From 9cd04197709364da43f7239b2742859a8125cea0 Mon Sep 17 00:00:00 2001
From: Techcable <Techcable@outlook.com>
Date: Mon, 14 Mar 2016 15:40:44 -0700
Subject: [PATCH] Optimize uuid conversions

Optimizes converting to and from mojang format.
Manually decode uuids to and from hex.

diff --git a/api/src/main/java/io/github/waterfallmc/waterfall/utils/Hex.java b/api/src/main/java/io/github/waterfallmc/waterfall/utils/Hex.java
new file mode 100644
index 00000000..ece5f798
--- /dev/null
+++ b/api/src/main/java/io/github/waterfallmc/waterfall/utils/Hex.java
@@ -0,0 +1,113 @@
+package io.github.waterfallmc.waterfall.utils;
+
+import java.util.Arrays;
+import java.util.Objects;
+
+public class Hex {
+
+    public static byte[] decode(CharSequence chars) {
+        byte[] bytes = new byte[chars.length() >> 1];
+        decode(chars, 0, bytes, 0, bytes.length);
+        return bytes;
+    }
+
+    public static void decode(char[] chars, int charOffset, byte[] dest, int offset, int length) {
+        decode(new CharSequence() {
+            @Override
+            public int length() {
+                return chars.length;
+            }
+
+            @Override
+            public char charAt(int index) {
+                return chars[index];
+            }
+
+            @Override
+            public CharSequence subSequence(int start, int end) {
+                return toString().substring(start, end);
+            }
+
+            @Override
+            public String toString() {
+                return new String(chars, charOffset, chars.length);
+            }
+        });
+    }
+
+    public static void decode(CharSequence chars, int charOffset, byte[] dest, int offset, int length) {
+        Objects.requireNonNull(chars, "Null chars");
+        Objects.requireNonNull(chars, "Null destination");
+        final int numChars = chars.length();
+        if ((numChars & 0x01) != 0) {
+            throw new IllegalArgumentException("Odd number of characters: " + numChars);
+        } else if (length < (numChars - charOffset) >> 1) {
+            throw new IllegalArgumentException("Too many bytes to fill with " + numChars + " characters: " + length);
+        } else if (offset < 0 || charOffset < 0 || length < 0 || length * 2 > numChars - charOffset || length > dest.length - offset) {
+            throw new IndexOutOfBoundsException();
+        }
+        for (int i = 0, charIndex = charOffset; i < length; i++) {
+            char first = chars.charAt(charIndex++);
+            char second = chars.charAt(charIndex++);
+            dest[i + offset] = (byte) ((toDigit(first) << 4) | (toDigit(second)));
+        }
+    }
+
+    public static String encodeString(byte[] bytes) {
+        return new String(encode(bytes));
+    }
+
+    public static char[] encode(byte[] bytes) {
+        char[] chars = new char[bytes.length << 1];
+        encode(chars, 0, bytes, 0, bytes.length);
+        return chars;
+    }
+
+    public static void encode(char[] chars, int charOffset, byte[] source, int offset, int length) {
+        Objects.requireNonNull(chars, "Null chars");
+        Objects.requireNonNull(chars, "Null bytes");
+        if (offset < 0 || charOffset < 0 || length < 0 || length * 2 > chars.length - charOffset || length > source.length - offset) {
+            throw new IndexOutOfBoundsException();
+        } else if (length == 0) {
+            return;
+        }
+        for (int i = 0, charIndex = charOffset; i < length; i++) {
+            byte b = source[i + offset];
+            chars[charIndex++] = fromDigit((byte) ((b >> 4) & 0xF));
+            chars[charIndex++] = fromDigit((byte) (b & 0xF));
+        }
+    }
+    private static final char[] ENCODE_TABLE = new char[]{
+            '0', '1', '2', '3', '4', '5', '6', '7',
+            '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'
+    };
+    private static final byte[] DECODE_TABLE = new byte[128];
+
+    static {
+        Arrays.fill(DECODE_TABLE, (byte) -1);
+        for (int value = 0; value < ENCODE_TABLE.length; value++) {
+            char c = ENCODE_TABLE[value];
+            DECODE_TABLE[c] = (byte) value;
+            char upper;
+            if ((upper = Character.toUpperCase(c)) != c) {
+                DECODE_TABLE[upper] = (byte) value;
+            }
+        }
+    }
+
+    public static byte toDigit(char c) {
+        byte value;
+        if (c < DECODE_TABLE.length) {
+            value = DECODE_TABLE[c];
+        } else {
+            value = -1;
+        }
+        if (value < 0) throw new IllegalArgumentException("Invalid character " + c);
+        return value;
+    }
+
+    private static char fromDigit(byte b) {
+        assert (b & 0xF) == b : "Out of range " + b;
+        return ENCODE_TABLE[b];
+    }
+}
\ No newline at end of file
diff --git a/api/src/main/java/io/github/waterfallmc/waterfall/utils/UUIDUtils.java b/api/src/main/java/io/github/waterfallmc/waterfall/utils/UUIDUtils.java
new file mode 100644
index 00000000..cc24dd35
--- /dev/null
+++ b/api/src/main/java/io/github/waterfallmc/waterfall/utils/UUIDUtils.java
@@ -0,0 +1,74 @@
+package io.github.waterfallmc.waterfall.utils;
+import java.util.UUID;
+
+import com.google.common.base.Preconditions;
+import com.google.common.primitives.Longs;
+
+public class UUIDUtils {
+    private UUIDUtils() {}
+
+    public static String undash(String id) {
+        return new StringBuilder( 32 ).append( id, 0, 8 ).append( id, 9, 13 ).append( id, 14, 18 ).append( id, 19, 23 ).append( id, 24, 36 ).toString();
+    }
+
+    public static String toMojangString(UUID id) {
+        Preconditions.checkNotNull(id, "Null id");
+        return Hex.encodeString(toBytes(id));
+    }
+
+    public static UUID fromString(String s) {
+        Preconditions.checkNotNull(s, "Null string");
+        if (s.length() == 36) { // UUID.toString() uuid
+            s = UUIDUtils.undash(s);
+        } else if (s.length() != 32) {
+            throw new IllegalArgumentException("Invalid UUID: " + s);
+        }
+        return fromMojangString0(s);
+    }
+
+    public static UUID fromMojangString(String s) {
+        Preconditions.checkNotNull(s, "Null string");
+        if (s.length() != 32) {
+            throw new IllegalArgumentException("UUID not in mojang format: " + s);
+        }
+        return fromMojangString0(s);
+    }
+
+    private static UUID fromMojangString0(String s) {
+        assert s != null : "Null string";
+        assert s.length() == 32 : "invalid length: " + s;
+        try {
+            return fromBytes(Hex.decode(s));
+        } catch (IllegalArgumentException e) {
+            throw new IllegalArgumentException("Invalid UUID: " + s);
+        }
+    }
+
+    public static byte[] toBytes(UUID id) {
+        Preconditions.checkNotNull(id, "Null id");
+        byte[] result = new byte[16];
+        long lsb = id.getLeastSignificantBits();
+        for (int i = 15; i >= 8; i--) {
+            result[i] = (byte) (lsb & 0xffL);
+            lsb >>= 8;
+        }
+        long msb = id.getMostSignificantBits();
+        for (int i = 7; i >= 0; i--) {
+            result[i] = (byte) (msb & 0xffL);
+            msb >>= 8;
+        }
+        return result;
+    }
+
+    public static UUID fromBytes(byte[] bytes) {
+        Preconditions.checkNotNull(bytes, "Null bytes");
+        if (bytes.length != 16) {
+            throw new IllegalArgumentException("Invalid length: " + bytes.length);
+        }
+        long msb = Longs.fromBytes(bytes[0], bytes[1], bytes[2], bytes[3],
+                bytes[4], bytes[5], bytes[6], bytes[7]);
+        long lsb = Longs.fromBytes(bytes[8], bytes[9], bytes[10], bytes[11],
+                bytes[12], bytes[13], bytes[14], bytes[15]);
+        return new UUID(msb, lsb);
+    }
+}
\ No newline at end of file
diff --git a/api/src/main/java/net/md_5/bungee/Util.java b/api/src/main/java/net/md_5/bungee/Util.java
index 5e5b53a7..684abf4c 100644
--- a/api/src/main/java/net/md_5/bungee/Util.java
+++ b/api/src/main/java/net/md_5/bungee/Util.java
@@ -2,11 +2,14 @@ package net.md_5.bungee;
 
 import com.google.common.base.Joiner;
 import com.google.common.primitives.UnsignedLongs;
+import com.google.common.primitives.Ints;
 import java.net.InetSocketAddress;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.util.UUID;
 
+import io.github.waterfallmc.waterfall.utils.Hex;
+
 /**
  * Series of utility classes to perform various operations.
  */
@@ -48,7 +51,7 @@ public class Util
      */
     public static String hex(int i)
     {
-        return String.format( "0x%02X", i );
+        return Hex.encodeString(Ints.toByteArray(i));
     }
 
     /**
diff --git a/api/src/main/java/net/md_5/bungee/api/ServerPing.java b/api/src/main/java/net/md_5/bungee/api/ServerPing.java
index 88d36ad2..fc92a7b5 100644
--- a/api/src/main/java/net/md_5/bungee/api/ServerPing.java
+++ b/api/src/main/java/net/md_5/bungee/api/ServerPing.java
@@ -74,7 +74,7 @@ public class ServerPing
 
         public String getId()
         {
-            return uniqueId.toString().replace( "-", "" );
+            return io.github.waterfallmc.waterfall.utils.UUIDUtils.undash( uniqueId.toString() ); // Waterfall
         }
     }
 
diff --git a/proxy/src/main/java/net/md_5/bungee/connection/InitialHandler.java b/proxy/src/main/java/net/md_5/bungee/connection/InitialHandler.java
index 7abc76c6..a43082e8 100644
--- a/proxy/src/main/java/net/md_5/bungee/connection/InitialHandler.java
+++ b/proxy/src/main/java/net/md_5/bungee/connection/InitialHandler.java
@@ -622,7 +622,7 @@ public class InitialHandler extends PacketHandler implements PendingConnection
     @Override
     public String getUUID()
     {
-        return uniqueId.toString().replace( "-", "" );
+        return io.github.waterfallmc.waterfall.utils.UUIDUtils.undash( uniqueId.toString() ); // Waterfall
     }
 
     @Override
-- 
2.21.0