rehash()
public
Rebuilds the hash based on the current hash values for
each key. If values of key
objects have changed since they were inserted, this method will reindex
hsh. If Hash#rehash is called
while an iterator is traversing the hash, a RuntimeError will be raised in the iterator.
a = [ "a", "b" ]
c = [ "c", "d" ]
h = { a => 100, c => 300 }
h[a]
a[0] = "z"
h[a]
h.rehash
h[a]
Show source
VALUE
rb_hash_rehash(VALUE hash)
{
VALUE tmp;
st_table *tbl;
if (RHASH_ITER_LEV(hash) > 0) {
rb_raise(rb_eRuntimeError, "rehash during iteration");
}
rb_hash_modify_check(hash);
if (RHASH_AR_TABLE_P(hash)) {
tmp = hash_alloc(0);
ar_alloc_table(tmp);
rb_hash_foreach(hash, rb_hash_rehash_i, (VALUE)tmp);
ar_free_and_clear_table(hash);
ar_copy(hash, tmp);
ar_free_and_clear_table(tmp);
}
else if (RHASH_ST_TABLE_P(hash)) {
st_table *old_tab = RHASH_ST_TABLE(hash);
tmp = hash_alloc(0);
tbl = st_init_table_with_size(old_tab->type, old_tab->num_entries);
RHASH_ST_TABLE_SET(tmp, tbl);
rb_hash_foreach(hash, rb_hash_rehash_i, (VALUE)tmp);
st_free_table(old_tab);
RHASH_ST_TABLE_SET(hash, tbl);
RHASH_ST_CLEAR(tmp);
}
hash_verify(hash);
return hash;
}