Revert "Write .meteor-portable-2.json files synchronously."

Ben Newman · Ben Newman · commit 07afae119d78 · 2018-01-19T18:57:44.000-05:00
This reverts commit 4e4e204.
diff --git a/tools/isobuild/meteor-npm.js b/tools/isobuild/meteor-npm.js
@@ -528,20 +528,21 @@ const isPortable = Profile("meteorNpm.isPortable", dir => {
         isPortable(files.pathJoin(dir, itemName)));
 
   if (canCache) {
-    try {
-      files.writeFile(
-        portableFile,
-        JSON.stringify(result) + "\n",
-        "utf8"
-      );
-    } catch (ignored) {
-      // Don't worry if the write fails, e.g. because the file system is
-      // read-only (#6591). Failing to write the file only means more work
-      // next time.
-    }
+    // Write the .meteor-portable file asynchronously, and don't worry
+    // if it fails, e.g. because the file system is read-only (#6591).
+    // Failing to write the file only means more work next time.
+    fs.writeFile(
+      portableFile,
+      JSON.stringify(result) + "\n",
+      error => {
+        // Once the asynchronous write finishes (successful or not), we no
+        // longer need to cache the written value in memory.
+        delete portableCache[portableFile];
+      },
+    );
 
-    // Cache the result immediately in memory so we don't have to wait for
-    // file change notifications to invalidate optimisticReadJsonOrNull.
+    // Cache the result immediately in memory so that the asynchronous
+    // write won't confuse synchronous optimisticReadJsonOrNull calls.
     portableCache[portableFile] = result;
   }
 
