/* * Copyright 2016 Rahel Lüthy * * 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 ch.netzwerg.paleo; import ch.netzwerg.paleo.ColumnIds.CategoryColumnId; import ch.netzwerg.paleo.impl.MetaDataBuilder; import io.vavr.collection.Array; import io.vavr.collection.Map; import io.vavr.collection.Set; import io.vavr.collection.Stream; import java.util.ArrayList; import java.util.LinkedHashMap; public final class CategoryColumn implements Column<CategoryColumnId> { private final CategoryColumnId id; private final Array<String> categories; private final Array<Integer> categoryIndexPerRowIndex; private final Map<String, String> metaData; private CategoryColumn(CategoryColumnId id, Array<String> categories, Array<Integer> categoryIndexPerRowIndex, Map<String, String> metaData) { this.id = id; this.categories = categories; this.categoryIndexPerRowIndex = categoryIndexPerRowIndex; this.metaData = metaData; } public static CategoryColumn of(CategoryColumnId id, String value) { return builder(id).add(value).build(); } public static CategoryColumn ofAll(CategoryColumnId id, String... values) { return builder(id).addAll(values).build(); } public static CategoryColumn ofAll(CategoryColumnId id, Iterable<String> values) { return builder(id).addAll(values).build(); } public static Builder builder(CategoryColumnId id) { return new Builder(id); } @Override public CategoryColumnId getId() { return id; } @Override public int getRowCount() { return categoryIndexPerRowIndex.length(); } @Override public Map<String, String> getMetaData() { return metaData; } public String getValueAt(int rowIndex) { return categories.get(categoryIndexPerRowIndex.get(rowIndex)); } public Set<String> getCategories() { return categories.toSet(); } /** * Creates a stream of individual row values (i.e. "explodes" categories). */ public Stream<String> valueStream() { return Stream.range(0, getRowCount()).map(this::getValueAt); } public static final class Builder implements Column.Builder<String, CategoryColumn> { private static final Integer DEFAULT_INDEX = -1; private final CategoryColumnId id; private final java.util.Map<String, Integer> indexByCategory; private final java.util.List<Integer> indexPerRow; private final MetaDataBuilder metaDataBuilder; private Builder(CategoryColumnId id) { this.id = id; this.indexByCategory = new LinkedHashMap<>(); this.indexPerRow = new ArrayList<>(); this.metaDataBuilder = new MetaDataBuilder(); } @Override public Builder add(String value) { Integer categoryIndex = indexByCategory.getOrDefault(value, DEFAULT_INDEX); if (categoryIndex < 0) { indexByCategory.put(value, indexByCategory.size()); categoryIndex = indexByCategory.size() - 1; } indexPerRow.add(categoryIndex); return this; } public Builder addAll(String... values) { return addAll(Stream.of(values)); } public Builder addAll(Iterable<String> values) { return Stream.ofAll(values).foldLeft(this, Builder::add); } @Override public Builder putMetaData(String key, String value) { metaDataBuilder.putMetaData(key, value); return this; } @Override public Builder putAllMetaData(Map<String, String> metaData) { metaDataBuilder.putAllMetaData(metaData); return this; } public CategoryColumn build() { Array<String> categories = Array.ofAll(indexByCategory.keySet()); return new CategoryColumn(id, categories, Array.ofAll(indexPerRow), metaDataBuilder.build()); } } }