[Feature] Add 'memorySearch' and 'memorySearchSync' for Nodejs

1) Add features.
2) Add unit tests.
3) Add benchmark.

binding/nodejs/tests/benchmarkTests/main.js

@@ -0,0 +1,94 @@
+const Benchmark = require('benchmark');
+
+const suite = new Benchmark.Suite();
+const searcher = require('../../ip2region').create('../../data/ip2region.db');
+const testDatas = require('../utils/testData');
+const asyncFor = require('../utils/asyncFor');
+
+suite.add("MemorySearchSync", () => {
+    for (let i = 0; i < testDatas.length; ++i) {
+        searcher.memorySearchSync(testDatas[i]);
+    }
+})
+    .add("BinarySearchSync", () => {
+        for (let i = 0; i < testDatas.length; ++i) {
+            searcher.binarySearchSync(testDatas[i]);
+        }
+    })
+    .add("BtreeSearchSync", () => {
+        for (let i = 0; i < testDatas.length; ++i) {
+            searcher.btreeSearchSync(testDatas[i]);
+        }
+    })
+    .add("MemorySearch", {
+        defer: true,
+        fn: function (completeCallBack) {
+            asyncFor(testDatas,
+                (v, c) => {
+                    searcher.memorySearch(v, () => {
+                        c();
+                    });
+                },
+                () => {
+                    completeCallBack.resolve();
+                });
+        }
+    })
+    .add("BinarySearch", {
+        defer: true,
+        fn: function (completeCallBack) {
+            asyncFor(testDatas,
+                (v, c) => {
+                    searcher.binarySearch(v, () => {
+                        c();
+                    });
+                },
+                () => {
+                    completeCallBack.resolve();
+                });
+        }
+    })
+    .add("BtreeSearch", {
+        defer: true,
+        fn: function (completeCallBack) {
+            asyncFor(testDatas,
+                (v, c) => {
+                    searcher.btreeSearch(v, () => {
+                        c();
+                    });
+                },
+                () => {
+                    completeCallBack.resolve();
+                });
+        }
+    })
+    .on('cycle', function (event) {
+        console.log(String(event.target));
+    })
+    .on('complete', function () {
+
+        let results = new Array();
+
+        for (let prop in this) {
+            if (!isNaN(prop)) {
+                const eachResult = {
+                    name: this[prop].name,
+                    mean: this[prop].stats.mean * 1000,  //second => millisecond
+                    moe: this[prop].stats.moe,
+                    rme: this[prop].stats.rme,
+                    sem: this[prop].stats.sem
+                }
+                results.push(eachResult);
+            }
+        }
+
+        results = results.sort((a, b) => { return a.mean - b.mean });
+
+        console.log(`Rand\t${'Name'.padEnd(20)}Time (in milliseconds)`);
+        let id = 1;
+
+        for (let r of results) {
+            console.log(`${id++}\t${r.name.padEnd(20)}${r.mean.toFixed(3)}`);
+        }
+    })
+    .run({ async: true });