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Diffstat (limited to 'include/hashtables.h')
| -rw-r--r-- | include/hashtables.h | 144 |
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_ |