Tamas Mate has posted comments on this change. ( http://gerrit.cloudera.org:8080/15345 )
Change subject: IMPALA-9398: Fix shell history duplication when cmdloop breaks ...................................................................... Patch Set 4: Hi Fang-Yu, It is a bit hard to create formatted text on gerrit, I am splitting the paragraphs with "---". --- ImpalaShell.postloop() will only be called once per ImpalaShell object lifetime because it is tied to ImpalaShell.is_alive. The postloop() does the persisting of history and can be reached when the Cmd.cmdloop() is stopped normally. This is where it is called: https://github.com/python/cpython/blob/master/Lib/cmd.py#L139 --- This postloop() can be reached when the postcmd() in line 139 returns True. ImpalaShell.postcmd() just returns the status provided by the caller. https://github.com/apache/impala/blob/master/shell/impala_shell.py#L664 --- The status can be the following three predefined in impala-shell.py CmdStatus: https://github.com/apache/impala/blob/master/shell/impala_shell.py#L81 --- I am skipping some part of the code flow here and changing my approach. From this point the relevant status is CmdStatus.ABORT, because that is the only one with True value which could stop the Cmd.cmdloop() normally. Abort is only returned by the ImpalaShell.do_quit(). This method can be called multiple ways, however it ties the ABORT and is_alive=False together. When is_alive is false, ImpalaShell's main loop terminates, therefore with normal quit both loops and ImpalaShell will be terminated. https://github.com/apache/impala/blob/master/shell/impala_shell.py#L787 --- The reading logic was moved to the constructor next to where the readline module is being imported. -- To view, visit http://gerrit.cloudera.org:8080/15345 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: If4faf46134f44d91e56748642f47d448707db53c Gerrit-Change-Number: 15345 Gerrit-PatchSet: 4 Gerrit-Owner: Tamas Mate <tm...@cloudera.com> Gerrit-Reviewer: David Knupp <dkn...@cloudera.com> Gerrit-Reviewer: Fang-Yu Rao <fangyu....@cloudera.com> Gerrit-Reviewer: Impala Public Jenkins <impala-public-jenk...@cloudera.com> Gerrit-Reviewer: Tamas Mate <tm...@cloudera.com> Gerrit-Reviewer: Vincent Tran <vtt...@cloudera.com> Gerrit-Comment-Date: Wed, 08 Apr 2020 09:18:51 +0000 Gerrit-HasComments: No
