Add own implementation of CAR reader

Cargo.toml

@@ -16,11 +16,10 @@ crate-type = ["rlib", "cdylib"]
 pyo3 = { version = "0.21.0-beta.0", features = ["generate-import-lib", "anyhow"] }
 python3-dll-a = "0.2.7"
 anyhow = "1.0.75"
-futures = "0.3"
 libipld = { version = "0.16.0", features = ["dag-cbor"] }
-iroh-car = "0.4.0"
 multibase = "0.9"
 byteorder = "1.5.0"
+multihash = "0.18.1"
 
 [workspace]
 members = [ "profiling" ]

pytests/test_decode_car.py

@@ -5,7 +5,6 @@
 
 from conftest import load_car_fixture
 
-
 _DID = os.environ.get('CAR_REPO_DID', 'did:plc:w4es6sfh43zlht3bgrzi5qzq')  # default is public bot in bsky.app
 _REPO_CAR_PATH = os.path.join(os.path.dirname(__file__), '..', 'data', 'repo.car')
 
@@ -27,3 +26,75 @@ def test_decode_car(benchmark, car) -> None:
     assert all(len(k) == 59 for k in blocks.keys())
     assert all(isinstance(v, dict) for v in blocks.values())
     assert all(v for v in blocks.values())  # not empty dict
+
+
+def test_decode_car_invalid_header_len() -> None:
+    with pytest.raises(ValueError) as exc_info:
+        libipld.decode_car(b'')
+
+    assert 'Invalid uvarint' in str(exc_info.value)
+
+
+def test_decode_car_invalid_header_type() -> None:
+    with pytest.raises(TypeError) as exc_info:
+        header_len = bytes.fromhex('33')  # 3
+        header_obj = libipld.encode_dag_cbor('strInsteadOfObj')
+        libipld.decode_car(header_len + header_obj)
+
+    assert "cannot be converted to 'PyDict'" in str(exc_info.value)
+
+
+def test_decode_car_invalid_header_version_key() -> None:
+    with pytest.raises(ValueError) as exc_info:
+        header_len = bytes.fromhex('33')  # 3
+        header_obj = libipld.encode_dag_cbor({'blabla': 'blabla'})
+        libipld.decode_car(header_len + header_obj)
+
+    assert 'Version is None' in str(exc_info.value)
+
+
+def test_decode_car_invalid_header_version_value() -> None:
+    with pytest.raises(ValueError) as exc_info:
+        header_len = bytes.fromhex('33')  # 3
+        header_obj = libipld.encode_dag_cbor({'version': 2})
+        libipld.decode_car(header_len + header_obj)
+
+    assert 'Version must be 1' in str(exc_info.value)
+
+
+def test_decode_car_invalid_header_roots_key() -> None:
+    with pytest.raises(ValueError) as exc_info:
+        header_len = bytes.fromhex('33')  # 3
+        header_obj = libipld.encode_dag_cbor({'version': 1})
+        libipld.decode_car(header_len + header_obj)
+
+    assert 'Roots is None' in str(exc_info.value)
+
+
+def test_decode_car_invalid_header_roots_value_type() -> None:
+    with pytest.raises(TypeError) as exc_info:
+        header_len = bytes.fromhex('33')  # 3
+        header_obj = libipld.encode_dag_cbor({'version': 1, 'roots': 123})
+        libipld.decode_car(header_len + header_obj)
+
+    assert "cannot be converted to 'PyList'" in str(exc_info.value)
+
+
+def test_decode_car_invalid_header_roots_value_empty_list() -> None:
+    with pytest.raises(ValueError) as exc_info:
+        header_len = bytes.fromhex('33')  # 3
+        header_obj = libipld.encode_dag_cbor({'version': 1, 'roots': []})
+        libipld.decode_car(header_len + header_obj)
+
+    assert 'Roots is empty' in str(exc_info.value)
+
+
+def test_decode_car_invalid_block_cid() -> None:
+    with pytest.raises(ValueError) as exc_info:
+        header_len = bytes.fromhex('33')  # 3
+        header_obj = libipld.encode_dag_cbor({'version': 1, 'roots': ['blabla']})
+        block1 = bytes.fromhex('33') + b'invalidSid'
+
+        libipld.decode_car(header_len + header_obj + block1)
+
+    assert 'Failed to read CID of block' in str(exc_info.value)