From b62a12c687bf1f6d6e0dde129ef783139592e6c0 Mon Sep 17 00:00:00 2001
From: Andreas Kling <awesomekling@gmail.com>
Date: Sun, 4 Aug 2019 11:47:21 +0200
Subject: [PATCH] JsonParser: Some minor optimizations

- Return more specific types from parse_array() and parse_object().
- Don't create a throwaway String in extract_while().
- Use a StringView in parse_number() to avoid a throwaway String.
---
 AK/JsonParser.cpp | 13 +++++++------
 AK/JsonParser.h   |  6 +++---
 2 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/AK/JsonParser.cpp b/AK/JsonParser.cpp
index 54fdbe4888..9d604fa2a8 100644
--- a/AK/JsonParser.cpp
+++ b/AK/JsonParser.cpp
@@ -31,12 +31,12 @@ void JsonParser::consume_while(C condition)
 }
 
 template<typename C>
-String JsonParser::extract_while(C condition)
+Vector<char, 128> JsonParser::extract_while(C condition)
 {
-    Vector<char, 1024> buffer;
+    Vector<char, 128> buffer;
     while (condition(peek()))
         buffer.append(consume());
-    return String::copy(buffer);
+    return buffer;
 };
 
 void JsonParser::consume_whitespace()
@@ -95,7 +95,7 @@ String JsonParser::consume_quoted_string()
     return String::copy(buffer);
 }
 
-JsonValue JsonParser::parse_object()
+JsonObject JsonParser::parse_object()
 {
     JsonObject object;
     consume_specific('{');
@@ -119,7 +119,7 @@ JsonValue JsonParser::parse_object()
     return object;
 }
 
-JsonValue JsonParser::parse_array()
+JsonArray JsonParser::parse_array()
 {
     JsonArray array;
     consume_specific('[');
@@ -145,7 +145,8 @@ JsonValue JsonParser::parse_string()
 
 JsonValue JsonParser::parse_number()
 {
-    auto number_string = extract_while([](char ch) { return ch == '-' || (ch >= '0' && ch <= '9'); });
+    auto number_buffer = extract_while([](char ch) { return ch == '-' || (ch >= '0' && ch <= '9'); });
+    StringView number_string(number_buffer.data(), number_buffer.size());
     bool ok;
     auto value = JsonValue(number_string.to_uint(ok));
     if (!ok)
diff --git a/AK/JsonParser.h b/AK/JsonParser.h
index 76f7d7e5bf..343530d7f4 100644
--- a/AK/JsonParser.h
+++ b/AK/JsonParser.h
@@ -23,8 +23,8 @@ private:
     void consume_specific(char expected_ch);
     void consume_string(const char*);
     String consume_quoted_string();
-    JsonValue parse_array();
-    JsonValue parse_object();
+    JsonArray parse_array();
+    JsonObject parse_object();
     JsonValue parse_number();
     JsonValue parse_string();
     JsonValue parse_false();
@@ -36,7 +36,7 @@ private:
     void consume_while(C);
 
     template<typename C>
-    String extract_while(C);
+    Vector<char, 128> extract_while(C);
 
     StringView m_input;
     int m_index { 0 };