Moved WatchManager.js from WatchKeeper

lib/WatchManager.js

@@ -0,0 +1,94 @@
+/**
+ * Copyright 2019 IBM Corp. All Rights Reserved.
+ *
+ * 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.
+ */
+
+const Watchman = require('./Watchman');
+const log = require('./bunyan-api').createLogger('WatchManager');
+const objectPath = require('object-path');
+const hash = require('object-hash');
+
+var _watchObjects = {};
+
+module.exports = function WatchManager() {
+  // private
+  let _saveWatch = function (wm, querySelector, startWatch = true) {
+    let selfLink = wm.selfLink;
+    _removeWatch(selfLink);
+    _watchObjects[selfLink] = { selfLink: wm.selfLink, watchman: wm, querySelectorHash: hash(querySelector) };
+    if (startWatch) {
+      wm.watch();
+    }
+    log.info(`Watch added: ${selfLink} ${JSON.stringify(querySelector)}`);
+    return _watchObjects[selfLink];
+  };
+
+  let _ensureWatch = function (options, objectHandler, globalWatch = false, startWatch = true) {
+    let querySelector = objectPath.get(options, 'requestOptions.qs', {});
+    let selfLink = options?.requestOptions?.uri;
+    let w = _getWatch(selfLink);
+    if (w && (!globalWatch || (globalWatch && w.querySelectorHash == hash(querySelector)))) {
+      return w;
+    }
+    var wm = new Watchman(options, objectHandler);
+    return _saveWatch(wm, querySelector, startWatch);
+  };
+
+  let _startWatch = function (selfLink) {
+    return _reWatch(selfLink);
+  };
+
+  let _removeWatch = function (selfLink) {
+    let w = objectPath.get(_getWatch(selfLink), 'watchman');
+    if (w) {
+      w.end();
+      delete _watchObjects[selfLink];
+      log.info(`Watch removed: ${selfLink}`);
+    }
+    return _watchObjects[selfLink];
+  };
+
+  let _getWatch = function (selfLink) {
+    return _watchObjects[selfLink];
+  };
+
+  let _reWatch = function (selfLink) {
+    let w = objectPath.get(_getWatch(selfLink), 'watchman');
+    if (w) {
+      w.watch();
+    }
+    return w;
+  };
+
+  // public
+  return {
+    saveWatch: _saveWatch,
+    ensureWatch: _ensureWatch,
+    startWatch: _startWatch,
+    removeWatch: _removeWatch,
+    removeAllWatches: function () {
+      let watches = Object.keys(_watchObjects);
+      watches.forEach(w => _removeWatch(w));
+    },
+    getWatch: _getWatch,
+    getAllWatches: function () {
+      return _watchObjects;
+    },
+    reWatch: _reWatch,
+    reWatchAll: function () {
+      let watches = Object.keys(_watchObjects);
+      watches.forEach(w => _reWatch(w));
+    }
+  };
+};