1 // Copyright 2017 The Bazel Authors. All rights reserved. 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 package com.google.devtools.build.android.desugar; 15 16 import static com.google.common.base.Preconditions.checkArgument; 17 18 import com.google.common.io.ByteStreams; 19 import java.io.BufferedOutputStream; 20 import java.io.IOException; 21 import java.io.InputStream; 22 import java.nio.file.Files; 23 import java.nio.file.Path; 24 import java.util.zip.CRC32; 25 import java.util.zip.ZipEntry; 26 import java.util.zip.ZipOutputStream; 27 28 /** Output provider is a zip file. */ 29 public class ZipOutputFileProvider implements OutputFileProvider { 30 31 private final ZipOutputStream out; 32 33 public ZipOutputFileProvider(Path root) throws IOException { 34 out = new ZipOutputStream(new BufferedOutputStream(Files.newOutputStream(root))); 35 } 36 37 @Override 38 public void copyFrom(String filename, InputFileProvider inputFileProvider) throws IOException { 39 // TODO(bazel-team): Avoid de- and re-compressing resource files 40 out.putNextEntry(inputFileProvider.getZipEntry(filename)); 41 try (InputStream is = inputFileProvider.getInputStream(filename)) { 42 ByteStreams.copy(is, out); 43 } 44 out.closeEntry(); 45 } 46 47 @Override 48 public void write(String filename, byte[] content) throws IOException { 49 checkArgument(filename.equals(DESUGAR_DEPS_FILENAME) || filename.endsWith(".class"), 50 "Expect file to be copied: %s", filename); 51 writeStoredEntry(out, filename, content); 52 } 53 54 @Override 55 public void close() throws IOException { 56 out.close(); 57 } 58 59 private static void writeStoredEntry(ZipOutputStream out, String filename, byte[] content) 60 throws IOException { 61 // Need to pre-compute checksum for STORED (uncompressed) entries) 62 CRC32 checksum = new CRC32(); 63 checksum.update(content); 64 65 ZipEntry result = new ZipEntry(filename); 66 result.setTime(0L); // Use stable timestamp Jan 1 1980 67 result.setCrc(checksum.getValue()); 68 result.setSize(content.length); 69 result.setCompressedSize(content.length); 70 // Write uncompressed, since this is just an intermediary artifact that 71 // we will convert to .dex 72 result.setMethod(ZipEntry.STORED); 73 74 out.putNextEntry(result); 75 out.write(content); 76 out.closeEntry(); 77 } 78 } 79
