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.cc b/runtime/base/file_magic.cc
new file mode 100644
index 0000000..9756338
--- /dev/null
+++ b/runtime/base/file_magic.cc
@@ -0,0 +1,58 @@
+/*
+ * 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.
+ */
+
+#include "file_magic.h"
+
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include "base/logging.h"
+#include "dex_file.h"
+#include "stringprintf.h"
+
+namespace art {
+
+ScopedFd OpenAndReadMagic(const char* filename, uint32_t* magic, std::string* error_msg) {
+ CHECK(magic != nullptr);
+ ScopedFd fd(open(filename, O_RDONLY, 0));
+ if (fd.get() == -1) {
+ *error_msg = StringPrintf("Unable to open '%s' : %s", filename, strerror(errno));
+ return ScopedFd();
+ }
+ int n = TEMP_FAILURE_RETRY(read(fd.get(), magic, sizeof(*magic)));
+ if (n != sizeof(*magic)) {
+ *error_msg = StringPrintf("Failed to find magic in '%s'", filename);
+ return ScopedFd();
+ }
+ if (lseek(fd.get(), 0, SEEK_SET) != 0) {
+ *error_msg = StringPrintf("Failed to seek to beginning of file '%s' : %s", filename,
+ strerror(errno));
+ return ScopedFd();
+ }
+ return fd;
+}
+
+bool IsZipMagic(uint32_t magic) {
+ return (('P' == ((magic >> 0) & 0xff)) &&
+ ('K' == ((magic >> 8) & 0xff)));
+}
+
+bool IsDexMagic(uint32_t magic) {
+ return DexFile::IsMagicValid(reinterpret_cast<const uint8_t*>(&magic));
+}
+
+} // namespace art