| // Copyright (C) 2016 The Android Open Source Project |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| package com.google.gerrit.index.query; |
| |
| import static com.google.common.base.Preconditions.checkArgument; |
| |
| import com.google.gerrit.index.IndexConfig; |
| import com.google.gerrit.index.PaginationType; |
| import java.util.Collection; |
| import java.util.List; |
| |
| public class AndSource<T> extends AndPredicate<T> implements DataSource<T> { |
| protected final FilteredSource<T> filteredSource; |
| |
| private final int start; |
| private final int cardinality; |
| private final IndexConfig indexConfig; |
| |
| public AndSource(Collection<? extends Predicate<T>> that, IndexConfig indexConfig) { |
| this(that, 0, indexConfig); |
| } |
| |
| public AndSource(Collection<? extends Predicate<T>> that, int start, IndexConfig indexConfig) { |
| super(that); |
| checkArgument(start >= 0, "negative start: %s", start); |
| this.start = start; |
| this.indexConfig = indexConfig; |
| |
| int c = Integer.MAX_VALUE; |
| Predicate<T> selectedSource = null; |
| int minCardinality = Integer.MAX_VALUE; |
| for (Predicate<T> p : getChildren()) { |
| if (p instanceof DataSource) { |
| DataSource<?> source = (DataSource<?>) p; |
| int cardinality = source.getCardinality(); |
| c = Math.min(c, source.getCardinality()); |
| |
| if (selectedSource == null |
| || cardinality < minCardinality |
| || (cardinality == minCardinality |
| && p.estimateCost() < selectedSource.estimateCost())) { |
| selectedSource = p; |
| minCardinality = cardinality; |
| } |
| } |
| } |
| if (selectedSource == null) { |
| throw new IllegalArgumentException("No DataSource Found"); |
| } |
| this.filteredSource = toDataSource(selectedSource); |
| this.cardinality = c; |
| } |
| |
| @Override |
| public ResultSet<T> read() { |
| return filteredSource.read(); |
| } |
| |
| @Override |
| public ResultSet<FieldBundle> readRaw() { |
| return filteredSource.readRaw(); |
| } |
| |
| @Override |
| public boolean match(T object) { |
| if (super.isMatchable() && !super.match(object)) { |
| return false; |
| } |
| |
| return true; |
| } |
| |
| protected List<T> transformBuffer(List<T> buffer) { |
| return buffer; |
| } |
| |
| @Override |
| public int getCardinality() { |
| return cardinality; |
| } |
| |
| @SuppressWarnings("unchecked") |
| private FilteredSource<T> toDataSource(Predicate<T> pred) { |
| if (indexConfig.paginationType().equals(PaginationType.NONE)) { |
| return new DatasourceWithoutPagination((DataSource<T>) pred, start, indexConfig); |
| } |
| return new DatasourceWithPagination((DataSource<T>) pred, start, indexConfig); |
| } |
| |
| private class DatasourceWithoutPagination extends FilteredSource<T> { |
| |
| public DatasourceWithoutPagination(DataSource<T> source, int start, IndexConfig indexConfig) { |
| super(source, start, indexConfig); |
| } |
| |
| @Override |
| protected boolean match(T object) { |
| return AndSource.this.match(object); |
| } |
| |
| @Override |
| protected boolean isMatchable() { |
| return AndSource.this.isMatchable(); |
| } |
| } |
| |
| private class DatasourceWithPagination extends PaginatingSource<T> { |
| |
| public DatasourceWithPagination(DataSource<T> source, int start, IndexConfig indexConfig) { |
| super(source, start, indexConfig); |
| } |
| |
| @Override |
| protected boolean match(T object) { |
| return AndSource.this.match(object); |
| } |
| |
| @Override |
| protected boolean isMatchable() { |
| return AndSource.this.isMatchable(); |
| } |
| } |
| } |