A method for uploading an object into a distributed storage system is implemented at a computing device The computing device splits an object into one or more chunks and uploads the one or more chunks into the distributed storage system. For each uploaded chunk, the computing device receives a write token from the distributed storage system, inserts an entry into an extents table of the object for the chunk in accordance with the received write token and the chunk ID, chunk offset, and chunk size of the chunk, generates a digest of the extents table, the digest representing the one or more chunks that the client expects to be within the distributed storage system, and sends the digest of the extents table to the distributed storage system. The distributed storage system is configured to use the digest to determine whether it has each of the one or more client-expected chunks.