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authorBjörn-Egil Dahlberg <[email protected]>2015-02-23 16:03:03 +0100
committerBjörn-Egil Dahlberg <[email protected]>2015-03-12 19:15:27 +0100
commit73885d5d098a58aa6a4e226d075ee90b24045c66 (patch)
tree25dfa48c5b744f90ee2c54d862d9d5f2855c6ab4
parentbb05557ff27e16e1e079e8f99b68713c7ca012c5 (diff)
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erts: Refactor maps:from_list/1
-rw-r--r--erts/emulator/beam/erl_map.c163
1 files changed, 85 insertions, 78 deletions
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
*/