| /* |
| * 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.beam.runners.dataflow.worker; |
| |
| import java.util.regex.Matcher; |
| import java.util.regex.Pattern; |
| import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.ImmutableList; |
| |
| /** Utilities for handling filepatterns. */ |
| public class Filepatterns { |
| private static final Pattern AT_N_SPEC = Pattern.compile("@(?<N>\\d+)"); |
| |
| /** |
| * Expands the filepattern containing an {@code @N} wildcard. |
| * |
| * <p>Returns N filenames with the wildcard replaced with a string of the form {@code |
| * 0000i-of-0000N}. For example, for "gs://bucket/file@2.ism", returns an iterable of two elements |
| * "gs://bucket/file-00000-of-00002.ism" and "gs://bucket/file-00001-of-00002.ism". |
| * |
| * <p>The sequence number and N are formatted with the same number of digits (prepended by zeros). |
| * with at least 5 digits. N must be smaller than 1 billion. |
| * |
| * <p>If the filepattern contains no wildcards, returns the filepattern unchanged. |
| * |
| * @throws IllegalArgumentException if more than one wildcard is detected. |
| */ |
| public static Iterable<String> expandAtNFilepattern(String filepattern) { |
| ImmutableList.Builder<String> builder = ImmutableList.builder(); |
| Matcher match = AT_N_SPEC.matcher(filepattern); |
| if (!match.find()) { |
| builder.add(filepattern); |
| } else { |
| int numShards = Integer.parseInt(match.group("N")); |
| String formatString = "-%0" + getShardWidth(numShards, filepattern) + "d-of-%05d"; |
| for (int i = 0; i < numShards; ++i) { |
| builder.add( |
| AT_N_SPEC.matcher(filepattern).replaceAll(String.format(formatString, i, numShards))); |
| } |
| if (match.find()) { |
| throw new IllegalArgumentException( |
| "More than one @N wildcard found in filepattern: " + filepattern); |
| } |
| } |
| return builder.build(); |
| } |
| |
| private static int getShardWidth(int numShards, String filepattern) { |
| if (numShards < 100000) { |
| return 5; |
| } |
| if (numShards < 1000000) { |
| return 6; |
| } |
| if (numShards < 10000000) { |
| return 7; |
| } |
| if (numShards < 100000000) { |
| return 8; |
| } |
| if (numShards < 1000000000) { |
| return 9; |
| } |
| throw new IllegalArgumentException( |
| "Unsupported number of shards: " + numShards + " in filepattern: " + filepattern); |
| } |
| } |