AK: Use a single StringBuilder throughout JSON serialization.

Author: https://github.com/awesomekling
Commit: https://github.com/SerenityOS/serenity/commit/ee347effac2

AK/JsonArray.cpp

@@ -1,15 +1,24 @@
 #include <AK/JsonArray.h>
 #include <AK/StringBuilder.h>
 
-String JsonArray::to_string() const
+namespace AK {
+
+void JsonArray::to_string(StringBuilder& builder) const
 {
-    StringBuilder builder;
     builder.append('[');
     for (int i = 0; i < m_values.size(); ++i) {
-        builder.append(m_values[i].to_string());
+        m_values[i].to_string(builder);
         if (i != size() - 1)
             builder.append(',');
     }
     builder.append(']');
+}
+
+String JsonArray::to_string() const
+{
+    StringBuilder builder;
+    to_string(builder);
     return builder.to_string();
 }
+
+}

AK/JsonArray.h

@@ -3,6 +3,8 @@
 #include <AK/JsonValue.h>
 #include <AK/Vector.h>
 
+namespace AK {
+
 class JsonArray {
 public:
     JsonArray() {}
@@ -18,7 +20,12 @@ public:
     void append(const JsonValue& value) { m_values.append(value); }
 
     String to_string() const;
+    void to_string(StringBuilder&) const;
 
 private:
     Vector<JsonValue> m_values;
 };
+
+}
+
+using AK::JsonArray;

AK/JsonObject.cpp

@@ -1,9 +1,10 @@
 #include <AK/JsonObject.h>
 #include <AK/StringBuilder.h>
 
-String JsonObject::to_string() const
+namespace AK {
+
+void JsonObject::to_string(StringBuilder& builder) const
 {
-    StringBuilder builder;
     int index = 0;
     builder.append('{');
     for_each_member([&] (auto& key, auto& value) {
@@ -11,11 +12,19 @@ String JsonObject::to_string() const
         builder.append(key);
         builder.append('"');
         builder.append(':');
-        builder.append(value.to_string());
+        value.to_string(builder);
         if (index != size() - 1)
             builder.append(',');
         ++index;
     });
     builder.append('}');
+}
+
+String JsonObject::to_string() const
+{
+    StringBuilder builder;
+    to_string(builder);
     return builder.to_string();
 }
+
+}

AK/JsonObject.h

@@ -4,6 +4,8 @@
 #include <AK/HashMap.h>
 #include <AK/JsonValue.h>
 
+namespace AK {
+
 class JsonObject {
 public:
     JsonObject() { }
@@ -39,7 +41,12 @@ public:
     }
 
     String to_string() const;
+    void to_string(StringBuilder&) const;
 
 private:
     HashMap<String, JsonValue> m_members;
 };
+
+}
+
+using AK::JsonObject;

AK/JsonValue.cpp

@@ -1,6 +1,9 @@
 #include <AK/JsonArray.h>
 #include <AK/JsonObject.h>
 #include <AK/JsonValue.h>
+#include <AK/StringBuilder.h>
+
+namespace AK {
 
 JsonValue::JsonValue(Type type)
     : m_type(type)
@@ -116,25 +119,43 @@ void JsonValue::clear()
     m_value.as_string = nullptr;
 }
 
-String JsonValue::to_string() const
+void JsonValue::to_string(StringBuilder& builder) const
 {
     switch (m_type) {
     case Type::String:
-        return String::format("\"%s\"", m_value.as_string->characters());
+        builder.appendf("\"%s\"", m_value.as_string->characters());
+        break;
     case Type::Array:
-        return m_value.as_array->to_string();
+        m_value.as_array->to_string(builder);
+        break;
     case Type::Object:
-        return m_value.as_object->to_string();
+        m_value.as_object->to_string(builder);
+        break;
     case Type::Bool:
-        return m_value.as_bool ? "true" : "false";
+        builder.append(m_value.as_bool ? "true" : "false");
+        break;
     case Type::Double:
-        return String::format("%g", m_value.as_double);
+        builder.appendf("%g", m_value.as_double);
+        break;
     case Type::Int:
-        return String::format("%d", m_value.as_int);
+        builder.appendf("%d", m_value.as_int);
+        break;
     case Type::Undefined:
-        return "undefined";
+        builder.append("undefined");
+        break;
     case Type::Null:
-        return "null";
-    }
+        builder.append("null");
+        break;
+    default:
         ASSERT_NOT_REACHED();
     }
+}
+
+String JsonValue::to_string() const
+{
+    StringBuilder builder;
+    to_string(builder);
+    return builder.to_string();
+}
+
+}

AK/JsonValue.h

@@ -2,8 +2,11 @@
 
 #include <AK/AKString.h>
 
+namespace AK {
+
 class JsonArray;
 class JsonObject;
+class StringBuilder;
 
 class JsonValue {
 public:
@@ -35,6 +38,7 @@ public:
     JsonValue(const JsonObject&);
 
     String to_string() const;
+    void to_string(StringBuilder&) const;
 
 private:
     void clear();
@@ -51,3 +55,7 @@ private:
         bool as_bool;
     } m_value;
 };
+
+}
+
+using AK::JsonValue;