From 73885d5d098a58aa6a4e226d075ee90b24045c66 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn-Egil=20Dahlberg?= Date: Mon, 23 Feb 2015 16:03:03 +0100 Subject: erts: Refactor maps:from_list/1 --- erts/emulator/beam/erl_map.c | 163 ++++++++++++++++++++++--------------------- 1 file changed, 85 insertions(+), 78 deletions(-) (limited to 'erts/emulator/beam/erl_map.c') diff --git a/erts/emulator/beam/erl_map.c b/erts/emulator/beam/erl_map.c index 69dd91d079..5e5e567642 100644 --- a/erts/emulator/beam/erl_map.c +++ b/erts/emulator/beam/erl_map.c @@ -69,6 +69,7 @@ static Eterm hashmap_to_list(Process *p, Eterm map); static Eterm hashmap_keys(Process *p, Eterm map); static Eterm hashmap_values(Process *p, Eterm map); static Eterm hashmap_delete(Process *p, Uint32 hx, Eterm key, Eterm node); +static Eterm map_from_validated_list(Process *p, Eterm list, Uint size); /* erlang:map_size/1 * the corresponding instruction is implemented in: @@ -227,13 +228,8 @@ BIF_RETTYPE maps_get_2(BIF_ALIST_2) { */ BIF_RETTYPE maps_from_list_1(BIF_ALIST_1) { - Eterm *kv, item = BIF_ARG_1; - Eterm *hp, *thp,*vs, *ks, keys, res; - map_t *mp; - Uint size = 0, unused_size = 0; - Sint c = 0; - Sint idx = 0; - + Eterm item = BIF_ARG_1, res, *kv; + Uint size = 0; if (is_list(item) || is_nil(item)) { /* Calculate size and check validity */ @@ -254,95 +250,106 @@ BIF_RETTYPE maps_from_list_1(BIF_ALIST_1) { if (is_not_nil(item)) goto error; - hp = HAlloc(BIF_P, 3 + 1 + (2 * size)); - thp = hp; - keys = make_tuple(hp); - *hp++ = make_arityval(size); - ks = hp; - hp += size; - mp = (map_t*)hp; - res = make_map(mp); - hp += MAP_HEADER_SIZE; - vs = hp; + BIF_RET(map_from_validated_list(BIF_P, BIF_ARG_1, size)); + } - mp->thing_word = MAP_HEADER; - mp->size = size; /* set later, might shrink*/ - mp->keys = keys; +error: - if (size == 0) - BIF_RET(res); + BIF_ERROR(BIF_P, BADARG); +} + +static Eterm map_from_validated_list(Process *p, Eterm list, Uint size) { + Eterm *kv, item = list; + Eterm *hp, *thp,*vs, *ks, keys, res; + map_t *mp; + Uint unused_size = 0; + Sint c = 0; + Sint idx = 0; - item = BIF_ARG_1; - /* first entry */ - kv = tuple_val(CAR(list_val(item))); - ks[0] = kv[1]; - vs[0] = kv[2]; - size = 1; - item = CDR(list_val(item)); + hp = HAlloc(p, 3 + 1 + (2 * size)); + thp = hp; + keys = make_tuple(hp); + *hp++ = make_arityval(size); + ks = hp; + hp += size; + mp = (map_t*)hp; + res = make_map(mp); + hp += MAP_HEADER_SIZE; + vs = hp; - /* insert sort key/value pairs */ - while(is_list(item)) { + mp->thing_word = MAP_HEADER; + mp->size = size; /* set later, might shrink*/ + mp->keys = keys; - kv = tuple_val(CAR(list_val(item))); + if (size == 0) + return res; - /* compare ks backwards - * idx represent word index to be written (hole position). - * We cannot copy the elements when searching since we might - * have an equal key. So we search for just the index first =( - * - * It is perhaps faster to move the values in the first pass. - * Check for uniqueness during insert phase and then have a - * second phace compacting the map if duplicates are found - * during insert. .. or do someother sort .. shell-sort perhaps. - */ + /* first entry */ + kv = tuple_val(CAR(list_val(item))); + ks[0] = kv[1]; + vs[0] = kv[2]; + size = 1; + item = CDR(list_val(item)); + + /* insert sort key/value pairs */ + while(is_list(item)) { + + kv = tuple_val(CAR(list_val(item))); + + /* compare ks backwards + * idx represent word index to be written (hole position). + * We cannot copy the elements when searching since we might + * have an equal key. So we search for just the index first =( + * + * It is perhaps faster to move the values in the first pass. + * Check for uniqueness during insert phase and then have a + * second phace compacting the map if duplicates are found + * during insert. .. or do someother sort .. shell-sort perhaps. + */ - idx = size; + idx = size; - while(idx > 0 && (c = CMP_TERM(kv[1],ks[idx-1])) < 0) { idx--; } + while(idx > 0 && (c = CMP_TERM(kv[1],ks[idx-1])) < 0) { idx--; } - if (c == 0) { - /* last compare was equal, - * i.e. we have to release memory - * and overwrite that key/value - */ - ks[idx-1] = kv[1]; - vs[idx-1] = kv[2]; - unused_size++; - } else { - Uint i = size; - while(i > idx) { - ks[i] = ks[i-1]; - vs[i] = vs[i-1]; - i--; - } - ks[idx] = kv[1]; - vs[idx] = kv[2]; - size++; + if (c == 0) { + /* last compare was equal, + * i.e. we have to release memory + * and overwrite that key/value + */ + ks[idx-1] = kv[1]; + vs[idx-1] = kv[2]; + unused_size++; + } else { + Uint i = size; + while(i > idx) { + ks[i] = ks[i-1]; + vs[i] = vs[i-1]; + i--; } - item = CDR(list_val(item)); + ks[idx] = kv[1]; + vs[idx] = kv[2]; + size++; } + item = CDR(list_val(item)); + } - if (unused_size) { - /* the key tuple is embedded in the heap - * write a bignum to clear it. - */ - /* release values as normal since they are on the top of the heap */ - - ks[size] = make_pos_bignum_header(unused_size - 1); - HRelease(BIF_P, vs + size + unused_size, vs + size); - } + if (unused_size) { + /* the key tuple is embedded in the heap + * write a bignum to clear it. + */ + /* release values as normal since they are on the top of the heap */ - *thp = make_arityval(size); - mp->size = size; - BIF_RET(res); + ks[size] = make_pos_bignum_header(unused_size - 1); + HRelease(p, vs + size + unused_size, vs + size); } -error: - - BIF_ERROR(BIF_P, BADARG); + *thp = make_arityval(size); + mp->size = size; + return res; } + /* maps:is_key/2 */ -- cgit v1.2.3