Improve tools for monitoring plugin

lib/workers/db-worker.js

@@ -797,6 +797,19 @@ COMMANDS.VALIDATE_LOGIN_BLOCK = function (data, cb) {
     Block.validateLoginBlock(Env, data.publicKey, data.signature, data.block, cb);
 };
 
+Object.keys(plugins || {}).forEach(name => {
+    let plugin = plugins[name];
+    if (!plugin.addWorkerCommands) { return; }
+    try {
+        let events = plugin.addWorkerCommands(Env);
+        Object.keys(events || {}).forEach(cmd => {
+            if (typeof(events[cmd]) !== "function") { return; }
+            if (COMMANDS[cmd]) { return; }
+            COMMANDS[cmd] = events[cmd];
+        });
+    } catch (e) {}
+});
+
 process.on('message', function (data) {
     if (!data || !data.txid || !data.pid) {
         return void process.send({
@@ -805,6 +818,13 @@ process.on('message', function (data) {
         });
     }
 
+    const command = COMMANDS[data.command];
+
+    // Command broadcasted to all workers: no callback expected
+    if (data.type === 'broadcast') {
+        return void command(data);
+    }
+
     const cb = function (err, value) {
         process.send({
             error: Util.serializeError(err),
@@ -822,7 +842,6 @@ process.on('message', function (data) {
         });
     }
 
-    const command = COMMANDS[data.command];
     if (typeof(command) !== 'function') {
         return void cb("E_BAD_COMMAND");
     }

lib/workers/index.js

@@ -315,6 +315,18 @@ Workers.initialize = function (Env, config, _cb) {
             }));
         });
     }).nThen(function () {
+        Env.broadcastWorkerCommand = (data) => {
+            workers.forEach(state => {
+                state.worker.send({
+                    type: 'broadcast',
+                    pid: PID,
+                    command: data.command,
+                    txid: data.txid
+                });
+            });
+            return workers;
+        };
+
         Env.computeIndex = function (Env, channel, cb) {
             Env.store.getWeakLock(channel, function (next) {
                 sendCommand({

server.js

@@ -185,6 +185,7 @@ nThen(function (w) {
         for (const worker of Object.values(Cluster.workers)) {
             sendCommand(worker, command, data /*, cb */);
         }
+        return Object.values(Cluster.workers);
     };
 
     var throttledEnvChange = Util.throttle(function () {