Initial commit

node_modules/neo4j-driver/lib/v1/internal/transaction-executor.js

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+'use strict';
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+
+var _promise = require('babel-runtime/core-js/promise');
+
+var _promise2 = _interopRequireDefault(_promise);
+
+var _classCallCheck2 = require('babel-runtime/helpers/classCallCheck');
+
+var _classCallCheck3 = _interopRequireDefault(_classCallCheck2);
+
+var _createClass2 = require('babel-runtime/helpers/createClass');
+
+var _createClass3 = _interopRequireDefault(_createClass2);
+
+var _error = require('../error');
+
+function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
+
+var DEFAULT_MAX_RETRY_TIME_MS = 30 * 1000; // 30 seconds
+/**
+ * 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.
+ */
+
+var DEFAULT_INITIAL_RETRY_DELAY_MS = 1000; // 1 seconds
+var DEFAULT_RETRY_DELAY_MULTIPLIER = 2.0;
+var DEFAULT_RETRY_DELAY_JITTER_FACTOR = 0.2;
+
+var TransactionExecutor = function () {
+  function TransactionExecutor(maxRetryTimeMs, initialRetryDelayMs, multiplier, jitterFactor) {
+    (0, _classCallCheck3.default)(this, TransactionExecutor);
+
+    this._maxRetryTimeMs = _valueOrDefault(maxRetryTimeMs, DEFAULT_MAX_RETRY_TIME_MS);
+    this._initialRetryDelayMs = _valueOrDefault(initialRetryDelayMs, DEFAULT_INITIAL_RETRY_DELAY_MS);
+    this._multiplier = _valueOrDefault(multiplier, DEFAULT_RETRY_DELAY_MULTIPLIER);
+    this._jitterFactor = _valueOrDefault(jitterFactor, DEFAULT_RETRY_DELAY_JITTER_FACTOR);
+
+    this._inFlightTimeoutIds = [];
+
+    this._verifyAfterConstruction();
+  }
+
+  (0, _createClass3.default)(TransactionExecutor, [{
+    key: 'execute',
+    value: function execute(transactionCreator, transactionWork) {
+      var _this = this;
+
+      return new _promise2.default(function (resolve, reject) {
+        _this._executeTransactionInsidePromise(transactionCreator, transactionWork, resolve, reject);
+      }).catch(function (error) {
+        var retryStartTimeMs = Date.now();
+        var retryDelayMs = _this._initialRetryDelayMs;
+        return _this._retryTransactionPromise(transactionCreator, transactionWork, error, retryStartTimeMs, retryDelayMs);
+      });
+    }
+  }, {
+    key: 'close',
+    value: function close() {
+      // cancel all existing timeouts to prevent further retries
+      this._inFlightTimeoutIds.forEach(function (timeoutId) {
+        return clearTimeout(timeoutId);
+      });
+      this._inFlightTimeoutIds = [];
+    }
+  }, {
+    key: '_retryTransactionPromise',
+    value: function _retryTransactionPromise(transactionCreator, transactionWork, error, retryStartTime, retryDelayMs) {
+      var _this2 = this;
+
+      var elapsedTimeMs = Date.now() - retryStartTime;
+
+      if (elapsedTimeMs > this._maxRetryTimeMs || !TransactionExecutor._canRetryOn(error)) {
+        return _promise2.default.reject(error);
+      }
+
+      return new _promise2.default(function (resolve, reject) {
+        var nextRetryTime = _this2._computeDelayWithJitter(retryDelayMs);
+        var timeoutId = setTimeout(function () {
+          // filter out this timeoutId when time has come and function is being executed
+          _this2._inFlightTimeoutIds = _this2._inFlightTimeoutIds.filter(function (id) {
+            return id !== timeoutId;
+          });
+          _this2._executeTransactionInsidePromise(transactionCreator, transactionWork, resolve, reject);
+        }, nextRetryTime);
+        // add newly created timeoutId to the list of all in-flight timeouts
+        _this2._inFlightTimeoutIds.push(timeoutId);
+      }).catch(function (error) {
+        var nextRetryDelayMs = retryDelayMs * _this2._multiplier;
+        return _this2._retryTransactionPromise(transactionCreator, transactionWork, error, retryStartTime, nextRetryDelayMs);
+      });
+    }
+  }, {
+    key: '_executeTransactionInsidePromise',
+    value: function _executeTransactionInsidePromise(transactionCreator, transactionWork, resolve, reject) {
+      var _this3 = this;
+
+      var tx = void 0;
+      try {
+        tx = transactionCreator();
+      } catch (error) {
+        // failed to create a transaction
+        reject(error);
+        return;
+      }
+
+      var resultPromise = this._safeExecuteTransactionWork(tx, transactionWork);
+
+      resultPromise.then(function (result) {
+        return _this3._handleTransactionWorkSuccess(result, tx, resolve, reject);
+      }).catch(function (error) {
+        return _this3._handleTransactionWorkFailure(error, tx, reject);
+      });
+    }
+  }, {
+    key: '_safeExecuteTransactionWork',
+    value: function _safeExecuteTransactionWork(tx, transactionWork) {
+      try {
+        var result = transactionWork(tx);
+        // user defined callback is supposed to return a promise, but it might not; so to protect against an
+        // incorrect API usage we wrap the returned value with a resolved promise; this is effectively a
+        // validation step without type checks
+        return _promise2.default.resolve(result);
+      } catch (error) {
+        return _promise2.default.reject(error);
+      }
+    }
+  }, {
+    key: '_handleTransactionWorkSuccess',
+    value: function _handleTransactionWorkSuccess(result, tx, resolve, reject) {
+      if (tx.isOpen()) {
+        // transaction work returned resolved promise and transaction has not been committed/rolled back
+        // try to commit the transaction
+        tx.commit().then(function () {
+          // transaction was committed, return result to the user
+          resolve(result);
+        }).catch(function (error) {
+          // transaction failed to commit, propagate the failure
+          reject(error);
+        });
+      } else {
+        // transaction work returned resolved promise and transaction is already committed/rolled back
+        // return the result returned by given transaction work
+        resolve(result);
+      }
+    }
+  }, {
+    key: '_handleTransactionWorkFailure',
+    value: function _handleTransactionWorkFailure(error, tx, reject) {
+      if (tx.isOpen()) {
+        // transaction work failed and the transaction is still open, roll it back and propagate the failure
+        tx.rollback().catch(function (ignore) {
+          // ignore the rollback error
+        }).then(function () {
+          return reject(error);
+        }); // propagate the original error we got from the transaction work
+      } else {
+        // transaction is already rolled back, propagate the error
+        reject(error);
+      }
+    }
+  }, {
+    key: '_computeDelayWithJitter',
+    value: function _computeDelayWithJitter(delayMs) {
+      var jitter = delayMs * this._jitterFactor;
+      var min = delayMs - jitter;
+      var max = delayMs + jitter;
+      return Math.random() * (max - min) + min;
+    }
+  }, {
+    key: '_verifyAfterConstruction',
+    value: function _verifyAfterConstruction() {
+      if (this._maxRetryTimeMs < 0) {
+        throw (0, _error.newError)('Max retry time should be >= 0: ' + this._maxRetryTimeMs);
+      }
+      if (this._initialRetryDelayMs < 0) {
+        throw (0, _error.newError)('Initial retry delay should >= 0: ' + this._initialRetryDelayMs);
+      }
+      if (this._multiplier < 1.0) {
+        throw (0, _error.newError)('Multiplier should be >= 1.0: ' + this._multiplier);
+      }
+      if (this._jitterFactor < 0 || this._jitterFactor > 1) {
+        throw (0, _error.newError)('Jitter factor should be in [0.0, 1.0]: ' + this._jitterFactor);
+      }
+    }
+  }], [{
+    key: '_canRetryOn',
+    value: function _canRetryOn(error) {
+      return error && error.code && (error.code === _error.SERVICE_UNAVAILABLE || error.code === _error.SESSION_EXPIRED || this._isTransientError(error));
+    }
+  }, {
+    key: '_isTransientError',
+    value: function _isTransientError(error) {
+      // Retries should not happen when transaction was explicitly terminated by the user.
+      // Termination of transaction might result in two different error codes depending on where it was
+      // terminated. These are really client errors but classification on the server is not entirely correct and
+      // they are classified as transient.
+
+      var code = error.code;
+      if (code.indexOf('TransientError') >= 0) {
+        if (code === 'Neo.TransientError.Transaction.Terminated' || code === 'Neo.TransientError.Transaction.LockClientStopped') {
+          return false;
+        }
+        return true;
+      }
+      return false;
+    }
+  }]);
+  return TransactionExecutor;
+}();
+
+exports.default = TransactionExecutor;
+;
+
+function _valueOrDefault(value, defaultValue) {
+  if (value || value === 0) {
+    return value;
+  }
+  return defaultValue;
+}