From bb66467386cfb2d88650bc26151f97ad073bedba Mon Sep 17 00:00:00 2001
From: noamteyssier <22600644+noamteyssier@users.noreply.github.com>
Date: Thu, 20 Aug 2026 11:12:03 -0700
Subject: [PATCH 1/2] refactor: use numbuffer instead of itoa

---
 src/bq/reader.rs      |  5 +++--
 src/cbq/core/block.rs | 11 ++++++-----
 src/vbq/reader.rs     |  7 ++++---
 3 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/src/bq/reader.rs b/src/bq/reader.rs
index 679b210..db0ea2a 100644
--- a/src/bq/reader.rs
+++ b/src/bq/reader.rs
@@ -7,6 +7,7 @@
 //! It supports both sequential and parallel processing of records,
 //! with configurable record layouts for different sequence types.
 
+use core::fmt::NumBuffer;
 use std::fs::File;
 use std::io::Read;
 use std::ops::Range;
@@ -920,7 +921,7 @@ impl ParallelReader for MmapReader {
                 }
 
                 // create a reusable buffer for translating record IDs
-                let mut translater = itoa::Buffer::new();
+                let mut translater = NumBuffer::new();
 
                 // initialize a decoding buffer
                 let mut dbuf = Vec::new();
@@ -959,7 +960,7 @@ impl ParallelReader for MmapReader {
                     // iterate over each index in the range
                     for (inner_idx, idx) in (range_start..range_end).enumerate() {
                         // translate the index
-                        let id_str = translater.format(idx);
+                        let id_str = idx.format_into(&mut translater);
 
                         // create the index buffer
                         let mut header_buf = [0; 20];
diff --git a/src/cbq/core/block.rs b/src/cbq/core/block.rs
index 1045fd7..1a45300 100644
--- a/src/cbq/core/block.rs
+++ b/src/cbq/core/block.rs
@@ -1,3 +1,4 @@
+use core::fmt::NumBuffer;
 use std::io;
 
 use bytemuck::{cast_slice, cast_slice_mut};
@@ -731,7 +732,7 @@ impl ColumnarBlock {
             index: 0,
             is_paired: self.header.is_paired(),
             has_headers: self.header.has_headers(),
-            header_buffer: itoa::Buffer::new(),
+            header_buffer: NumBuffer::new(),
         }
     }
 }
@@ -756,8 +757,8 @@ pub struct RefRecordIter<'a> {
     /// Preallocated buffer for quality scores
     qbuf: &'a [u8],
 
-    /// Preallocated itoa buffer for converting global record index to string
-    header_buffer: itoa::Buffer,
+    /// Preallocated NumBuffer for converting global record index to string
+    header_buffer: NumBuffer<usize>,
 }
 impl<'a> Iterator for RefRecordIter<'a> {
     type Item = RefRecord<'a>;
@@ -830,9 +831,9 @@ struct RefRecordIndex {
     index_len: usize,
 }
 impl RefRecordIndex {
-    fn new(index: usize, itoa_buf: &mut itoa::Buffer) -> Self {
+    fn new(index: usize, buf: &mut NumBuffer<usize>) -> Self {
         let mut index_buf = [0u8; 20];
-        let header_str = itoa_buf.format(index);
+        let header_str = index.format_into(buf);
         let index_len = header_str.len();
         index_buf[..index_len].copy_from_slice(header_str.as_bytes());
         Self {
diff --git a/src/vbq/reader.rs b/src/vbq/reader.rs
index ef5b931..174321f 100644
--- a/src/vbq/reader.rs
+++ b/src/vbq/reader.rs
@@ -49,6 +49,7 @@
 //! }
 //! ```
 
+use core::fmt::NumBuffer;
 use std::fs::File;
 use std::ops::Range;
 use std::path::Path;
@@ -542,7 +543,7 @@ impl RecordBlock {
 pub struct RecordBlockIter<'a> {
     block: &'a RecordBlock,
     pos: usize,
-    header_buffer: itoa::Buffer,
+    header_buffer: NumBuffer<u64>,
     qbuf: &'a [u8],
 }
 impl<'a> RecordBlockIter<'a> {
@@ -551,7 +552,7 @@ impl<'a> RecordBlockIter<'a> {
         Self {
             block,
             pos: 0,
-            header_buffer: itoa::Buffer::new(),
+            header_buffer: NumBuffer::new(),
             qbuf: &block.qbuf,
         }
     }
@@ -571,7 +572,7 @@ impl<'a> Iterator for RecordBlockIter<'a> {
         let mut header_buf = [0; 20];
         let mut header_len = 0;
         if meta.s_header_span.len == 0 && meta.x_header_span.len == 0 {
-            let header_str = self.header_buffer.format(index);
+            let header_str = index.format_into(&mut self.header_buffer);
             header_len = header_str.len();
             header_buf[..header_len].copy_from_slice(header_str.as_bytes());
         }

From 9afb075ce3cdb0e68ce0a732c9d7e5d10f45e660 Mon Sep 17 00:00:00 2001
From: noamteyssier <22600644+noamteyssier@users.noreply.github.com>
Date: Thu, 20 Aug 2026 11:12:11 -0700
Subject: [PATCH 2/2] dep: drop itoa as dependency

---
 Cargo.toml | 1 -
 1 file changed, 1 deletion(-)

diff --git a/Cargo.toml b/Cargo.toml
index bb976a0..50fc46b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -17,7 +17,6 @@ bitnuc-deprec = { package ="bitnuc", version = "0.4.1" }
 bitnuc = { version = "0.5.1" }
 bytemuck = { version = "1.25.1", features = ["derive", "extern_crate_alloc"] }
 byteorder = "1.5.0"
-itoa = "1.0.18"
 memchr = "2.8.3"
 memmap2 = "0.9.11"
 num_cpus = "1.17.0"