org.apache.drill.exec.store.parquet.metadata.MetadataPathUtils.java Source code

Introduction

Here is the source code for org.apache.drill.exec.store.parquet.metadata.MetadataPathUtils.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 org.apache.drill.exec.store.parquet.metadata;

import org.apache.drill.shaded.guava.com.google.common.collect.Lists;
import org.apache.drill.common.util.DrillVersionInfo;
import org.apache.hadoop.fs.Path;

import java.util.ArrayList;
import java.util.List;

import static org.apache.drill.exec.store.parquet.metadata.MetadataVersion.Constants.SUPPORTED_VERSIONS;
import static org.apache.drill.exec.store.parquet.metadata.Metadata_V3.ParquetFileMetadata_v3;
import static org.apache.drill.exec.store.parquet.metadata.Metadata_V3.ParquetTableMetadata_v3;

/**
 * Util class that contains helper methods for converting paths in the table and directory metadata structures
 */
public class MetadataPathUtils {

    /**
     * Helper method that converts a list of relative paths to absolute ones
     *
     * @param paths list of relative paths
     * @param baseDir base parent directory
     * @return list of absolute paths
     */
    public static List<Path> convertToAbsolutePaths(List<Path> paths, String baseDir) {
        if (!paths.isEmpty()) {
            List<Path> absolutePaths = Lists.newArrayList();
            for (Path relativePath : paths) {
                Path absolutePath = (relativePath.isAbsolute()) ? relativePath : new Path(baseDir, relativePath);
                absolutePaths.add(absolutePath);
            }
            return absolutePaths;
        }
        return paths;
    }

    /**
     * Convert a list of files with relative paths to files with absolute ones
     *
     * @param files list of files with relative paths
     * @param baseDir base parent directory
     * @return list of files with absolute paths
     */
    public static List<ParquetFileMetadata_v3> convertToFilesWithAbsolutePaths(List<ParquetFileMetadata_v3> files,
            String baseDir) {
        if (!files.isEmpty()) {
            List<ParquetFileMetadata_v3> filesWithAbsolutePaths = Lists.newArrayList();
            for (ParquetFileMetadata_v3 file : files) {
                Path relativePath = file.getPath();
                // create a new file if old one contains a relative path, otherwise use an old file
                ParquetFileMetadata_v3 fileWithAbsolutePath = (relativePath.isAbsolute()) ? file
                        : new ParquetFileMetadata_v3(new Path(baseDir, relativePath), file.length, file.rowGroups);
                filesWithAbsolutePaths.add(fileWithAbsolutePath);
            }
            return filesWithAbsolutePaths;
        }
        return files;
    }

    /**
     * Creates a new parquet table metadata from the {@code tableMetadataWithAbsolutePaths} parquet table.
     * A new parquet table will contain relative paths for the files and directories.
     *
     * @param tableMetadataWithAbsolutePaths parquet table metadata with absolute paths for the files and directories
     * @param baseDir base parent directory
     * @return parquet table metadata with relative paths for the files and directories
     */
    public static ParquetTableMetadata_v3 createMetadataWithRelativePaths(
            ParquetTableMetadata_v3 tableMetadataWithAbsolutePaths, Path baseDir) {
        List<Path> directoriesWithRelativePaths = new ArrayList<>();
        for (Path directory : tableMetadataWithAbsolutePaths.getDirectories()) {
            directoriesWithRelativePaths.add(relativize(baseDir, directory));
        }
        List<ParquetFileMetadata_v3> filesWithRelativePaths = Lists.newArrayList();
        for (ParquetFileMetadata_v3 file : tableMetadataWithAbsolutePaths.files) {
            filesWithRelativePaths.add(
                    new ParquetFileMetadata_v3(relativize(baseDir, file.getPath()), file.length, file.rowGroups));
        }
        return new ParquetTableMetadata_v3(SUPPORTED_VERSIONS.last().toString(), tableMetadataWithAbsolutePaths,
                filesWithRelativePaths, directoriesWithRelativePaths, DrillVersionInfo.getVersion());
    }

    /**
     * Constructs relative path from child full path and base path. Or return child path if the last one is already relative
     *
     * @param childPath full absolute path
     * @param baseDir base path (the part of the Path, which should be cut off from child path)
     * @return relative path
     */
    public static Path relativize(Path baseDir, Path childPath) {
        Path fullPathWithoutSchemeAndAuthority = Path.getPathWithoutSchemeAndAuthority(childPath);
        Path basePathWithoutSchemeAndAuthority = Path.getPathWithoutSchemeAndAuthority(baseDir);

        // Since hadoop Path hasn't relativize() we use uri.relativize() to get relative path
        Path relativeFilePath = new Path(
                basePathWithoutSchemeAndAuthority.toUri().relativize(fullPathWithoutSchemeAndAuthority.toUri()));
        if (relativeFilePath.isAbsolute()) {
            throw new IllegalStateException(String.format("Path %s is not a subpath of %s.",
                    basePathWithoutSchemeAndAuthority.toUri().getPath(),
                    fullPathWithoutSchemeAndAuthority.toUri().getPath()));
        }
        return relativeFilePath;
    }

}