add stringid for mapping between strings and ints

Makefile.am

@@ -137,6 +137,8 @@ UTIL_FILES   =		\
     stream.hpp		\
     string.cpp		\
     string.hpp		\
+    stringid.cpp	\
+    stringid.hpp	\
     time.cpp		\
     time.hpp		\
     types.hpp		\

stringid.cpp

@@ -0,0 +1,61 @@
+/*
+ * This file is part of libgim.
+ *
+ * libgim 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, either version 3 of the License, or (at your option) any later
+ * version.
+ *
+ * libgim 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 libgim.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright 2014 Danny Robson <danny@nerdcruft.net>
+ */
+
+#include "stringid.hpp"
+
+#include "raii.hpp"
+
+#include <stdexcept>
+#include <mutex>
+
+using util::stringid;
+
+
+//-----------------------------------------------------------------------------
+stringid::id_t
+stringid::add (const std::string key) {
+    auto pos = m_map.find (key);
+    if (pos != m_map.end ())
+        throw std::invalid_argument ("duplicate stringid key");
+
+    static std::mutex s_lock;
+    std::lock_guard<std::mutex> raii (s_lock);
+
+    id_t id = m_map.size ();
+    m_map[key] = id;
+    return id;   
+}
+
+
+//-----------------------------------------------------------------------------
+stringid::id_t
+stringid::find (const std::string &key) const {
+    auto pos = m_map.find (key);
+    if (pos == m_map.end ())
+        throw std::out_of_range ("invalid stringid key");
+
+    return pos->second;
+}
+
+
+//-----------------------------------------------------------------------------
+void
+stringid::clear (void) {
+    m_map.clear ();
+}

stringid.hpp

@@ -0,0 +1,41 @@
+/*
+ * This file is part of libgim.
+ *
+ * libgim 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, either version 3 of the License, or (at your option) any later
+ * version.
+ *
+ * libgim 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 libgim.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright 2014 Danny Robson <danny@nerdcruft.net>
+ */
+
+#ifndef __UTIL_STRINGID_HPP
+#define __UTIL_STRINGID_HPP
+
+#include <map>
+#include <string>
+
+namespace util {
+    class stringid {
+        public:
+            typedef unsigned id_t;
+
+            id_t add  (std::string);
+            id_t find (const std::string&) const;
+
+            void clear (void);
+
+        private:
+            std::map<const std::string, id_t> m_map;
+    };
+}
+
+#endif

test/Makefile.am

@@ -21,9 +21,10 @@ TEST_BIN = 		\
 	range 		\
 	region		\
 	ripemd		\
-	signal		\
 	sha1		\
 	sha2		\
+	signal		\
+	stringid	\
 	version
 
 AM_DEFAULT_SOURCE_EXT = .cpp

test/stringid.cpp

@@ -0,0 +1,42 @@
+/*
+ * This file is part of libgim.
+ *
+ * libgim 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, either version 3 of the License, or (at your option) any later
+ * version.
+ *
+ * libgim 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 libgim.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright 2014 Danny Robson <danny@nerdcruft.net>
+ */
+
+#include "../stringid.hpp"
+#include "../debug.hpp"
+
+#include <cstdlib>
+#include <stdexcept>
+
+int
+main (int, char**) {
+    util::stringid map;
+
+    CHECK_THROWS (std::out_of_range, map.find ("invalid"));
+
+    auto id1 = map.add ("first");
+    CHECK_EQ (id1, map.find ("first"));
+
+    CHECK_THROWS (std::out_of_range, map.find ("invalid"));
+
+    auto id2 = map.add ("second");
+    CHECK_EQ (id1 + 1, id2);
+    CHECK_EQ (id1, map.find ("first"));
+
+    return EXIT_SUCCESS;
+}