Merge pull request #3 from saurabhb17/master

secondary files

1 files changed, 144 insertions, 0 deletions

diff --git a/include/hashtables.h b/include/hashtables.h
new file mode 100644
index 0000000..72bc1fd
--- /dev/null
+++ b/include/hashtables.h
@@ -0,0 +1,144 @@
+#ifndef HASHTABLES_H_
+#define HASHTABLES_H_
+/*
+ * This program source code file is part of KiCad, a free EDA CAD application.
+ *
+ * Copyright (C) 2012 SoftPLC Corporation, Dick Hollenbeck <dick@softplc.com>
+ * Copyright (C) 2012 KiCad Developers, see CHANGELOG.TXT for contributors.
+ *
+ * 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; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * 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, you may find one here:
+ * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
+ * or you may search the http://www.gnu.org website for the version 2 license,
+ * or you may write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+ */
+
+#include <base_struct.h>
+#include <wx/string.h>
+
+// Three strategies for providing a portable hashtable are given.
+// C++, boost, and wx, in that order.  C++ solution is no good for mingw.
+// So boost seems best for all platforms.
+
+
+#if 0   // C++ std::unordered_map, maybe in the future
+
+#include <unordered_map>
+
+
+/// Map a C string to an integer.  Used in DSNLEXER.
+typedef std::unordered_map< std::string, int >          KEYWORD_MAP;
+
+/// Map a C string to an EDA_RECT.
+/// The key is the classname of the derived wxformbuilder dialog.
+typedef std::unordered_map< std::string, EDA_RECT >     RECT_MAP;
+
+
+#elif 1     // boost::unordered_map
+
+// fix a compile bug at line 97 of boost/detail/container_fwd.hpp
+#define BOOST_DETAIL_TEST_FORCE_CONTAINER_FWD
+
+#include <boost/unordered_map.hpp>
+
+// see http://www.boost.org/doc/libs/1_49_0/doc/html/boost/unordered_map.html
+
+/// Equality test for "const char*" type used in very specialized KEYWORD_MAP below
+struct iequal_to : std::binary_function< const char*, const char*, bool >
+{
+    bool operator()( const char* x, const char* y ) const
+    {
+        return !strcmp( x, y );
+    }
+};
+
+
+/// Very fast and efficient hash function for "const char*" type, used in specialized
+/// KEYWORD_MAP below.
+/// taken from: http://www.boost.org/doc/libs/1_53_0/libs/unordered/examples/fnv1.hpp
+struct fnv_1a
+{
+    /* not used, std::string is too slow:
+    std::size_t operator()( std::string const& text ) const
+    {
+        std::size_t hash = 2166136261u;
+
+        for( std::string::const_iterator it = text.begin(), end = text.end();
+                it != end;  ++it )
+        {
+            hash ^= *it;
+            hash *= 16777619;
+        }
+        return hash;
+    }
+    */
+
+    std::size_t operator()( const char* it ) const
+    {
+        std::size_t hash = 2166136261u;
+
+        for( ; *it;  ++it )
+        {
+            hash ^= (unsigned char) *it;
+            hash *= 16777619;
+        }
+        return hash;
+    }
+};
+
+
+/// Hash function for wxString, counterpart of std::string hash
+struct WXSTRING_HASH : std::unary_function<wxString, std::size_t>
+{
+    std::size_t operator()( const wxString& aString ) const
+    {
+        std::size_t hash = 2166136261u;
+
+        for( wxString::const_iterator it = aString.begin(); it != aString.end(); ++it )
+        {
+            unsigned ch = static_cast<unsigned>( *it );
+            hash ^= ch;
+            hash *= 16777619;
+        }
+        return hash;
+    }
+};
+
+
+/**
+ * Type KEYWORD_MAP
+ * is a hashtable made of a const char* and an int.  Note that use of this
+ * type outside very specific circumstances is foolish since there is no storage
+ * provided for the actual C string itself.  This type assumes use with type KEYWORD
+ * that is created by CMake and that table creates *constant* storage for C strings
+ * (and pointers to those C strings).  Here we are only interested in the C strings
+ * themselves and only the pointers are duplicated within the hashtable.
+ * If the strings were not constant and fixed, this type would not work.
+ * Also note that normally a hashtable (i.e. unordered_map) using a const char* key
+ * would simply compare the 32 bit or 64 bit pointers themselves, rather than
+ * the C strings which they are known to point to in this context.
+ * I force the latter behavior by supplying both "hash" and "equality" overloads
+ * to the hashtable (unordered_map) template.
+ * @author Dick Hollenbeck
+ */
+typedef boost::unordered_map< const char*, int, fnv_1a, iequal_to >     KEYWORD_MAP;
+
+
+/// Map a std::string to an EDA_RECT.
+/// The key is the classname of the derived wxformbuilder dialog.
+typedef boost::unordered_map< std::string, EDA_RECT >  RECT_MAP;
+
+#endif
+
+#endif // HASHTABLES_H_