perf: remove lodash deps for smaller memory footprint

lib/cluster/ClusterSubscriber.ts

@@ -1,7 +1,8 @@
 import {EventEmitter} from 'events'
 import ConnectionPool from './ConnectionPool'
-import {sample, noop} from '../utils/lodash'
+import {noop} from '../utils/lodash'
 import {getNodeKey} from './util'
+import {sample} from '../utils'
 
 const Redis = require('../redis')
 const debug = require('../utils/debug')('ioredis:cluster:subscriber')

lib/cluster/ConnectionPool.ts

@@ -1,6 +1,6 @@
 import {parseURL} from '../utils'
 import {EventEmitter} from 'events'
-import {noop, defaults, values} from '../utils/lodash'
+import {noop, defaults} from '../utils/lodash'
 import {IRedisOptions, getNodeKey} from './util'
 
 const Redis = require('../redis')
@@ -23,7 +23,8 @@ export default class ConnectionPool extends EventEmitter {
   }
 
   public getNodes(role: 'all' | 'master' | 'slave' = 'all'): any[] {
-    return values(this.nodes[role])
+    const nodes = this.nodes[role]
+    return Object.keys(nodes).map((key) => nodes[key])
   }
 
   /**

lib/cluster/index.js

@@ -348,7 +348,7 @@ Cluster.prototype.refreshSlotsCache = function (callback) {
     }
   };
 
-  var keys = _.shuffle(Object.keys(this.connectionPool.nodes.all));
+  var keys = utils.shuffle(Object.keys(this.connectionPool.nodes.all));
 
   var lastNodeError = null;
 
@@ -426,7 +426,7 @@ Cluster.prototype.sendCommand = function (command, stream, node) {
     command.__is_reject_overwritten = true;
     var reject = command.reject;
     command.reject = function (err) {
-      var partialTry = _.partial(tryConnection, true);
+      var partialTry = tryConnection.bind(null, true)
       _this.handleError(err, ttl, {
         moved: function (slot, key) {
           debug('command %s is moved to %s', command.name, key);
@@ -511,8 +511,8 @@ Cluster.prototype.sendCommand = function (command, stream, node) {
           }
         }
         if (!redis) {
-          redis = _.sample(_this.connectionPool.nodes[to]) ||
-            _.sample(_this.connectionPool.nodes.all);
+          redis = utils.sample(_this.connectionPool.getNodes(to)) ||
+            utils.sample(_this.connectionPool.getNodes('all'));
         }
       }
       if (node && !node.redis) {

lib/commander.js

@@ -26,7 +26,9 @@ function Commander() {
   this.scriptsSet = {};
 }
 
-var commands = _.difference(require('redis-commands').list, ['monitor']);
+var commands = require('redis-commands').list.filter(function (command) {
+  return command !== 'monitor'
+})
 commands.push('sentinel');
 
 /**
@@ -53,7 +55,7 @@ Commander.prototype.createBuiltinCommand = function (commandName) {
   };
 };
 
-_.forEach(commands, function (commandName) {
+commands.forEach(function (commandName) {
   Commander.prototype[commandName] = generateFunction(commandName, 'utf8');
   Commander.prototype[commandName + 'Buffer'] = generateFunction(commandName, null);
 });

lib/connectors/SentinelConnector/index.ts

@@ -1,6 +1,5 @@
 import {createConnection, Socket} from 'net'
-import {sample} from '../../utils/lodash'
-import {CONNECTION_CLOSED_ERROR_MSG, packObject} from '../../utils'
+import {CONNECTION_CLOSED_ERROR_MSG, packObject, sample} from '../../utils'
 import {TLSSocket} from 'tls'
 import {ITcpConnectionOptions, isIIpcConnectionOptions} from '../StandaloneConnector'
 import SentinelIterator from './SentinelIterator'

lib/pipeline.js

@@ -217,7 +217,7 @@ Pipeline.prototype.exec = function (callback) {
     this.nodeifiedPromise = true;
     asCallback(this.promise, callback);
   }
-  if (_.isEmpty(this._queue)) {
+  if (!this._queue.length) {
     this.resolve([]);
   }
   var pipelineSlot, i;

lib/redis/parser.js

@@ -70,7 +70,7 @@ exports.returnError = function (err) {
 };
 
 var sharedBuffers = {};
-_.forEach(['message', 'pmessage', 'subscribe', 'psubscribe', 'unsubscribe', 'punsubscribe'], function (str) {
+['message', 'pmessage', 'subscribe', 'psubscribe', 'unsubscribe', 'punsubscribe'].forEach(function (str) {
   sharedBuffers[str] = Buffer.from(str);
 });
 exports.returnReply = function (reply) {

lib/utils/index.ts

@@ -293,6 +293,33 @@ export function sample<T> (array: T[], from: number = 0): T {
   }
   return array[from + Math.floor(Math.random() * (length - from))]
 }
+/**
+ * Shuffle the array using the Fisher-Yates Shuffle.
+ * This method will mutate the original array.
+ *
+ * @export
+ * @template T
+ * @param {T[]} array
+ * @returns {T[]}
+ */
+export function shuffle<T> (array: T[]): T[] {
+  let counter = array.length
+
+  // While there are elements in the array
+  while (counter > 0) {
+    // Pick a random index
+    const index = Math.floor(Math.random() * counter)
+
+    // Decrease counter by 1
+    counter--
+
+    // And swap the last element with it
+    [array[counter], array[index]] = [array[index], array[counter]]
+  }
+
+  return array
+}
+
 
 /**
  * Error message for connection being disconnected

lib/utils/lodash.js

@@ -1,13 +1,5 @@
 'use strict';
 
-exports.forEach = require('lodash.foreach');
-exports.pick = require('lodash.pick');
 exports.defaults = require('lodash.defaults');
 exports.noop = function () {};
-exports.difference = require('lodash.difference');
-exports.sample = require('lodash.sample');
 exports.flatten = require('lodash.flatten');
-exports.isEmpty = require('lodash.isempty');
-exports.values = require('lodash.values');
-exports.shuffle = require('lodash.shuffle');
-exports.partial = require('lodash.partial');

package.json

@@ -33,15 +33,7 @@
     "denque": "^1.1.0",
     "flexbuffer": "0.0.6",
     "lodash.defaults": "^4.2.0",
-    "lodash.difference": "^4.5.0",
     "lodash.flatten": "^4.4.0",
-    "lodash.foreach": "^4.5.0",
-    "lodash.isempty": "^4.4.0",
-    "lodash.partial": "^4.2.1",
-    "lodash.pick": "^4.4.0",
-    "lodash.sample": "^4.2.1",
-    "lodash.shuffle": "^4.2.0",
-    "lodash.values": "^4.3.0",
     "redis-commands": "^1.3.5",
     "redis-errors": "^1.2.0",
     "redis-parser": "^3.0.0",

test/unit/utils.js

@@ -167,4 +167,53 @@ describe('utils', function () {
       Math.random.restore();
     });
   });
+
+  describe('.shuffle', function () {
+    function compareArray (arr1, arr2) {
+      if (arr1.length !== arr2.length) {
+        return false
+      }
+      arr1.sort()
+      arr2.sort()
+      for (let i = 0; i < arr1.length; i++) {
+        if (arr1[i] !== arr2[i]) {
+          return false
+        }
+      }
+      return true
+    }
+    function testShuffle (arr) {
+      const origin = arr.slice(0)
+      expect(compareArray(origin, utils.shuffle(arr))).to.eql(true)
+    }
+    it('contains all items', () => {
+      testShuffle([1])
+      testShuffle([1, 2])
+      testShuffle([2, 1])
+      testShuffle([1, 1, 1])
+      testShuffle([1, 2, 3])
+      testShuffle([3, -1, 0, 2, -1])
+      testShuffle(['a', 'b', 'd', 'c'])
+      testShuffle(['c', 'b'])
+    })
+
+    it('mutates the original array', () => {
+      const arr = [3, 7]
+      const ret = utils.shuffle(arr)
+      expect(arr === ret).to.eql(true)
+    })
+
+    it('shuffles the array', () => {
+      const arr = [1, 2, 3, 4]
+      const copy = arr.slice(0)
+      while (true) {
+        utils.shuffle(copy)
+        for (let i = 0; i < copy.length; i++) {
+          if (arr[i] !== copy[i]) {
+            return
+          }
+        }
+      }
+    })
+  })
 });