Adds tool.hatch.build.targets.sdist.compress-level

Author: cstigen

backend/src/hatchling/builders/sdist.py

@@ -28,7 +28,7 @@
 
 
 class SdistArchive:
-    def __init__(self, name: str, *, reproducible: bool) -> None:
+    def __init__(self, name: str, *, reproducible: bool, compress_level: int) -> None:
         """
         https://peps.python.org/pep-0517/#source-distributions
         """
@@ -38,7 +38,8 @@ def __init__(self, name: str, *, reproducible: bool) -> None:
 
         raw_fd, self.path = tempfile.mkstemp(suffix='.tar.gz')
         self.fd = os.fdopen(raw_fd, 'w+b')
-        self.gz = gzip.GzipFile(fileobj=self.fd, mode='wb', mtime=self.timestamp)
+
+        self.gz = gzip.GzipFile(fileobj=self.fd, mode='wb', mtime=self.timestamp, compresslevel=compress_level)
         self.tf = tarfile.TarFile(fileobj=self.gz, mode='w', format=tarfile.PAX_FORMAT)
         self.gettarinfo = lambda *args, **kwargs: self.normalize_tar_metadata(self.tf.gettarinfo(*args, **kwargs))
 
@@ -90,10 +91,32 @@ class SdistBuilderConfig(BuilderConfig):
     def __init__(self, *args: Any, **kwargs: Any) -> None:
         super().__init__(*args, **kwargs)
 
+        self.__compress_level: int | None = None
         self.__core_metadata_constructor: Callable[..., str] | None = None
         self.__strict_naming: bool | None = None
         self.__support_legacy: bool | None = None
 
+    @property
+    def compress_level(self) -> int:
+        if self.__compress_level is None:
+            try:
+                compress_level = int(self.target_config.get('compress-level', 9))
+            except ValueError as e:
+                message = f'Field `tool.hatch.build.{self.plugin_name}.compress-level` must be an integer'
+                raise TypeError(message) from e
+
+            if not (0 <= compress_level <= 9):  # noqa: PLR2004
+                message = (
+                    'Value field '
+                    f'`tool.hatch.build.targets.{self.plugin_name}.compress-level` '
+                    'must be an integer from 0 to 9'
+                )
+                raise ValueError(message)
+
+            self.__compress_level = compress_level
+
+        return self.__compress_level
+
     @property
     def core_metadata_constructor(self) -> Callable[..., str]:
         if self.__core_metadata_constructor is None:
@@ -166,7 +189,9 @@ def clean(  # noqa: PLR6301
     def build_standard(self, directory: str, **build_data: Any) -> str:
         found_packages = set()
 
-        with SdistArchive(self.artifact_project_id, reproducible=self.config.reproducible) as archive:
+        with SdistArchive(
+            self.artifact_project_id, reproducible=self.config.reproducible, compress_level=self.config.compress_level
+        ) as archive:
             for included_file in self.recurse_included_files():
                 if self.config.support_legacy:
                     possible_package, file_name = os.path.split(included_file.relative_path)

docs/config/build.md

@@ -180,6 +180,17 @@ skip-excluded-dirs = true
 !!! warning
     This may result in not shipping desired files. For example, if you want to include the file `a/b/c.txt` but your [VCS ignores](#vcs) `a/b`, the file `c.txt` will not be seen because its parent directory will not be entered. In such cases you can use the [`force-include`](#forced-inclusion) option.
 
+## Compression level
+
+You can change the level used for compressing the sdist tarballs. In some circumstances, lowering it from the default of 9 can massively reduce build times without affecting the output size too much.
+
+```toml config-example
+[tool.hatch.build.targets.sdist]
+compress-level = 1
+```
+
+Accepted values are 0 (no compression) to 9 (highest compression).
+
 ## Reproducible builds
 
 By default, [build targets](#build-targets) will build in a reproducible manner provided that they support that behavior. To disable this, set `reproducible` to `false`: