Add JS binding SimRank library. (#135)

This change is a good example of how we can easily bind Native code to
JS side if using Bacardi.

ISSUE=#129

examples/electron/main.js

@@ -70,5 +70,3 @@ app.on('activate', () => {
 
 // In this file you can include the rest of your app's specific main process
 // code. You can also put them in separate files and require them here.
-const bacardi = require('bindings')('bacardi.node');
-let electronNative = new bacardi.ElectronNative();

examples/electron/native/electron_native.cc

@@ -17,3 +17,19 @@
 #include "examples/electron/native/electron_native.h"
 
 ElectronNative::ElectronNative() {}
+
+ElectronNative::ElectronNative(int32_t k, double c)
+    : SimRank<std::string>(k, c) {}
+
+void ElectronNative::AddEdge(const std::string& head, const std::string& tail) {
+  add_edge(head, tail);
+}
+
+void ElectronNative::CalculateSimRank() {
+  calculate_simrank();
+}
+
+double ElectronNative::Similarity(const std::string& node1,
+                                  const std::string& node2) {
+  return similarity(node1, node2);
+}

examples/electron/native/electron_native.gypi

@@ -17,6 +17,7 @@
     'examples_electron_native_cpp_files': [
       'electron_native.cc',
       'electron_native.h',
+      'simrank/simrank.hpp',
     ],
 
     'examples_electron_native_idl_files': [

examples/electron/native/electron_native.h

@@ -17,9 +17,18 @@
 #ifndef EXAMPLES_ELECTRON_NATIVE_ELECTRON_NATIVE_H_
 #define EXAMPLES_ELECTRON_NATIVE_ELECTRON_NATIVE_H_
 
-class ElectronNative {
+#include <string>
+
+#include "examples/electron/native/simrank/simrank.hpp"
+
+class ElectronNative : public SimRank<std::string> {
  public:
   ElectronNative();
+  ElectronNative(int32_t k, double c);
+
+  void AddEdge(const std::string& head, const std::string& tail);
+  void CalculateSimRank();
+  double Similarity(const std::string& node1, const std::string& node2);
 };
 
 #endif  // EXAMPLES_ELECTRON_NATIVE_ELECTRON_NATIVE_H_

examples/electron/native/electron_native.idl

@@ -14,5 +14,12 @@
  * limitations under the License.
  */
 
+[
+  Constructor(),
+  Constructor(long k, double c)
+]
 interface ElectronNative {
+  void addEdge(string head, string tail);
+  void calculateSimRank();
+  double similarity(string node1, string node2);
 };

examples/electron/renderer.js

@@ -1,3 +1,43 @@
-// This file is required by the index.html file and will
-// be executed in the renderer process for that window.
-// All of the Node.js APIs are available in this process.
+/**
+ * Copyright (c) 2017 The Bacardi Authors.
+ *
+ * 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.
+ */
+
+// This is JS porting implementation from simrank/example/main.cpp.
+
+const bacardi = require('bindings')('bacardi.node');
+
+let electronNative = new bacardi.ElectronNative(5, 0.8);
+let nodes = ['Univ', 'ProfA', 'ProfB', 'StudentA', 'StudentB'];
+
+electronNative.addEdge(nodes[0], nodes[1]);
+electronNative.addEdge(nodes[0], nodes[2]);
+electronNative.addEdge(nodes[1], nodes[3]);
+electronNative.addEdge(nodes[3], nodes[0]);
+electronNative.addEdge(nodes[2], nodes[4]);
+electronNative.addEdge(nodes[4], nodes[2]);
+
+electronNative.calculateSimRank();
+
+nodes.forEach(node_a => {
+  nodes.forEach(node_b => {
+    if (node_a >= node_b)
+      return;
+    let s = electronNative.similarity(node_a, node_b);
+    if (s > 0) {
+      document.write(
+          'similarity(' + node_a + ', ' + node_b + ') = ' + s + '<br>');
+    }
+  });
+});