Create packstream components in BoltProtocol

Moved creation of `Packer` and `Unpacker` into `BoltProtocol` because
they are in lockstep with each other. This makes protocol handshaker
simpler because it only needs to do a single version check. Introduced
a class that represents Bolt V2 with different packing and unpacking
capabilities.

Author: lutovich

src/v1/internal/bolt-protocol-v1.js

@@ -17,19 +17,20 @@
  * limitations under the License.
  */
 import RequestMessage from './request-message';
+import * as v1 from './packstream-v1';
 
 export default class BoltProtocol {
 
   /**
    * @constructor
    * @param {Connection} connection the connection.
-   * @param {Packer} packer the packer.
-   * @param {Unpacker} unpacker the unpacker.
+   * @param {Chunker} chunker the chunker.
+   * @param {boolean} disableLosslessIntegers if this connection should convert all received integers to native JS numbers.
    */
-  constructor(connection, packer, unpacker) {
+  constructor(connection, chunker, disableLosslessIntegers) {
     this._connection = connection;
-    this._packer = packer;
-    this._unpacker = unpacker;
+    this._packer = this._createPacker(chunker);
+    this._unpacker = this._createUnpacker(disableLosslessIntegers);
   }
 
   /**
@@ -110,4 +111,12 @@ export default class BoltProtocol {
     const message = RequestMessage.reset();
     this._connection.write(message, observer, true);
   }
+
+  _createPacker(chunker) {
+    return new v1.Packer(chunker);
+  }
+
+  _createUnpacker(disableLosslessIntegers) {
+    return new v1.Unpacker(disableLosslessIntegers);
+  }
 }

src/v1/internal/bolt-protocol-v2.js

@@ -0,0 +1,35 @@
+/**
+ * Copyright (c) 2002-2018 "Neo4j,"
+ * Neo4j Sweden AB [http://neo4j.com]
+ *
+ * This file is part of Neo4j.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import BoltProtocolV1 from './bolt-protocol-v1';
+import * as v2 from './packstream-v2';
+
+export default class BoltProtocol extends BoltProtocolV1 {
+
+  constructor(connection, chunker, disableLosslessIntegers) {
+    super(connection, chunker, disableLosslessIntegers);
+  }
+
+  _createPacker(chunker) {
+    return new v2.Packer(chunker);
+  }
+
+  _createUnpacker(disableLosslessIntegers) {
+    return new v2.Unpacker(disableLosslessIntegers);
+  }
+}

src/v1/internal/protocol-handshaker.js

@@ -19,18 +19,24 @@
 
 import {alloc} from './buf';
 import {newError} from '../error';
-import * as v1 from './packstream-v1';
-import * as v2 from './packstream-v2';
-import BoltProtocol from './bolt-protocol-v1';
+import BoltProtocolV1 from './bolt-protocol-v1';
+import BoltProtocolV2 from './bolt-protocol-v2';
 
 const HTTP_MAGIC_PREAMBLE = 1213486160; // == 0x48545450 == "HTTP"
 const BOLT_MAGIC_PREAMBLE = 0x6060B017;
 
-const PACKER_CONSTRUCTORS_BY_VERSION = [null, v1.Packer, v2.Packer];
-const UNPACKER_CONSTRUCTORS_BY_VERSION = [null, v1.Unpacker, v2.Unpacker];
+const LATEST_PROTOCOL_VERSION = 2;
 
 export default class ProtocolHandshaker {
 
+  /**
+   * @constructor
+   * @param {Connection} connection the connection owning this protocol.
+   * @param {NodeChannel|WebSocketChannel} channel the network channel.
+   * @param {Chunker} chunker the message chunker.
+   * @param {boolean} disableLosslessIntegers flag to use native JS numbers.
+   * @param {Logger} log the logger.
+   */
   constructor(connection, channel, chunker, disableLosslessIntegers, log) {
     this._connection = connection;
     this._channel = channel;
@@ -44,7 +50,7 @@ export default class ProtocolHandshaker {
    * @return {BoltProtocol} the protocol.
    */
   createLatestProtocol() {
-    return this._createProtocolWithVersion(PACKER_CONSTRUCTORS_BY_VERSION.length - 1);
+    return this._createProtocolWithVersion(LATEST_PROTOCOL_VERSION);
   }
 
   /**
@@ -62,54 +68,27 @@ export default class ProtocolHandshaker {
    */
   readHandshakeResponse(buffer) {
     const proposedVersion = buffer.readInt32();
-
-    if (proposedVersion === 1 || proposedVersion === 2) {
-      return this._createProtocolWithVersion(proposedVersion);
-    } else if (proposedVersion === HTTP_MAGIC_PREAMBLE) {
-      throw newError('Server responded HTTP. Make sure you are not trying to connect to the http endpoint ' +
-        '(HTTP defaults to port 7474 whereas BOLT defaults to port 7687)');
-    } else {
-      throw newError('Unknown Bolt protocol version: ' + proposedVersion);
+    if (this._log.isDebugEnabled()) {
+      this._log.debug(`${this} negotiated protocol version ${proposedVersion}`);
     }
+    return this._createProtocolWithVersion(proposedVersion);
   }
 
   /**
    * @return {BoltProtocol}
    * @private
    */
   _createProtocolWithVersion(version) {
-    if (this._log.isDebugEnabled()) {
-      this._log.debug(`${this} negotiated protocol version ${version}`);
-    }
-    const packer = this._createPackerForProtocolVersion(version);
-    const unpacker = this._createUnpackerForProtocolVersion(version);
-    return new BoltProtocol(this._connection, packer, unpacker);
-  }
-
-  /**
-   * @param {number} version
-   * @return {Packer}
-   * @private
-   */
-  _createPackerForProtocolVersion(version) {
-    const packerConstructor = PACKER_CONSTRUCTORS_BY_VERSION[version];
-    if (!packerConstructor) {
-      throw new Error(`Packer can't be created for protocol version ${version}`);
-    }
-    return new packerConstructor(this._chunker);
-  }
-
-  /**
-   * @param {number} version
-   * @return {Unpacker}
-   * @private
-   */
-  _createUnpackerForProtocolVersion(version) {
-    const unpackerConstructor = UNPACKER_CONSTRUCTORS_BY_VERSION[version];
-    if (!unpackerConstructor) {
-      throw new Error(`Unpacker can't be created for protocol version ${version}`);
+    if (version === 1) {
+      return new BoltProtocolV1(this._connection, this._chunker, this._disableLosslessIntegers);
+    } else if (version === 2) {
+      return new BoltProtocolV2(this._connection, this._chunker, this._disableLosslessIntegers);
+    } else if (version === HTTP_MAGIC_PREAMBLE) {
+      throw newError('Server responded HTTP. Make sure you are not trying to connect to the http endpoint ' +
+        '(HTTP defaults to port 7474 whereas BOLT defaults to port 7687)');
+    } else {
+      throw newError('Unknown Bolt protocol version: ' + version);
     }
-    return new unpackerConstructor(this._disableLosslessIntegers);
   }
 }
 

test/internal/bolt-protocol-v1.test.js

@@ -17,7 +17,7 @@
  * limitations under the License.
  */
 
-import BoltProtocol from '../../src/v1/internal/bolt-protocol-v1';
+import BoltProtocolV1 from '../../src/v1/internal/bolt-protocol-v1';
 import RequestMessage from '../../src/v1/internal/request-message';
 import Bookmark from '../../src/v1/internal/bookmark';
 
@@ -42,11 +42,11 @@ class MessageRecorder {
   }
 }
 
-describe('BoltProtocol', () => {
+describe('BoltProtocolV1', () => {
 
   it('should initialize the connection', () => {
     const recorder = new MessageRecorder();
-    const protocol = new BoltProtocol(recorder, null, null);
+    const protocol = new BoltProtocolV1(recorder, null, false);
 
     const clientName = 'js-driver/1.2.3';
     const authToken = {username: 'neo4j', password: 'secret'};
@@ -62,7 +62,7 @@ describe('BoltProtocol', () => {
 
   it('should run a statement', () => {
     const recorder = new MessageRecorder();
-    const protocol = new BoltProtocol(recorder, null, null);
+    const protocol = new BoltProtocolV1(recorder, null, false);
 
     const statement = 'RETURN $x, $y';
     const parameters = {x: 'x', y: 'y'};
@@ -81,7 +81,7 @@ describe('BoltProtocol', () => {
 
   it('should reset the connection', () => {
     const recorder = new MessageRecorder();
-    const protocol = new BoltProtocol(recorder, null, null);
+    const protocol = new BoltProtocolV1(recorder, null, false);
 
     const observer = {};
 
@@ -95,7 +95,7 @@ describe('BoltProtocol', () => {
 
   it('should begin a transaction', () => {
     const recorder = new MessageRecorder();
-    const protocol = new BoltProtocol(recorder, null, null);
+    const protocol = new BoltProtocolV1(recorder, null, false);
 
     const bookmark = new Bookmark('neo4j:bookmark:v1:tx42');
     const observer = {};
@@ -113,7 +113,7 @@ describe('BoltProtocol', () => {
 
   it('should commit a transaction', () => {
     const recorder = new MessageRecorder();
-    const protocol = new BoltProtocol(recorder, null, null);
+    const protocol = new BoltProtocolV1(recorder, null, false);
 
     const observer = {};
 
@@ -130,7 +130,7 @@ describe('BoltProtocol', () => {
 
   it('should rollback a transaction', () => {
     const recorder = new MessageRecorder();
-    const protocol = new BoltProtocol(recorder, null, null);
+    const protocol = new BoltProtocolV1(recorder, null, false);
 
     const observer = {};