the begginning

primitives/blockcache/fsutils.cpp

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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. */
+
+#include <unistd.h>
+#include <string>
+//#define NDEBUG
+#include <cassert>
+#include <climits>
+using namespace std;
+
+#include <boost/tokenizer.hpp>
+#include <boost/filesystem.hpp>
+using namespace boost;
+namespace fs=boost::filesystem;
+
+#include "fsutils.h"
+#include "exceptclasses.h"
+
+namespace
+{
+
+const string resolveInDir(const string& dir, const string& name)
+{
+	idbassert(!dir.empty() && !name.empty());
+	string ret;
+	fs::path path(dir);
+	if (!fs::exists(path))
+		return ret;
+	idbassert(fs::exists(path));
+	path /= name;
+	if (!fs::exists(path))
+		return ret;
+	idbassert(fs::exists(path));
+#ifndef _MSC_VER
+	if (!fs::is_symlink(path))
+		return ret;
+	idbassert(fs::is_symlink(path));
+	char* realname = (char*)alloca(PATH_MAX+1);
+	ssize_t realnamelen = readlink(path.string().c_str(), realname, PATH_MAX);
+	if (realnamelen <= 0)
+		return ret;
+	realname[realnamelen] = 0;
+	fs::path linkname(realname);
+	fs::path realpath("/dev");
+	realpath /= linkname.filename();
+	ret = realpath.string();
+#endif
+	return ret;
+}
+
+inline const string label2dev(const string& name)
+{
+	return resolveInDir("/dev/disk/by-label", name);
+}
+
+inline const string uuid2dev(const string& name)
+{
+	return resolveInDir("/dev/disk/by-uuid", name);
+}
+
+}
+
+namespace fsutils
+{
+
+const string symname2devname(const string& sympath)
+{
+	string ret;
+#ifndef _MSC_VER
+	typedef boost::tokenizer<boost::char_separator<char> > tokenizer;
+	boost::char_separator<char> sep("=");
+	tokenizer tokens(sympath, sep);
+	tokenizer::iterator tok_iter = tokens.begin();
+
+	idbassert(tok_iter != tokens.end());
+	string symtype = *tok_iter;
+	if (symtype != "LABEL" && symtype != "UUID")
+		return ret;
+
+	idbassert(symtype == "LABEL" || symtype == "UUID");
+
+	++tok_iter;
+	idbassert(tok_iter != tokens.end());
+	string symname = *tok_iter;
+
+	++tok_iter;
+	idbassert(tok_iter == tokens.end());
+
+	if (symtype == "LABEL")
+		ret = label2dev(symname);
+	else if (symtype == "UUID")
+		ret = uuid2dev(symname);
+#endif
+	return ret;
+}
+
+}
+