Sparse.cpp

// SPDX-License-Identifier: MIT OR MPL-2.0 OR LGPL-2.1-or-later OR GPL-2.0-or-later
// Copyright 2011, SIL International, All rights reserved.

#include <cassert>
#include "inc/Sparse.h"
#include "inc/bits.h"

using namespace graphite2;

const sparse::chunk sparse::empty_chunk = {0,0};

sparse::~sparse() throw()
{
    if (m_array.map == &empty_chunk) return;
    free(m_array.values);
}


sparse::mapped_type sparse::operator [] (const key_type k) const throw()
{
    mapped_type         g = key_type(k/SIZEOF_CHUNK - m_nchunks) >> (sizeof k*8 - 1);
    const chunk &       c = m_array.map[g*k/SIZEOF_CHUNK];
    const mask_t        m = c.mask >> (SIZEOF_CHUNK - 1 - (k%SIZEOF_CHUNK));
    g *= m & 1;

    return g*m_array.values[g*(c.offset + bit_set_count(m >> 1))];
}


size_t sparse::capacity() const throw()
{
    size_t n = m_nchunks,
           s = 0;

    for (const chunk *ci=m_array.map; n; --n, ++ci)
        s += bit_set_count(ci->mask);

    return s;
}