Minor huge pages library changes

[folly.git] / folly / experimental / io / FsUtil.h

diff --git a/folly/experimental/io/FsUtil.h b/folly/experimental/io/FsUtil.h
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+/*
+ * Copyright 2012 Facebook, Inc.
+ *
+ * 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 FOLLY_IO_FSUTIL_H_
+#define FOLLY_IO_FSUTIL_H_
+
+#include <boost/filesystem.hpp>
+
+namespace folly {
+namespace fs {
+
+// Functions defined in this file are meant to extend the
+// boost::filesystem library; functions will be named according to boost's
+// naming conventions instead of ours.  For convenience, import the
+// boost::filesystem namespace into folly::fs.
+using namespace ::boost::filesystem;
+
+/**
+ * Check whether "path" starts with "prefix".
+ * That is, if prefix has n path elements, then the first n elements of
+ * path must be the same as prefix.
+ *
+ * There is a special case if prefix ends with a slash:
+ * /foo/bar/ is not a prefix of /foo/bar, but both /foo/bar and /foo/bar/
+ * are prefixes of /foo/bar/baz.
+ */
+bool starts_with(const path& p, const path& prefix);
+
+/**
+ * If "path" starts with "prefix", return "path" with "prefix" removed.
+ * Otherwise, throw filesystem_error.
+ */
+path remove_prefix(const path& p, const path& prefix);
+
+/**
+ * Canonicalize the parent path, leaving the filename (last component)
+ * unchanged.  You may use this before creating a file instead of
+ * boost::filesystem::canonical, which requires that the entire path exists.
+ */
+path canonical_parent(const path& p, const path& basePath = current_path());
+
+}  // namespace fs
+}  // namespace folly
+
+#endif /* FOLLY_IO_FSUTIL_H_ */
+