Add reverse type lookup for small performance gain

closes #2170

Author: dougwilson

Changes.md

@@ -6,6 +6,7 @@ you spot any mistakes.
 
 ## HEAD
 
+* Add reverse type lookup for small performance gain #2170
 * Fix `connection.threadId` missing on handshake failure
 * Fix duplicate packet name in debug output
 * Fix no password support for old password protocol

lib/protocol/constants/types.js

@@ -1,33 +1,72 @@
-// Manually extracted from mysql-5.7.9/include/mysql.h.pp
-// some more info here: http://dev.mysql.com/doc/refman/5.5/en/c-api-prepared-statement-type-codes.html
-exports.DECIMAL     = 0x00; // aka DECIMAL (http://dev.mysql.com/doc/refman/5.0/en/precision-math-decimal-changes.html)
-exports.TINY        = 0x01; // aka TINYINT, 1 byte
-exports.SHORT       = 0x02; // aka SMALLINT, 2 bytes
-exports.LONG        = 0x03; // aka INT, 4 bytes
-exports.FLOAT       = 0x04; // aka FLOAT, 4-8 bytes
-exports.DOUBLE      = 0x05; // aka DOUBLE, 8 bytes
-exports.NULL        = 0x06; // NULL (used for prepared statements, I think)
-exports.TIMESTAMP   = 0x07; // aka TIMESTAMP
-exports.LONGLONG    = 0x08; // aka BIGINT, 8 bytes
-exports.INT24       = 0x09; // aka MEDIUMINT, 3 bytes
-exports.DATE        = 0x0a; // aka DATE
-exports.TIME        = 0x0b; // aka TIME
-exports.DATETIME    = 0x0c; // aka DATETIME
-exports.YEAR        = 0x0d; // aka YEAR, 1 byte (don't ask)
-exports.NEWDATE     = 0x0e; // aka ?
-exports.VARCHAR     = 0x0f; // aka VARCHAR (?)
-exports.BIT         = 0x10; // aka BIT, 1-8 byte
-exports.TIMESTAMP2  = 0x11; // aka TIMESTAMP with fractional seconds
-exports.DATETIME2   = 0x12; // aka DATETIME with fractional seconds
-exports.TIME2       = 0x13; // aka TIME with fractional seconds
-exports.JSON        = 0xf5; // aka JSON
-exports.NEWDECIMAL  = 0xf6; // aka DECIMAL
-exports.ENUM        = 0xf7; // aka ENUM
-exports.SET         = 0xf8; // aka SET
-exports.TINY_BLOB   = 0xf9; // aka TINYBLOB, TINYTEXT
-exports.MEDIUM_BLOB = 0xfa; // aka MEDIUMBLOB, MEDIUMTEXT
-exports.LONG_BLOB   = 0xfb; // aka LONGBLOG, LONGTEXT
-exports.BLOB        = 0xfc; // aka BLOB, TEXT
-exports.VAR_STRING  = 0xfd; // aka VARCHAR, VARBINARY
-exports.STRING      = 0xfe; // aka CHAR, BINARY
-exports.GEOMETRY    = 0xff; // aka GEOMETRY
+/**
+ * MySQL type constants
+ *
+ * Extracted from version 5.7.19
+ *
+ * !! Generated by generate-type-constants.js, do not modify by hand !!
+ */
+
+exports.DECIMAL     = 0;
+exports.TINY        = 1;
+exports.SHORT       = 2;
+exports.LONG        = 3;
+exports.FLOAT       = 4;
+exports.DOUBLE      = 5;
+exports.NULL        = 6;
+exports.TIMESTAMP   = 7;
+exports.LONGLONG    = 8;
+exports.INT24       = 9;
+exports.DATE        = 10;
+exports.TIME        = 11;
+exports.DATETIME    = 12;
+exports.YEAR        = 13;
+exports.NEWDATE     = 14;
+exports.VARCHAR     = 15;
+exports.BIT         = 16;
+exports.TIMESTAMP2  = 17;
+exports.DATETIME2   = 18;
+exports.TIME2       = 19;
+exports.JSON        = 245;
+exports.NEWDECIMAL  = 246;
+exports.ENUM        = 247;
+exports.SET         = 248;
+exports.TINY_BLOB   = 249;
+exports.MEDIUM_BLOB = 250;
+exports.LONG_BLOB   = 251;
+exports.BLOB        = 252;
+exports.VAR_STRING  = 253;
+exports.STRING      = 254;
+exports.GEOMETRY    = 255;
+
+// Lookup-by-number table
+exports[0]   = 'DECIMAL';
+exports[1]   = 'TINY';
+exports[2]   = 'SHORT';
+exports[3]   = 'LONG';
+exports[4]   = 'FLOAT';
+exports[5]   = 'DOUBLE';
+exports[6]   = 'NULL';
+exports[7]   = 'TIMESTAMP';
+exports[8]   = 'LONGLONG';
+exports[9]   = 'INT24';
+exports[10]  = 'DATE';
+exports[11]  = 'TIME';
+exports[12]  = 'DATETIME';
+exports[13]  = 'YEAR';
+exports[14]  = 'NEWDATE';
+exports[15]  = 'VARCHAR';
+exports[16]  = 'BIT';
+exports[17]  = 'TIMESTAMP2';
+exports[18]  = 'DATETIME2';
+exports[19]  = 'TIME2';
+exports[245] = 'JSON';
+exports[246] = 'NEWDECIMAL';
+exports[247] = 'ENUM';
+exports[248] = 'SET';
+exports[249] = 'TINY_BLOB';
+exports[250] = 'MEDIUM_BLOB';
+exports[251] = 'LONG_BLOB';
+exports[252] = 'BLOB';
+exports[253] = 'VAR_STRING';
+exports[254] = 'STRING';
+exports[255] = 'GEOMETRY';

lib/protocol/packets/Field.js

@@ -9,7 +9,7 @@ function Field(options) {
   this.db     = options.packet.db;
   this.table  = options.packet.table;
   this.name   = options.packet.name;
-  this.type   = typeToString(options.packet.type);
+  this.type   = Types[options.packet.type];
   this.length = options.packet.length;
 }
 
@@ -24,11 +24,3 @@ Field.prototype.buffer = function () {
 Field.prototype.geometry = function () {
   return this.parser.parseGeometryValue();
 };
-
-function typeToString(t) {
-  for (var k in Types) {
-    if (Types[k] === t) return k;
-  }
-
-  return undefined;
-}

lib/protocol/packets/RowDataPacket.js

@@ -123,10 +123,7 @@ function typeCast(field, parser, timeZone, supportBigNumbers, bigNumberStrings,
 
 function typeMatch(type, list) {
   if (Array.isArray(list)) {
-    for (var i = 0; i < list.length; i++) {
-      if (Types[list[i]] === type) return true;
-    }
-    return false;
+    return list.indexOf(Types[type]) !== -1;
   } else {
     return Boolean(list);
   }

test/unit/test-Mysql.js

@@ -37,12 +37,24 @@ test('Mysql.Types', {
     assert.equal(Mysql.Types, common.Types);
   },
 
-  'string names to integer values': function() {
+  'contains string to integer values': function() {
     var types = Object.keys(Mysql.Types);
     assert.ok(types.length > 0);
     types.forEach(function (type) {
-      assert.ok(/^[A-Z_]+/.test(type));
-      assert.equal(typeof Mysql.Types[type], 'number');
+      if (!/^[0-9]+$/.test(type)) {
+        assert.ok(/^[A-Z_]+/.test(type));
+        assert.equal(typeof Mysql.Types[type], 'number');
+      }
+    });
+  },
+
+  'contains integer values to string names': function() {
+    var types = Object.keys(Mysql.Types);
+    assert.ok(types.length > 0);
+    types.forEach(function (type) {
+      if (/^[0-9]+$/.test(type)) {
+        assert.equal(typeof Mysql.Types[type], 'string');
+      }
     });
   }
 });

tool/generate-type-constants.js

@@ -0,0 +1,91 @@
+#!/usr/bin/env node
+var fs     = require('fs');
+var path   = require('path');
+var script = path.basename(__filename);
+
+var srcDir = process.argv[2];
+if (!srcDir) {
+  var args = [];
+  args[0] = process.argv[0].indexOf(' ') !== -1
+    ? '"' + process.argv[0] + '"'
+    : process.argv[0];
+  args[1] = process.argv[1].indexOf(' ') !== -1
+    ? '"' + process.argv[1] + '"'
+    : process.argv[1];
+  args[2] = path.join('path', 'to', 'mysql', 'src');
+  console.error('Usage: ' + args.join(' '));
+  process.exit(1);
+}
+
+var types      = extractTypes(srcDir);
+var targetFile = path.join(__dirname, '..', 'lib', 'protocol', 'constants', 'types.js');
+var stream     = fs.createWriteStream(targetFile);
+var version    = extractMySqlVersion(srcDir);
+
+stream.write('/**\n * MySQL type constants\n *\n * Extracted from version ' + version + '\n *\n * !! Generated by ' + script + ', do not modify by hand !!\n */\n\n');
+
+var alignment = types.reduce(maxLength, 0);
+for (var i = 0; i < types.length; i++) {
+  if (i in types) {
+    stream.write('exports.' + types[i] + (new Array(alignment - types[i].length + 1)).join(' ') + ' = ' + i + ';\n');
+  }
+}
+
+stream.write('\n// Lookup-by-number table\n');
+
+var alignment = String(types.length).length;
+for (var i = 0; i < types.length; i++) {
+  if (i in types) {
+    stream.write('exports[' + i + ']' + (new Array(alignment - String(i).length + 1)).join(' ') + ' = \'' + types[i] + '\';\n');
+  }
+}
+
+console.log('Wrote constants to ' + targetFile);
+
+function extractMySqlVersion(srcDir) {
+  var versionFile = path.join(srcDir, 'VERSION');
+  var contents    = fs.readFileSync(versionFile, 'utf-8');
+  var dictionary  = Object.create(null);
+
+  contents.split('\n').forEach(function (line) {
+    var pair = line.split('=');
+    var key  = pair[0];
+    var val  = pair.slice(1).join('=').trimRight();
+    dictionary[key] = val;
+  });
+
+  return dictionary.MYSQL_VERSION_MAJOR + '.' +
+    dictionary.MYSQL_VERSION_MINOR + '.' +
+    dictionary.MYSQL_VERSION_PATCH;
+}
+
+function extractTypes(srcDir) {
+  var headerFile = path.join(srcDir, 'include', 'mysql.h.pp');
+  var contents   = fs.readFileSync(headerFile, 'utf-8');
+  var enumRegexp = /typedef enum enum_field_types {([^}]*)}/m;
+  var match      = enumRegexp.exec(contents);
+  var regexp     = /([A-Z0-9_]+)(?: *= *([0-9]+))?/g;
+
+  if (!match) {
+    throw new Error('Cannot locate enum enum_field_types in "' + headerFile + '"');
+  }
+
+  var enumContents = match[1];
+  var index        = 0;
+  var types        = [];
+
+  while ((match = regexp.exec(enumContents))) {
+    var name = match[1];
+    var num  = Number(match[2]) || index++;
+
+    if (name.indexOf('MYSQL_TYPE_') === 0) {
+      types[num] = name.substring(11);
+    }
+  }
+
+  return types;
+}
+
+function maxLength(max, value) {
+  return Math.max(max, value.length);
+}