_filename_len = read_u32(file)?;
         let maybe_parent_file = if parent_filename_len > 0 {
             let mut parent_filename_bytes = vec![0; parent_filename_len as usize];
             file.read_exact(&mut parent_filename_bytes)
@@ -253,11 +257,16 @@ impl ReadonlyIndexSegment {
         change_id_length: usize,
     ) -> Result<Arc<ReadonlyIndexSegment>, ReadonlyIndexLoadError> {
         let from_io_err = |err| ReadonlyIndexLoadError::from_io_err(&name, err);
+        let read_u32 = |file: &mut dyn Read| {
+            let mut buf = [0; 4];
+            file.read_exact(&mut buf).map_err(from_io_err)?;
+            Ok(u32::from_le_bytes(buf))
+        };
         let num_parent_commits = parent_file
             .as_ref()
             .map_or(0, |segment| segment.as_composite().num_commits());
-        let num_local_commits = file.read_u32::<LittleEndian>().map_err(from_io_err)?;
-        let num_parent_overflow_entries = file.read_u32::<LittleEndian>().map_err(from_io_err)?;
+        let num_local_commits = read_u32(file)?;
+        let num_parent_overflow_entries = read_u32(file)?;
         let mut data = vec![];
         file.read_to_end(&mut data).map_err(from_io_err)?;
         let commit_graph_entry_size = CommitGraphEntry::size(commit_id_length, change_id_length);
diff --git a/lib/src/stacked_table.rs b/lib/src/stacked_table.rs
index 9f1b8789c..afa3d4435 100644
--- a/lib/src/stacked_table.rs
+++ b/lib/src/stacked_table.rs
@@ -29,7 +29,6 @@ use std::path::PathBuf;
 use std::sync::{Arc, RwLock};
 
 use blake2::{Blake2b512, Digest};
-use byteorder::{LittleEndian, ReadBytesExt};
 use tempfile::NamedTempFile;
 use thiserror::Error;
 
@@ -74,7 +73,12 @@ impl ReadonlyTable {
         name: String,
         key_size: usize,
     ) -> TableStoreResult<Arc<ReadonlyTable>> {
-        let parent_filename_len = file.read_u32::<LittleEndian>()?;
+        let read_u32 = |file: &mut dyn Read| -> io::Result<u32> {
+            let mut buf = [0; 4];
+            file.read_exact(&mut buf)?;
+            Ok(u32::from_le_bytes(buf))
+        };
+        let parent_filename_len = read_u32(file)?;
         let maybe_parent_file = if parent_filename_len > 0 {
             let mut parent_filename_bytes = vec![0; parent_filename_len as usize];
             file.read_exact(&mut parent_filename_bytes)?;
@@ -84,7 +88,7 @@ impl ReadonlyTable {
         } else {
             None
         };
-        let num_local_entries = file.read_u32::<LittleEndian>()? as usize;
+        let num_local_entries = read_u32(file)? as usize;
         let index_size = num_local_entries * ReadonlyTableIndexEntry::size(key_size);
         let mut data = vec![];
         file.read_to_end(&mut data)?;