| /** |
| * 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.hadoop.fs; |
| |
| import java.io.IOException; |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| |
| @InterfaceAudience.Private |
| @InterfaceStability.Unstable |
| class GlobExpander { |
| |
| static class StringWithOffset { |
| String string; |
| int offset; |
| public StringWithOffset(String string, int offset) { |
| super(); |
| this.string = string; |
| this.offset = offset; |
| } |
| } |
| |
| /** |
| * Expand globs in the given <code>filePattern</code> into a collection of |
| * file patterns so that in the expanded set no file pattern has a |
| * slash character ("/") in a curly bracket pair. |
| * @param filePattern |
| * @return expanded file patterns |
| * @throws IOException |
| */ |
| public static List<String> expand(String filePattern) throws IOException { |
| List<String> fullyExpanded = new ArrayList<String>(); |
| List<StringWithOffset> toExpand = new ArrayList<StringWithOffset>(); |
| toExpand.add(new StringWithOffset(filePattern, 0)); |
| while (!toExpand.isEmpty()) { |
| StringWithOffset path = toExpand.remove(0); |
| List<StringWithOffset> expanded = expandLeftmost(path); |
| if (expanded == null) { |
| fullyExpanded.add(path.string); |
| } else { |
| toExpand.addAll(0, expanded); |
| } |
| } |
| return fullyExpanded; |
| } |
| |
| /** |
| * Expand the leftmost outer curly bracket pair containing a |
| * slash character ("/") in <code>filePattern</code>. |
| * @param filePattern |
| * @return expanded file patterns |
| * @throws IOException |
| */ |
| private static List<StringWithOffset> expandLeftmost(StringWithOffset |
| filePatternWithOffset) throws IOException { |
| |
| String filePattern = filePatternWithOffset.string; |
| int leftmost = leftmostOuterCurlyContainingSlash(filePattern, |
| filePatternWithOffset.offset); |
| if (leftmost == -1) { |
| return null; |
| } |
| int curlyOpen = 0; |
| StringBuilder prefix = new StringBuilder(filePattern.substring(0, leftmost)); |
| StringBuilder suffix = new StringBuilder(); |
| List<String> alts = new ArrayList<String>(); |
| StringBuilder alt = new StringBuilder(); |
| StringBuilder cur = prefix; |
| for (int i = leftmost; i < filePattern.length(); i++) { |
| char c = filePattern.charAt(i); |
| if (cur == suffix) { |
| cur.append(c); |
| } else if (c == '\\') { |
| i++; |
| if (i >= filePattern.length()) { |
| throw new IOException("Illegal file pattern: " |
| + "An escaped character does not present for glob " |
| + filePattern + " at " + i); |
| } |
| c = filePattern.charAt(i); |
| cur.append(c); |
| } else if (c == '{') { |
| if (curlyOpen++ == 0) { |
| alt.setLength(0); |
| cur = alt; |
| } else { |
| cur.append(c); |
| } |
| |
| } else if (c == '}' && curlyOpen > 0) { |
| if (--curlyOpen == 0) { |
| alts.add(alt.toString()); |
| alt.setLength(0); |
| cur = suffix; |
| } else { |
| cur.append(c); |
| } |
| } else if (c == ',') { |
| if (curlyOpen == 1) { |
| alts.add(alt.toString()); |
| alt.setLength(0); |
| } else { |
| cur.append(c); |
| } |
| } else { |
| cur.append(c); |
| } |
| } |
| List<StringWithOffset> exp = new ArrayList<StringWithOffset>(); |
| for (String string : alts) { |
| exp.add(new StringWithOffset(prefix + string + suffix, prefix.length())); |
| } |
| return exp; |
| } |
| |
| /** |
| * Finds the index of the leftmost opening curly bracket containing a |
| * slash character ("/") in <code>filePattern</code>. |
| * @param filePattern |
| * @return the index of the leftmost opening curly bracket containing a |
| * slash character ("/"), or -1 if there is no such bracket |
| * @throws IOException |
| */ |
| private static int leftmostOuterCurlyContainingSlash(String filePattern, |
| int offset) throws IOException { |
| int curlyOpen = 0; |
| int leftmost = -1; |
| boolean seenSlash = false; |
| for (int i = offset; i < filePattern.length(); i++) { |
| char c = filePattern.charAt(i); |
| if (c == '\\') { |
| i++; |
| if (i >= filePattern.length()) { |
| throw new IOException("Illegal file pattern: " |
| + "An escaped character does not present for glob " |
| + filePattern + " at " + i); |
| } |
| } else if (c == '{') { |
| if (curlyOpen++ == 0) { |
| leftmost = i; |
| } |
| } else if (c == '}' && curlyOpen > 0) { |
| if (--curlyOpen == 0 && leftmost != -1 && seenSlash) { |
| return leftmost; |
| } |
| } else if (c == '/' && curlyOpen > 0) { |
| seenSlash = true; |
| } |
| } |
| return -1; |
| } |
| |
| } |