| // Copyright (C) 2017 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.common.collect.ImmutableList; |
| import com.google.common.collect.ImmutableListMultimap; |
| import com.google.common.collect.Iterables; |
| import com.google.common.collect.ListMultimap; |
| import com.google.gerrit.index.IndexedField; |
| import com.google.gerrit.index.IndexedField.SearchSpec; |
| import com.google.gerrit.index.SchemaFieldDefs.SchemaField; |
| |
| /** FieldBundle is an abstraction that allows retrieval of raw values from different sources. */ |
| public class FieldBundle { |
| |
| // Map String => List{Integer, Long, Timestamp, String, byte[]} |
| private ImmutableListMultimap<String, Object> fields; |
| |
| /** |
| * Depending on the index implementation 1) either {@link IndexedField} are stored once and |
| * referenced by {@link com.google.gerrit.index.IndexedField.SearchSpec} on the queries, 2) or |
| * each {@link com.google.gerrit.index.IndexedField.SearchSpec} is stored individually. |
| * |
| * <p>In case #1 {@link #storesIndexedFields} is set to {@code true} and the {@link #fields} |
| * contain a map from {@link IndexedField#name()} to a stored value. |
| * |
| * <p>In case #2 {@link #storesIndexedFields} is set to {@code false} and the {@link #fields} |
| * contain a map from {@link SearchSpec#name()} to a stored value. |
| */ |
| private final boolean storesIndexedFields; |
| |
| public FieldBundle(ListMultimap<String, Object> fields, boolean storesIndexedFields) { |
| this.fields = ImmutableListMultimap.copyOf(fields); |
| this.storesIndexedFields = storesIndexedFields; |
| } |
| |
| /** |
| * Get a field's value based on the field definition. |
| * |
| * @param schemaField the definition of the field of which the value should be retrieved. The |
| * field must be stored and contained in the result set as specified by {@link |
| * com.google.gerrit.index.QueryOptions}. |
| * @param <T> Data type of the returned object based on the field definition |
| * @return Either a single element or an Iterable based on the field definition. An empty list is |
| * returned for repeated fields that are not contained in the result. |
| * @throws IllegalArgumentException if the requested field is not stored or not present. This |
| * check is only enforced on non-repeatable fields. |
| */ |
| @SuppressWarnings("unchecked") |
| public <T> T getValue(SchemaField<?, T> schemaField) { |
| checkArgument(schemaField.isStored(), "Field must be stored"); |
| String storedFieldName = |
| storesIndexedFields && schemaField instanceof IndexedField<?, ?>.SearchSpec |
| ? ((IndexedField<?, ?>.SearchSpec) schemaField).getField().name() |
| : schemaField.getName(); |
| checkArgument( |
| fields.containsKey(storedFieldName) || schemaField.isRepeatable(), |
| "Field %s is not in result set %s", |
| storedFieldName, |
| fields.keySet()); |
| |
| ImmutableList<Object> result = fields.get(storedFieldName); |
| if (schemaField.isRepeatable()) { |
| return (T) result; |
| } |
| return (T) Iterables.getOnlyElement(result); |
| } |
| } |