/*
* Redberry: symbolic tensor computations.
*
* Copyright (c) 2010-2012:
* Stanislav Poslavsky <stvlpos@mail.ru>
* Bolotin Dmitriy <bolotin.dmitriy@gmail.com>
*
* This file is part of Redberry.
*
* Redberry 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 3 of the License, or
* (at your option) any later version.
*
* Redberry 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 Redberry. If not, see <http://www.gnu.org/licenses/>.
*/
package cc.redberry.core.indexmapping;
import java.util.Arrays;
import cc.redberry.core.tensor.Integral;
import cc.redberry.core.tensor.SimpleTensor;
import cc.redberry.core.tensor.Tensor;
import cc.redberry.core.combinatorics.IntPermutationsGenerator;
import cc.redberry.core.utils.stretces.PrecalculatedStretches;
import cc.redberry.core.utils.stretces.Stretch;
/**
*
* @author Dmitry Bolotin
* @author Stanislav Poslavsky
*/
final class ProviderIntegralFactory implements IndexMappingProviderFactory {
static final ProviderIntegralFactory INSTANCE = new ProviderIntegralFactory();
private ProviderIntegralFactory() {
}
@Override
public IndexMappingProvider create(IndexMappingProvider opu, Tensor from, Tensor to, boolean allowDiffStates) {
final Integral intFrom = (Integral) from, intTo = (Integral) to;
final SimpleTensor[] varsFrom = intFrom.vars(), varsTo = intTo.vars();
if (varsFrom.length != varsTo.length)
return IndexMappingProvider.Util.EMPTY_PROVIDER;
Arrays.sort(varsFrom); //TODO change to quick Sort
Arrays.sort(varsTo); //TODO change to quick Sort
int i;
int[] hashes = new int[varsFrom.length];
for (i = 0; i < varsFrom.length; ++i)
if ((hashes[i] = varsFrom[i].hashCode()) != varsTo[i].hashCode())
return IndexMappingProvider.Util.EMPTY_PROVIDER;
PrecalculatedStretches stretches = new PrecalculatedStretches(hashes);
for (Stretch stretch : stretches)
if (stretch.length == 1)
if (!IndexMappings.mappingExists(varsFrom[stretch.from], varsTo[stretch.from], allowDiffStates))
return IndexMappingProvider.Util.EMPTY_PROVIDER;
STRETCHES:
for (Stretch stretch : stretches)
if (stretch.length != 1) {
PERMUTATIONS:
for (int[] permutation : new IntPermutationsGenerator(stretch.length)) {
for (i = 0; i < stretch.length; ++i)
if (!IndexMappings.mappingExists(varsFrom[stretch.from + i], varsTo[stretch.from + permutation[i]], allowDiffStates))
continue PERMUTATIONS;
continue STRETCHES;
}
return IndexMappingProvider.Util.EMPTY_PROVIDER;
}
return IndexMappings.createPort(opu, intFrom.target(), intTo.target(), allowDiffStates);
}
}