Replace object with Map for performance

lib/session.js

@@ -1817,7 +1817,7 @@ function processDeclarations(
 
   function func(leafParam, leafIsObject, leafTimestamp, _paths) {
     const currentPath = _paths[0];
-    const children = {};
+    const children = new Map();
     let declareTimestamp = 0;
     let declareAttributeTimestamps;
     let declareAttributeValues;
@@ -1830,15 +1830,18 @@ function processDeclarations(
     for (const path of _paths) {
       if (path.length > currentPath.length) {
         const fragment = path[currentPath.length];
-        if (!children[fragment]) {
-          children[fragment] = [];
+        let child = children.get(fragment);
+        if (!child) {
           if (path.length > currentPath.length + 1) {
             // This is to ensure we don't descend more than one step at a time
             const p = common.addPathMeta(path.slice(0, currentPath.length + 1));
-            children[fragment].push(p);
+            child = [p];
+          } else {
+            child = [];
           }
+          children.set(fragment, child);
         }
-        children[fragment].push(path);
+        child.push(path);
         continue;
       }
 
@@ -2041,18 +2044,19 @@ function processDeclarations(
         }
     }
 
-    for (const child of Object.keys(children)) {
+    for (let [fragment, child] of children) {
       // This fine expression avoids duplicate visits, don't ask.
       if (
-        ((currentPath.wildcard ^ children[child][0].wildcard) &
+        ((currentPath.wildcard ^ child[0].wildcard) &
           ((1 << currentPath.length) - 1)) >>
           leafParam.length ===
         0
       ) {
-        if (child !== "*" && children["*"])
-          children[child] = children[child].concat(children["*"]);
-
-        func(leafParam, leafIsObject, leafTimestamp, children[child]);
+        if (fragment !== "*") {
+          const wildcardChild = children.get("*");
+          if (wildcardChild) child = child.concat(wildcardChild);
+        }
+        func(leafParam, leafIsObject, leafTimestamp, child);
       }
     }
   }