Refresh cache before running WriteBundleRequest

..only if the packaging request didn't run in the main thread.
parcel-bundler · Jul 7, 2023 · 7f06109 · 7f06109
1 parent 206c6c3
commit 7f06109
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Showing 2 changed files with 12 additions and 10 deletions.
diff --git a/packages/core/core/src/requests/WriteBundleRequest.js b/packages/core/core/src/requests/WriteBundleRequest.js
@@ -129,16 +129,6 @@ async function run({input, options, api}) {
   if (info.isLargeBlob) {
     contentStream = options.cache.getStream(cacheKeys.content);
   } else {
-    // Force a refresh of the cache to avoid a race condition
-    // between threaded reads and writes that can result in an LMDB cache miss:
-    //   1. Thread A has read some value from cache, necessitating a read transaction.
-    //   2. Concurrently, Thread B finishes a packaging request.
-    //   3. Subsequently, Thread A is tasked with this request, but fails because the read transaction is stale.
-    // This only occurs if the reading thread has a transaction that was created before the writing thread committed,
-    // and the transaction is still live when the reading thread attempts to get the written value.
-    // See https://github.com/parcel-bundler/parcel/issues/9121
-    options.cache.refresh();
-
     contentStream = blobToStream(
       await options.cache.getBlob(cacheKeys.content),
     );

diff --git a/packages/core/core/src/requests/WriteBundlesRequest.js b/packages/core/core/src/requests/WriteBundlesRequest.js
@@ -101,6 +101,18 @@ async function run({input, api, farm, options}) {
 
         let info = await api.runRequest(request);
 
+        if (!useMainThread) {
+          // Force a refresh of the cache to avoid a race condition
+          // between threaded reads and writes that can result in an LMDB cache miss:
+          //   1. The main thread has read some value from cache, necessitating a read transaction.
+          //   2. Concurrently, Thread A finishes a packaging request.
+          //   3. Subsequently, the main thread is tasked with this request, but fails because the read transaction is stale.
+          // This only occurs if the reading thread has a transaction that was created before the writing thread committed,
+          // and the transaction is still live when the reading thread attempts to get the written value.
+          // See https://github.com/parcel-bundler/parcel/issues/9121
+          options.cache.refresh();
+        }
+
         bundleInfoMap[bundle.id] = info;
         if (!info.hashReferences.length) {
           hashRefToNameHash.set(