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convert hashmap comparison functions to oideq()

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The comparison functions used for hashmaps don't care about
strict ordering; they only want to compare entries for
equality. Let's use the oideq() function instead, which can
potentially be better optimized. Note that unlike the
previous patches mass-converting calls like "!oidcmp()",
this patch could actually provide an improvement even with
the current implementation. Those comparison functions are
passed around as function pointers, so at compile-time the
compiler cannot realize that the caller (which is in another
file completely) will treat the return value as a boolean.

Note that this does change the return values in quite a
subtle way (it's still an int, but now the sign bit is
irrelevant for ordering). Because of their funny
hashmap-specific signature, it's unlikely that any of these
static functions would be reused for more generic ordering.
But to be double-sure, let's stop using "cmp" in their
names.

Calling them "eq" doesn't quite work either, because the
hashmap convention is actually _inverted_. "0" means "same",
and non-zero means "different". So I've called them "neq" by
convention here.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Jeff King
2018-08-28 17:22:55 -04:00
committed by Junio C Hamano
parent 67947c34ae
commit cc00e5ce6b
3 changed files with 13 additions and 13 deletions
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12
oidmap.c
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@ -1,14 +1,14 @@
#include "cache.h"
#include "oidmap.h"
static int cmpfn(const void *hashmap_cmp_fn_data,
const void *entry, const void *entry_or_key,
const void *keydata)
static int oidmap_neq(const void *hashmap_cmp_fn_data,
const void *entry, const void *entry_or_key,
const void *keydata)
{
const struct oidmap_entry *entry_ = entry;
if (keydata)
return oidcmp(&entry_->oid, (const struct object_id *) keydata);
return oidcmp(&entry_->oid,
return !oideq(&entry_->oid, (const struct object_id *) keydata);
return !oideq(&entry_->oid,
&((const struct oidmap_entry *) entry_or_key)->oid);
}
@ -21,7 +21,7 @@ static int hash(const struct object_id *oid)
void oidmap_init(struct oidmap *map, size_t initial_size)
{
hashmap_init(&map->map, cmpfn, NULL, initial_size);
hashmap_init(&map->map, oidmap_neq, NULL, initial_size);
}
void oidmap_free(struct oidmap *map, int free_entries)