refactor platform slightly, expose to module

Author: tjfontaine

dns.js

@@ -22,6 +22,8 @@ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 
 "use strict";
 
+exports.platform = require('./lib/platform');
+
 exports.createServer = require('./lib/server').createServer;
 exports.createUDPServer = require('./lib/server').createUDPServer;
 exports.createTCPServer = require('./lib/server').createTCPServer;

lib/platform.js

@@ -28,62 +28,117 @@ var fs = require('fs'),
   util = require('util');
 
 var Platform = function () {
-  this.name_server_ready = false;
-  this.hosts_file_ready = false;
+  this._nsReady = false;
+  this._hostsReady = false;
 
   Object.defineProperty(this, 'ready', {
     get: function () {
-      return this.name_server_ready && this.hosts_file_ready;
+      return this._nsReady && this._hostsReady;
     },
   });
 
-  this.initNameServers();
-  this.initHostsFile();
-  this.populate();
+  this._watches = {};
+
+  Object.defineProperty(this, 'watching', {
+    get: function () {
+      return Object.keys(this._watches).length > 0;
+    },
+    set: function (value) {
+      if (value)
+        this._watchFiles();
+      else {
+        for (k in this._watches) {
+          this._watches[k].close();
+          delete this._watches[k];
+        }
+      }
+    },
+  });
+
+  this._initNameServers();
+  this._initHostsFile();
+  this._populate();
 };
 util.inherits(Platform, EventEmitter);
 
-Platform.prototype.initNameServers = function () {
-  this.name_server_ready = false;
+Platform.prototype.realod = function () {
+  this.emit('unready');
+  this._initNameServers();
+  this._initHostsFile();
+  this._populate();
+};
+
+Platform.prototype._initNameServers = function () {
+  this._nsReady = false;
   this.name_servers = [];
   this.search_path = [];
   this.timeout = 5 * 1000;
   this.attempts = 5;
   this.edns = false;
 };
 
-Platform.prototype.initHostsFile = function () {
-  this.hosts_file_ready = false;
+Platform.prototype._initHostsFile = function () {
+  this._hostsReady = false;
   this.hosts = {};
 };
 
-Platform.prototype.populate = function () {
+Platform.prototype._populate = function () {
   var hostsfile, self = this;
 
   switch (os.platform()) {
+    case 'win32':
+      this.name_servers = [
+        {
+          address: '8.8.8.8',
+          port: 53,
+        },
+        {
+          address: '8.8.4.4.',
+          port: 53,
+        },
+      ];
+      hosts = path.join(process.env.SystemRoot, '\\System32\\drivers\\etc\\hosts');
+      break;
     default:
-      fs.watchFile('/etc/resolv.conf', {persistent: false}, function (cur, prev) {
-        if (cur.mtime !== prev.mtime) {
-          self.initNameServers();
-          self.parseResolv();
-        }
-      });
       this.parseResolv();
       hostsfile = '/etc/hosts';
       break;
   }
 
-  fs.watchFile(hostsfile, { persistent: false }, function (cur, prev) {
-    if (cur.mtime !== prev.mtime) {
-      self.initHostsFile();
-      self.parseHosts(hostsfile);
-    }
-  });
+  this._parseHosts(hostsfile);
+};
+
+Platform.prototype._watchFiles = function () {
+  var self = this, watchParams;
+
+  watchParams = {
+    persistent: false,
+  };
 
-  this.parseHosts(hostsfile);
+  switch (os.platform()) {
+    case 'win32':
+      //TODO XXX FIXME: it would be nice if this existed
+      break;
+    default:
+      this._watches.resolve = fs.watch('/etc/resolv.conf', watchParams, function (event, filename) {
+        if (event === 'change') {
+          self.emit('unready');
+          self._initNameServers();
+          self.parseResolv();
+        }
+      });
+      this._watches.hosts = fs.watch('/etc/hosts', watchParams, function (event, filename) {
+        if (event === 'change') {
+          self.emit('unready');
+          self._initHostsFile();
+          self._parseHosts(hostsfile);
+        }
+      });
+      break;
+  }
 };
 
-Platform.prototype.checkReady = function () {
+Platform.prototype._checkReady = function () {
   if (this.ready) {
     this.emit('ready');
   }
@@ -135,12 +190,12 @@ Platform.prototype.parseResolv = function () {
       }
     });
 
-    self.name_server_ready = true;
-    self.checkReady();
+    self._nsReady = true;
+    self._checkReady();
   });
 };
 
-Platform.prototype.parseHosts = function (hostsfile) {
+Platform.prototype._parseHosts = function (hostsfile) {
   var self = this;
 
   fs.readFile(hostsfile, 'ascii', function (err, file) {
@@ -164,8 +219,8 @@ Platform.prototype.parseHosts = function (hostsfile) {
       }
     });
 
-    self.hosts_file_ready = true;
-    self.checkReady();
+    self._hostsReady = true;
+    self._checkReady();
   });
 };