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authorSverker Eriksson <[email protected]>2014-11-13 19:59:27 +0100
committerSverker Eriksson <[email protected]>2014-11-13 19:59:27 +0100
commitafd79e01d3375d8e8217b258ffb4d9b90541c922 (patch)
tree23f92991654da751e2ceac090ef0c7c30d5277f6
parent7adc2c36b0e839384baac50be35c0999d1e546df (diff)
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erts: Optimize ets:lookup and ets:take for bags
by reducing number of iterations through objects with matching key
-rw-r--r--erts/emulator/beam/erl_db_hash.c28
1 files changed, 16 insertions, 12 deletions
diff --git a/erts/emulator/beam/erl_db_hash.c b/erts/emulator/beam/erl_db_hash.c
index 633a2272ad..6e8d892561 100644
--- a/erts/emulator/beam/erl_db_hash.c
+++ b/erts/emulator/beam/erl_db_hash.c
@@ -382,7 +382,7 @@ static HashDbTerm* search_list(DbTableHash* tb, Eterm key,
static void shrink(DbTableHash* tb, int nactive);
static void grow(DbTableHash* tb, int nactive);
static Eterm build_term_list(Process* p, HashDbTerm* ptr1, HashDbTerm* ptr2,
- DbTableHash*);
+ Uint sz, DbTableHash*);
static int analyze_pattern(DbTableHash *tb, Eterm pattern,
struct mp_info *mpi);
@@ -887,13 +887,17 @@ get_term_list(Process *p, DbTableHash *tb, Eterm key, HashValue hval,
{
HashDbTerm* b2 = b1->next;
Eterm copy;
+ Uint sz = b1->dbterm.size + 2;
if (tb->common.status & (DB_BAG | DB_DUPLICATE_BAG)) {
while (b2 && has_key(tb, b2, key, hval)) {
+ if (b2->hvalue != INVALID_HASH)
+ sz += b2->dbterm.size + 2;
+
b2 = b2->next;
}
}
- copy = build_term_list(p, b1, b2, tb);
+ copy = build_term_list(p, b1, b2, sz, tb);
CHECK_TABLES();
if (bend) {
*bend = b2;
@@ -1253,7 +1257,7 @@ static int db_slot_hash(Process *p, DbTable *tbl, Eterm slot_term, Eterm *ret)
lck = RLOCK_HASH(tb, slot);
nactive = NACTIVE(tb);
if (slot < nactive) {
- *ret = build_term_list(p, BUCKET(tb, slot), 0, tb);
+ *ret = build_term_list(p, BUCKET(tb, slot), NULL, 0, tb);
retval = DB_ERROR_NONE;
}
else if (slot == nactive) {
@@ -2536,23 +2540,23 @@ static int free_seg(DbTableHash *tb, int free_records)
** Copy terms from ptr1 until ptr2
** works for ptr1 == ptr2 == 0 => []
** or ptr2 == 0
+** sz is either precalculated heap size or 0 if not known
*/
static Eterm build_term_list(Process* p, HashDbTerm* ptr1, HashDbTerm* ptr2,
- DbTableHash* tb)
+ Uint sz, DbTableHash* tb)
{
- int sz = 0;
HashDbTerm* ptr;
Eterm list = NIL;
Eterm copy;
Eterm *hp, *hend;
- ptr = ptr1;
- while(ptr != ptr2) {
-
- if (ptr->hvalue != INVALID_HASH)
- sz += ptr->dbterm.size + 2;
-
- ptr = ptr->next;
+ if (!sz) {
+ ptr = ptr1;
+ while(ptr != ptr2) {
+ if (ptr->hvalue != INVALID_HASH)
+ sz += ptr->dbterm.size + 2;
+ ptr = ptr->next;
+ }
}
hp = HAlloc(p, sz);