Partial file

How it works

Players and unzip tools sometimes open it anyway. Content-Length and a hash catch it. A partial object in a bucket can be served until you delete it. Rename-into-place avoids publishing the partial.

A download shows 2.0 GB of a 2.4 GB archive. Unzip fails at the directory. The size check would have failed first. They resume the remaining 400 MB.

How it differs

A partial file is not a proxy. A proxy is a complete smaller encode. A partial is an accident.

Progress at 100 percent can still be short if the client computed the bar from a bad length.

Trust the byte count.

On the ticket

• The practical close is a log line: time, actor, byte count, result.
• Without that line the transfer is a story.
• With it, the next person can see whether this door did what the ticket claimed.
• If the path is shared, say so in the partner profile so a later change does not silently pick a different limit, key, or region.
• On a real ticket, write down the door, the byte count, and the clock.
• For partial file, that means naming the host or bucket, the expected size, and the time the other side must have a complete file.
• A progress bar is not that record.
• A 200 response that arrives before the complete call is not that record.
• If a retry is allowed, say how many and whether it resumes.
• If a person must approve the send, name the person.
• Partners who receive partial file files should match on hash or size before they import.
• A same-length corrupt file passes a size check and fails a hash.
• Keep the published hash off the only channel an attacker can edit, or treat it as a corruption check rather than a substitution check.
• When the path changes, new key, new region, new cap, update the profile the same day so the next run does not use a stale limit.