Remove caching of tasks, faults and operations

No longer seems to provide significant performance benefit to justify the
drawback of the added code complexity and the additional DB write query.

lib/cwmp.ts

@@ -53,10 +53,8 @@ import {
   SessionContext,
   AcsRequest,
   SessionFault,
-  Operation,
   Fault,
   Expression,
-  Task,
   SoapMessage,
   InformRequest,
   Preset,
@@ -768,8 +766,6 @@ async function nextRpc(sessionContext: SessionContext): Promise<void> {
 }
 
 async function endSession(sessionContext: SessionContext): Promise<void> {
-  let saveCache = sessionContext.cacheUntil != null;
-
   if (sessionContext.provisions.length) {
     const fault = {
       code: "session_terminated",
@@ -794,7 +790,6 @@ async function endSession(sessionContext: SessionContext): Promise<void> {
 
   if (sessionContext.operationsTouched) {
     for (const k of Object.keys(sessionContext.operationsTouched)) {
-      saveCache = true;
       if (sessionContext.operations[k]) {
         promises.push(
           saveOperation(
@@ -810,7 +805,6 @@ async function endSession(sessionContext: SessionContext): Promise<void> {
   }
 
   if (sessionContext.doneTasks?.length) {
-    saveCache = true;
     promises.push(
       clearTasks(sessionContext.deviceId, sessionContext.doneTasks)
     );
@@ -818,7 +812,6 @@ async function endSession(sessionContext: SessionContext): Promise<void> {
 
   if (sessionContext.faultsTouched) {
     for (const k of Object.keys(sessionContext.faultsTouched)) {
-      saveCache = true;
       if (sessionContext.faults[k]) {
         sessionContext.faults[k].retries = sessionContext.retries[k];
         promises.push(
@@ -830,18 +823,6 @@ async function endSession(sessionContext: SessionContext): Promise<void> {
     }
   }
 
-  if (saveCache) {
-    promises.push(
-      cacheDueTasksAndFaultsAndOperations(
-        sessionContext.deviceId,
-        sessionContext.tasks,
-        sessionContext.faults,
-        sessionContext.operations,
-        sessionContext.cacheUntil
-      )
-    );
-  }
-
   await Promise.all(promises);
   await lock.releaseLock(
     `cwmp_session_${sessionContext.deviceId}`,
@@ -987,66 +968,6 @@ setInterval(() => {
   stats.initiatedSessions = 0;
 }, 10000).unref();
 
-async function getDueTasksAndFaultsAndOperations(
-  deviceId,
-  timestamp
-): Promise<{
-  tasks: Task[];
-  faults: { [channel: string]: SessionFault };
-  operations: { [commandKey: string]: Operation };
-  ttl: number;
-}> {
-  const res = await cache.get(`${deviceId}_tasks_faults_operations`);
-  if (res) {
-    const resParsed = JSON.parse(res);
-    return {
-      tasks: resParsed.tasks || [],
-      faults: resParsed.faults || {},
-      operations: resParsed.operations || {},
-      ttl: 0,
-    };
-  }
-
-  const res2 = await Promise.all([
-    getDueTasks(deviceId, timestamp),
-    getFaults(deviceId),
-    getOperations(deviceId),
-  ]);
-  return {
-    tasks: res2[0][0],
-    faults: res2[1],
-    operations: res2[2],
-    ttl: res2[0][1] || 0,
-  };
-}
-
-async function cacheDueTasksAndFaultsAndOperations(
-  deviceId,
-  tasks,
-  faults,
-  operations,
-  cacheUntil
-): Promise<void> {
-  const v = {
-    tasks: null,
-    faults: null,
-    operations: null,
-  };
-  if (tasks.length) v.tasks = tasks;
-  if (Object.keys(faults).length) v.faults = faults;
-  if (Object.keys(operations).length) v.operations = operations;
-
-  let ttl;
-  if (cacheUntil) ttl = Math.trunc((Date.now() - cacheUntil) / 1000);
-  else ttl = config.get("MAX_CACHE_TTL", deviceId);
-
-  await cache.set(
-    `${deviceId}_tasks_faults_operations`,
-    JSON.stringify(v),
-    ttl
-  );
-}
-
 async function reportBadState(sessionContext: SessionContext): Promise<void> {
   logger.accessError({
     message: "Bad session state",
@@ -1640,19 +1561,14 @@ async function listenerAsync(
   _sessionContext.httpResponse = httpResponse;
   _sessionContext.sessionId = crypto.randomBytes(8).toString("hex");
 
-  const {
-    tasks: dueTasks,
-    faults,
-    operations,
-    ttl: cacheUntil,
-  } = await getDueTasksAndFaultsAndOperations(
-    deviceId,
-    _sessionContext.timestamp
-  );
+  const [dueTasks, faults, operations] = await Promise.all([
+    getDueTasks(deviceId, _sessionContext.timestamp),
+    getFaults(deviceId),
+    getOperations(deviceId),
+  ]);
 
-  _sessionContext.tasks = dueTasks;
+  _sessionContext.tasks = dueTasks[0];
   _sessionContext.operations = operations;
-  _sessionContext.cacheUntil = cacheUntil;
   _sessionContext.faults = faults;
   _sessionContext.retries = {};
   for (const [k, v] of Object.entries(_sessionContext.faults)) {