1 files changed, 40 insertions, 0 deletions
diff --git a/dom/indexedDB/IndexedDBCommon.cpp b/dom/indexedDB/IndexedDBCommon.cpp
new file mode 100644
index 0000000000..63a6fd2fb6
--- /dev/null
+++ b/dom/indexedDB/IndexedDBCommon.cpp
@@ -0,0 +1,40 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "IndexedDBCommon.h"
+
+#include "js/StructuredClone.h"
+#include "mozilla/SnappyUncompressInputStream.h"
+
+namespace mozilla::dom::indexedDB {
+
+// aStructuredCloneData is a parameter rather than a return value because one
+// caller preallocates it on the heap not immediately before calling for some
+// reason. Maybe this could be changed.
+nsresult SnappyUncompressStructuredCloneData(
+    nsIInputStream& aInputStream, JSStructuredCloneData& aStructuredCloneData) {
+  const auto snappyInputStream =
+      MakeRefPtr<SnappyUncompressInputStream>(&aInputStream);
+
+  char buffer[kFileCopyBufferSize];
+
+  QM_TRY(CollectEach(
+      [&snappyInputStream = *snappyInputStream, &buffer] {
+        QM_TRY_RETURN(MOZ_TO_RESULT_INVOKE_MEMBER(snappyInputStream, Read,
+                                                  buffer, sizeof(buffer)));
+      },
+      [&aStructuredCloneData,
+       &buffer](const uint32_t& numRead) -> Result<Ok, nsresult> {
+        QM_TRY(OkIf(aStructuredCloneData.AppendBytes(buffer, numRead)),
+               Err(NS_ERROR_OUT_OF_MEMORY));
+
+        return Ok{};
+      }));
+
+  return NS_OK;
+}
+
+}  // namespace mozilla::dom::indexedDB