Store Compiled Packet Parsers in a global cache - Resolves #722

index.js

@@ -2,6 +2,7 @@ var SqlString = require('sqlstring');
 
 var Connection = require('./lib/connection.js');
 var ConnectionConfig = require('./lib/connection_config.js');
+var parserCache = require("./lib/parsers/parser_cache");
 
 module.exports.createConnection = function(opts) {
   return new Connection({ config: new ConnectionConfig(opts) });
@@ -61,3 +62,11 @@ exports.__defineGetter__('Charsets', function() {
 exports.__defineGetter__('CharsetToEncoding', function() {
   return require('./lib/constants/charset_encodings.js');
 });
+
+exports.setMaxParserCache = function (max) {
+  parserCache.setMaxCache(max);
+};
+
+exports.clearParserCache = function () {
+  parserCache.clearCache();
+};

lib/commands/execute.js

@@ -6,7 +6,7 @@ var Packets = require('../packets/index.js');
 
 var objectAssign = require('object-assign');
 
-var compileParser = require('../compile_binary_parser.js');
+var getBinaryParser = require('../parsers/binary_parser.js');
 
 function Execute(options, callback) {
   Command.call(this);
@@ -33,13 +33,7 @@ function Execute(options, callback) {
 util.inherits(Execute, Command);
 
 Execute.prototype.buildParserFromFields = function(fields, connection) {
-  var parserKey = connection.keyFromFields(fields, this.options);
-  var parser = connection.binaryProtocolParsers[parserKey];
-  if (!parser) {
-    parser = compileParser(fields, this.options, connection.config);
-    connection.binaryProtocolParsers[parserKey] = parser;
-  }
-  return parser;
+  return getBinaryParser(fields, this.options, connection.config);
 };
 
 Execute.prototype.start = function(packet, connection) {

lib/commands/query.js

@@ -7,7 +7,7 @@ var objectAssign = require('object-assign');
 
 var Command = require('./command.js');
 var Packets = require('../packets/index.js');
-var compileParser = require('../compile_text_parser.js');
+var getTextParser = require('../parsers/text_parser.js');
 var ServerStatus = require('../constants/server_status.js');
 var CharsetToEncoding = require('../constants/charset_encodings.js');
 
@@ -195,15 +195,10 @@ Query.prototype.readField = function(packet, connection) {
   }
 
   // last field received
-  if (this._receivedFieldsCount == this._fieldCount) {
+  if (this._receivedFieldsCount === this._fieldCount) {
     var fields = this._fields[this._resultIndex];
     this.emit('fields', fields);
-    var parserKey = connection.keyFromFields(fields, this.options);
-    this._rowParser = connection.textProtocolParsers[parserKey];
-    if (!this._rowParser) {
-      this._rowParser = compileParser(fields, this.options, connection.config);
-      connection.textProtocolParsers[parserKey] = this._rowParser;
-    }
+    this._rowParser = getTextParser(fields, this.options, connection.config);
     return Query.prototype.fieldsEOF;
   }
   return Query.prototype.readField;

lib/connection.js

@@ -58,19 +58,6 @@ function Connection(opts) {
     }
   });
 
-  // TODO: make it lru cache
-  // https://github.com/mercadolibre/node-simple-lru-cache
-  // or https://github.com/rsms/js-lru
-  // or https://github.com/monsur/jscache
-  // or https://github.com/isaacs/node-lru-cache
-  //
-  // key is field.name + ':' + field.columnType + ':' field.flags + '/'
-  this.textProtocolParsers = {};
-
-  // TODO: not sure if cache should be separate (same key as with textProtocolParsers)
-  // or part of prepared statements cache (key is sql query)
-  this.binaryProtocolParsers = {};
-
   this.serverCapabilityFlags = 0;
   this.authorized = false;
 
@@ -639,25 +626,6 @@ Connection.prototype.resume = function resume() {
   this.stream.resume();
 };
 
-Connection.prototype.keyFromFields = function keyFromFields(fields, options) {
-  var res =
-    typeof options.nestTables +
-    '/' +
-    options.nestTables +
-    '/' +
-    options.rowsAsArray +
-    options.supportBigNumbers +
-    '/' +
-    options.bigNumberStrings +
-    '/' +
-    typeof options.typeCast;
-  for (var i = 0; i < fields.length; ++i) {
-    res +=
-      '/' + fields[i].name + ':' + fields[i].columnType + ':' + fields[i].flags;
-  }
-  return res;
-};
-
 Connection.statementKey = function(options) {
   return (
     typeof options.nestTables +

lib/compile_binary_parser.js → lib/parsers/binary_parser.js

@@ -1,10 +1,10 @@
-var FieldFlags = require('./constants/field_flags.js');
-var Charsets = require('./constants/charsets.js');
-var CharsetToEncoding = require('./constants/charset_encodings.js');
-var Types = require('./constants/types.js');
-var srcEscape = require('./helpers').srcEscape;
+var FieldFlags = require('../constants/field_flags.js');
+var Charsets = require('../constants/charsets.js');
+var CharsetToEncoding = require('../constants/charset_encodings.js');
+var Types = require('../constants/types.js');
+var srcEscape = require('../helpers').srcEscape;
 var genFunc = require('generate-function');
-
+var parserCache = require('./parser_cache.js');
 var typeNames = [];
 for (var t in Types) {
   typeNames[Types[t]] = t;
@@ -181,4 +181,8 @@ function readCodeFor(field, config, options, fieldNum) {
   }
 }
 
-module.exports = compile;
+function getBinaryParser(fields, options, config) {
+  return parserCache.getParser('binary', fields, options, config, compile);
+}
+
+module.exports = getBinaryParser;

lib/parsers/parser_cache.js

@@ -0,0 +1,53 @@
+var LRU = require('lru-cache');
+
+var parserCache = new LRU({
+  max: 15000
+});
+
+function keyFromFields(type, fields, options) {
+  var res =
+    type +
+    '/' +
+    typeof options.nestTables +
+    '/' +
+    options.nestTables +
+    '/' +
+    options.rowsAsArray +
+    options.supportBigNumbers +
+    '/' +
+    options.bigNumberStrings +
+    '/' +
+    typeof options.typeCast;
+  for (var i = 0; i < fields.length; ++i) {
+    res +=
+      '/' + fields[i].name + ':' + fields[i].columnType + ':' + fields[i].flags;
+  }
+  return res;
+}
+
+function getParser(type, fields, options, config, compiler) {
+  var key = keyFromFields(type, fields, options);
+  var parser = parserCache.get(key);
+
+  if (parser) {
+    return parser;
+  }
+
+  parser = compiler(fields, options, config);
+  parserCache.set(key, parser);
+  return parser;
+}
+
+function setMaxCache(max) {
+  parserCache.max = max;
+}
+
+function clearCache() {
+  parserCache.reset();
+}
+
+module.exports = {
+  getParser: getParser,
+  setMaxCache: setMaxCache,
+  clearCache: clearCache
+};

lib/compile_text_parser.js → lib/parsers/text_parser.js

@@ -1,8 +1,9 @@
-var Types = require('./constants/types.js');
-var Charsets = require('./constants/charsets.js');
-var CharsetToEncoding = require('./constants/charset_encodings.js');
-var srcEscape = require('./helpers').srcEscape;
+var Types = require('../constants/types.js');
+var Charsets = require('../constants/charsets.js');
+var CharsetToEncoding = require('../constants/charset_encodings.js');
+var srcEscape = require('../helpers').srcEscape;
 var genFunc = require('generate-function');
+var parserCache = require('./parser_cache.js');
 
 var typeNames = [];
 for (var t in Types) {
@@ -189,4 +190,7 @@ function readCodeFor(type, charset, encodingExpr, config, options) {
   }
 }
 
-module.exports = compile;
+function getTextParser(fields, options, config) {
+  return parserCache.getParser('text', fields, options, config, compile);
+}
+module.exports = getTextParser;