diff options
Diffstat (limited to 'erts/emulator/beam/erl_db_hash.c')
| -rw-r--r-- | erts/emulator/beam/erl_db_hash.c | 51 |
1 files changed, 47 insertions, 4 deletions
diff --git a/erts/emulator/beam/erl_db_hash.c b/erts/emulator/beam/erl_db_hash.c index 06dac8f161..063808eb79 100644 --- a/erts/emulator/beam/erl_db_hash.c +++ b/erts/emulator/beam/erl_db_hash.c @@ -171,10 +171,53 @@ static ERTS_INLINE void add_fixed_deletion(DbTableHash* tb, int ix) #define MAX_HASH 0xEFFFFFFFUL #define INVALID_HASH 0xFFFFFFFFUL -/* optimised version of make_hash (normal case? atomic key) */ -#define MAKE_HASH(term) \ - ((is_atom(term) ? (atom_tab(atom_val(term))->slot.bucket.hvalue) : \ - make_hash2(term)) % MAX_HASH) +static ERTS_INLINE HashValue +MAKE_HASH(Eterm term) +{ + if (is_atom(term)) { + /* + * optimised version of make_hash, although poor hashvalue + * (normal case? atomic key) + */ + return atom_tab(atom_val(term))->slot.bucket.hvalue; + } + if (is_ref(term)) { + /* + * make_hash2() produce poor hash values + * for refs. + */ + int no; + Uint32 *ref; + HashValue hval; + if (is_internal_ref(term)) { + no = (int) internal_ref_no_of_numbers(term); + ref = internal_ref_numbers(term); + } + else { + no = (int) external_ref_no_of_numbers(term); + ref = external_ref_numbers(term); + } + switch (no) { + case 3: + ref_limit: + if (!ref[2]) + no = 2; + case 2: + if (!ref[1]) + no = 1; + case 1: + break; + default: + no = 3; + goto ref_limit; + } + hval = (HashValue) block_hash((byte *) ref, + no * sizeof(Uint32), + 0x08d12e65); + return hval % MAX_HASH; + } + return make_hash2(term) % MAX_HASH; +} #ifdef ERTS_SMP # define DB_HASH_LOCK_MASK (DB_HASH_LOCK_CNT-1) |