1 files changed, 81 insertions, 0 deletions
diff --git a/xpcom/base/MemoryInfo.h b/xpcom/base/MemoryInfo.h
new file mode 100644
index 0000000000..d122f6d377
--- /dev/null
+++ b/xpcom/base/MemoryInfo.h
@@ -0,0 +1,81 @@
+/* -*- 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/. */
+
+#ifndef mozilla_MemoryInfo_h
+#define mozilla_MemoryInfo_h
+
+#include <cstddef>
+#include <cstdint>
+#include "mozilla/Attributes.h"
+#include "mozilla/EnumSet.h"
+/**
+ * MemoryInfo is a helper class which describes the attributes and sizes of a
+ * particular region of VM memory on Windows. It roughtly corresponds to the
+ * values in a MEMORY_BASIC_INFORMATION struct, summed over an entire region or
+ * memory.
+ */
+
+namespace mozilla {
+
+class MemoryInfo final {
+ public:
+  enum class Perm : uint8_t {
+    Read,
+    Write,
+    Execute,
+    CopyOnWrite,
+    Guard,
+    NoCache,
+    WriteCombine,
+  };
+  enum class PageType : uint8_t {
+    Image,
+    Mapped,
+    Private,
+  };
+
+  using PermSet = EnumSet<Perm>;
+  using PageTypeSet = EnumSet<PageType>;
+
+  MemoryInfo() = default;
+  MOZ_IMPLICIT MemoryInfo(const MemoryInfo&) = default;
+
+  uintptr_t Start() const { return mStart; }
+  uintptr_t End() const { return mEnd; }
+
+  PageTypeSet Type() const { return mType; }
+  PermSet Perms() const { return mPerms; }
+
+  size_t Reserved() const { return mReserved; }
+  size_t Committed() const { return mCommitted; }
+  size_t Free() const { return mFree; }
+  size_t Size() const { return mSize; }
+
+  // Returns a MemoryInfo object containing the sums of all region sizes,
+  // divided into Reserved, Committed, and Free, depending on their State
+  // properties.
+  //
+  // The entire range of aSize bytes starting at aPtr must correspond to a
+  // single allocation. This restriction is enforced in debug builds.
+  static MemoryInfo Get(const void* aPtr, size_t aSize);
+
+ private:
+  uintptr_t mStart = 0;
+  uintptr_t mEnd = 0;
+
+  size_t mReserved = 0;
+  size_t mCommitted = 0;
+  size_t mFree = 0;
+  size_t mSize = 0;
+
+  PageTypeSet mType{};
+
+  PermSet mPerms{};
+};
+
+}  // namespace mozilla
+
+#endif  // mozilla_MemoryInfo_h