Re: [PATCH v8 4/4] cache-tree: Write updated cache-tree after commit

From: Junio C Hamano <gitster@pobox.com>
Date: Jul 14, 2014, 22:16 UTC
Message-ID: <xmqq8unvy4bf.fsf@gitster.dls.corp.google.com>
In-Reply-To: <53C42453.1090109@ramsay1.demon.co.uk>

Ramsay Jones <ramsay@ramsay1.demon.co.uk> writes:

Show 12 quoted lines

> On 14/07/14 18:51, Junio C Hamano wrote:
>> Ramsay Jones <ramsay@ramsay1.demon.co.uk> writes:
>> 
>>> that the merge commit 7608c87e fails. Looking at the details of the
>>> merge resolution, made me think of Duy's split index work.
>> 
>> Yes, there is a deliberately dropped hunk from dt/cache-tree-repair
>> in that merge, because the topic relied on being able to say "here
>> is the file descriptor, write the index to it", which no longer is
>> available with the split-index topic.
>
> Ah, OK. Sounds like everything is under control then.

Wasn't, but now I think it is ;-)

David, could you please double check the conflict resolution at 882426ea (Merge branch 'dt/cache-tree-repair' into jch, 2014-07-14), at about the middle between master..pu? By eyeballing

    git diff 882426ea^ 882426ea

we should see what your series would have done if it were based on top of the nd/split-index topic. The most iffy is the first hunk of change to builtin/commit.c, which is more or less my rewrite of what you did on top of 'master'.

The change to builtin/checkout.c also seems somewhat iffy in that we treat the_index.cache_tree (aka "active_cache_tree") as if cache trees are something we can manipulate independent of a particular index_state (which has been the rule for a long time), even though in the world order after nd/split-index topic, cache_tree_update() can no longer be used on a cache-tree that is not associated to a particular index_state. It is not a problem with your series, but comes from nd/split-index topic, and it might indicate a slight unevenness of the API (i.e. we may want to either insist that the public API to muck with a cache-tree outside cache-tree.c must be accessed via an index-state and never via a bare cache-tree structure, by insisting that cache_tree_fully_valid() to take a pointer to an index-state as well; or we may want to go the other way and allow API users to pass a bare cache-tree without the index-state when the latter is not absolutely necessary, by changing cache_tree_update() to take a cache-tree, not an index-state).