* Refactor federation sender, again
* Clean up better
* Missing operators
* Try to get overflowed events from database
* Fix queries
* Log less
* Comments
* nil PDUs/EDUs shouldn't happen but guard against them for safety
* Tweak logging
* Fix transaction coalescing
* Update comments
* Check nils more
* Remove channels as they add extra complexity and possibly will deadlock
* Don't hold lock while sending transaction
* Less spam about sleeping queues
* Comments
* Bug-fixing
* Don't try to rehydrate twice
* Don't queue in memory for blacklisted destinations
* Don't queue in memory for blacklisted destinations
* Fix a couple of bugs
* Check for duplicates when pulling things out of the database
* Durable transactions, some more refactoring
* Revert "Durable transactions, some more refactoring"
This reverts commit 5daf924eaa.
* Fix deadlock
* Set RewritesState once
* Check if any new state provided
* Obey rewritesState
* Don't nuke everything the sync API knows when purging state
* Fix panic from duplicate insert
* Consistency
* Use HasState
* Remove nolint
* Clean up joined rooms on state rewrite
* Add QueryDeviceMessages to serve up device keys and stream IDs
* Consume key change events in fedsender
Don't yet send them to destinations as we haven't worked them out yet
* Send device list updates to all required servers
* Glue it all together
* Initial persistence of blacklists
* Move statistics folder
* Make MaxFederationRetries configurable
* Set lower failure thresholds for Yggdrasil demos
* Still write events into database for blacklisted hosts (they can be tidied up later)
* Review comments
* Deduplicate FS database, add some EDU persistence groundwork
* Extend TransactionWriter to use optional existing transaction, use that for FS SQLite database writes
* Fix build due to bad keyserver import
* Working EDU persistence
* gocyclo, unsurprisingly
* Remove unused
* Update copyright notices
