/*
* Redberry: symbolic tensor computations.
*
* Copyright (c) 2010-2014:
* 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 cc.redberry.core.utils.OutputPort;
import cc.redberry.core.combinatorics.IntPermutationsGenerator;
import cc.redberry.core.number.Complex;
import cc.redberry.core.tensor.Product;
import cc.redberry.core.tensor.ProductContent;
import cc.redberry.core.tensor.Tensor;
import cc.redberry.core.utils.stretces.PrecalculatedStretches;
import cc.redberry.core.utils.stretces.Stretch;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
/**
* {@link Product}-specific mapping provider.
*
* @author Dmitry Bolotin
* @author Stanislav Poslavsky
* @see SimpleProductMappingsPort
* @since 1.0
*/
final class ProviderProduct implements IndexMappingProvider {
static final IndexMappingProviderFactory FACTORY = new IndexMappingProviderFactory() {
@Override
public IndexMappingProvider create(IndexMappingProvider opu, Tensor from, Tensor to) {
Product pfrom = (Product) from,
pto = (Product) to;
if (pfrom.sizeWithoutFactor() != pto.sizeWithoutFactor())
return IndexMappingProvider.Util.EMPTY_PROVIDER;
Boolean booluon = compareFactors(pfrom.getFactor(), pto.getFactor());
if (booluon == null)
return IndexMappingProvider.Util.EMPTY_PROVIDER;
if (pfrom.getFactor().equals(pto.getFactor()))
for (int i = 0; i < pfrom.sizeWithoutFactor(); ++i)
if (pfrom.getWithoutFactor(i).hashCode() != pto.getWithoutFactor(i).hashCode())
return IndexMappingProvider.Util.EMPTY_PROVIDER;
ProductContent fromContent = pfrom.getContent(), toContent = pto.getContent();
if (!fromContent.getStructureOfContractionsHashed().equals(toContent.getStructureOfContractionsHashed()))
return IndexMappingProvider.Util.EMPTY_PROVIDER;
Tensor[] fromScalars = pfrom.getAllScalarsWithoutFactor(), toScalars = pto.getAllScalarsWithoutFactor();
if (fromScalars.length != toScalars.length)
return IndexMappingProvider.Util.EMPTY_PROVIDER;
if (fromScalars.length != 1 && !testScalars(fromScalars, toScalars))
return IndexMappingProvider.Util.EMPTY_PROVIDER;
// Temporary, until scalars mappings does not work
if (booluon)
return new MinusIndexMappingProviderWrapper(new ProviderProduct(opu, pfrom, pto));
return new ProviderProduct(opu, pfrom, pto);
// True variant
// return new ProviderProduct(opu, fromC.getNonScalarContent(), toC.getNonScalarContent(), allowDiffStates);
}
};
private static Boolean compareFactors(Complex c1, Complex c2) {
if (c1.equals(c2))
return Boolean.FALSE;
if (c1.equals(c2.negate()))
return Boolean.TRUE;
return null;
}
private static boolean testScalars(Tensor[] from, Tensor[] to) {
if (from.length != to.length)
return false;
int i;
int[] hashes = new int[from.length];
for (i = 0; i < from.length; ++i)
if ((hashes[i] = from[i].hashCode()) != to[i].hashCode())
return false;
PrecalculatedStretches precalculatedStretches = new PrecalculatedStretches(hashes);
for (Stretch stretch : precalculatedStretches)
if (stretch.length == 1)
if (!mappingExists(from[stretch.from], to[stretch.from]))
return false;
OUTER:
for (Stretch stretch : precalculatedStretches)
if (stretch.length > 1) {
SEMIOUTER:
for (int[] permutation : new IntPermutationsGenerator(stretch.length)) {
for (i = 0; i < stretch.length; ++i)
if (!mappingExists(from[stretch.from + i], to[stretch.from + permutation[i]]))
continue SEMIOUTER; // This permutation is bad
continue OUTER; //Good permutation has been found
}
return false; //No good combinatorics found
}
return true;
}
private static boolean mappingExists(Tensor from, Tensor to) {
final IndexMappingProvider pp = IndexMappings.createPort(
IndexMappingProvider.Util.singleton(new IndexMappingBufferImpl()),
from, to);
pp.tick();
return pp.take() != null;
}
// private final ProductContent from, to;
// private PermutationsProvider permutationsProvider;
private final DummyIndexMappingProvider dummyProvider;
private final OutputPort<IndexMappingBuffer> op;
private ProviderProduct(final OutputPort<IndexMappingBuffer> opu,
final Product from, final Product to) {
this.dummyProvider = new DummyIndexMappingProvider(opu);
// this.from = from;
// this.to = to;
int begin = 0;
int i;
ProductContent fromContent = from.getContent(),
toContent = to.getContent();
// List<PermutationsProvider> disjointProviders = new ArrayList<>();
List<Pair> stretches = new ArrayList<>();
//non permutable
List<IndexMappingProvider> providers = new ArrayList<>();
IndexMappingProvider lastOutput = dummyProvider;
Tensor[] indexlessFrom = from.getIndexless(), indexlessTo = to.getIndexless();
for (i = 1; i <= indexlessFrom.length; ++i)
if (i == indexlessFrom.length || indexlessFrom[i].hashCode() != indexlessFrom[i - 1].hashCode()) {
if (i - 1 != begin)
providers.add(lastOutput =
new PermutatorProvider(lastOutput, Arrays.copyOfRange(indexlessFrom, begin, i),
Arrays.copyOfRange(indexlessTo, begin, i)));
begin = i;
}
begin = 0;
for (i = 1; i <= indexlessFrom.length; ++i)
if (i == indexlessFrom.length || indexlessFrom[i].hashCode() != indexlessFrom[i - 1].hashCode()) {
if (i - 1 == begin)
providers.add(lastOutput =
IndexMappings.createPort(lastOutput,
indexlessFrom[begin],
indexlessTo[begin]));
begin = i;
}
begin = 0;
for (i = 1; i <= fromContent.size(); ++i)
if (i == fromContent.size() || !fromContent.getStructureOfContractionsHashed().get(i).equals(fromContent.getStructureOfContractionsHashed().get(i - 1))) {
if (i - 1 != begin)
stretches.add(new Pair(fromContent.getRange(begin, i), toContent.getRange(begin, i)));
else
providers.add(lastOutput =
IndexMappings.createPort(lastOutput,
fromContent.get(begin),
toContent.get(begin)));
begin = i;
}
Collections.sort(stretches);
// if (!npFrom.isEmpty())
// lastOutput = new SimpleProductMappingsPort(dummyProvider,
// npFrom.toArray(new Tensor[npFrom.size()]),
// npTo.toArray(new Tensor[npTo.size()]), allowDiffStates);
// if (stretches.isEmpty())
// this.op = lastOutput;
// else
for (Pair p : stretches)
providers.add(lastOutput = new PermutatorProvider(lastOutput,
p.from, p.to));
this.op = new SimpleProductMappingsPort(providers.toArray(new IndexMappingProvider[providers.size()]));
}
@Override
public boolean tick() {
return dummyProvider.tick();
}
@Override
public IndexMappingBuffer take() {
IndexMappingBuffer buffer = op.take();
if (buffer == null)
return null;
buffer.removeContracted();
return buffer;
}
protected static class Pair implements Comparable<Pair> {
public final Tensor[] from, to;
public Pair(final Tensor[] from, final Tensor[] to) {
this.from = from;
this.to = to;
}
@Override
public int compareTo(Pair o) {
return Integer.compare(from.length, o.from.length);
}
}
}