diff options
| -rw-r--r-- | erts/emulator/beam/erl_process_dict.c | 49 |
1 files changed, 28 insertions, 21 deletions
diff --git a/erts/emulator/beam/erl_process_dict.c b/erts/emulator/beam/erl_process_dict.c index 3c80f0e0f6..1ec81f50a3 100644 --- a/erts/emulator/beam/erl_process_dict.c +++ b/erts/emulator/beam/erl_process_dict.c @@ -577,11 +577,12 @@ static Eterm pd_hash_put(Process *p, Eterm id, Eterm value) { unsigned int hval; Eterm *hp; + Eterm *tp; Eterm tpl; Eterm old; Eterm tmp; int needed; - int i = 0; + int key_at = 0; #ifdef DEBUG Eterm *hp_limit; #endif @@ -603,21 +604,26 @@ static Eterm pd_hash_put(Process *p, Eterm id, Eterm value) */ needed = 3; /* {Key,Value} tuple */ if (is_boxed(old)) { - /* - * We don't want to compare keys twice, so we'll always - * reserve the space for two CONS cells. - */ - needed += 2+2; + ASSERT(is_tuple(old)); + tp = tuple_val(old); + if (EQ(tp[1], id)) { + key_at = 1; + } + else { + needed += 2+2; + } } else if (is_list(old)) { - i = 0; - for (tmp = old; tmp != NIL && !EQ(tuple_val(TCAR(tmp))[1], id); tmp = TCDR(tmp)) { - ++i; - } - if (is_nil(tmp)) { - i = -1; - needed += 2; - } else { - needed += 2*(i+1); + int i = 1; + + needed += 2; + for (tmp = old; tmp != NIL; tmp = TCDR(tmp)) { + tp = tuple_val(TCAR(tmp)); + if (EQ(tp[1], id)) { + key_at = i; + needed += 2*(key_at-1); + break; + } + ++i; } } if (HeapWordsLeft(p) < needed) { @@ -648,7 +654,8 @@ static Eterm pd_hash_put(Process *p, Eterm id, Eterm value) ++(p->dictionary->numElements); } else if (is_boxed(old)) { ASSERT(is_tuple(old)); - if (EQ(tuple_val(old)[1],id)) { + if (key_at) { + ASSERT(EQ(tuple_val(old)[1],id)); ARRAY_PUT(p->dictionary, hval, tpl); return tuple_val(old)[2]; } else { @@ -661,7 +668,7 @@ static Eterm pd_hash_put(Process *p, Eterm id, Eterm value) ASSERT(hp <= hp_limit); } } else if (is_list(old)) { - if (i == -1) { + if (!key_at) { /* * New key. Simply prepend the tuple to the beginning of the list. */ @@ -672,7 +679,7 @@ static Eterm pd_hash_put(Process *p, Eterm id, Eterm value) ++(p->dictionary->numElements); } else { /* - * i = Number of CDRs to skip to reach the changed element in the list. + * key_at = Key position in the list. * * Replace old value in list. To avoid pointers from the old generation * to the new, we must rebuild the list from the beginning up to and @@ -681,17 +688,17 @@ static Eterm pd_hash_put(Process *p, Eterm id, Eterm value) Eterm nlist; int j; - hp = HeapOnlyAlloc(p, (i+1)*2); + hp = HeapOnlyAlloc(p, key_at*2); /* Find the list element to change. */ - for (j = 0, nlist = old; j < i; j++, nlist = TCDR(nlist)) { + for (j = 1, nlist = old; j < key_at; j++, nlist = TCDR(nlist)) { ; } ASSERT(EQ(tuple_val(TCAR(nlist))[1], id)); nlist = TCDR(nlist); /* Unchanged part of list. */ /* Rebuild list before the updated element. */ - for (tmp = old; i-- > 0; tmp = TCDR(tmp)) { + for (tmp = old; --key_at > 0; tmp = TCDR(tmp)) { nlist = CONS(hp, TCAR(tmp), nlist); hp += 2; } |