As of Go 1.16, functionality provided in io/ioutil has been depreciated
in favour of the io or os packages. Now that Go has been
upgraded in go.mod, the linter will not pass without these changes.
In this commit, we start a timer if a mailbox stream is completely
un-occupied (neither read or write stream is occupied). The timer
stopped if either of the streams are occupied and is reset if both
streams are unoccupied.
In this commit, we add a mailbox-read-count metric. This will be
incremented each time a mailbox with an _odd_ stream ID is read from.
We do this because we assume that a full duplex connection is being used
meaning that there will be 2 streams that have a matching ID except for
the last byte. And so to avoid duplicating the data, we only record the
odd streams. We also assume that for every read, there will be a write
and so we only record the reads.
With this commit we fix a bug in the hashmail server that didn't return
a read stream properly if it was closed from the client side.
Co-authored-by: Elle Mouton <elle.mouton@gmail.com>
