refactor: move archive extraction logic in its own module

src/ops2deb/extracter.py

@@ -0,0 +1,91 @@
+import asyncio
+import bz2
+import gzip
+import io
+import shutil
+import tarfile
+from pathlib import Path
+
+import unix_ar
+import zstandard
+
+from ops2deb import logger
+from ops2deb.exceptions import Ops2debExtractError
+from ops2deb.utils import log_and_raise
+
+
+def _unpack_gz(file_path: str, extract_path: str) -> None:
+    output_path = Path(extract_path) / Path(file_path).stem
+    with output_path.open("wb") as output:
+        with gzip.open(file_path, "rb") as gz_archive:
+            shutil.copyfileobj(gz_archive, output)
+
+
+def _unpack_bz2(file_path: str, extract_path: str) -> None:
+    output_path = Path(extract_path) / Path(file_path).stem
+    with output_path.open(mode="wb") as output:
+        with bz2.open(file_path, "rb") as bz2_archive:
+            shutil.copyfileobj(bz2_archive, output)
+
+
+def _unpack_deb(file_path: str, extract_path: str) -> None:
+    ar_file = unix_ar.open(file_path)
+    file_names = [info.name.decode("utf-8") for info in ar_file.infolist()]
+    for file_name in file_names:
+        if file_name.startswith("debian-binary"):
+            continue
+        tarball = ar_file.open(file_name)
+        tar_file = tarfile.open(fileobj=tarball)
+        try:
+            tar_file.extractall(Path(extract_path) / file_name.split(".")[0])
+        finally:
+            tar_file.close()
+
+
+def _unpack_zst(file_path: str, extract_path: str) -> None:
+    output_path = Path(extract_path) / Path(file_path).stem
+    dctx = zstandard.ZstdDecompressor()
+    with open(file_path, "rb") as ifh, output_path.open("wb") as ofh:
+        dctx.copy_stream(ifh, ofh)
+
+
+def _unpack_tar_zst(file_path: str, extract_path: str) -> None:
+    dctx = zstandard.ZstdDecompressor()
+    with open(file_path, "rb") as ifh, io.BytesIO() as ofh:
+        dctx.copy_stream(ifh, ofh)
+        ofh.seek(0)
+        with tarfile.open(fileobj=ofh) as tar_file:
+            tar_file.extractall(extract_path)
+
+
+shutil.register_unpack_format("gz", [".gz"], _unpack_gz)
+shutil.register_unpack_format("bz2", [".bz2"], _unpack_bz2)
+shutil.register_unpack_format("deb", [".deb"], _unpack_deb)
+shutil.register_unpack_format("zsttar", [".tar.zst"], _unpack_tar_zst)
+shutil.register_unpack_format("zst", [".zst"], _unpack_zst)
+
+
+def is_archive_format_supported(archive_path: Path) -> bool:
+    for name, extensions, _ in shutil.get_unpack_formats():
+        for extension in extensions:
+            if archive_path.name.endswith(extension):
+                return True
+    return False
+
+
+async def extract_archive(archive_path: Path, extract_path: Path) -> None:
+    tmp_extract_path = f"{extract_path}_tmp"
+    Path(tmp_extract_path).mkdir(exist_ok=True)
+    logger.info(f"Extracting {archive_path.name}...")
+
+    try:
+        await asyncio.get_running_loop().run_in_executor(
+            None, shutil.unpack_archive, archive_path, tmp_extract_path
+        )
+    except Exception as e:
+        error = f"Failed to extract archive {archive_path}"
+        if str(e):
+            error += f" ({e})"
+        log_and_raise(Ops2debExtractError(error))
+
+    shutil.move(tmp_extract_path, extract_path)

src/ops2deb/fetcher.py

@@ -1,80 +1,24 @@
 import asyncio
-import bz2
-import gzip
 import hashlib
-import io
 import shutil
-import tarfile
 from dataclasses import dataclass
 from pathlib import Path
 from typing import Sequence
 
 import aiofiles
 import httpx
-import unix_ar
-import zstandard
 
 from ops2deb import logger
 from ops2deb.client import client_factory
-from ops2deb.exceptions import Ops2debError, Ops2debExtractError, Ops2debFetcherError
+from ops2deb.exceptions import Ops2debError, Ops2debFetcherError
+from ops2deb.extracter import extract_archive, is_archive_format_supported
 from ops2deb.lockfile import Lock
 from ops2deb.parser import Configuration
 from ops2deb.utils import log_and_raise, separate_results_from_errors
 
 DEFAULT_CACHE_DIRECTORY = Path("/tmp/ops2deb_cache")
 
 
-def _unpack_gz(file_path: str, extract_path: str) -> None:
-    output_path = Path(extract_path) / Path(file_path).stem
-    with output_path.open("wb") as output:
-        with gzip.open(file_path, "rb") as gz_archive:
-            shutil.copyfileobj(gz_archive, output)
-
-
-def _unpack_bz2(file_path: str, extract_path: str) -> None:
-    output_path = Path(extract_path) / Path(file_path).stem
-    with output_path.open(mode="wb") as output:
-        with bz2.open(file_path, "rb") as bz2_archive:
-            shutil.copyfileobj(bz2_archive, output)
-
-
-def _unpack_deb(file_path: str, extract_path: str) -> None:
-    ar_file = unix_ar.open(file_path)
-    file_names = [info.name.decode("utf-8") for info in ar_file.infolist()]
-    for file_name in file_names:
-        if file_name.startswith("debian-binary"):
-            continue
-        tarball = ar_file.open(file_name)
-        tar_file = tarfile.open(fileobj=tarball)
-        try:
-            tar_file.extractall(Path(extract_path) / file_name.split(".")[0])
-        finally:
-            tar_file.close()
-
-
-def _unpack_zst(file_path: str, extract_path: str) -> None:
-    output_path = Path(extract_path) / Path(file_path).stem
-    dctx = zstandard.ZstdDecompressor()
-    with open(file_path, "rb") as ifh, output_path.open("wb") as ofh:
-        dctx.copy_stream(ifh, ofh)
-
-
-def _unpack_tar_zst(file_path: str, extract_path: str) -> None:
-    dctx = zstandard.ZstdDecompressor()
-    with open(file_path, "rb") as ifh, io.BytesIO() as ofh:
-        dctx.copy_stream(ifh, ofh)
-        ofh.seek(0)
-        with tarfile.open(fileobj=ofh) as tar_file:
-            tar_file.extractall(extract_path)
-
-
-shutil.register_unpack_format("gz", [".gz"], _unpack_gz)
-shutil.register_unpack_format("bz2", [".bz2"], _unpack_bz2)
-shutil.register_unpack_format("deb", [".deb"], _unpack_deb)
-shutil.register_unpack_format("zsttar", [".tar.zst"], _unpack_tar_zst)
-shutil.register_unpack_format("zst", [".zst"], _unpack_zst)
-
-
 async def _download_file(url: str, download_path: Path) -> None:
     tmp_path = f"{download_path}.part"
     logger.info(f"Downloading {download_path.name}...")
@@ -106,32 +50,6 @@ async def _hash_file(file_path: Path) -> str:
     return sha256_hash.hexdigest()
 
 
-def is_archive_format_supported(archive_path: Path) -> bool:
-    for name, extensions, _ in shutil.get_unpack_formats():
-        for extension in extensions:
-            if archive_path.name.endswith(extension):
-                return True
-    return False
-
-
-async def extract_archive(archive_path: Path, extract_path: Path) -> None:
-    tmp_extract_path = f"{extract_path}_tmp"
-    Path(tmp_extract_path).mkdir(exist_ok=True)
-    logger.info(f"Extracting {archive_path.name}...")
-
-    try:
-        await asyncio.get_running_loop().run_in_executor(
-            None, shutil.unpack_archive, archive_path, tmp_extract_path
-        )
-    except Exception as e:
-        error = f"Failed to extract archive {archive_path}"
-        if str(e):
-            error += f" ({e})"
-        log_and_raise(Ops2debExtractError(error))
-
-    shutil.move(tmp_extract_path, extract_path)
-
-
 @dataclass
 class FetchResult:
     url: str