jcoffey-dev
3f832e17b2
Export wrote one message per request and said nothing while it did, so a large mailbox took hours of silence. Messages now go in batches of up to the target's maxObjectsInSet (at most 50), their blobs uploaded several at once, up to maxConcurrentUpload and no more than --threads; each upload thread reads the archive through its own read-only connection. Every message is still counted on its own: one the target rejects fails alone, a request too large is split, and a method error on the whole call is retried a message at a time. A batch is sent once. If it ends without a clear answer -- a dropped connection, a gateway timeout, a partial failure -- the target is read again, the messages that arrived count as created, and only the rest are imported again, so none is doubled. A progress line (count, rate, time left) is printed every few seconds for mail, contacts and events, and each type ends with a line of what was created, updated, left unchanged and failed.