add git-lfs package (#8)

.gitignore

@@ -19,3 +19,6 @@ capnproto/capnproto/install/
 
 # built ffmpeg
 ffmpeg/ffmpeg/install/
+
+# downloaded git-lfs
+git-lfs/git_lfs/bin/

git-lfs/build.sh

@@ -0,0 +1,57 @@
+#!/usr/bin/env bash
+set -e
+
+DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" >/dev/null && pwd)"
+cd "$DIR"
+
+VERSION="3.6.1"
+INSTALL_DIR="$DIR/git_lfs/bin"
+
+# Idempotent: skip if already present
+if [ -x "$INSTALL_DIR/git-lfs" ]; then
+  echo "git-lfs already present, skipping download."
+  exit 0
+fi
+
+OS="$(uname -s)"
+ARCH="$(uname -m)"
+
+case "${OS}-${ARCH}" in
+  Linux-x86_64)   PLATFORM="linux-amd64"  ; EXT="tar.gz" ;;
+  Linux-aarch64)  PLATFORM="linux-arm64"   ; EXT="tar.gz" ;;
+  Darwin-arm64)   PLATFORM="darwin-arm64"  ; EXT="zip" ;;
+  *)
+    echo "Unsupported platform: ${OS}-${ARCH}" >&2
+    exit 1
+    ;;
+esac
+
+FILENAME="git-lfs-${PLATFORM}-v${VERSION}.${EXT}"
+URL="https://github.com/git-lfs/git-lfs/releases/download/v${VERSION}/${FILENAME}"
+
+echo "Downloading $FILENAME ..."
+curl -fSL -o "$FILENAME" "$URL"
+
+echo "Extracting ..."
+mkdir -p "$INSTALL_DIR"
+if [ "$EXT" = "zip" ]; then
+  python3 -c "
+import zipfile, sys
+with zipfile.ZipFile('$FILENAME') as zf:
+  for info in zf.infolist():
+    if info.filename.endswith('/git-lfs'):
+      with open('$INSTALL_DIR/git-lfs', 'wb') as f:
+        f.write(zf.read(info))
+      break
+"
+else
+  tar --strip-components=1 -xzf "$FILENAME" -C "$INSTALL_DIR" --wildcards '*/git-lfs'
+fi
+
+chmod +x "$INSTALL_DIR/git-lfs"
+strip "$INSTALL_DIR/git-lfs" 2>/dev/null || true
+
+rm -f "$FILENAME"
+
+echo "Installed git-lfs to $INSTALL_DIR"
+du -sh "$INSTALL_DIR"

git-lfs/git_lfs/__init__.py

@@ -0,0 +1,15 @@
+import os
+import sys
+
+BIN_DIR = os.path.join(os.path.dirname(__file__), "bin")
+
+
+def _run():
+  binary = os.path.join(BIN_DIR, "git-lfs")
+  os.execvp(binary, [binary] + sys.argv[1:])
+
+
+def smoketest():
+  import subprocess
+  binary = os.path.join(BIN_DIR, "git-lfs")
+  subprocess.run([binary, "--version"], check=True)

git-lfs/pyproject.toml

@@ -0,0 +1,18 @@
+[build-system]
+requires = ["setuptools>=64", "wheel"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "git-lfs"
+version = "3.6.1"
+description = "Git Large File Storage extension"
+requires-python = ">=3.8"
+
+[project.scripts]
+git-lfs = "git_lfs:_run"
+
+[tool.setuptools.packages.find]
+include = ["git_lfs*"]
+
+[tool.setuptools.package-data]
+git_lfs = ["bin/**/*"]

git-lfs/setup.py

@@ -0,0 +1,61 @@
+import os
+import platform
+import subprocess
+
+from setuptools.command.build_py import build_py
+
+try:
+  from wheel.bdist_wheel import bdist_wheel
+except ImportError:
+  bdist_wheel = None
+
+
+class BuildGitLfs(build_py):
+  """Run build.sh to download git-lfs before collecting package data."""
+
+  def run(self):
+    pkg_dir = os.path.dirname(os.path.abspath(__file__))
+    marker = os.path.join(pkg_dir, "git_lfs", "bin", "git-lfs")
+
+    if not os.path.exists(marker):
+      build_script = os.path.join(pkg_dir, "build.sh")
+      subprocess.check_call(["bash", build_script], cwd=pkg_dir)
+
+    super().run()
+
+
+cmdclass = {"build_py": BuildGitLfs}
+
+if bdist_wheel is not None:
+
+  class PlatformWheel(bdist_wheel):
+    """Produce a platform-specific, Python-version-agnostic wheel."""
+
+    def finalize_options(self):
+      super().finalize_options()
+      self.root_is_pure = False
+
+    def get_tag(self):
+      system = platform.system()
+      machine = platform.machine()
+
+      if system == "Linux":
+        plat = f"linux_{machine}"
+      elif system == "Darwin":
+        plat = "macosx_11_0_arm64"
+      else:
+        plat = f"{system.lower()}_{machine}"
+
+      return "py3", "none", plat
+
+  cmdclass["bdist_wheel"] = PlatformWheel
+
+
+def setup():
+  from setuptools import setup as _setup
+
+  _setup(cmdclass=cmdclass)
+
+
+if __name__ == "__main__":
+  setup()