VolumeVerifier: Add zip support for datfile

Source/Core/Common/MinizipUtil.h

@@ -0,0 +1,42 @@
+// Copyright 2019 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <algorithm>
+
+#include <minizip/unzip.h>
+
+#include "Common/CommonTypes.h"
+#include "Common/ScopeGuard.h"
+
+namespace Common
+{
+// Reads all of the current file. destination must be big enough to fit the whole file.
+template <typename ContiguousContainer>
+bool ReadFileFromZip(unzFile file, ContiguousContainer* destination)
+{
+  const u32 MAX_BUFFER_SIZE = 65535;
+
+  if (unzOpenCurrentFile(file) != UNZ_OK)
+    return false;
+
+  Common::ScopeGuard guard{[&] { unzCloseCurrentFile(file); }};
+
+  u32 bytes_to_go = static_cast<u32>(destination->size());
+  while (bytes_to_go > 0)
+  {
+    const int bytes_read =
+        unzReadCurrentFile(file, &(*destination)[destination->size() - bytes_to_go],
+                           std::min(bytes_to_go, MAX_BUFFER_SIZE));
+
+    if (bytes_read < 0)
+      return false;
+
+    bytes_to_go -= static_cast<u32>(bytes_read);
+  }
+
+  return true;
+}
+}  // namespace Common