work on say and gather

lib/utils/resources.js

@@ -0,0 +1,50 @@
+const assert = require('assert');
+
+//this obj is meant to be mixed in into another class
+//NB: it is required that the class have a 'logger' property
+module.exports = {
+  resources: new Map(),
+  addResource(name, resource) {
+    this.logger.debug(`addResource: adding ${name}`);
+
+    // duck-typing: resources must have a destroy function and a 'connected' proerty
+    assert(typeof resource.destroy === 'function');
+    assert('connected' in resource);
+
+    this.resources.set(name, resource);
+  },
+  getResource(name) {
+    return this.resources.get(name);
+  },
+  hasResource(name) {
+    return this.resources.has(name);
+  },
+  removeResource(name) {
+    this.logger.debug(`removeResource: removing ${name}`);
+    this.resources.delete(name);
+  },
+  async clearResource(name) {
+    const r = this.resources.get(name);
+    if (r) {
+      this.logger.debug(`clearResource deleting ${name}`);
+      try {
+        if (r.connected) r.destroy();
+      }
+      catch (err) {
+        this.logger.error(err, `clearResource error deleting ${name}`);
+      }
+      this.resources.delete(r);
+    }
+  },
+  async clearResources() {
+    for (const [name, resource] of Array.from(this.resources).reverse()) {
+      try {
+        this.logger.info(`deleting ${name}`);
+        if (resource.connected) await resource.destroy();
+      } catch (err) {
+        this.logger.error(err, `clearResources: error deleting ${name}`);
+      }
+    }
+    this.resources.clear();
+  }
+};