feat(storage): support full_object_checksum in AsyncAppendableObjectWriter (googleapis#17658)

Add support for verifying `full_object_checksum` on finalising/closing
appendable object uploads.

Author: chandra-siri

packages/google-cloud-storage/google/cloud/storage/asyncio/async_appendable_object_writer.py

@@ -547,12 +547,30 @@ async def flush(self) -> int:
         self.bytes_appended_since_last_flush = 0
         return self.persisted_size
 
-    async def close(self, finalize_on_close=False) -> Union[int, _storage_v2.Object]:
+    async def close(
+        self,
+        finalize_on_close=False,
+        full_object_checksum: Optional[int] = None,
+    ) -> Union[int, _storage_v2.Object]:
         """Closes the underlying bidi-gRPC stream.
 
         :type finalize_on_close: bool
         :param finalize_on_close: Finalizes the Appendable Object. No more data
           can be appended.
+        :type full_object_checksum: int
+        :param full_object_checksum: (Optional) This should be the CRC32C checksum of
+            the entire contents of the object as a 32-bit integer.
+            Used only when finalize_on_close is True.
+
+            It can be obtained by running:
+
+            .. code-block:: python
+
+                import google_crc32c
+
+                data = b"Hello, world!"
+                crc32c_int = google_crc32c.value(data)
+                print(crc32c_int)
 
         rtype: Union[int, _storage_v2.Object]
         returns: Updated `self.persisted_size` by default after closing the
@@ -561,20 +579,32 @@ async def close(self, finalize_on_close=False) -> Union[int, _storage_v2.Object]
 
         :raises ValueError: If the stream is not open (i.e., `open()` has not
             been called).
+        :raises ValueError: If full_object_checksum is provided but
+            finalize_on_close is False.
+        :raises google.api_core.exceptions.InvalidArgument: If the provided
+            full_object_checksum does not match the checksum computed by the
+            server.
 
         """
         if not self._is_stream_open:
             raise ValueError("Stream is not open. Call open() before close().")
 
+        if full_object_checksum is not None and not finalize_on_close:
+            raise ValueError(
+                "full_object_checksum can only be provided when finalize_on_close is True."
+            )
+
         if finalize_on_close:
-            return await self.finalize()
+            return await self.finalize(full_object_checksum=full_object_checksum)
 
         await self.write_obj_stream.close()
 
         self._is_stream_open = False
         return self.persisted_size
 
-    async def finalize(self) -> _storage_v2.Object:
+    async def finalize(
+        self, full_object_checksum: Optional[int] = None
+    ) -> _storage_v2.Object:
         """Finalizes the Appendable Object.
 
         Note: Once finalized no more data can be appended.
@@ -585,18 +615,40 @@ async def finalize(self) -> _storage_v2.Object:
         However if `.finalize()` is called no more data can be appended to the
         object.
 
+        :type full_object_checksum: int
+        :param full_object_checksum: (Optional) This should be the CRC32C checksum of
+            the entire contents of the object as a 32-bit integer.
+
+            It can be obtained by running:
+
+            .. code-block:: python
+
+                import google_crc32c
+
+                data = b"Hello, world!"
+                crc32c_int = google_crc32c.value(data)
+                print(crc32c_int)
+
         rtype: google.cloud.storage_v2.types.Object
         returns: The finalized object resource.
 
         :raises ValueError: If the stream is not open (i.e., `open()` has not
             been called).
+        :raises google.api_core.exceptions.InvalidArgument: If the provided
+            full_object_checksum does not match the checksum computed by the
+            server.
         """
         if not self._is_stream_open:
             raise ValueError("Stream is not open. Call open() before finalize().")
 
-        await self.write_obj_stream.send(
-            _storage_v2.BidiWriteObjectRequest(finish_write=True)
-        )
+        finalize_req = _storage_v2.BidiWriteObjectRequest(finish_write=True)
+
+        if full_object_checksum is not None:
+            finalize_req.object_checksums = _storage_v2.ObjectChecksums(
+                crc32c=full_object_checksum
+            )
+
+        await self.write_obj_stream.send(finalize_req)
         response = await self.write_obj_stream.recv()
         self.object_resource = response.resource
         self.persisted_size = self.object_resource.size

packages/google-cloud-storage/tests/system/test_zonal.py

@@ -10,6 +10,7 @@
 # python additional imports
 import google_crc32c
 import pytest
+from google.api_core import exceptions
 from google.api_core.exceptions import FailedPrecondition, NotFound, OutOfRange
 
 # current library imports
@@ -1046,3 +1047,68 @@ async def _run():
         blobs_to_delete.append(storage_client.bucket(_ZONAL_BUCKET).blob(object_name))
 
     event_loop.run_until_complete(_run())
+
+
+def test_finalize_with_correct_checksum(
+    storage_client,
+    blobs_to_delete,
+    event_loop,
+    grpc_client_direct,
+):
+    object_name = f"appendable_checksum_success_{uuid.uuid4()}"
+    object_data = b"Hello, appendable object with correct checksum!"
+    object_checksum = google_crc32c.value(object_data)
+
+    async def _run():
+        writer = AsyncAppendableObjectWriter(
+            grpc_client_direct, _ZONAL_BUCKET, object_name
+        )
+        await writer.open()
+        await writer.append(object_data)
+        object_metadata = await writer.finalize(full_object_checksum=object_checksum)
+
+        assert object_metadata.size == len(object_data)
+        assert int(object_metadata.checksums.crc32c) == object_checksum
+
+        # clean up
+        blobs_to_delete.append(storage_client.bucket(_ZONAL_BUCKET).blob(object_name))
+        del writer
+        gc.collect()
+
+    event_loop.run_until_complete(_run())
+
+
+def test_finalize_with_incorrect_checksum_fails(
+    storage_client,
+    blobs_to_delete,
+    event_loop,
+    grpc_client_direct,
+):
+    object_name = f"appendable_checksum_fail_{uuid.uuid4()}"
+    object_data = b"Hello, appendable object with incorrect checksum!"
+    object_checksum = google_crc32c.value(object_data)
+    incorrect_checksum = object_checksum + 1
+
+    async def _run():
+        writer = AsyncAppendableObjectWriter(
+            grpc_client_direct, _ZONAL_BUCKET, object_name
+        )
+        await writer.open()
+        await writer.append(object_data)
+
+        # Finalization should fail with an exception due to mismatch
+        with pytest.raises(exceptions.InvalidArgument) as excinfo:
+            await writer.finalize(full_object_checksum=incorrect_checksum)
+
+        # Assert that the error relates to checksum verification/mismatch
+        error_msg = str(excinfo.value).lower()
+        assert (
+            "crc32c" in error_msg or "checksum" in error_msg or "mismatch" in error_msg
+        )
+
+        # clean up
+        blobs_to_delete.append(storage_client.bucket(_ZONAL_BUCKET).blob(object_name))
+        del writer
+        gc.collect()
+
+    event_loop.run_until_complete(_run())

packages/google-cloud-storage/tests/unit/asyncio/test_async_appendable_object_writer.py

@@ -503,3 +503,52 @@ async def test_methods_require_open_stream_raises(self, mock_appendable_writer):
         for coro in methods:
             with pytest.raises(ValueError, match="Stream is not open"):
                 await coro
+
+    @pytest.mark.asyncio
+    async def test_finalize_with_checksum(self, mock_appendable_writer):
+        writer = self._make_one(mock_appendable_writer["mock_client"])
+        writer._is_stream_open = True
+        writer.write_obj_stream = mock_appendable_writer["mock_stream"]
+
+        resource = storage_type.Object(size=999)
+        mock_appendable_writer[
+            "mock_stream"
+        ].recv.return_value = storage_type.BidiWriteObjectResponse(resource=resource)
+
+        checksum = 12345678
+        res = await writer.finalize(full_object_checksum=checksum)
+
+        assert res == resource
+        assert writer.persisted_size == 999
+        mock_appendable_writer["mock_stream"].send.assert_awaited_with(
+            storage_type.BidiWriteObjectRequest(
+                finish_write=True,
+                object_checksums=storage_type.ObjectChecksums(crc32c=checksum),
+            )
+        )
+        mock_appendable_writer["mock_stream"].close.assert_awaited()
+        assert not writer._is_stream_open
+
+    @pytest.mark.asyncio
+    async def test_close_with_checksum_and_finalize(self, mock_appendable_writer):
+        writer = self._make_one(mock_appendable_writer["mock_client"])
+        writer._is_stream_open = True
+        writer.finalize = AsyncMock()
+
+        checksum = 12345678
+        await writer.close(finalize_on_close=True, full_object_checksum=checksum)
+        writer.finalize.assert_awaited_once_with(full_object_checksum=checksum)
+
+    @pytest.mark.asyncio
+    async def test_close_with_checksum_without_finalize_raises(
+        self, mock_appendable_writer
+    ):
+        writer = self._make_one(mock_appendable_writer["mock_client"])
+        writer._is_stream_open = True
+
+        checksum = 12345678
+        with pytest.raises(
+            ValueError,
+            match="full_object_checksum can only be provided when finalize_on_close is True",
+        ):
+            await writer.close(finalize_on_close=False, full_object_checksum=checksum)