Defer tail declarations

declare() calls that aren't followed by commit() are applied at the end
of the provision script. This change defers those until all provisions
have been executed. This prevents certain cases of preset loop faults.

lib/session.js

@@ -588,6 +588,7 @@ function runProvisions(
 
         if ((counter -= 2) === 1) {
           allDeclarations = Array.prototype.concat.apply([], allDeclarations);
+          if (done) for (const d of allDeclarations) d.defer = false;
           allClear = Array.prototype.concat.apply([], allClear);
           callback(null, null, done, allDeclarations, allClear);
         }
@@ -597,6 +598,7 @@ function runProvisions(
 
   if ((counter -= 2) === 1) {
     allDeclarations = Array.prototype.concat.apply([], allDeclarations);
+    if (done) for (const d of allDeclarations) d.defer = false;
     allClear = Array.prototype.concat.apply([], allClear);
     callback(null, null, done, allDeclarations, allClear);
   }
@@ -720,6 +722,7 @@ function runVirtualParameters(
 
         if ((counter -= 2) === 1) {
           allDeclarations = Array.prototype.concat.apply([], allDeclarations);
+          if (done) for (const d of allDeclarations) d.defer = false;
           allClear = Array.prototype.concat.apply([], allClear);
           callback(
             null,
@@ -735,6 +738,7 @@ function runVirtualParameters(
 
   if ((counter -= 2) === 1) {
     allDeclarations = Array.prototype.concat.apply([], allDeclarations);
+    if (done) for (const d of allDeclarations) d.defer = false;
     allClear = Array.prototype.concat.apply([], allClear);
     callback(
       null,
@@ -787,10 +791,10 @@ function runDeclarations(sessionContext, declarations) {
     }
   }
 
-  function mergeAttributeValues(p, attrs) {
+  function mergeAttributeValues(p, attrs, defer) {
     let cur = allDeclareAttributeValues.get(p);
     if (!cur) {
-      allDeclareAttributeValues.set(p, attrs);
+      if (!defer) allDeclareAttributeValues.set(p, attrs);
     } else {
       cur = Object.assign({}, cur, attrs);
       allDeclareAttributeValues.set(p, cur);
@@ -798,7 +802,7 @@ function runDeclarations(sessionContext, declarations) {
   }
 
   for (const declaration of declarations) {
-    let path = common.addPathMeta(declaration[0]);
+    let path = common.addPathMeta(declaration.path);
     let unpacked;
 
     if ((path.alias | path.wildcard) & 1 || path[0] === "VirtualParameters") {
@@ -817,17 +821,20 @@ function runDeclarations(sessionContext, declarations) {
       sessionContext.deviceData.paths.add(["FactoryReset"]);
 
     if (path.alias) {
-      const aliasDecs = device.getAliasDeclarations(path, declaration[1] || 1);
+      const aliasDecs = device.getAliasDeclarations(
+        path,
+        declaration.pathGet || 1
+      );
       for (const ad of aliasDecs) {
-        const p = sessionContext.deviceData.paths.add(ad[0]);
+        const p = sessionContext.deviceData.paths.add(ad.path);
         allDeclareTimestamps.set(
           p,
-          Math.max(ad[1] || 1, allDeclareTimestamps.get(p) || 0)
+          Math.max(ad.pathGet || 1, allDeclareTimestamps.get(p) || 0)
         );
         let attrTrackers;
-        if (ad[2]) {
-          attrTrackers = Object.keys(ad[2]);
-          mergeAttributeTimestamps(p, ad[2]);
+        if (ad.attrGet) {
+          attrTrackers = Object.keys(ad.attrGet);
+          mergeAttributeTimestamps(p, ad.attrGet);
         }
 
         device.track(
@@ -842,38 +849,41 @@ function runDeclarations(sessionContext, declarations) {
       for (const u of unpacked) {
         allDeclareTimestamps.set(
           u,
-          Math.max(declaration[1] || 1, allDeclareTimestamps.get(u) || 0)
+          Math.max(declaration.pathGet || 1, allDeclareTimestamps.get(u) || 0)
         );
-        if (declaration[2]) mergeAttributeTimestamps(u, declaration[2]);
+        if (declaration.attrGet)
+          mergeAttributeTimestamps(u, declaration.attrGet);
       }
     } else {
       path = sessionContext.deviceData.paths.add(path);
       allDeclareTimestamps.set(
         path,
-        Math.max(declaration[1] || 1, allDeclareTimestamps.get(path) || 0)
+        Math.max(declaration.pathGet || 1, allDeclareTimestamps.get(path) || 0)
       );
-      if (declaration[2]) mergeAttributeTimestamps(path, declaration[2]);
+      if (declaration.attrGet)
+        mergeAttributeTimestamps(path, declaration.attrGet);
       device.track(sessionContext.deviceData, path, "prerequisite");
     }
 
-    if (declaration[4]) {
+    if (declaration.attrSet) {
       if (path.alias | path.wildcard) {
         if (!unpacked)
           unpacked = device.unpack(sessionContext.deviceData, path);
 
-        for (const u of unpacked) mergeAttributeValues(u, declaration[4]);
+        for (const u of unpacked)
+          mergeAttributeValues(u, declaration.attrSet, declaration.defer);
       } else {
-        mergeAttributeValues(path, declaration[4]);
+        mergeAttributeValues(path, declaration.attrSet, declaration.defer);
       }
     }
 
-    if (declaration[3] != null) {
+    if (declaration.pathSet != null) {
       let minInstances, maxInstances;
-      if (Array.isArray(declaration[3])) {
-        minInstances = declaration[3][0];
-        maxInstances = declaration[3][1];
+      if (Array.isArray(declaration.pathSet)) {
+        minInstances = declaration.pathSet[0];
+        maxInstances = declaration.pathSet[1];
       } else {
-        minInstances = maxInstances = declaration[3];
+        minInstances = maxInstances = declaration.pathSet;
       }
 
       let parent = common.addPathMeta(path.slice(0, -1));
@@ -903,7 +913,8 @@ function runDeclarations(sessionContext, declarations) {
           unpacked,
           keys,
           minInstances,
-          maxInstances
+          maxInstances,
+          declaration.defer
         );
       } else {
         const parentsUnpacked = device.unpack(
@@ -921,7 +932,8 @@ function runDeclarations(sessionContext, declarations) {
             ),
             keys,
             minInstances,
-            maxInstances
+            maxInstances,
+            declaration.defer
           );
         }
       }
@@ -1002,14 +1014,15 @@ function rpcRequest(sessionContext, _declarations, callback) {
 
         for (const d of decs) {
           // Enforce max timestamp
-          if (d[1] > sessionContext.timestamp) d[1] = sessionContext.timestamp;
-          for (const [k, v] of Object.entries(d[2])) {
+          if (d.pathGet > sessionContext.timestamp)
+            d.pathGet = sessionContext.timestamp;
+          for (const [k, v] of Object.entries(d.attrGet)) {
             if (v > sessionContext.timestamp)
-              d[2][k] = sessionContext.timestamp;
+              d.attrGet[k] = sessionContext.timestamp;
           }
 
-          for (const ad of device.getAliasDeclarations(d[0], 1))
-            loadPath(sessionContext, ad[0]);
+          for (const ad of device.getAliasDeclarations(d.path, 1))
+            loadPath(sessionContext, ad.path);
         }
 
         clear(sessionContext, toClear, err => {
@@ -1032,8 +1045,8 @@ function rpcRequest(sessionContext, _declarations, callback) {
     );
 
     for (const d of _declarations) {
-      for (const ad of device.getAliasDeclarations(d[0], 1))
-        loadPath(sessionContext, ad[0]);
+      for (const ad of device.getAliasDeclarations(d.path, 1))
+        loadPath(sessionContext, ad.path);
     }
 
     return void loadParameters(sessionContext, err => {
@@ -2115,7 +2128,8 @@ function processInstances(
   parameters,
   keys,
   minInstances,
-  maxInstances
+  maxInstances,
+  defer
 ) {
   let instancesToCreate, instancesToDelete;
   if (parent[0] === "Downloads") {
@@ -2136,6 +2150,9 @@ function processInstances(
     }
   }
 
+  if (defer && instancesToCreate.size === 0 && instancesToDelete.size === 0)
+    return;
+
   let counter = 0;
   for (const p of parameters) {
     ++counter;
@@ -2559,7 +2576,7 @@ function deserialize(sessionContextString, callback) {
       virtualParametersCache.set(sessionContext, virtualParameters);
 
       for (const decs of sessionContext.declarations)
-        for (const d of decs) common.addPathMeta(d[0]);
+        for (const d of decs) common.addPathMeta(d.path);
 
       const deviceData = initDeviceData();
       for (const r of sessionContext.deviceData) {