diff options
| author | Jean byroot Boussier <[email protected]> | 2024-06-20 19:39:20 +0200 |
|---|---|---|
| committer | GitHub <[email protected]> | 2024-06-20 10:39:20 -0700 |
| commit | d1ffd5ecfa62a049b7c508f30b6912a890de1b32 (patch) | |
| tree | 2c898bf560f82fb415593570cad2d8fe632b08aa | |
| parent | a3eb5e5c70eaee12964cdd807b8f19950003141f (diff) | |
String.new(capacity:) don't substract termlen (#11027)
[Bug #20585]
This was changed in 36a06efdd9f0604093dccbaf96d4e2cb17874dc8 because
`String.new(1024)` would end up allocating `1025` bytes, but the problem
with this change is that the caller may be trying to right size a String.
So instead, we should just better document the behavior of `capacity:`.
Co-authored-by: Jean Boussier <[email protected]>
| -rw-r--r-- | doc/string/new.rdoc | 4 | ||||
| -rw-r--r-- | string.c | 7 | ||||
| -rw-r--r-- | test/-ext-/string/test_capacity.rb | 2 |
3 files changed, 6 insertions, 7 deletions
diff --git a/doc/string/new.rdoc b/doc/string/new.rdoc index d955e61c87..1d44291f76 100644 --- a/doc/string/new.rdoc +++ b/doc/string/new.rdoc @@ -46,6 +46,10 @@ which may in turn affect performance: String.new(capacity: 1) String.new('foo', capacity: 4096) +Note that Ruby strings are null-terminated internally, so the internal +buffer size will be one or more bytes larger than the requested capacity +depending on the encoding. + The +string+, +encoding+, and +capacity+ arguments may all be used together: String.new('hello', encoding: 'UTF-8', capacity: 25) @@ -1970,12 +1970,7 @@ rb_str_s_new(int argc, VALUE *argv, VALUE klass) } } - long fake_len = capa - termlen; - if (fake_len < 0) { - fake_len = 0; - } - - VALUE str = str_new0(klass, NULL, fake_len, termlen); + VALUE str = str_new0(klass, NULL, capa, termlen); STR_SET_LEN(str, 0); TERM_FILL(RSTRING_PTR(str), termlen); diff --git a/test/-ext-/string/test_capacity.rb b/test/-ext-/string/test_capacity.rb index 2c6c51fdda..bcca64d85a 100644 --- a/test/-ext-/string/test_capacity.rb +++ b/test/-ext-/string/test_capacity.rb @@ -23,7 +23,7 @@ class Test_StringCapacity < Test::Unit::TestCase def test_s_new_capacity assert_equal("", String.new(capacity: 1000)) assert_equal(String, String.new(capacity: 1000).class) - assert_equal(10_000 - 1, capa(String.new(capacity: 10_000))) # Real capa doesn't account for termlen + assert_equal(10_000, capa(String.new(capacity: 10_000))) assert_equal("", String.new(capacity: -1000)) assert_equal(capa(String.new(capacity: -10000)), capa(String.new(capacity: -1000))) |