1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-07-27 02:27:43 +00:00

LibJS+AK: Use Vector<u16, 1> for UTF-16 string storage

It's very common to encounter single-character strings in JavaScript on
the web. We can make such strings significantly lighter by having a
1-character inline capacity on the Vectors.
This commit is contained in:
Andreas Kling 2021-10-02 17:37:15 +02:00
parent ae0bdda86e
commit 024367d82e
7 changed files with 27 additions and 26 deletions

View file

@ -140,7 +140,7 @@ JS_DEFINE_NATIVE_FUNCTION(StringConstructor::from_char_code)
// 22.1.2.2 String.fromCodePoint ( ...codePoints ), https://tc39.es/ecma262/#sec-string.fromcodepoint
JS_DEFINE_NATIVE_FUNCTION(StringConstructor::from_code_point)
{
Vector<u16> string;
Vector<u16, 1> string;
string.ensure_capacity(vm.argument_count()); // This will be an under-estimate if any code point is > 0xffff.
for (size_t i = 0; i < vm.argument_count(); ++i) {

View file

@ -17,7 +17,7 @@ static NonnullRefPtr<Utf16StringImpl> the_empty_utf16_string()
return empty_string;
}
Utf16StringImpl::Utf16StringImpl(Vector<u16> string)
Utf16StringImpl::Utf16StringImpl(Vector<u16, 1> string)
: m_string(move(string))
{
}
@ -27,7 +27,7 @@ NonnullRefPtr<Utf16StringImpl> Utf16StringImpl::create()
return adopt_ref(*new Utf16StringImpl());
}
NonnullRefPtr<Utf16StringImpl> Utf16StringImpl::create(Vector<u16> string)
NonnullRefPtr<Utf16StringImpl> Utf16StringImpl::create(Vector<u16, 1> string)
{
return adopt_ref(*new Utf16StringImpl(move(string)));
}
@ -39,13 +39,13 @@ NonnullRefPtr<Utf16StringImpl> Utf16StringImpl::create(StringView const& string)
NonnullRefPtr<Utf16StringImpl> Utf16StringImpl::create(Utf16View const& view)
{
Vector<u16> string;
Vector<u16, 1> string;
string.ensure_capacity(view.length_in_code_units());
string.append(view.data(), view.length_in_code_units());
return create(move(string));
}
Vector<u16> const& Utf16StringImpl::string() const
Vector<u16, 1> const& Utf16StringImpl::string() const
{
return m_string;
}
@ -62,7 +62,7 @@ Utf16String::Utf16String()
{
}
Utf16String::Utf16String(Vector<u16> string)
Utf16String::Utf16String(Vector<u16, 1> string)
: m_string(Detail::Utf16StringImpl::create(move(string)))
{
}
@ -77,7 +77,7 @@ Utf16String::Utf16String(Utf16View const& string)
{
}
Vector<u16> const& Utf16String::string() const
Vector<u16, 1> const& Utf16String::string() const
{
return m_string->string();
}

View file

@ -20,18 +20,18 @@ public:
~Utf16StringImpl() = default;
static NonnullRefPtr<Utf16StringImpl> create();
static NonnullRefPtr<Utf16StringImpl> create(Vector<u16>);
static NonnullRefPtr<Utf16StringImpl> create(Vector<u16, 1>);
static NonnullRefPtr<Utf16StringImpl> create(StringView const&);
static NonnullRefPtr<Utf16StringImpl> create(Utf16View const&);
Vector<u16> const& string() const;
Vector<u16, 1> const& string() const;
Utf16View view() const;
private:
Utf16StringImpl() = default;
explicit Utf16StringImpl(Vector<u16> string);
explicit Utf16StringImpl(Vector<u16, 1> string);
Vector<u16> m_string;
Vector<u16, 1> m_string;
};
}
@ -39,11 +39,11 @@ private:
class Utf16String {
public:
Utf16String();
explicit Utf16String(Vector<u16>);
explicit Utf16String(Vector<u16, 1>);
explicit Utf16String(StringView const&);
explicit Utf16String(Utf16View const&);
Vector<u16> const& string() const;
Vector<u16, 1> const& string() const;
Utf16View view() const;
Utf16View substring_view(size_t code_unit_offset, size_t code_unit_length) const;
Utf16View substring_view(size_t code_unit_offset) const;