ART: Add FdFile::Copy() to copy data from another file.
Also move utilities for inspecting file magic numbers to
base/file_magic.{h,cc} and drop the unused IsOatMagic().
Change-Id: I2cc4dd18a5e8b9738fb386c8057faad3722bdd68
diff --git a/runtime/base/file_magic.h b/runtime/base/file_magic.h
new file mode 100644
index 0000000..f7e4bad
--- /dev/null
+++ b/runtime/base/file_magic.h
@@ -0,0 +1,36 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ART_RUNTIME_BASE_FILE_MAGIC_H_
+#define ART_RUNTIME_BASE_FILE_MAGIC_H_
+
+#include <stdint.h>
+#include <string>
+
+#include "ScopedFd.h"
+
+namespace art {
+
+// Open file and read magic number
+ScopedFd OpenAndReadMagic(const char* filename, uint32_t* magic, std::string* error_msg);
+
+// Check whether the given magic matches a known file type.
+bool IsZipMagic(uint32_t magic);
+bool IsDexMagic(uint32_t magic);
+
+} // namespace art
+
+#endif // ART_RUNTIME_BASE_FILE_MAGIC_H_