AK: Add a Stream wrapper that counts read bytes

1 files changed, 32 insertions, 0 deletions

diff --git a/AK/CountingStream.h b/AK/CountingStream.h
new file mode 100644
index 0000000000..3afd1f4b48
--- /dev/null
+++ b/AK/CountingStream.h
@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2023, Tim Schumacher <timschumi@gmx.de>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/MaybeOwned.h>
+#include <AK/Stream.h>
+
+namespace AK {
+
+class CountingStream : public Stream {
+public:
+    CountingStream(MaybeOwned<Stream>);
+
+    u64 read_bytes() const;
+
+    virtual ErrorOr<Bytes> read_some(Bytes) override;
+    virtual ErrorOr<void> discard(size_t discarded_bytes) override;
+    virtual ErrorOr<size_t> write_some(ReadonlyBytes) override;
+    virtual bool is_eof() const override;
+    virtual bool is_open() const override;
+    virtual void close() override;
+
+private:
+    MaybeOwned<Stream> m_stream;
+    u64 m_read_bytes { 0 };
+};
+
+}