Include test cases for handling zero-size files in rohmu.

test/test_rohmu.py

@@ -0,0 +1,158 @@
+import hashlib
+import logging
+import os
+import pathlib
+from tempfile import NamedTemporaryFile
+
+import pytest
+from rohmu import get_transfer, rohmufile
+from rohmu.object_storage.base import BaseTransfer
+from rohmu.rohmufile import create_sink_pipeline
+from rohmu.typing import Metadata
+
+from .base import CONSTANT_TEST_RSA_PRIVATE_KEY, CONSTANT_TEST_RSA_PUBLIC_KEY
+
+EMPTY_FILE_SHA1 = "da39a3ee5e6b4b0d3255bfef95601890afd80709"
+
+log = logging.getLogger(__name__)
+
+
+@pytest.mark.parametrize("compress_algorithm", ["lzma", "snappy", "zstd"])
+@pytest.mark.parametrize("file_size", [0, 1], ids=["0byte_file", "1byte_file"])
+def test_rohmu_with_local_storage(compress_algorithm: str, file_size: int, tmp_path):
+    hash_algorithm = "sha1"
+    compression_level = 0
+
+    # 0 - Prepare the file
+    orig_file = tmp_path / "hello.bin"
+    content = os.urandom(file_size)
+    orig_file.write_bytes(content)
+
+    original_file_size = os.path.getsize(orig_file)
+    assert original_file_size == len(content)
+
+    # 1 - Compress the file
+    compressed_filepath = tmp_path / "compressed" / "hello_compressed"
+    compressed_filepath.parent.mkdir(exist_ok=True)
+    hasher = hashlib.new(hash_algorithm)
+    compressed_file_size = _compress_file(orig_file, compressed_filepath, compress_algorithm, compression_level, hasher)
+    file_hash = hasher.hexdigest()
+
+    log.info(
+        "original_file_size: %s, original_file_hash: %s, compressed_file_size: %s", original_file_size, file_hash,
+        compressed_file_size
+    )
+
+    # 2 - Upload the compressed file
+    upload_dir = tmp_path / "uploaded"
+    upload_dir.mkdir()
+    storage_config = {
+        "directory": str(upload_dir),
+        "storage_type": "local",
+    }
+    storage = get_transfer(storage_config)
+
+    metadata = {
+        "encryption-key-id": "No matter",
+        "compression-algorithm": compress_algorithm,
+        "compression-level": compression_level,
+        "Content-Length": str(compressed_file_size)
+    }
+    file_key = "compressed/hello_compressed"
+    _upload_compressed_file(storage=storage, file_to_upload=str(compressed_filepath), file_key=file_key, metadata=metadata)
+
+    # 3 - Decrypt and decompress
+    # 3.1 Use file downloading rohmu API
+    decompressed_filepath = tmp_path / "hello_decompressed_1"
+
+    decompressed_size = _download_and_decompress_with_file(storage, str(decompressed_filepath), file_key, metadata)
+    assert len(content) == decompressed_size
+    # Compare content
+    content_decrypted = decompressed_filepath.read_bytes()
+    hasher = hashlib.new(hash_algorithm)
+    hasher.update(content_decrypted)
+    assert hasher.hexdigest() == file_hash
+    assert content_decrypted == content
+
+    # 3.2 Use rohmu SinkIO API
+    decompressed_filepath = tmp_path / "hello_decompressed_2"
+    decompressed_size = _download_and_decompress_with_sink(storage, str(decompressed_filepath), file_key, metadata)
+    assert len(content) == decompressed_size
+
+    # Compare content
+    content_decrypted = decompressed_filepath.read_bytes()
+    hasher = hashlib.new(hash_algorithm)
+    hasher.update(content_decrypted)
+    assert hasher.hexdigest() == file_hash
+    assert content_decrypted == content
+
+    if file_size == 0:
+        assert EMPTY_FILE_SHA1 == hasher.hexdigest()
+
+
+def _key_lookup(key_id: str) -> str:  # pylint: disable=unused-argument
+    return CONSTANT_TEST_RSA_PRIVATE_KEY
+
+
+def _compress_file(input_file: pathlib.Path, output_file: pathlib.Path, algorithm: str, compress_level: int, hasher) -> int:
+    with open(input_file, "rb") as input_obj, NamedTemporaryFile(
+        dir=output_file.parent, prefix=output_file.name, suffix=".tmp-compress"
+    ) as output_obj:
+        _, compressed_file_size = rohmufile.write_file(
+            data_callback=hasher.update,
+            input_obj=input_obj,
+            output_obj=output_obj,
+            compression_algorithm=algorithm,
+            compression_level=compress_level,
+            rsa_public_key=CONSTANT_TEST_RSA_PUBLIC_KEY,
+            log_func=log.debug,
+        )
+        os.link(output_obj.name, output_file)
+    return compressed_file_size
+
+
+def _upload_compressed_file(storage: BaseTransfer, file_to_upload: str, file_key: str, metadata: Metadata) -> None:
+    def upload_progress_callback(n_bytes: int) -> None:
+        log.debug("File: '%s', uploaded %d bytes", file_key, n_bytes)
+
+    with open(file_to_upload, "rb") as f:
+        storage.store_file_object(file_key, f, metadata=metadata, upload_progress_fn=upload_progress_callback)
+
+
+def _download_and_decompress_with_sink(storage: BaseTransfer, output_path: str, file_key: str, metadata: Metadata) -> int:
+    data, _ = storage.get_contents_to_string(file_key)
+    file_size = len(data)
+
+    with open(output_path, "wb") as target_file:
+        output = create_sink_pipeline(
+            output=target_file, file_size=file_size, metadata=metadata, key_lookup=_key_lookup, throttle_time=0
+        )
+        output.write(data)
+    decompressed_size = os.path.getsize(output_path)
+    return decompressed_size
+
+
+def _download_and_decompress_with_file(storage: BaseTransfer, output_path: str, file_key: str, metadata: Metadata) -> int:
+    # Download the compressed file
+    file_download_path = output_path + ".tmp"
+
+    def download_progress_callback(bytes_written: int, input_size: int) -> None:
+        log.debug("File: '%s', downloaded %d of %d bytes", file_key, bytes_written, input_size)
+
+    with open(file_download_path, "wb") as f:
+        storage.get_contents_to_fileobj(file_key, f, progress_callback=download_progress_callback)
+
+    # Decrypt and decompress
+    with open(file_download_path, "rb") as input_obj, open(output_path, "wb") as output_obj:
+        _, decompressed_size = rohmufile.read_file(
+            input_obj=input_obj,
+            output_obj=output_obj,
+            metadata=metadata,
+            key_lookup=_key_lookup,
+            log_func=log.debug,
+        )
+        output_obj.flush()
+
+    # Delete temporary file
+    os.unlink(file_download_path)
+    return decompressed_size