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author | tpearson <tpearson@283d02a7-25f6-0310-bc7c-ecb5cbfe19da> | 2010-03-01 18:37:05 +0000 |
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committer | tpearson <tpearson@283d02a7-25f6-0310-bc7c-ecb5cbfe19da> | 2010-03-01 18:37:05 +0000 |
commit | 145364a8af6a1fec06556221e66d4b724a62fc9a (patch) | |
tree | 53bd71a544008c518034f208d64c932dc2883f50 /src/base/PropertyName.h | |
download | rosegarden-145364a8af6a1fec06556221e66d4b724a62fc9a.tar.gz rosegarden-145364a8af6a1fec06556221e66d4b724a62fc9a.zip |
Added old abandoned KDE3 version of the RoseGarden MIDI tool
git-svn-id: svn://anonsvn.kde.org/home/kde/branches/trinity/applications/rosegarden@1097595 283d02a7-25f6-0310-bc7c-ecb5cbfe19da
Diffstat (limited to 'src/base/PropertyName.h')
-rw-r--r-- | src/base/PropertyName.h | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/src/base/PropertyName.h b/src/base/PropertyName.h new file mode 100644 index 0000000..f9e8c20 --- /dev/null +++ b/src/base/PropertyName.h @@ -0,0 +1,158 @@ +// -*- c-basic-offset: 4 -*- + + +/* + Rosegarden + A sequencer and musical notation editor. + + This program is Copyright 2000-2008 + Guillaume Laurent <[email protected]>, + Chris Cannam <[email protected]>, + Richard Bown <[email protected]> + + The moral right of the authors to claim authorship of this work + has been asserted. + + 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. See the file + COPYING included with this distribution for more information. +*/ + +#ifndef _PROPERTY_NAME_H_ +#define _PROPERTY_NAME_H_ + +#include <string> +#include <map> +#include <iostream> + +namespace Rosegarden +{ + +/** + + A PropertyName is something that can be constructed from a string, + compared quickly as an int, hashed as a key in a hash map, and + streamed out again as a string. It must have accompanying functors + PropertyNamesEqual and PropertyNameHash which compare and hash + PropertyName objects. + + The simplest implementation is a string: + + typedef std::string PropertyName; + + struct PropertyNamesEqual { + bool operator() (const PropertyName &s1, const PropertyName &s2) const { + return s1 == s2; + } + }; + + struct PropertyNameHash { + static std::hash<const char *> _H; + size_t operator() (const PropertyName &s) const { + return _H(s.c_str()); + } + }; + + std::hash<const char *> PropertyNameHash::_H; + + but our implementation is faster in practice: while it behaves + outwardly like a string, for the Event that makes use of it, + it performs much like a machine integer. It also shares + strings, reducing storage sizes if there are many names in use. + + A big caveat with this class is that it is _not_ safe to persist + the values of PropertyNames and assume that the original strings + can be recovered; they can't. The values are assigned on demand, + and there's no guarantee that a given string will always map to + the same value (on separate invocations of the program). This + is why there's no PropertyName(int) constructor and no mechanism + for storing PropertyNames in properties. (Of course, you can + store the string representation of a PropertyName in a property; + but that's slow.) + +*/ + +class PropertyName +{ +public: + PropertyName() : m_value(-1) { } + PropertyName(const char *cs) { std::string s(cs); m_value = intern(s); } + PropertyName(const std::string &s) : m_value(intern(s)) { } + PropertyName(const PropertyName &p) : m_value(p.m_value) { } + ~PropertyName() { } + + PropertyName &operator=(const char *cs) { + std::string s(cs); + m_value = intern(s); + return *this; + } + PropertyName &operator=(const std::string &s) { + m_value = intern(s); + return *this; + } + PropertyName &operator=(const PropertyName &p) { + m_value = p.m_value; + return *this; + } + + bool operator==(const PropertyName &p) const { + return m_value == p.m_value; + } + bool operator< (const PropertyName &p) const { + return m_value < p.m_value; + } + + const char *c_str() const { + return getName().c_str(); + } + + std::string getName() const /* throw (CorruptedValue) */; + + int getValue() const { return m_value; } + + static const PropertyName EmptyPropertyName; + +private: + typedef std::map<std::string, int> intern_map; + typedef intern_map::value_type intern_pair; + + typedef std::map<int, std::string> intern_reverse_map; + typedef intern_reverse_map::value_type intern_reverse_pair; + + static intern_map *m_interns; + static intern_reverse_map *m_internsReversed; + static int m_nextValue; + + int m_value; + + static int intern(const std::string &s); +}; + +inline std::ostream& operator<<(std::ostream &out, const PropertyName &n) { + out << n.getName(); + return out; +} + +inline std::string operator+(const std::string &s, const PropertyName &n) { + return s + n.getName(); +} + +struct PropertyNamesEqual +{ + bool operator() (const PropertyName &s1, const PropertyName &s2) const { + return s1 == s2; + } +}; + +struct PropertyNameHash +{ + size_t operator() (const PropertyName &s) const { + return static_cast<size_t>(s.getValue()); + } +}; + +} + +#endif |