Stores temporary cache files under cache directory. (GoogleContainerT…

…ools#1037)

jib-core/src/main/java/com/google/cloud/tools/jib/filesystem/TemporaryDirectory.java

@@ -32,12 +32,13 @@ public class TemporaryDirectory implements Closeable {
   private final Path temporaryDirectory;
 
   /**
-   * Creates a new temporary directory.
+   * Creates a new temporary directory under an existing {@code parentDirectory}.
    *
+   * @param parentDirectory the directory to create the temporary directory within
    * @throws IOException if an I/O exception occurs
    */
-  public TemporaryDirectory() throws IOException {
-    temporaryDirectory = Files.createTempDirectory(null);
+  public TemporaryDirectory(Path parentDirectory) throws IOException {
+    temporaryDirectory = Files.createTempDirectory(parentDirectory, null);
   }
 
   /**

jib-core/src/main/java/com/google/cloud/tools/jib/ncache/DefaultCacheStorageFiles.java

@@ -26,6 +26,7 @@ class DefaultCacheStorageFiles {
   private static final String LAYERS_DIRECTORY = "layers";
   private static final String METADATA_FILENAME = "metadata";
   private static final String SELECTORS_DIRECTORY = "selectors";
+  private static final String TEMPORARY_DIRECTORY = "tmp";
 
   /**
    * Returns whether or not {@code file} is a layer contents file.
@@ -140,4 +141,13 @@ Path getLayersDirectory() {
   Path getLayerDirectory(DescriptorDigest layerDigest) {
     return getLayersDirectory().resolve(layerDigest.getHash());
   }
+
+  /**
+   * Gets the directory to store temporary files.
+   *
+   * @return the directory for temporary files
+   */
+  Path getTemporaryDirectory() {
+    return cacheDirectory.resolve(TEMPORARY_DIRECTORY);
+  }
 }

jib-core/src/main/java/com/google/cloud/tools/jib/ncache/DefaultCacheStorageWriter.java

@@ -25,10 +25,13 @@
 import java.io.BufferedOutputStream;
 import java.io.IOException;
 import java.nio.file.AtomicMoveNotSupportedException;
+import java.nio.file.DirectoryNotEmptyException;
 import java.nio.file.FileAlreadyExistsException;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.StandardCopyOption;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 import java.util.zip.GZIPOutputStream;
 
 /** Writes to the default cache storage engine. */
@@ -59,6 +62,10 @@ private WrittenLayer(
    * @throws IOException if an I/O exception occurs
    */
   private static void moveIfDoesNotExist(Path source, Path destination) throws IOException {
+    if (Files.exists(destination)) {
+      return;
+    }
+
     try {
       Files.move(source, destination, StandardCopyOption.ATOMIC_MOVE);
 
@@ -75,6 +82,15 @@ private static void moveIfDoesNotExist(Path source, Path destination) throws IOE
 
       } catch (FileAlreadyExistsException alsoIgnored) {
         // Same reasoning
+
+      } catch (DirectoryNotEmptyException ex) {
+        // The file system cannot rename directories, so we must resort to copying the directory.
+        Files.createDirectory(destination);
+        try (Stream<Path> sourceFiles = Files.list(source)) {
+          for (Path sourceFile : sourceFiles.collect(Collectors.toList())) {
+            Files.copy(sourceFile, destination.resolve(sourceFile.getFileName()));
+          }
+        }
       }
     }
   }
@@ -108,8 +124,11 @@ CacheEntry write(CacheWrite cacheWrite) throws IOException {
     // Creates the layers directory if it doesn't exist.
     Files.createDirectories(defaultCacheStorageFiles.getLayersDirectory());
 
-    // Creates the temporary directory.
-    try (TemporaryDirectory temporaryDirectory = new TemporaryDirectory()) {
+    // Creates the temporary directory. The temporary directory must be in the same FileStore as the
+    // final location for Files.move to work.
+    Files.createDirectories(defaultCacheStorageFiles.getTemporaryDirectory());
+    try (TemporaryDirectory temporaryDirectory =
+        new TemporaryDirectory(defaultCacheStorageFiles.getTemporaryDirectory())) {
       Path temporaryLayerDirectory = temporaryDirectory.getDirectory();
 
       // Writes the layer file to the temporary directory.

jib-core/src/test/java/com/google/cloud/tools/jib/filesystem/TemporaryDirectoryTest.java

@@ -42,7 +42,8 @@ private static void createFilesInDirectory(Path directory)
 
   @Test
   public void testClose_directoryDeleted() throws IOException, URISyntaxException {
-    try (TemporaryDirectory temporaryDirectory = new TemporaryDirectory()) {
+    try (TemporaryDirectory temporaryDirectory =
+        new TemporaryDirectory(temporaryFolder.newFolder().toPath())) {
       createFilesInDirectory(temporaryDirectory.getDirectory());
 
       temporaryDirectory.close();
@@ -54,7 +55,8 @@ public void testClose_directoryDeleted() throws IOException, URISyntaxException
   public void testClose_directoryNotDeletedIfMoved() throws IOException, URISyntaxException {
     Path destinationParent = temporaryFolder.newFolder().toPath();
 
-    try (TemporaryDirectory temporaryDirectory = new TemporaryDirectory()) {
+    try (TemporaryDirectory temporaryDirectory =
+        new TemporaryDirectory(temporaryFolder.newFolder().toPath())) {
       createFilesInDirectory(temporaryDirectory.getDirectory());
 
       Assert.assertFalse(Files.exists(destinationParent.resolve("destination")));

jib-core/src/test/java/com/google/cloud/tools/jib/ncache/DefaultCacheStorageFilesTest.java

@@ -178,4 +178,10 @@ public void testGetLayerDirectory() throws DigestException {
             "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"),
         testDefaultCacheStorageFiles.getLayerDirectory(layerDigest));
   }
+
+  @Test
+  public void testGetTemporaryDirectory() {
+    Assert.assertEquals(
+        Paths.get("cache/directory/tmp"), testDefaultCacheStorageFiles.getTemporaryDirectory());
+  }
 }