improve error handling with rpc response API

lib/hk-util.js

@@ -772,7 +772,9 @@ HK.initializeIndexWorkers = function (Env, config, _cb) {
 
     const workers = [];
 
-    const response = Util.response();
+    const response = Util.response(function (errLabel, info) {
+        Env.Log.error('HK_DB_WORKER__' + errLabel, info);
+    });
     const initWorker = function (worker, cb) {
         //console.log("initializing index worker");
         const txid = Util.uid();
@@ -798,14 +800,7 @@ HK.initializeIndexWorkers = function (Env, config, _cb) {
                 return;
             }
             //console.log(res);
-            try {
-                response.handle(res.txid, [res.error, res.value]);
-            } catch (err) {
-                Env.Log.error("INDEX_WORKER", {
-                    error: err,
-                    response: res,
-                });
-            }
+            response.handle(res.txid, [res.error, res.value]);
         });
         worker.on('exit', function () {
             var idx = workers.indexOf(worker);
@@ -945,7 +940,9 @@ HK.initializeValidationWorkers = function (Env) {
         workers.push(fork('lib/workers/check-signature.js'));
     }
 
-    const response = Util.response();
+    const response = Util.response(function (errLabel, info) {
+        Env.Log.error('HK_VALIDATE_WORKER__' + errLabel, info);
+    });
 
     var initWorker = function (worker) {
         worker.on('message', function (res) {

www/common/common-util.js

@@ -81,10 +81,16 @@
         });
     };
 
-    Util.response = function () {
+    Util.response = function (errorHandler) {
         var pending = {};
         var timeouts = {};
 
+        if (typeof(errorHandler) !== 'function') {
+            errorHandler = function (label) {
+                throw new Error(label);
+            };
+        }
+
         var clear = function (id) {
             clearTimeout(timeouts[id]);
             delete timeouts[id];
@@ -92,8 +98,8 @@
         };
 
         var expect = function (id, fn, ms) {
-            if (typeof(id) !== 'string') { throw new Error("EXPECTED_STRING"); }
-            if (typeof(fn) !== 'function') { throw new Error("EXPECTED_CALLBACK"); }
+            if (typeof(id) !== 'string') { errorHandler('EXPECTED_STRING'); }
+            if (typeof(fn) !== 'function') { errorHandler('EXPECTED_CALLBACK'); }
             pending[id] = fn;
             if (typeof(ms) === 'number' && ms) {
                 timeouts[id] = setTimeout(function () {
@@ -105,8 +111,21 @@
 
         var handle = function (id, args) {
             var fn = pending[id];
-            if (typeof(fn) !== 'function') { throw new Error("MISSING_CALLBACK"); }
-            pending[id].apply(null, Array.isArray(args)? args : [args]);
+            if (typeof(fn) !== 'function') {
+                errorHandler("MISSING_CALLBACK", {
+                    id: id,
+                    args: args,
+                });
+            }
+            try {
+                pending[id].apply(null, Array.isArray(args)? args : [args]);
+            } catch (err) {
+                errorHandler('HANDLER_ERROR', {
+                    error: err,
+                    id: id,
+                    args: args,
+                });
+            }
             clear(id);
         };