ladybird/AK/JsonObjectSerializer.h
Andreas Kling cc98ea1956 Json: Add serializer fast-path for string values
Passing these through the generic JsonValue path was causing us to
instantiate temporary JsonValues that incurred a heap allocation.
This avoids that by adding specialized overloads for string types.
2019-09-04 14:40:11 +02:00

101 lines
2.1 KiB
C++

#pragma once
#include <AK/JsonArraySerializer.h>
#include <AK/JsonValue.h>
namespace AK {
template<typename Builder>
class JsonObjectSerializer {
public:
explicit JsonObjectSerializer(Builder& builder)
: m_builder(builder)
{
m_builder.append('{');
}
JsonObjectSerializer(const JsonObjectSerializer&) = delete;
JsonObjectSerializer(JsonObjectSerializer&&) = delete;
~JsonObjectSerializer()
{
if (!m_finished)
finish();
}
void add(const StringView& key, const JsonValue& value)
{
begin_item(key);
value.serialize(m_builder);
}
void add(const StringView& key, const StringView& value)
{
begin_item(key);
m_builder.append('"');
m_builder.append(value);
m_builder.append('"');
}
void add(const StringView& key, const String& value)
{
begin_item(key);
m_builder.append('"');
m_builder.append(value);
m_builder.append('"');
}
void add(const StringView& key, const char* value)
{
begin_item(key);
m_builder.append('"');
m_builder.append(value);
m_builder.append('"');
}
JsonArraySerializer<Builder> add_array(const StringView& key)
{
begin_item(key);
return JsonArraySerializer(m_builder);
}
JsonObjectSerializer<Builder> add_object(const StringView& key)
{
begin_item(key);
return JsonObjectSerializer(m_builder);
}
void finish()
{
ASSERT(!m_finished);
m_finished = true;
m_builder.append('}');
}
private:
void begin_item(const StringView& key)
{
if (!m_empty)
m_builder.append(',');
m_empty = false;
m_builder.append('"');
m_builder.append(key);
m_builder.append("\":");
}
Builder& m_builder;
bool m_empty { true };
bool m_finished { false };
};
template<typename Builder>
JsonObjectSerializer<Builder> JsonArraySerializer<Builder>::add_object()
{
begin_item();
return JsonObjectSerializer(m_builder);
}
}
using AK::JsonObjectSerializer;