Merge pull request #450 from ali-ince/2.0-bolt-v4

Add multi-database support

Author: zhenlineo

src/driver.js

@@ -109,12 +109,13 @@ class Driver {
 
   /**
    * Verifies connectivity of this driver by trying to open a connection with the provided driver options.
+   * @param {string} [db=''] the target database to verify connectivity for.
    * @returns {Promise<object>} promise resolved with server info or rejected with error.
    */
-  verifyConnectivity () {
+  verifyConnectivity ({ db = '' } = {}) {
     const connectionProvider = this._getOrCreateConnectionProvider()
     const connectivityVerifier = new ConnectivityVerifier(connectionProvider)
-    return connectivityVerifier.verify()
+    return connectivityVerifier.verify({ db })
   }
 
   /**
@@ -178,18 +179,29 @@ class Driver {
    * it is closed, the underlying connection will be released to the connection
    * pool and made available for others to use.
    *
-   * @param {string} [mode=WRITE] the access mode of this session, allowed values are {@link READ} and {@link WRITE}.
-   * @param {string|string[]} [bookmarkOrBookmarks=null] the initial reference or references to some previous
+   * @param {string} [defaultAccessMode=WRITE] the access mode of this session, allowed values are {@link READ} and {@link WRITE}.
+   * @param {string|string[]} [bookmarks=null] the initial reference or references to some previous
    * transactions. Value is optional and absence indicates that that the bookmarks do not exist or are unknown.
+   * @param {string} [db=''] the database this session will connect to.
    * @return {Session} new session.
    */
-  session (mode, bookmarkOrBookmarks) {
-    const sessionMode = Driver._validateSessionMode(mode)
+  session ({
+    defaultAccessMode = WRITE,
+    bookmarks: bookmarkOrBookmarks,
+    db = ''
+  } = {}) {
+    const sessionMode = Driver._validateSessionMode(defaultAccessMode)
     const connectionProvider = this._getOrCreateConnectionProvider()
     const bookmark = bookmarkOrBookmarks
       ? new Bookmark(bookmarkOrBookmarks)
       : Bookmark.empty()
-    return new Session(sessionMode, connectionProvider, bookmark, this._config)
+    return new Session({
+      mode: sessionMode,
+      db,
+      connectionProvider,
+      bookmark,
+      config: this._config
+    })
   }
 
   static _validateSessionMode (rawMode) {

src/internal/bolt-protocol-util.js

@@ -0,0 +1,60 @@
+/**
+ * Copyright (c) 2002-2019 "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 { newError } from '../error'
+
+/**
+ * @param {TxConfig} txConfig the auto-commit transaction configuration.
+ * @param {Connection} connection the connection.
+ * @param {StreamObserver} observer the response observer.
+ */
+function assertTxConfigIsEmpty (txConfig, connection, observer) {
+  if (txConfig && !txConfig.isEmpty()) {
+    const error = newError(
+      'Driver is connected to the database that does not support transaction configuration. ' +
+        'Please upgrade to neo4j 3.5.0 or later in order to use this functionality'
+    )
+
+    // unsupported API was used, consider this a fatal error for the current connection
+    connection._handleFatalError(error)
+    observer.onError(error)
+    throw error
+  }
+}
+
+/**
+ * Asserts that the passed-in database name is empty.
+ * @param {string} db
+ * @param {Connection} connection
+ * @param {StreamObserver} observer
+ */
+function assertDbIsEmpty (db, connection, observer) {
+  if (db) {
+    const error = newError(
+      'Driver is connected to the database that does not support multiple databases. ' +
+        'Please upgrade to neo4j 4.0.0 or later in order to use this functionality'
+    )
+
+    // unsupported API was used, consider this a fatal error for the current connection
+    connection._handleFatalError(error)
+    observer.onError(error)
+    throw error
+  }
+}
+
+export { assertDbIsEmpty, assertTxConfigIsEmpty }

src/internal/bolt-protocol-v1.js

@@ -18,10 +18,10 @@
  */
 import RequestMessage from './request-message'
 import * as v1 from './packstream-v1'
-import { newError } from '../error'
 import Bookmark from './bookmark'
 import TxConfig from './tx-config'
 import { ACCESS_MODE_WRITE } from './constants'
+import { assertDbIsEmpty, assertTxConfigIsEmpty } from './bolt-protocol-util'
 
 export default class BoltProtocol {
   /**
@@ -78,13 +78,15 @@ export default class BoltProtocol {
 
   /**
    * Begin an explicit transaction.
+   * @param {StreamObserver} observer the response observer.
    * @param {Bookmark} bookmark the bookmark.
    * @param {TxConfig} txConfig the configuration.
+   * @param {string} db the target database name.
    * @param {string} mode the access mode.
-   * @param {StreamObserver} observer the response observer.
    */
-  beginTransaction (bookmark, txConfig, mode, observer) {
+  beginTransaction (observer, { bookmark, txConfig, db, mode }) {
     assertTxConfigIsEmpty(txConfig, this._connection, observer)
+    assertDbIsEmpty(db, this._connection, observer)
 
     const runMessage = RequestMessage.run(
       'BEGIN',
@@ -103,14 +105,11 @@ export default class BoltProtocol {
   commitTransaction (observer) {
     // WRITE access mode is used as a place holder here, it has
     // no effect on behaviour for Bolt V1 & V2
-    this.run(
-      'COMMIT',
-      {},
-      Bookmark.empty(),
-      TxConfig.empty(),
-      ACCESS_MODE_WRITE,
-      observer
-    )
+    this.run('COMMIT', {}, observer, {
+      bookmark: Bookmark.empty(),
+      txConfig: TxConfig.empty(),
+      mode: ACCESS_MODE_WRITE
+    })
   }
 
   /**
@@ -120,28 +119,28 @@ export default class BoltProtocol {
   rollbackTransaction (observer) {
     // WRITE access mode is used as a place holder here, it has
     // no effect on behaviour for Bolt V1 & V2
-    this.run(
-      'ROLLBACK',
-      {},
-      Bookmark.empty(),
-      TxConfig.empty(),
-      ACCESS_MODE_WRITE,
-      observer
-    )
+    this.run('ROLLBACK', {}, observer, {
+      bookmark: Bookmark.empty(),
+      txConfig: TxConfig.empty(),
+      mode: ACCESS_MODE_WRITE
+    })
   }
 
   /**
    * Send a Cypher statement through the underlying connection.
    * @param {string} statement the cypher statement.
    * @param {object} parameters the statement parameters.
+   * @param {StreamObserver} observer the response observer.
    * @param {Bookmark} bookmark the bookmark.
    * @param {TxConfig} txConfig the auto-commit transaction configuration.
+   * @param {string} db the target database name.
    * @param {string} mode the access mode.
-   * @param {StreamObserver} observer the response observer.
    */
-  run (statement, parameters, bookmark, txConfig, mode, observer) {
-    // bookmark and mode are ignored in this versioon of the protocol
+  run (statement, parameters, observer, { bookmark, txConfig, db, mode }) {
+    // bookmark and mode are ignored in this version of the protocol
     assertTxConfigIsEmpty(txConfig, this._connection, observer)
+    // passing in a db name on this protocol version throws an error
+    assertDbIsEmpty(db, this._connection, observer)
 
     const runMessage = RequestMessage.run(statement, parameters)
     const pullAllMessage = RequestMessage.pullAll()
@@ -167,22 +166,3 @@ export default class BoltProtocol {
     return new v1.Unpacker(disableLosslessIntegers)
   }
 }
-
-/**
- * @param {TxConfig} txConfig the auto-commit transaction configuration.
- * @param {Connection} connection the connection.
- * @param {StreamObserver} observer the response observer.
- */
-function assertTxConfigIsEmpty (txConfig, connection, observer) {
-  if (!txConfig.isEmpty()) {
-    const error = newError(
-      'Driver is connected to the database that does not support transaction configuration. ' +
-        'Please upgrade to neo4j 3.5.0 or later in order to use this functionality'
-    )
-
-    // unsupported API was used, consider this a fatal error for the current connection
-    connection._handleFatalError(error)
-    observer.onError(error)
-    throw error
-  }
-}

src/internal/bolt-protocol-v3.js

@@ -18,6 +18,7 @@
  */
 import BoltProtocolV2 from './bolt-protocol-v2'
 import RequestMessage from './request-message'
+import { assertDbIsEmpty } from './bolt-protocol-util'
 
 export default class BoltProtocol extends BoltProtocolV2 {
   transformMetadata (metadata) {
@@ -47,9 +48,10 @@ export default class BoltProtocol extends BoltProtocolV2 {
     this._connection.write(message, observer, true)
   }
 
-  beginTransaction (bookmark, txConfig, mode, observer) {
+  beginTransaction (observer, { bookmark, txConfig, db, mode }) {
+    assertDbIsEmpty(db, this._connection, observer)
     prepareToHandleSingleResponse(observer)
-    const message = RequestMessage.begin(bookmark, txConfig, mode)
+    const message = RequestMessage.begin({ bookmark, txConfig, mode })
     this._connection.write(message, observer, true)
   }
 
@@ -65,14 +67,15 @@ export default class BoltProtocol extends BoltProtocolV2 {
     this._connection.write(message, observer, true)
   }
 
-  run (statement, parameters, bookmark, txConfig, mode, observer) {
-    const runMessage = RequestMessage.runWithMetadata(
-      statement,
-      parameters,
+  run (statement, parameters, observer, { bookmark, txConfig, db, mode }) {
+    // passing in a db name on this protocol version throws an error
+    assertDbIsEmpty(db, this._connection, observer)
+
+    const runMessage = RequestMessage.runWithMetadata(statement, parameters, {
       bookmark,
       txConfig,
       mode
-    )
+    })
     const pullAllMessage = RequestMessage.pullAll()
 
     this._connection.write(runMessage, observer, false)

src/internal/bolt-protocol-v4.js

@@ -0,0 +1,40 @@
+/**
+ * Copyright (c) 2002-2019 "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 BoltProtocolV3 from './bolt-protocol-v3'
+import RequestMessage from './request-message'
+
+export default class BoltProtocol extends BoltProtocolV3 {
+  beginTransaction (observer, { bookmark, txConfig, db, mode }) {
+    const message = RequestMessage.begin({ bookmark, txConfig, db, mode })
+    this._connection.write(message, observer, true)
+  }
+
+  run (statement, parameters, observer, { bookmark, txConfig, db, mode }) {
+    const runMessage = RequestMessage.runWithMetadata(statement, parameters, {
+      bookmark,
+      txConfig,
+      db,
+      mode
+    })
+    const pullMessage = RequestMessage.pull()
+
+    this._connection.write(runMessage, observer, false)
+    this._connection.write(pullMessage, observer, true)
+  }
+}

src/internal/connection-holder.js

@@ -18,6 +18,8 @@
  */
 
 import { newError } from '../error'
+import { assertString } from './util'
+import { ACCESS_MODE_WRITE } from './constants'
 
 /**
  * Utility to lazily initialize connections and return them back to the pool when unused.
@@ -26,10 +28,12 @@ export default class ConnectionHolder {
   /**
    * @constructor
    * @param {string} mode - the access mode for new connection holder.
+   * @param {string} db - the target database name.
    * @param {ConnectionProvider} connectionProvider - the connection provider to acquire connections from.
    */
-  constructor (mode, connectionProvider) {
+  constructor ({ mode = ACCESS_MODE_WRITE, db = '', connectionProvider } = {}) {
     this._mode = mode
+    this._db = db ? assertString(db, 'db') : ''
     this._connectionProvider = connectionProvider
     this._referenceCount = 0
     this._connectionPromise = Promise.resolve(null)
@@ -43,14 +47,23 @@ export default class ConnectionHolder {
     return this._mode
   }
 
+  /**
+   * Returns the target database name
+   * @returns {string} db name
+   */
+  db () {
+    return this._db
+  }
+
   /**
    * Make this holder initialize new connection if none exists already.
    * @return {undefined}
    */
   initializeConnection () {
     if (this._referenceCount === 0) {
       this._connectionPromise = this._connectionProvider.acquireConnection(
-        this._mode
+        this._mode,
+        this._db
       )
     }
     this._referenceCount++