chore: release json2xml 6.4.0

HISTORY.rst

@@ -1,4 +1,12 @@
 
+6.4.0 / 2026-07-13
+==================
+
+  * perf: buffer Rust serializer writes in bounded 16 KiB chunks, reducing large-payload conversion time while keeping serializer memory near 80 MiB
+  * chore: release ``json2xml-rs`` 0.4.1 and require it from ``json2xml[fast]`` for accelerated installs
+  * docs: record before-and-after Rust buffering benchmarks and the unchanged XML output size
+
+
 6.3.0 / 2026-06-10
 ==================
 

RELEASE_NOTES.md

@@ -1,3 +1,24 @@
+# json2xml 6.4.0 and json2xml_rs 0.4.1
+
+Released 2026-07-13.
+
+## Highlights
+
+- Added bounded 16 KiB buffering to the Rust serializer's direct Python-bytes output path.
+- Reduced the 5,000-record benchmark median from roughly 4.8 ms to 2.4 ms while keeping serializer memory near 80 MiB.
+- Kept XML output byte-for-byte identical.
+
+## Package Versions
+
+- Python package: `json2xml==6.4.0`
+- Rust accelerator package: `json2xml-rs==0.4.1`
+- Fast install: `pip install "json2xml[fast]"`
+
+## Verification
+
+The release passed the Python and Rust test suites, Rust wheel builds across supported platforms, and the Rust wheel compatibility matrix.
+
+
 # json2xml 6.3.0 and json2xml_rs 0.4.0
 
 Released 2026-06-10.

json2xml/__init__.py

@@ -2,4 +2,4 @@
 
 __author__ = """Vinit Kumar"""
 __email__ = "mail@vinitkumar.me"
-__version__ = "6.3.0"
+__version__ = "6.4.0"

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "json2xml"
-version = "6.3.0"
+version = "6.4.0"
 description = "Simple Python Library to convert JSON to XML"
 readme = "README.rst"
 requires-python = ">=3.10"
@@ -50,7 +50,7 @@ dev = [
     "pygments>=2.20.0",
     "xmltodict>=0.12.0",
 ]
-fast = ["json2xml-rs>=0.4.0"]
+fast = ["json2xml-rs>=0.4.1"]
 
 [tool.pytest.ini_options]
 testpaths = ["tests"]

rust/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "json2xml_rs"
-version = "0.4.0"
+version = "0.4.1"
 edition = "2024"
 rust-version = "1.96"
 description = "Fast native JSON to XML conversion for Python"

rust/README.md

@@ -76,7 +76,7 @@ The Rust implementation is expected to be 5-15x faster than pure Python for:
 - Type dispatch (compiled match statements vs. `isinstance()` chains)
 - String building (pre-allocated buffers vs. f-string concatenation)
 
-Version 0.4.0 builds on the direct Python bytes writer with lower allocation
+Version 0.4.1 builds on the direct Python bytes writer with lower allocation
 pressure in hot serializer paths. The previous 0.3.0 release reduced the
 measured serializer RSS delta for a 100,000-record benchmark by about 49%
 compared with the earlier Rust implementation.

rust/pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "maturin"
 
 [project]
 name = "json2xml_rs"
-version = "0.4.0"
+version = "0.4.1"
 description = "Fast native JSON to XML conversion - Rust extension for json2xml"
 readme = "README.md"
 requires-python = ">=3.9"