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Diffstat (limited to 'gfx/graphite2/src/inc/Sparse.h')
| -rw-r--r-- | gfx/graphite2/src/inc/Sparse.h | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/gfx/graphite2/src/inc/Sparse.h b/gfx/graphite2/src/inc/Sparse.h new file mode 100644 index 000000000..4a8e3fa7d --- /dev/null +++ b/gfx/graphite2/src/inc/Sparse.h @@ -0,0 +1,171 @@ +/* GRAPHITE2 LICENSING + + Copyright 2011, SIL International + All rights reserved. + + This library is free software; you can redistribute it and/or modify + it under the terms of the GNU Lesser General Public License as published + by the Free Software Foundation; either version 2.1 of 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 + Lesser General Public License for more details. + + You should also have received a copy of the GNU Lesser General Public + License along with this library in the file named "LICENSE". + If not, write to the Free Software Foundation, 51 Franklin Street, + Suite 500, Boston, MA 02110-1335, USA or visit their web page on the + internet at http://www.fsf.org/licenses/lgpl.html. + +Alternatively, the contents of this file may be used under the terms of the +Mozilla Public License (http://mozilla.org/MPL) or 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. +*/ +#pragma once +#include <iterator> +#include <utility> + +#include "inc/Main.h" + +namespace graphite2 { + + +// A read-only packed fast sparse array of uint16 with uint16 keys. +// Like most container classes this has capacity and size properties and these +// refer to the number of stored entries and the number of addressable entries +// as normal. However due the sparse nature the capacity is always <= than the +// size. +class sparse +{ +public: + typedef uint16 key_type; + typedef uint16 mapped_type; + typedef std::pair<const key_type, mapped_type> value_type; + +private: + typedef unsigned long mask_t; + + static const unsigned char SIZEOF_CHUNK = (sizeof(mask_t) - sizeof(key_type))*8; + + struct chunk + { + mask_t mask:SIZEOF_CHUNK; + key_type offset; + }; + + static const chunk empty_chunk; + sparse(const sparse &); + sparse & operator = (const sparse &); + +public: + template<typename I> + sparse(I first, const I last); + sparse() throw(); + ~sparse() throw(); + + operator bool () const throw(); + mapped_type operator [] (const key_type k) const throw(); + + size_t capacity() const throw(); + size_t size() const throw(); + + size_t _sizeof() const throw(); + + CLASS_NEW_DELETE; + +private: + union { + chunk * map; + mapped_type * values; + } m_array; + key_type m_nchunks; +}; + + +inline +sparse::sparse() throw() : m_nchunks(0) +{ + m_array.map = const_cast<graphite2::sparse::chunk *>(&empty_chunk); +} + + +template <typename I> +sparse::sparse(I attr, const I last) +: m_nchunks(0) +{ + m_array.map = 0; + + // Find the maximum extent of the key space. + size_t n_values=0; + long lastkey = -1; + for (I i = attr; i != last; ++i, ++n_values) + { + const typename std::iterator_traits<I>::value_type v = *i; + if (v.second == 0) { --n_values; continue; } + if (v.first <= lastkey) { m_nchunks = 0; return; } + + lastkey = v.first; + const key_type k = v.first / SIZEOF_CHUNK; + if (k >= m_nchunks) m_nchunks = k+1; + } + if (m_nchunks == 0) + { + m_array.map=const_cast<graphite2::sparse::chunk *>(&empty_chunk); + return; + } + + m_array.values = grzeroalloc<mapped_type>((m_nchunks*sizeof(chunk) + sizeof(mapped_type)-1) + / sizeof(mapped_type) + + n_values); + + if (m_array.values == 0) + { + free(m_array.values); m_array.map=0; + return; + } + + // coverity[forward_null : FALSE] Since m_array is union and m_array.values is not NULL + chunk * ci = m_array.map; + ci->offset = (m_nchunks*sizeof(chunk) + sizeof(mapped_type)-1)/sizeof(mapped_type); + mapped_type * vi = m_array.values + ci->offset; + for (; attr != last; ++attr, ++vi) + { + const typename std::iterator_traits<I>::value_type v = *attr; + if (v.second == 0) { --vi; continue; } + + chunk * const ci_ = m_array.map + v.first/SIZEOF_CHUNK; + + if (ci != ci_) + { + ci = ci_; + ci->offset = vi - m_array.values; + } + + ci->mask |= 1UL << (SIZEOF_CHUNK - 1 - (v.first % SIZEOF_CHUNK)); + *vi = v.second; + } +} + + +inline +sparse::operator bool () const throw() +{ + return m_array.map != 0; +} + +inline +size_t sparse::size() const throw() +{ + return m_nchunks*SIZEOF_CHUNK; +} + +inline +size_t sparse::_sizeof() const throw() +{ + return sizeof(sparse) + capacity()*sizeof(mapped_type) + m_nchunks*sizeof(chunk); +} + +} // namespace graphite2 |