The RPC server was performing some of the shutdown logic in the wrong
order, that is, logging the the server has shut down, waiting for all
server goroutines to finish, and then closing a channel to notify
server goroutines to stop. These three items have been reversed to
fix a hang where goroutines currently being waited on had not shut
down because they did not receive the notification.
While here, the server waitgroup was incremented for a goroutine that
was running without it, another select statement was added to stop a
duplicate close (which never occured last commit when I added the
select statements), and the "stopping rescan" logging was moved to
debug to make the ^C shutdown logging nicer.
This changes the protocol between btcd and btcwallet to follow
JSON-RPC specifications sending notifications as requests with an
empty ID.
The notification request context handling has been greatly cleaned up
now that IDs no longer need to be saved when sending notifications.
This commit changes all code which deals with extracting addresses from
scripts to use the btcscript API ExtractPkScriptAddrs which in turn makes
use of the new btcutil.Address interface.
This provides much cleaner code for dealing with arbitrary script
destinations which is extensible without having to churn the APIs if new
destination types are added.
Since the command to handler mappings are the most often modified and
referenced code in rpcserver.go and rpcwebsocket.go, move them near the
top of their respective files.
This commit cleans up the standard RPC command hanlding a bit by removing
the websocket specific notification channel from the handlers. This was
previously required because the sendrawtransaction, when called from a
websocket enabled connection, needs to add a notification for when the
transaction is mined.
This commit modifies that to instead implement a websocket extended
version of sendrawtransaction which invokes the standard handler and adds
the notification. In addition, the main send was modified to first look
if the command has a websocket specific handler first, and then falls back
to standard commands, rather than the previous approach of first checking
for a standard command and falling through to websocket commands. This
essentially allows websockets connections to extend commands with the same
name with additional functionality such as what was done in this commit.
The rpcserver.go file is starting to get a bit unwieldy. This commit
moves the separable websocket specific bits into a separate file named
rpcwebsocket.go.
