com.github.pms1.tppt.p2.AbstractZipComparator Maven / Gradle / Ivy

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package com.github.pms1.tppt.p2;

import java.io.IOException;
import java.nio.file.FileSystem;
import java.nio.file.FileSystems;
import java.nio.file.FileVisitResult;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.SimpleFileVisitor;
import java.nio.file.attribute.BasicFileAttributes;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.function.Consumer;
import java.util.zip.ZipError;

import org.codehaus.plexus.component.annotations.Requirement;

import com.google.common.collect.Sets;

abstract public class AbstractZipComparator implements FileComparator {

	@Requirement(hint = BinaryComparator.HINT)
	private FileComparator binaryComparator;

	@Override
	public final void compare(FileId file1, Path p1, FileId file2, Path p2, Consumer dest)
			throws IOException {

		try (FileSystem fs1 = FileSystems.newFileSystem(p1, getClass().getClassLoader())) {
			Map s1 = asMap(file1, fs1);

			try (FileSystem fs2 = FileSystems.newFileSystem(p2, getClass().getClassLoader())) {
				Map s2 = asMap(file2, fs2);

				for (String p : Sets.union(s1.keySet(), s2.keySet())) {
					Path pc1 = s1.get(p);
					if (pc1 == null) {
						dest.accept(new ArchiveContentAddedDelta(file1, file2, p));
						continue;
					}
					Path pc2 = s2.get(p);
					if (pc2 == null) {
						dest.accept(new ArchiveContentRemovedDelta(file1, file2, p));
						continue;
					}

					FileId c1 = FileId.newChild(file1, pc1);
					FileId c2 = FileId.newChild(file2, pc2);
					List binaryDelta = new ArrayList<>();
					binaryComparator.compare(c1, pc1, c2, pc2, binaryDelta::add);

					if (binaryDelta.isEmpty())
						continue;

					FileComparator comparator = getComparator(p);
					if (comparator == null) {
						binaryDelta.forEach(dest);
						continue;
					}

					comparator.compare(c1, pc1, c2, pc2, dest);
				}
			} catch (ZipError e) {
				throw new UnparseableZipException(file2, e);
			}

		} catch (ZipError e) {
			throw new UnparseableZipException(file1, e);
		}
	}

	abstract protected FileComparator getComparator(String p);

	static class UnparseableZipException extends SemanticException {

		public UnparseableZipException(FileId file, Throwable parent) {
			super(file, parent.toString(), parent);
		}

	}

	private Map asMap(FileId fileId, FileSystem fs1) throws IOException {
		Map result = new HashMap<>();
		try {
			Files.walkFileTree(fs1.getPath("/"), new SimpleFileVisitor() {
				@Override
				public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
					result.put(file.toString(), file);
					return super.visitFile(file, attrs);
				}
			});
		} catch (ArrayIndexOutOfBoundsException e) {
			// seen on some IBM Jars, e.g.
			// com.ibm.help.common.accessibility.doc_7.6.0.v20130521_2201.jar
			// cygwin's unzip also reports errors on those.
			throw new UnparseableZipException(fileId, e);

		}
		return result;
	}

}