diff options
author | shyouhei <shyouhei@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2017-09-05 04:48:19 +0000 |
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committer | shyouhei <shyouhei@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2017-09-05 04:48:19 +0000 |
commit | 0eb7359cc775c9d4c8dad68dd9dbf38c9680071e (patch) | |
tree | a4e596d906225086566efe79e792a3f204a16b57 | |
parent | e5684558262ead5253b9fce36efaea6a6ae6acab (diff) |
add rb_hash_new_with_size()
Sometimes, size of a hash can be calcluated a priori. By providing
such info to the constructor we can avoid unnecessary internal re-
allocations. This can boost for instance creation of hash literals.
[Bug #13861]
Signed-off-by: Urabe, Shyouhei <shyouhei@ruby-lang.org>
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59744 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
-rw-r--r-- | hash.c | 11 | ||||
-rw-r--r-- | insns.def | 2 | ||||
-rw-r--r-- | internal.h | 1 | ||||
-rw-r--r-- | vm.c | 2 |
4 files changed, 13 insertions, 3 deletions
@@ -432,6 +432,15 @@ rb_hash_new(void) return hash_alloc(rb_cHash); } +VALUE +rb_hash_new_with_size(st_index_t size) +{ + VALUE ret = rb_hash_new(); + if (size) + RHASH(ret)->ntbl = st_init_table_with_size(&objhash, size); + return ret; +} + static VALUE hash_dup(VALUE hash, VALUE klass, VALUE flags) { @@ -1927,7 +1936,7 @@ rb_hash_transform_values(VALUE hash) VALUE result; RETURN_SIZED_ENUMERATOR(hash, 0, 0, hash_enum_size); - result = rb_hash_new(); + result = rb_hash_new_with_size(RHASH_SIZE(hash)); if (!RHASH_EMPTY_P(hash)) { rb_hash_foreach(hash, transform_values_i, result); } @@ -496,7 +496,7 @@ newhash { RUBY_DTRACE_CREATE_HOOK(HASH, num); - val = rb_hash_new(); + val = rb_hash_new_with_size(num / 2); if (num) { rb_hash_bulk_insert(num, STACK_ADDR_FROM_TOP(num), val); diff --git a/internal.h b/internal.h index 6b13725caf..5f85909461 100644 --- a/internal.h +++ b/internal.h @@ -1242,6 +1242,7 @@ void ruby_sized_xfree(void *x, size_t size); /* hash.c */ struct st_table *rb_hash_tbl_raw(VALUE hash); +VALUE rb_hash_new_with_size(st_index_t size); VALUE rb_hash_has_key(VALUE hash, VALUE key); VALUE rb_hash_default_value(VALUE hash, VALUE key); VALUE rb_hash_set_default_proc(VALUE hash, VALUE proc); @@ -2694,7 +2694,7 @@ m_core_hash_from_ary(VALUE self, VALUE ary) static VALUE core_hash_from_ary(VALUE ary) { - VALUE hash = rb_hash_new(); + VALUE hash = rb_hash_new_with_size(RARRAY_LEN(ary) / 2); RUBY_DTRACE_CREATE_HOOK(HASH, (Check_Type(ary, T_ARRAY), RARRAY_LEN(ary))); return core_hash_merge_ary(hash, ary); |