content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to you 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 org.apache.calcite.rel.type;
  
  import org.apache.calcite.linq4j.Ord;
  import org.apache.calcite.sql.type.SqlTypeName;
  
  import com.google.common.collect.ImmutableMap;
  
  import org.checkerframework.checker.nullness.qual.Nullable;
  
  import java.io.Serializable;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  import static java.util.Objects.requireNonNull;
  
  /**
   * RelRecordType represents a structured type having named fields.
   */
  public class RelRecordType extends RelDataTypeImpl implements Serializable {
    /** Name resolution policy; usually {@link StructKind#FULLY_QUALIFIED}. */
    private final StructKind kind;
    private final boolean nullable;
    private final @Nullable Map<String, RelDataTypeField> fieldNameMap;
  
    /** Minimum number of fields where it is worth populating {@link #fieldNameMap}
     * to accelerate lookups by field name. */
    private static final int THRESHOLD = 20;
  
    //~ Constructors -----------------------------------------------------------
  
    /**
     * Creates a <code>RecordType</code>. This should only be called from a
     * factory method.
     *
     * @param kind Name resolution policy
     * @param fields List of fields
     * @param nullable Whether this record type allows null values
     */
    public RelRecordType(StructKind kind, List<RelDataTypeField> fields, boolean nullable) {
      super(fields);
      this.nullable = nullable;
      this.kind = requireNonNull(kind, "kind");
      if (fields.size() > THRESHOLD) {
        final Map<String, RelDataTypeField> map = new HashMap<>();
        for (RelDataTypeField f : fields) {
          map.putIfAbsent(f.getName(), f);
          if (f.isDynamicStar()) {
            // the first dynamic star field is cached with a special name
            map.putIfAbsent("", f);
          }
        }
        this.fieldNameMap = ImmutableMap.copyOf(map);
      } else {
        this.fieldNameMap = null;
      }
      computeDigest();
    }
  
    /**
     * Creates a <code>RecordType</code>. This should only be called from a
     * factory method.
     * Shorthand for <code>RelRecordType(kind, fields, false)</code>.
     */
    public RelRecordType(StructKind kind, List<RelDataTypeField> fields) {
      this(kind, fields, false);
    }
  
    /**
     * Creates a <code>RecordType</code>. This should only be called from a
     * factory method.
     * Shorthand for <code>RelRecordType(StructKind.FULLY_QUALIFIED, fields, false)</code>.
     */
    public RelRecordType(List<RelDataTypeField> fields) {
      this(StructKind.FULLY_QUALIFIED, fields, false);
    }
  
    //~ Methods ----------------------------------------------------------------
  
    @Override public SqlTypeName getSqlTypeName() {
      return SqlTypeName.ROW;
    }
  
    @Override public boolean isNullable() {
      return nullable;
    }
  
    @Override public int getPrecision() {
      // REVIEW: angel 18-Aug-2005 Put in fake implementation for precision
      return 0;
    }
  
    @Override public StructKind getStructKind() {
      return kind;
    }
  
    @Override protected @Nullable Map<String, RelDataTypeField> getFieldMap() {
      return fieldNameMap;
    }
  
    @Override protected void generateTypeString(StringBuilder sb, boolean withDetail) {
      sb.append("RecordType");
      switch (kind) {
      case PEEK_FIELDS:
        sb.append(":peek");
        break;
      case PEEK_FIELDS_DEFAULT:
        sb.append(":peek_default");
        break;
      case PEEK_FIELDS_NO_EXPAND:
        sb.append(":peek_no_expand");
        break;
      default:
        break;
      }
      sb.append("(");
      for (Ord<RelDataTypeField> ord : Ord.zip(requireNonNull(fieldList, "fieldList"))) {
        if (ord.i > 0) {
          sb.append(", ");
        }
        RelDataTypeField field = ord.e;
        if (withDetail) {
          sb.append(field.getType().getFullTypeString());
        } else {
          sb.append(field.getType().toString());
        }
        sb.append(" ");
        sb.append(field.getName());
      }
      sb.append(")");
    }
  
    /**
     * Per {@link Serializable} API, provides a replacement object to be written
     * during serialization.
     *
     * <p>This implementation converts this RelRecordType into a
     * SerializableRelRecordType, whose <code>readResolve</code> method converts
     * it back to a RelRecordType during deserialization.
     */
    private Object writeReplace() {
      return new SerializableRelRecordType(requireNonNull(fieldList, "fieldList"));
    }
  
    //~ Inner Classes ----------------------------------------------------------
  
    /**
     * Skinny object which has the same information content as a
     * {@link RelRecordType} but skips redundant stuff like digest and the
     * immutable list.
     */
    private static class SerializableRelRecordType implements Serializable {
      private final List<RelDataTypeField> fields;
  
      private SerializableRelRecordType(List<RelDataTypeField> fields) {
        this.fields = requireNonNull(fields, "fields");
      }
  
      /**
       * Per {@link Serializable} API. See
       * {@link RelRecordType#writeReplace()}.
       */
      private Object readResolve() {
        return new RelRecordType(fields);
      }
    }
  }
  