Class StorageGrpc.StorageImplBase (2.2.3)

API Overview and Naming Syntax

The GCS gRPC API allows applications to read and write data through the abstractions of buckets and objects. For a description of these abstractions please see https://cloud.google.com/storage/docs. Resources are named as follows:

• Projects are referred to as they are defined by the Resource Manager API, using strings like projects/123456 or projects/my-string-id.
• Buckets are named using string names of the form: projects/{project}/buckets/{bucket} For globally unique buckets, _ may be substituted for the project.
• Objects are uniquely identified by their name along with the name of the bucket they belong to, as separate strings in this API. For example: ReadObjectRequest { bucket: 'projects/_/buckets/my-bucket' object: 'my-object' } Note that object names can contain / characters, which are treated as any other character (no special directory semantics).

Determines the persisted_size for an object that is being written, which can then be used as the write_offset for the next Write() call. If the object does not exist (i.e., the object has been deleted, or the first Write() has not yet reached the service), this method returns the error NOT_FOUND. The client may call QueryWriteStatus() at any time to determine how much data has been processed for this object. This is useful if the client is buffering data and needs to know which data can be safely evicted. For any sequence of QueryWriteStatus() calls for a given object name, the sequence of returned persisted_size values will be non-decreasing.

Reads an object's data.

Starts a resumable write. How long the write operation remains valid, and what happens when the write operation becomes invalid, are service-dependent.

Stores a new object and metadata. An object can be written either in a single message stream or in a resumable sequence of message streams. To write using a single stream, the client should include in the first message of the stream an WriteObjectSpec describing the destination bucket, object, and any preconditions. Additionally, the final message must set 'finish_write' to true, or else it is an error. For a resumable write, the client should instead call StartResumableWrite() and provide that method an WriteObjectSpec. They should then attach the returned upload_id to the first message of each following call to Create. If there is an error or the connection is broken during the resumable Create(), the client should check the status of the Create() by calling QueryWriteStatus() and continue writing from the returned persisted_size. This may be less than the amount of data the client previously sent. The service will not view the object as complete until the client has sent a WriteObjectRequest with finish_write set to true. Sending any requests on a stream after sending a request with finish_write set to true will cause an error. The client should check the response it receives to determine how much data the service was able to commit and whether the service views the object as complete.