daemon: Reset the goal

[m-blaha]

New D-Bus API to reset the goal.

Resolves: #1653

Changes:

3cd0a6e (Marek Blaha, 5 minutes ago)
dnfdaemon: D-Bus API to reset the goal

With this patch the user can re-use the session to resolve multiple
transactions without running them. The use case might be to check what
dependencies would be installed with given package.

d77231b (Marek Blaha, 17 hours ago)
dnfdaemon: Add reset_goal() method

The method resets the current goal and transaction, which is necessary for
scenarios where the user wants to reuse the D-Bus session to resolve or
execute multiple transactions.

5dbe16a (Marek Blaha, 17 hours ago)
goal: Add missing members to reset() method

The reset() method currently does not reset all Goal members. This patch
adds those that are missing.

[m-blaha]

I'm not totally sure about automatically resetting after the transaction is done. The transaction might still be needed for follow-up calls, like collecting RPM errors that happened during execution.
@mcrha Would it be OK for you to manually call the reset() method at some point after the transaction is done?

[mcrha]

Aha, you are right. If the errors reported by Goal::get_transaction_problems_string() or Goal::get_transaction_problems() still require the failed transaction, then it's perfectly fine to have the reset() called manually.

In fact, I planned to call the reset() always before I start a transaction (not exactly before Goal::do_transaction() call), to make sure nothing is left from the previous calls/transactions.

[mcrha]

I gave a quick test to the changes in the current form and it works as expected in my use case. I tried to install/uninstall packages with not shared and with shared session and both cases work fine, including when "simulating" a transaction to figure out needed size to download/install.

[jan-kolarik]

@m-blaha The tests should be passing after merging the #1711. Could you please rebase to check it?

[m-blaha]

@m-blaha The tests should be passing after merging the #1711. Could you please rebase to check it?

Sorry for the delay, I missed the message. Rebased.