Re: [PATCH v5 04/16] promisor-remote: implement promisor_remote_get_direct()
From: Christian Couder <hidden>
Date: 2019-06-25 13:50:36
On Fri, May 31, 2019 at 7:10 AM Christian Couder [off-list ref] wrote:
On Thu, May 30, 2019 at 7:21 PM Derrick Stolee [off-list ref] wrote:quoted
On 4/9/2019 12:11 PM, Christian Couder wrote:
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+{ + int i, missing_nr = 0; + int *missing = xcalloc(oid_nr, sizeof(*missing)); + struct object_id *old_oids = *oids; + struct object_id *new_oids; + int old_fetch_if_missing = fetch_if_missing; + + fetch_if_missing = 0;This global 'fetch_if_missing' swap seems very fragile. I'm guessing you are using it to prevent a loop when calling oid_object_info_extended() below. Can you instead pass a flag to the method that disables the fetch_if_missing behavior?If such a flag existed when I wrote the function I would certainly have used it, as I also dislike this kind of messing with a global (and globals in general). I will see if I can do something about it according to what you suggest later in this thread.
In the V6 patch series I just sent, the new OBJECT_INFO_SKIP_FETCH_OBJECT flag that you introduced is used.
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+ for (i = 0; i < oid_nr; i++) + if (oid_object_info_extended(the_repository, &old_oids[i], NULL, 0)) {A use of "the_repository" this deep in new code is asking for a refactor later to remove it. Please try to pass a "struct repository *r" through your methods so we minimize references to the_repository (and the amount of work required to remove them later).Ok, I will take a look at that.
A "struct repository *r" is passed in V6. I forgot to mention that in the cover letter.
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+ missing_nr = remove_fetched_oids(&missing_oids, missing_nr, to_free);Here is the one call, and after this assignment "missing_nr" does mean the number of missing objects. However, I do think this could be clarified by using remaining_nr and remaining_oids.Ok, I will take a look at using "remaining_nr" and "remaining_oids".
Done in V6 too.
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+ if (missing_nr) { + to_free = 1; + continue; + }Now this block took a bit to grok. You use to_free in the if(to_free) free(missing_oids); below. But it also changes the behavior of remove_fetched_oids(). This means that the first time remove_fetched_oids() will preserve the list (because it is the input list) but all later calls will free the newly-created intermediate list. This checks out. What is confusing to me: is there any reason that missing_nr would be zero in this situation?I don't think so but I will check again, and maybe add a comment.
Actually missing_nr, or now remaining_nr, would be 0 if all the promised objects have been fetched.
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+ } + res = 0; + break; + } + + if (to_free) + free(missing_oids); + + return res; +}While the test coverage report brought this patch to my attention, it does seem correct. I still think a test exposing this method would be good, especially one that requires a fetch_objects() call to multiple remotes to really exercise the details of remove_fetched_oids().Yeah, I would like to actually test it. I will take another look at what can be done to test this. Perhaps I will look at what can be done to still get some objects when fetching from a promisor/partial clone remote even when it doesn't have all of the objects we request.
I haven't improved test coverage or looked at how we could better handle a partial fetch. I plan to look at that soon. Thanks, Christian.