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29c2bd5fa8
This is similar to many of our uses of sha1-array, but it overcomes one limitation of a sha1-array: when you are de-duplicating a large input with relatively few unique entries, sha1-array uses 20 bytes per non-unique entry. Whereas this set will use memory linear in the number of unique entries (albeit a few more than 20 bytes due to hashmap overhead). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
50 lines
1015 B
C
50 lines
1015 B
C
#include "cache.h"
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#include "oidset.h"
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struct oidset_entry {
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struct hashmap_entry hash;
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struct object_id oid;
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};
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static int oidset_hashcmp(const void *va, const void *vb,
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const void *vkey)
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{
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const struct oidset_entry *a = va, *b = vb;
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const struct object_id *key = vkey;
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return oidcmp(&a->oid, key ? key : &b->oid);
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}
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int oidset_contains(const struct oidset *set, const struct object_id *oid)
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{
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struct hashmap_entry key;
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if (!set->map.cmpfn)
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return 0;
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hashmap_entry_init(&key, sha1hash(oid->hash));
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return !!hashmap_get(&set->map, &key, oid);
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}
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int oidset_insert(struct oidset *set, const struct object_id *oid)
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{
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struct oidset_entry *entry;
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if (!set->map.cmpfn)
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hashmap_init(&set->map, oidset_hashcmp, 0);
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if (oidset_contains(set, oid))
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return 1;
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entry = xmalloc(sizeof(*entry));
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hashmap_entry_init(&entry->hash, sha1hash(oid->hash));
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oidcpy(&entry->oid, oid);
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hashmap_add(&set->map, entry);
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return 0;
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}
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void oidset_clear(struct oidset *set)
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{
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hashmap_free(&set->map, 1);
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}
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