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

@ -21,9 +21,10 @@ static constexpr u32 replacement_code_point = 0xfffd;
static constexpr u32 first_supplementary_plane_code_point = 0x10000;
template<typename UtfViewType>
static Vector<u16> to_utf16_impl(UtfViewType const& view) requires(IsSame<UtfViewType, Utf8View> || IsSame<UtfViewType, Utf32View>)
static Vector<u16, 1> to_utf16_impl(UtfViewType const& view) requires(IsSame<UtfViewType, Utf8View> || IsSame<UtfViewType, Utf32View>)
{
Vector<u16> utf16_data;
Vector<u16, 1> utf16_data;
utf16_data.ensure_capacity(view.length());
for (auto code_point : view)
code_point_to_utf16(utf16_data, code_point);
@ -31,22 +32,22 @@ static Vector<u16> to_utf16_impl(UtfViewType const& view) requires(IsSame<UtfVie
return utf16_data;
}
Vector<u16> utf8_to_utf16(StringView const& utf8_view)
Vector<u16, 1> utf8_to_utf16(StringView const& utf8_view)
{
return to_utf16_impl(Utf8View { utf8_view });
}
Vector<u16> utf8_to_utf16(Utf8View const& utf8_view)
Vector<u16, 1> utf8_to_utf16(Utf8View const& utf8_view)
{
return to_utf16_impl(utf8_view);
}
Vector<u16> utf32_to_utf16(Utf32View const& utf32_view)
Vector<u16, 1> utf32_to_utf16(Utf32View const& utf32_view)
{
return to_utf16_impl(utf32_view);
}
void code_point_to_utf16(Vector<u16>& string, u32 code_point)
void code_point_to_utf16(Vector<u16, 1>& string, u32 code_point)
{
VERIFY(is_unicode(code_point));

View file

@ -16,10 +16,10 @@
namespace AK {
Vector<u16> utf8_to_utf16(StringView const&);
Vector<u16> utf8_to_utf16(Utf8View const&);
Vector<u16> utf32_to_utf16(Utf32View const&);
void code_point_to_utf16(Vector<u16>&, u32);
Vector<u16, 1> utf8_to_utf16(StringView const&);
Vector<u16, 1> utf8_to_utf16(Utf8View const&);
Vector<u16, 1> utf32_to_utf16(Utf32View const&);
void code_point_to_utf16(Vector<u16, 1>&, u32);
class Utf16View;

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;

View file

@ -470,7 +470,7 @@ ALWAYS_INLINE ExecutionResult OpCode_Compare::execute(MatchInput const& input, M
return ExecutionResult::Failed_ExecuteLowPrioForks;
Optional<String> str;
Vector<u16> utf16;
Vector<u16, 1> utf16;
Vector<u32> data;
data.ensure_capacity(length);
for (size_t i = offset; i < offset + length; ++i)
@ -557,7 +557,7 @@ ALWAYS_INLINE void OpCode_Compare::compare_char(MatchInput const& input, MatchSt
auto input_view = input.view.substring_view(state.string_position, 1);
Optional<String> str;
Vector<u16> utf16;
Vector<u16, 1> utf16;
auto compare_view = input_view.construct_as_same({ &ch1, 1 }, str, utf16);
bool equal;
if (input.regex_options & AllFlags::Insensitive)

View file

@ -139,7 +139,7 @@ public:
return view;
}
RegexStringView construct_as_same(Span<u32> data, Optional<String>& optional_string_storage, Vector<u16>& optional_utf16_storage) const
RegexStringView construct_as_same(Span<u32> data, Optional<String>& optional_string_storage, Vector<u16, 1>& optional_utf16_storage) const
{
auto view = m_view.visit(
[&]<typename T>(T const&) {