1 /* 2 * Copyright (C) 2010 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package vogar; 18 19 import java.io.File; 20 import java.util.List; 21 import vogar.commands.Command; 22 import vogar.commands.Mkdir; 23 24 public class HostFileCache implements FileCache { 25 private final File CACHE_ROOT = new File("/tmp/vogar-md5-cache"); 26 27 private final Log log; 28 private final Mkdir mkdir; 29 30 public HostFileCache(Log log, Mkdir mkdir) { 31 this.log = log; 32 this.mkdir = mkdir; 33 } 34 35 private void cp(File source, File destination) { 36 List<String> rawResult = new Command.Builder(log).args("cp", source, destination).execute(); 37 // A successful copy returns no results. 38 if (!rawResult.isEmpty()) { 39 throw new RuntimeException("Couldn't copy " + source + " to " + destination 40 + ": " + rawResult.get(0)); 41 } 42 } 43 44 private void mv(File source, File destination) { 45 List<String> rawResult = new Command.Builder(log).args("mv", source, destination).execute(); 46 // A successful move returns no results. 47 if (!rawResult.isEmpty()) { 48 throw new RuntimeException("Couldn't move " + source + " to " + destination 49 + ": " + rawResult.get(0)); 50 } 51 } 52 53 public void copyFromCache(String key, File destination) { 54 File cachedFile = new File(CACHE_ROOT, key); 55 cp(cachedFile, destination); 56 } 57 58 public void copyToCache(File source, String key) { 59 File cachedFile = new File(CACHE_ROOT, key); 60 mkdir.mkdirs(CACHE_ROOT); 61 // Copy it onto the same file system first, then atomically move it into place. 62 // That way, if we fail, we don't leave anything dangerous lying around. 63 File temporary = new File(cachedFile + ".tmp"); 64 cp(source, temporary); 65 mv(temporary, cachedFile); 66 } 67 68 public boolean existsInCache(String key) { 69 return new File(CACHE_ROOT, key).exists(); 70 } 71 } 72
