the begginning

utils/idbdatafile/IDBFileSystem.h

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+/* Copyright (C) 2014 InfiniDB, Inc.
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License
+   as published by the Free Software Foundation; version 2 of
+   the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+   MA 02110-1301, USA. */
+
+#ifndef IDBFILESYSTEM_H_
+#define IDBFILESYSTEM_H_
+
+#include <sys/types.h>
+#include <list>
+#include "IDBDataFile.h"
+#include "IDBFactory.h"
+
+namespace idbdatafile
+{
+
+/**
+ * IDBFileSystem is a combination abstract base class and factory. The
+ * purpose is to encapsulate access to various file system functions
+ * across different file system types including hdfs.
+ */
+class IDBFileSystem
+{
+public:
+	/**
+	 * The TYPE enum defines the supported underlying filesystem types
+	 */
+	enum Types
+	{
+		UNKNOWN = 0x00,
+		POSIX = 0x0001,
+		HDFS  = 0x0002
+	};
+
+	/**
+	 * Destructor
+	 */
+	virtual ~IDBFileSystem();
+
+	/**
+	 * getFs() returns a reference to the IDBFileSystem instance for the
+	 * specified type
+	 */
+	static IDBFileSystem& getFs(IDBDataFile::Types type);
+
+	/**
+	 * mkdir() creates a directory specified by pathname including any
+	 * parent directories if needed.
+	 * Returns 0 on success, -1 on error
+	 */
+	virtual int mkdir(const char *pathname) = 0;
+
+	/**
+	 * remove() removes a path from the filesystem.  It will handle
+	 * both files and directories (including non-empty directories).  Note
+	 * that a call to remove of a path that does not exist will return as
+	 * success.
+	 *
+	 * Returns 0 on success, -1 on error
+	 */
+	virtual int remove(const char *pathname) = 0;
+
+	/**
+	 * rename() names a file, moving it between directories if required.
+	 * Returns 0 on success, -1 on error
+	 */
+	virtual int rename(const char *oldpath, const char *newpath) = 0;
+
+	/**
+	 * size() returns the size of the file specified by path.
+	 * Returns the size on success, -1 on error
+	 */
+	virtual off64_t size(const char* path) const = 0;
+
+	/**
+	 * exists() checks for the existence of a particular path.
+	 * Returns true if exists, false otherwise.
+	 */
+	virtual bool exists(const char* pathname) const = 0;
+
+	/**
+	 * listDirectory() returns the contents of the directory as a
+	 * list of strings.  For now, no indication of whether each
+	 * item is a file or directory - both files and subdirectories
+	 * will be returned.
+	 * Returns 0 on success.  -1 on error (incl if directory does
+	 * not exist.
+	 */
+
+	virtual int listDirectory(const char* pathname, std::list<std::string>& contents) const = 0;
+
+	/**
+	 * isDir() returns whether or not the path is a directory
+	 */
+	virtual bool isDir(const char* pathname) const = 0;
+
+	/**
+	 * copyfile() copies the source file to the destination file
+	 * Returns 0 on success.  -1 on error.
+	 */
+	virtual int copyFile(const char* srcPath, const char* destPath) const = 0;
+
+	/**
+	 * isFsUp() checks if the filesystem is up
+	 * Returns 0 on success.  -1 on error.
+	 */
+	virtual bool filesystemIsUp() const { return true; }
+
+protected:
+	IDBFileSystem( Types type );
+
+private:
+	Types m_type;
+};
+
+/**
+ * getFs() returns a reference to the IDBFileSystem instance for the
+ * specified type
+ */
+inline
+IDBFileSystem& IDBFileSystem::getFs(IDBDataFile::Types type)
+{
+	return IDBFactory::getFs(type);
+}
+
+}
+
+#endif /* IDBFILESYSTEM_H_ */