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-rw-r--r--dom/ipc/MemMapSnapshot.cpp45
1 files changed, 45 insertions, 0 deletions
diff --git a/dom/ipc/MemMapSnapshot.cpp b/dom/ipc/MemMapSnapshot.cpp
new file mode 100644
index 0000000000..53accfdb1b
--- /dev/null
+++ b/dom/ipc/MemMapSnapshot.cpp
@@ -0,0 +1,45 @@
+/* -*- 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 "MemMapSnapshot.h"
+
+#include "mozilla/AutoMemMap.h"
+#include "mozilla/ResultExtensions.h"
+#include "mozilla/Try.h"
+#include "mozilla/ipc/FileDescriptor.h"
+
+namespace mozilla::ipc {
+
+Result<Ok, nsresult> MemMapSnapshot::Init(size_t aSize) {
+ MOZ_ASSERT(!mInitialized);
+
+ if (NS_WARN_IF(!mMem.CreateFreezeable(aSize))) {
+ return Err(NS_ERROR_FAILURE);
+ }
+ if (NS_WARN_IF(!mMem.Map(aSize))) {
+ return Err(NS_ERROR_FAILURE);
+ }
+
+ mInitialized = true;
+ return Ok();
+}
+
+Result<Ok, nsresult> MemMapSnapshot::Finalize(loader::AutoMemMap& aMem) {
+ MOZ_ASSERT(mInitialized);
+
+ if (NS_WARN_IF(!mMem.Freeze())) {
+ return Err(NS_ERROR_FAILURE);
+ }
+ // TakeHandle resets mMem, so call max_size first.
+ size_t size = mMem.max_size();
+ FileDescriptor memHandle(mMem.TakeHandle());
+ MOZ_TRY(aMem.initWithHandle(memHandle, size));
+
+ mInitialized = false;
+ return Ok();
+}
+
+} // namespace mozilla::ipc