Commit cc00e5ce authored by Jeff King's avatar Jeff King Committed by Junio C Hamano

convert hashmap comparison functions to oideq()

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

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: 's avatarJeff King <>
Signed-off-by: 's avatarJunio C Hamano <>
parent 67947c34
......@@ -62,7 +62,7 @@ static const char *prio_names[] = {
N_("head"), N_("lightweight"), N_("annotated"),
static int commit_name_cmp(const void *unused_cmp_data,
static int commit_name_neq(const void *unused_cmp_data,
const void *entry,
const void *entry_or_key,
const void *peeled)
......@@ -70,7 +70,7 @@ static int commit_name_cmp(const void *unused_cmp_data,
const struct commit_name *cn1 = entry;
const struct commit_name *cn2 = entry_or_key;
return oidcmp(&cn1->peeled, peeled ? peeled : &cn2->peeled);
return !oideq(&cn1->peeled, peeled ? peeled : &cn2->peeled);
static inline struct commit_name *find_commit_name(const struct object_id *peeled)
......@@ -596,7 +596,7 @@ int cmd_describe(int argc, const char **argv, const char *prefix)
return cmd_name_rev(args.argc, args.argv, prefix);
hashmap_init(&names, commit_name_cmp, NULL, 0);
hashmap_init(&names, commit_name_neq, NULL, 0);
for_each_rawref(get_name, NULL);
if (!hashmap_get_size(&names) && !always)
die(_("No names found, cannot describe anything."));
#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)
......@@ -28,14 +28,14 @@ int commit_patch_id(struct commit *commit, struct diff_options *options,
* When we cannot load the full patch-id for both commits for whatever
* reason, the function returns -1 (i.e. return error(...)). Despite
* the "cmp" in the name of this function, the caller only cares about
* the "neq" in the name of this function, the caller only cares about
* the return value being zero (a and b are equivalent) or non-zero (a
* and b are different), and returning non-zero would keep both in the
* result, even if they actually were equivalent, in order to err on
* the side of safety. The actual value being negative does not have
* any significance; only that it is non-zero matters.
static int patch_id_cmp(const void *cmpfn_data,
static int patch_id_neq(const void *cmpfn_data,
const void *entry,
const void *entry_or_key,
const void *unused_keydata)
......@@ -53,7 +53,7 @@ static int patch_id_cmp(const void *cmpfn_data,
commit_patch_id(b->commit, opt, &b->patch_id, 0))
return error("Could not get patch ID for %s",
return oidcmp(&a->patch_id, &b->patch_id);
return !oideq(&a->patch_id, &b->patch_id);
int init_patch_ids(struct patch_ids *ids)
......@@ -63,7 +63,7 @@ int init_patch_ids(struct patch_ids *ids)
ids->diffopts.detect_rename = 0;
ids->diffopts.flags.recursive = 1;
hashmap_init(&ids->patches, patch_id_cmp, &ids->diffopts, 256);
hashmap_init(&ids->patches, patch_id_neq, &ids->diffopts, 256);
return 0;
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment