From f2483801c5a3bb9851c041cd1c9f644727ac5033 Mon Sep 17 00:00:00 2001
From: Bob Weinand <bobwei9@hotmail.com>
Date: Thu, 21 Apr 2016 16:44:59 +0200
Subject: [PATCH] Optimize column definition parsing by 25%

---
 lib/Connection.php | 52 +++++++++++++---------------------------------
 lib/DataTypes.php  | 26 +++++++++++++++++++++++
 2 files changed, 41 insertions(+), 37 deletions(-)

diff --git a/lib/Connection.php b/lib/Connection.php
index 57c6d4e..e2ccd7f 100644
--- a/lib/Connection.php
+++ b/lib/Connection.php
@@ -661,8 +661,7 @@ private function parseOk($packet) {
 		}
 
 		if ($this->capabilities & self::CLIENT_SESSION_TRACK) {
-			$this->connInfo->statusInfo = DataTypes::decodeString(substr($packet, $off), $intlen, $strlen);
-			$off += $intlen + $strlen;
+			$this->connInfo->statusInfo = DataTypes::decodeStringOff($packet, $off);
 
 			if ($this->connInfo->statusFlags & StatusFlags::SERVER_SESSION_STATE_CHANGED) {
 				$sessionState = DataTypes::decodeString(substr($packet, $off), $intlen, $sessionStateLen);
@@ -870,26 +869,13 @@ private function parseColumnDefinition($packet) {
 		$column = [];
 
 		if ($this->capabilities & self::CLIENT_PROTOCOL_41) {
-			$column["catalog"] = DataTypes::decodeString(substr($packet, $off), $intlen, $len);
-			$off += $intlen + $len;
-
-			$column["schema"] = DataTypes::decodeString(substr($packet, $off), $intlen, $len);
-			$off += $intlen + $len;
-
-			$column["table"] = DataTypes::decodeString(substr($packet, $off), $intlen, $len);
-			$off += $intlen + $len;
-
-			$column["original_table"] = DataTypes::decodeString(substr($packet, $off), $intlen, $len);
-			$off += $intlen + $len;
-
-			$column["name"] = DataTypes::decodeString(substr($packet, $off), $intlen, $len);
-			$off += $intlen + $len;
-
-			$column["original_name"] = DataTypes::decodeString(substr($packet, $off), $intlen, $len);
-			$off += $intlen + $len;
-
-			$fixlen = DataTypes::decodeInt(substr($packet, $off), $len);
-			$off += $len;
+			$column["catalog"] = DataTypes::decodeStringOff($packet, $off);
+			$column["schema"] = DataTypes::decodeStringOff($packet, $off);
+			$column["table"] = DataTypes::decodeStringOff($packet, $off);
+			$column["original_table"] = DataTypes::decodeStringOff($packet, $off);
+			$column["name"] = DataTypes::decodeStringOff($packet, $off);
+			$column["original_name"] = DataTypes::decodeStringOff($packet, $off);
+			$fixlen = DataTypes::decodeIntOff($packet, $off);
 
 			$len = 0;
 			$column["charset"] = DataTypes::decode_int16(substr($packet, $off + $len));
@@ -905,31 +891,24 @@ private function parseColumnDefinition($packet) {
 
 			$off += $fixlen;
 		} else {
-			$column["table"] = DataTypes::decodeString(substr($packet, $off), $intlen, $len);
-			$off += $intlen + $len;
-
-			$column["name"] = DataTypes::decodeString(substr($packet, $off), $intlen, $len);
-			$off += $intlen + $len;
-
-			$collen = DataTypes::decodeInt(substr($packet, $off), $len);
-			$off += $len;
+			$column["table"] = DataTypes::decodeStringOff($packet, $off);
+			$column["name"] = DataTypes::decodeStringOff($packet, $off);
 
+			$collen = DataTypes::decodeIntOff($packet, $off);
 			$column["columnlen"] = DataTypes::decode_intByLen(substr($packet, $off), $collen);
 			$off += $collen;
 
-			$typelen = DataTypes::decodeInt(substr($packet, $off), $len);
-			$off += $len;
-
+			$typelen = DataTypes::decodeIntOff($packet, $off);
 			$column["type"] = DataTypes::decode_intByLen(substr($packet, $off), $typelen);
 			$off += $typelen;
 
 			$len = 1;
-			$flaglen = $this->capabilities & self::CLIENT_LONG_FLAG ? DataTypes::decodeInt(substr($packet, $off), $len) : ord($packet[$off]);
+			$flaglen = $this->capabilities & self::CLIENT_LONG_FLAG ? DataTypes::decodeInt(substr($packet, $off, 9), $len) : ord($packet[$off]);
 			$off += $len;
 
 			if ($flaglen > 2) {
 				$len = 2;
-				$column["flags"] = DataTypes::decode_int16(substr($packet, $off));
+				$column["flags"] = DataTypes::decode_int16(substr($packet, $off, 4));
 			} else {
 				$len = 1;
 				$column["flags"] = ord($packet[$off]);
@@ -984,8 +963,7 @@ private function handleTextResultsetRow($packet) {
 				$fields[] = null;
 				$off += 1;
 			} else {
-				$fields[] = DataTypes::decodeString(substr($packet, $off), $intlen, $len);
-				$off += $intlen + $len;
+				$fields[] = DataTypes::decodeStringOff($packet, $off);
 			}
 		}
 		$this->result->rowFetched($fields);
diff --git a/lib/DataTypes.php b/lib/DataTypes.php
index 320671f..fd9916a 100644
--- a/lib/DataTypes.php
+++ b/lib/DataTypes.php
@@ -190,6 +190,32 @@ public static function decodeNullString($str, &$len = 0) {
 		return substr($str, 0, $len = strpos($str, "\0"));
 	}
 
+	public static function decodeStringOff($str, &$off) {
+		$len = self::decodeIntOff($str, $off);
+		$off += $len;
+		return substr($str, $off - $len, $len);
+	}
+
+	public static function decodeIntOff($str, &$off) {
+		$int = ord($str[$off]);
+		if ($int < 0xfb) {
+			$off += 1;
+			return $int;
+		} elseif ($int == 0xfc) {
+			$off += 3;
+			return self::decode_int16(substr($str, $off - 2, 2));
+		} elseif ($int == 0xfd) {
+			$off += 4;
+			return self::decode_int24(substr($str, $off - 3, 3));
+		} elseif ($int == 0xfe) {
+			$off += 9;
+			return self::decode_int64(substr($str, $off - 8, 8));
+		} else {
+			// If that happens connection is borked...
+			throw new \RangeException("$int is not in ranges [0x00, 0xfa] or [0xfc, 0xfe]");
+		}
+	}
+
 	public static function decodeString($str, &$intlen = 0, &$len = 0) {
 		$len = self::decodeInt($str, $intlen);
 		return substr($str, $intlen, $len);