com.cloudera.impala.catalog.StructField.java Source code

Introduction

Here is the source code for com.cloudera.impala.catalog.StructField.java

Source

// 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 com.cloudera.impala.catalog;

import org.apache.commons.lang3.StringUtils;

import com.cloudera.impala.thrift.TColumnType;
import com.cloudera.impala.thrift.TStructField;
import com.cloudera.impala.thrift.TTypeNode;

/**
 * TODO: Support comments for struct fields. The Metastore does not properly store
 * comments of struct fields. We set comment_ to null to avoid compatibility issues.
 */
public class StructField {
    protected final String name_;
    protected final Type type_;
    protected final String comment_;
    protected int position_; // in struct

    public StructField(String name, Type type, String comment) {
        name_ = name;
        type_ = type;
        comment_ = comment;
    }

    public StructField(String name, Type type) {
        this(name, type, null);
    }

    public String getComment() {
        return comment_;
    }

    public String getName() {
        return name_;
    }

    public Type getType() {
        return type_;
    }

    public int getPosition() {
        return position_;
    }

    public void setPosition(int position) {
        position_ = position;
    }

    public String toSql(int depth) {
        String typeSql = (depth < Type.MAX_NESTING_DEPTH) ? type_.toSql(depth) : "...";
        StringBuilder sb = new StringBuilder(name_);
        if (type_ != null)
            sb.append(":" + typeSql);
        if (comment_ != null)
            sb.append(String.format(" COMMENT '%s'", comment_));
        return sb.toString();
    }

    /**
     * Pretty prints this field with lpad number of leading spaces.
     * Calls prettyPrint(lpad) on this field's type.
     */
    public String prettyPrint(int lpad) {
        String leftPadding = StringUtils.repeat(' ', lpad);
        StringBuilder sb = new StringBuilder(leftPadding + name_);
        if (type_ != null) {
            // Pass in the padding to make sure nested fields are aligned properly,
            // even if we then strip the top-level padding.
            String typeStr = type_.prettyPrint(lpad);
            typeStr = typeStr.substring(lpad);
            sb.append(":" + typeStr);
        }
        if (comment_ != null)
            sb.append(String.format(" COMMENT '%s'", comment_));
        return sb.toString();
    }

    public void toThrift(TColumnType container, TTypeNode node) {
        TStructField field = new TStructField();
        field.setName(name_);
        if (comment_ != null)
            field.setComment(comment_);
        node.struct_fields.add(field);
        type_.toThrift(container);
    }

    @Override
    public boolean equals(Object other) {
        if (!(other instanceof StructField))
            return false;
        StructField otherStructField = (StructField) other;
        return otherStructField.name_.equals(name_) && otherStructField.type_.equals(type_);
    }
}