From: Junio C Hamano <gitster@pobox.com>
To: Michael Haggerty <mhagger@alum.mit.edu>
Cc: "Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>,
"Stefan Beller" <sbeller@google.com>,
"Johannes Schindelin" <Johannes.Schindelin@gmx.de>,
"David Turner" <novalis@novalis.org>,
git@vger.kernel.org
Subject: Re: [PATCH 1/5] refs: store submodule ref stores in a hashmap
Date: Thu, 09 Feb 2017 12:34:04 -0800 [thread overview]
Message-ID: <xmqqh943p0hv.fsf@gitster.mtv.corp.google.com> (raw)
In-Reply-To: <a944446c4c374125082f5ad8b79e731704b66196.1486629195.git.mhagger@alum.mit.edu> (Michael Haggerty's message of "Thu, 9 Feb 2017 14:26:58 +0100")
Michael Haggerty <mhagger@alum.mit.edu> writes:
> Aside from scaling better, this means that the submodule name needn't be
> stored in the ref_store instance anymore (which will be changed in a
> moment).
Nice. I like the latter reason very much (this is not a suggestion
to change the description).
> +struct submodule_hash_entry
> +{
> + struct hashmap_entry ent; /* must be the first member! */
> +
> + struct ref_store *refs;
> +
> + /* NUL-terminated name of submodule: */
> + char submodule[FLEX_ARRAY];
> +};
> +
> +static int submodule_hash_cmp(const void *entry, const void *entry_or_key,
> + const void *keydata)
> +{
> + const struct submodule_hash_entry *e1 = entry, *e2 = entry_or_key;
> + const char *submodule = keydata;
> +
> + return strcmp(e1->submodule, submodule ? submodule : e2->submodule);
I would have found it more readable if it were like so:
const char *submodule = keydata ? keydata : e2->submodule;
return strcmp(e1->submodule, submodule);
but I suspect the difference is not that huge.
> +}
> +
> +static struct submodule_hash_entry *alloc_submodule_hash_entry(
> + const char *submodule, struct ref_store *refs)
> +{
> + size_t len = strlen(submodule);
> + struct submodule_hash_entry *entry = malloc(sizeof(*entry) + len + 1);
I think this (and the later memcpy) is what FLEX_ALLOC_MEM() was
invented for.
> + hashmap_entry_init(entry, strhash(submodule));
> + entry->refs = refs;
> + memcpy(entry->submodule, submodule, len + 1);
> + return entry;
> +}
> ...
> @@ -1373,16 +1405,17 @@ void base_ref_store_init(struct ref_store *refs,
> die("BUG: main_ref_store initialized twice");
>
> refs->submodule = "";
> - refs->next = NULL;
> main_ref_store = refs;
> } else {
> - if (lookup_ref_store(submodule))
> + refs->submodule = xstrdup(submodule);
> +
> + if (!submodule_ref_stores.tablesize)
> + hashmap_init(&submodule_ref_stores, submodule_hash_cmp, 20);
Makes me wonder what "20" stands for. Perhaps the caller should be
allowed to say "I do not quite care what initial size is" by passing
0 or some equally but more clealy meaningless value (which of course
would be outside the scope of this series).
next prev parent reply other threads:[~2017-02-09 22:24 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-09 13:26 [PATCH 0/5] Store submodules in a hash, not a linked list Michael Haggerty
2017-02-09 13:26 ` [PATCH 1/5] refs: store submodule ref stores in a hashmap Michael Haggerty
2017-02-09 16:58 ` Stefan Beller
2017-02-09 17:40 ` Michael Haggerty
2017-02-09 17:43 ` Stefan Beller
2017-02-09 19:32 ` Jeff King
2017-02-09 20:34 ` Junio C Hamano [this message]
2017-02-10 4:04 ` Jeff King
2017-02-10 10:23 ` Michael Haggerty
2017-02-09 13:26 ` [PATCH 2/5] refs: push the submodule attribute down Michael Haggerty
2017-02-09 17:03 ` Stefan Beller
2017-02-09 21:07 ` Junio C Hamano
2017-02-09 13:27 ` [PATCH 3/5] register_ref_store(): new function Michael Haggerty
2017-02-09 17:20 ` Stefan Beller
2017-02-09 18:14 ` Michael Haggerty
2017-02-09 21:16 ` Junio C Hamano
2017-02-09 13:27 ` [PATCH 4/5] files_ref_store::submodule: use NULL for the main repository Michael Haggerty
2017-02-09 17:25 ` Stefan Beller
2017-02-09 21:19 ` Junio C Hamano
2017-02-09 21:36 ` Stefan Beller
2017-02-09 13:27 ` [PATCH 5/5] read_loose_refs(): read refs using resolve_ref_recursively() Michael Haggerty
2017-02-09 17:39 ` Stefan Beller
2017-02-09 19:48 ` [PATCH 0/5] Store submodules in a hash, not a linked list Junio C Hamano
2017-02-09 19:58 ` Jeff King
2017-02-09 21:23 ` Michael Haggerty
2017-02-10 0:40 ` Jeff King
2017-02-10 10:27 ` Michael Haggerty
2017-02-13 2:39 ` Duy Nguyen
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