Bug 1671369 - Change GetBodyUsage to return a Result. r=dom-workers-and-storage-reviewers,ttung

Differential Revision: https://phabricator.services.mozilla.com/D93769

dom/cache/QuotaClient.cpp

@@ -34,85 +34,82 @@ using mozilla::ipc::AssertIsOnBackgroundThread;
 
 namespace {
 
-nsresult GetBodyUsage(nsIFile* aMorgueDir, const Atomic<bool>& aCanceled,
-                      UsageInfo* aUsageInfo, const bool aInitializing) {
+Result<UsageInfo, nsresult> GetBodyUsage(nsIFile& aMorgueDir,
+                                         const Atomic<bool>& aCanceled,
+                                         const bool aInitializing) {
   AssertIsOnIOThread();
 
-  nsCOMPtr<nsIDirectoryEnumerator> entries;
-  nsresult rv = aMorgueDir->GetDirectoryEntries(getter_AddRefs(entries));
-  if (NS_WARN_IF(NS_FAILED(rv))) {
-    return rv;
+  UsageInfo usageInfo;
+
+  // XXX The following loop (including the cancellation check) is very similar
+  // to QuotaClient::GetDatabaseFilenames in dom/indexedDB/ActorsParent.cpp
+  // (Also, it is a fallible variant of std::reduce)
+  CACHE_TRY_INSPECT(const auto& entries, MOZ_TO_RESULT_INVOKE_TYPED(
+                                             nsCOMPtr<nsIDirectoryEnumerator>,
+                                             aMorgueDir, GetDirectoryEntries));
+
+  CACHE_TRY(CollectEach(
+      [&entries, &aCanceled]() -> Result<nsCOMPtr<nsIFile>, nsresult> {
+        if (aCanceled) {
+          return nsCOMPtr<nsIFile>{};
         }
 
-  nsCOMPtr<nsIFile> bodyDir;
-  while (NS_SUCCEEDED(rv = entries->GetNextFile(getter_AddRefs(bodyDir))) &&
-         bodyDir && !aCanceled) {
-    if (NS_WARN_IF(QuotaManager::IsShuttingDown())) {
-      return NS_ERROR_ABORT;
-    }
-    bool isDir;
-    rv = bodyDir->IsDirectory(&isDir);
-    if (NS_WARN_IF(NS_FAILED(rv))) {
-      return rv;
-    }
+        CACHE_TRY_RETURN(MOZ_TO_RESULT_INVOKE_TYPED(nsCOMPtr<nsIFile>, entries,
+                                                    GetNextFile));
+      },
+      [&usageInfo, aInitializing](
+          const nsCOMPtr<nsIFile>& bodyDir) -> Result<Ok, nsresult> {
+        CACHE_TRY(OkIf(!QuotaManager::IsShuttingDown()), Err(NS_ERROR_ABORT));
+
+        CACHE_TRY_INSPECT(const bool& isDir,
+                          MOZ_TO_RESULT_INVOKE(bodyDir, IsDirectory));
 
         if (!isDir) {
-      QuotaInfo dummy;
-      DebugOnly<nsresult> result =
-          RemoveNsIFile(dummy, bodyDir, /* aTrackQuota */ false);
-      // Try to remove the unexpected files, and keep moving on even if it fails
-      // because it might be created by virus or the operation system
+          const DebugOnly<nsresult> result =
+              RemoveNsIFile(QuotaInfo{}, bodyDir, /* aTrackQuota */ false);
+          // Try to remove the unexpected files, and keep moving on even if it
+          // fails because it might be created by virus or the operation system
           MOZ_ASSERT(NS_SUCCEEDED(result));
-      continue;
+          return Ok{};
         }
 
-    const QuotaInfo dummy;
-    const auto getUsage = [&aUsageInfo](nsIFile* bodyFile,
+        const auto getUsage = [&usageInfo](nsIFile* bodyFile,
                                            const nsACString& leafName,
-                                        bool& fileDeleted) {
+                                           bool& fileDeleted) -> nsresult {
           MOZ_DIAGNOSTIC_ASSERT(bodyFile);
           Unused << leafName;
 
-      int64_t fileSize;
-      nsresult rv = bodyFile->GetFileSize(&fileSize);
-      if (NS_WARN_IF(NS_FAILED(rv))) {
-        return rv;
-      }
+          CACHE_TRY_INSPECT(const int64_t& fileSize,
+                            MOZ_TO_RESULT_INVOKE(bodyFile, GetFileSize));
           MOZ_DIAGNOSTIC_ASSERT(fileSize >= 0);
-      // FIXME: Separate file usage and database usage in OriginInfo so that the
-      // workaround for treating body file size as database usage can be
+          // FIXME: Separate file usage and database usage in OriginInfo so that
+          // the workaround for treating body file size as database usage can be
           // removed.
           //
           // This is needed because we want to remove the mutex lock for padding
-      // files. The lock is needed because the padding file is accessed on the
-      // QM IO thread while getting origin usage and is accessed on the Cache IO
-      // thread in normal Cache operations.
-      // Using the cached usage in QM while getting origin usage can remove the
-      // access on the QM IO thread and thus we can remove the mutex lock.
-      // However, QM only separates usage types in initialization, and the
-      // separation is gone after that. So, before extending the separation of
-      // usage types in QM, this is a workaround to avoid the file usage
-      // mismatching in our tests. Note that file usage hasn't been exposed to
-      // users yet.
-      *aUsageInfo += DatabaseUsageType(Some(fileSize));
+          // files. The lock is needed because the padding file is accessed on
+          // the QM IO thread while getting origin usage and is accessed on the
+          // Cache IO thread in normal Cache operations. Using the cached usage
+          // in QM while getting origin usage can remove the access on the QM IO
+          // thread and thus we can remove the mutex lock. However, QM only
+          // separates usage types in initialization, and the separation is gone
+          // after that. So, before extending the separation of usage types in
+          // QM, this is a workaround to avoid the file usage mismatching in our
+          // tests. Note that file usage hasn't been exposed to users yet.
+          usageInfo += DatabaseUsageType(Some(fileSize));
 
           fileDeleted = false;
 
           return NS_OK;
         };
-    rv = BodyTraverseFiles(dummy, bodyDir, getUsage,
+        CACHE_TRY(BodyTraverseFiles(QuotaInfo{}, bodyDir, getUsage,
                                     /* aCanRemoveFiles */
                                     aInitializing,
-                           /* aTrackQuota */ false);
-    if (NS_WARN_IF(NS_FAILED(rv))) {
-      return rv;
-    }
-  }
-  if (NS_WARN_IF(NS_FAILED(rv))) {
-    return rv;
-  }
+                                    /* aTrackQuota */ false));
+        return Ok{};
+      }));
 
-  return NS_OK;
+  return usageInfo;
 }
 
 Result<int64_t, nsresult> LockedGetPaddingSizeFromDB(
@@ -399,6 +396,7 @@ Result<UsageInfo, nsresult> CacheQuotaClient::GetUsageForOriginInternal(
 
   // XXX The following loop (including the cancellation check) is very similar
   // to QuotaClient::GetDatabaseFilenames in dom/indexedDB/ActorsParent.cpp
+  // (Also, it is a fallible variant of std::reduce)
   CACHE_TRY_INSPECT(const auto& entries,
                     MOZ_TO_RESULT_INVOKE_TYPED(nsCOMPtr<nsIDirectoryEnumerator>,
                                                dir, GetDirectoryEntries));
@@ -427,7 +425,9 @@ Result<UsageInfo, nsresult> CacheQuotaClient::GetUsageForOriginInternal(
           if (leafName.EqualsLiteral("morgue")) {
             // XXX This didn't use to warn for NS_ERROR_ABORT, should we keep
             // that? (but it was and is propagated)
-            CACHE_TRY(GetBodyUsage(file, aCanceled, &usageInfo, aInitializing));
+            CACHE_TRY_INSPECT(const auto& bodyUsageInfo,
+                              GetBodyUsage(*file, aCanceled, aInitializing));
+            usageInfo += bodyUsageInfo;
           } else {
             NS_WARNING("Unknown Cache directory found!");
           }