Fix file filter bug:

There're many 'invalid/unused' members inside a group, so use  all group members count to do cid % operation will filter most files out.
Also it will increase the probability during the probabilityFilter.
So enhance the code to filter out invalid group members

src/tasks/group-info-updater-task.ts

@@ -3,6 +3,9 @@ import { AppContext } from '../types/context';
 import { SimpleTask } from '../types/tasks';
 import { formatError } from '../utils';
 import { makeIntervalTask } from './task-utils';
+import { Identity } from '../chain';
+import { ValidNodeAnchors } from './node-info-updater-task';
+import _ from 'lodash';
 
 async function handleUpdate(context: AppContext, logger: Logger) {
   const { api } = context;
@@ -26,11 +29,35 @@ async function handleUpdate(context: AppContext, logger: Logger) {
 
     // Get group members
     const members = await api.groupMembers(groupOwner);
-    members.sort();
-    const nodeIndex = members.indexOf(api.getChainAccount());
+
+    /// Filter valid members
+    // First get swork.Identities of the members
+    const queries = [];
+    for (const member of members) {
+      const query = [api.chainApi().query.swork.identities, member];
+      queries.push(query);
+    }
+    const identities = await api.chainApi().queryMulti(queries);
+
+    // Perform the filter
+    const validMembers = [];
+    for (let i = 0; i < members.length; i++) {
+      const member = members[i];
+      const idCodec = identities[i];
+      if (!_.isNil(idCodec) && !idCodec.isEmpty) {
+        const id = idCodec.toJSON() as Identity;
+        const anchor = id.anchor;
+        if (ValidNodeAnchors.has(anchor)) {
+          validMembers.push(member);
+        }
+      }
+    }
+
+    validMembers.sort();
+    const nodeIndex = validMembers.indexOf(api.getChainAccount());
     context.groupInfo = {
       groupAccount: groupOwner,
-      totalMembers: members.length,
+      totalMembers: validMembers.length,
       nodeIndex,
     };
   } catch (e) {

src/tasks/node-info-updater-task.ts

@@ -12,11 +12,14 @@ import { makeIntervalTask } from './task-utils';
 const WorkReportKey =
   '0x2e3b7ab5757e6bbf28d3df3b5e01d6b9b7e949778e4650a54fcc65ad1f1ba39f';
 
+export const ValidNodeAnchors = new Set();
+
 async function handleUpdate(context: AppContext, logger: Logger) {
   const { api } = context;
   try {
     let lastKey = null;
     let totalCount = 0;
+    let tempValidNodeAnchors = new Set();
     // eslint-disable-next-line
     while (true) {
       const keys = await (lastKey
@@ -30,21 +33,33 @@ async function handleUpdate(context: AppContext, logger: Logger) {
         .map(extractReportAnchorFromKey)
         .filter()
         .value();
-      const workReports = await Bluebird.mapSeries(validKeys, async (k) => {
-        // logger.info('loading workreport for key: %s', k);
-        return api.chainApi().query.swork.workReports(k);
-      });
-      const validReports = _.filter(workReports, (r) => {
-        if (!r) {
-          return false;
-        }
-        const report = r.toJSON() as any; // eslint-disable-line
-        if (!report) {
-          logger.error('invalid workreport loaded');
-          return false;
+
+      // Get work reports from chain in multi mode
+      const queries = [];
+      for (const anchor of validKeys) {
+        const query = [api.chainApi().query.swork.workReports, anchor];
+        queries.push(query);
+      }
+      const workReports = await api.chainApi().queryMulti(queries);
+
+      // Filter out valid reports
+      const validReports = [];
+      for (let i = 0; i < validKeys.length; i++) {
+        const anchor = validKeys[i];
+        const reportCodec = workReports[i];
+        if (!_.isNil(reportCodec) && !reportCodec.isEmpty) {
+          const report = reportCodec.toJSON() as any;
+          if (!_.isNil(report)) {
+            if (report.report_slot >= currentSlot - SLOT_LENGTH) {
+              validReports.push(report);
+              tempValidNodeAnchors.add(anchor);
+            }
+          } else {
+            logger.error('invalid workreport loaded');
+          }
         }
-        return report.report_slot >= currentSlot - SLOT_LENGTH;
-      });
+      }
+
       logger.info('load %d valid work reports', _.size(validReports));
       totalCount += _.size(validReports);
       // wait for a short while to reduce system load
@@ -59,6 +74,9 @@ async function handleUpdate(context: AppContext, logger: Logger) {
     context.nodeInfo = {
       nodeCount: totalCount,
     };
+    // Update the global ValidNodeAnchors data which will be used by group-info-updater-task
+    ValidNodeAnchors.clear();
+    tempValidNodeAnchors.forEach(anchor => ValidNodeAnchors.add(anchor));
   } catch (e) {
     logger.error('failed updating node info: %s', formatError(e));
   }