| // Copyright 2021 The Bazel Authors. All rights reserved. |
| // |
| // Licensed 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.google.devtools.build.lib.vfs; |
| |
| import java.util.Collections; |
| import java.util.Iterator; |
| import java.util.NoSuchElementException; |
| |
| /** |
| * Lazily iterates over the segments of a path string. |
| * |
| * <p>Expects the path string to already be normalized. |
| */ |
| final class PathSegmentIterator implements Iterator<String> { |
| |
| static Iterator<String> create(String normalizedPath, int driveStrLength) { |
| return normalizedPath.length() > driveStrLength |
| ? new PathSegmentIterator(normalizedPath, driveStrLength) |
| : Collections.emptyIterator(); |
| } |
| |
| private final String normalizedPath; |
| private int start; |
| |
| private PathSegmentIterator(String normalizedPath, int driveStrLength) { |
| this.normalizedPath = normalizedPath; |
| this.start = driveStrLength; |
| } |
| |
| @Override |
| public boolean hasNext() { |
| return start < normalizedPath.length(); |
| } |
| |
| @Override |
| public String next() { |
| if (!hasNext()) { |
| throw new NoSuchElementException("No more segments: " + normalizedPath); |
| } |
| int end = start + 1; |
| while (end < normalizedPath.length() |
| && normalizedPath.charAt(end) != PathFragment.SEPARATOR_CHAR) { |
| end++; |
| } |
| String segment = normalizedPath.substring(start, end); |
| start = end + 1; |
| return segment; |
| } |
| } |