Stop creating message in NonSuchFileException unnecessarily

NoSuchFileException is thrown 29686 times during compilation of Music app
but its message is not obtained even once. location.getDescription is not
a cheap operation and message creation uses string concatenation as well.
Instead of creating a message eagerily this change stores a reference to
a location in the NonSuchFileExpection object and creates the message
only when it's needed. This speeds up the creation of NoSuchFileException
almost 40 times which makes a difference if we multiply it by almost 30k times
it's created. We will also save on GC as it saves at least 3 object creations
per NoSuchFileException which makes over 90k object creations saved.

Fix also other exceptions in com.android.sched.util.file.

Change-Id: Ibc2a413891a2e24be786f440196e9a4276215cc0

16 files changed, 275 insertions, 70 deletions

diff --git a/sched/src/com/android/sched/util/file/CannotCreateFileException.java b/sched/src/com/android/sched/util/file/CannotCreateFileException.java
index bf5b1fe..b637a54 100644
--- a/sched/src/com/android/sched/util/file/CannotCreateFileException.java
+++ b/sched/src/com/android/sched/util/file/CannotCreateFileException.java
@@ -16,25 +16,38 @@
 
 package com.android.sched.util.file;
 
+import com.android.sched.util.location.HasLocation;
 import com.android.sched.util.location.Location;
 
-import java.io.IOException;
-
 import javax.annotation.CheckForNull;
 import javax.annotation.Nonnull;
 
 /**
  * Exception when a file or directory can not be created.
  */
-public class CannotCreateFileException extends IOException {
+public class CannotCreateFileException extends WithLocationException {
   private static final long serialVersionUID = 1L;
 
   public CannotCreateFileException(@Nonnull Location location) {
-    this(location, null);
+    super(location, null);
   }
 
   public CannotCreateFileException(@Nonnull Location location,
       @CheckForNull Throwable cause) {
-    super(location.getDescription() + " can not be created", cause);
+    super(location, cause);
+  }
+
+  public CannotCreateFileException(@Nonnull HasLocation locationProvider) {
+    super(locationProvider, null);
+  }
+
+  public CannotCreateFileException(@Nonnull HasLocation locationProvider,
+      @CheckForNull Throwable cause) {
+    super(locationProvider, cause);
+  }
+
+  @Override
+  protected String createMessage(@Nonnull String description) {
+    return description + " can not be created";
   }
 }
diff --git a/sched/src/com/android/sched/util/file/CannotDeleteFileException.java b/sched/src/com/android/sched/util/file/CannotDeleteFileException.java
index 0779bda..7691d6c 100644
--- a/sched/src/com/android/sched/util/file/CannotDeleteFileException.java
+++ b/sched/src/com/android/sched/util/file/CannotDeleteFileException.java
@@ -16,25 +16,38 @@
 
 package com.android.sched.util.file;
 
+import com.android.sched.util.location.HasLocation;
 import com.android.sched.util.location.Location;
 
-import java.io.IOException;
-
 import javax.annotation.CheckForNull;
 import javax.annotation.Nonnull;
 
 /**
  * Exception thrown when deletion of a file or a directory fails.
  */
-public class CannotDeleteFileException extends IOException {
+public class CannotDeleteFileException extends WithLocationException {
   private static final long serialVersionUID = 1L;
 
   public CannotDeleteFileException(@Nonnull Location location) {
-    this(location, null);
+    super(location, null);
+  }
+
+  public CannotDeleteFileException(@Nonnull Location location,
+      @CheckForNull Throwable cause) {
+    super(location, cause);
+  }
+
+  public CannotDeleteFileException(@Nonnull HasLocation locationProvider) {
+    super(locationProvider, null);
+  }
+
+  public CannotDeleteFileException(@Nonnull HasLocation locationProvider,
+      @CheckForNull Throwable cause) {
+    super(locationProvider, cause);
   }
 
-  public CannotDeleteFileException(
-      @Nonnull Location location, @CheckForNull Throwable cause) {
-    super(location.getDescription() + " can not be deleted", cause);
+  @Override
+  protected String createMessage(@Nonnull String description) {
+    return description + " can not be deleted";
   }
 }
diff --git a/sched/src/com/android/sched/util/file/CannotReadException.java b/sched/src/com/android/sched/util/file/CannotReadException.java
index d34fecf..9b00a93 100644
--- a/sched/src/com/android/sched/util/file/CannotReadException.java
+++ b/sched/src/com/android/sched/util/file/CannotReadException.java
@@ -16,25 +16,38 @@
 
 package com.android.sched.util.file;
 
+import com.android.sched.util.location.HasLocation;
 import com.android.sched.util.location.Location;
 
-import java.io.IOException;
-
 import javax.annotation.CheckForNull;
 import javax.annotation.Nonnull;
 
 /**
  * Exception when a file can not be read.
  */
-public class CannotReadException extends IOException {
+public class CannotReadException extends WithLocationException {
   private static final long serialVersionUID = 1L;
 
   public CannotReadException(@Nonnull Location location) {
-    this(location, null);
+    super(location, null);
   }
 
   public CannotReadException(@Nonnull Location location,
       @CheckForNull Throwable cause) {
-    super(location.getDescription() + " can not be read", cause);
+    super(location, cause);
+  }
+
+  public CannotReadException(@Nonnull HasLocation locationProvider) {
+    super(locationProvider, null);
+  }
+
+  public CannotReadException(@Nonnull HasLocation locationProvider,
+      @CheckForNull Throwable cause) {
+    super(locationProvider, cause);
+  }
+
+  @Override
+  protected String createMessage(@Nonnull String description) {
+    return description + " can not be read";
   }
 }
diff --git a/sched/src/com/android/sched/util/file/CannotSetPermissionException.java b/sched/src/com/android/sched/util/file/CannotSetPermissionException.java
index 3f15f1d..59c203b 100644
--- a/sched/src/com/android/sched/util/file/CannotSetPermissionException.java
+++ b/sched/src/com/android/sched/util/file/CannotSetPermissionException.java
@@ -18,19 +18,22 @@ package com.android.sched.util.file;
 
 import com.android.sched.util.file.FileOrDirectory.ChangePermission;
 import com.android.sched.util.file.FileOrDirectory.Permission;
+import com.android.sched.util.location.HasLocation;
 import com.android.sched.util.location.Location;
 
-import java.io.IOException;
-
 import javax.annotation.CheckForNull;
 import javax.annotation.Nonnull;
 
 /**
  * Exception when a file or directory can not be set to the expected permission.
  */
-public class CannotSetPermissionException extends IOException {
+public class CannotSetPermissionException extends WithLocationException {
   private static final long serialVersionUID = 1L;
 
+  private final int permission;
+  @Nonnull
+  private final ChangePermission change;
+
   public CannotSetPermissionException(@Nonnull Location location, int permission,
       @Nonnull ChangePermission change) {
     this(location, permission, change, null);
@@ -38,10 +41,29 @@ public class CannotSetPermissionException extends IOException {
 
   public CannotSetPermissionException(@Nonnull Location location, int permission,
       @Nonnull ChangePermission change, @CheckForNull Throwable cause) {
-    super(location.getDescription() + " can not be set " +
-      ((permission == Permission.READ)    ? "readable" :
-      ((permission == Permission.WRITE)   ? "writable" :
-      ((permission == Permission.EXECUTE) ? "executable" : "???"))) +
-      ((change == ChangePermission.EVERYBODY) ? " for everybody" : ""), cause);
+    super(location, cause);
+    this.permission = permission;
+    this.change = change;
+  }
+
+  public CannotSetPermissionException(@Nonnull HasLocation locationProvider, int permission,
+      @Nonnull ChangePermission change) {
+    this(locationProvider, permission, change, null);
+  }
+
+  public CannotSetPermissionException(@Nonnull HasLocation locationProvider, int permission,
+      @Nonnull ChangePermission change, @CheckForNull Throwable cause) {
+    super(locationProvider, cause);
+    this.permission = permission;
+    this.change = change;
+  }
+
+  @Override
+  protected String createMessage(@Nonnull String description) {
+    return description + " can not be set " +
+        ((permission == Permission.READ)    ? "readable" :
+        ((permission == Permission.WRITE)   ? "writable" :
+        ((permission == Permission.EXECUTE) ? "executable" : "???"))) +
+        ((change == ChangePermission.EVERYBODY) ? " for everybody" : "");
   }
 }
diff --git a/sched/src/com/android/sched/util/file/FileAlreadyExistsException.java b/sched/src/com/android/sched/util/file/FileAlreadyExistsException.java
index 4e1f070..8c622ee 100644
--- a/sched/src/com/android/sched/util/file/FileAlreadyExistsException.java
+++ b/sched/src/com/android/sched/util/file/FileAlreadyExistsException.java
@@ -16,25 +16,38 @@
 
 package com.android.sched.util.file;
 
+import com.android.sched.util.location.HasLocation;
 import com.android.sched.util.location.Location;
 
-import java.io.IOException;
-
 import javax.annotation.CheckForNull;
 import javax.annotation.Nonnull;
 
 /**
  * Exception when a file or directory of that name already exists.
  */
-public class FileAlreadyExistsException extends IOException {
+public class FileAlreadyExistsException extends WithLocationException {
   private static final long serialVersionUID = 1L;
 
   public FileAlreadyExistsException(@Nonnull Location location) {
-    this(location, null);
+    super(location, null);
+  }
+
+  public FileAlreadyExistsException(@Nonnull Location location,
+      @CheckForNull Throwable cause) {
+    super(location, cause);
+  }
+
+  public FileAlreadyExistsException(@Nonnull HasLocation locationProvider) {
+    super(locationProvider, null);
+  }
+
+  public FileAlreadyExistsException(@Nonnull HasLocation locationProvider,
+      @CheckForNull Throwable cause) {
+    super(locationProvider, cause);
   }
 
-  public FileAlreadyExistsException(
-      @Nonnull Location location, @CheckForNull Throwable cause) {
-    super(location.getDescription() + " already exists", cause);
+  @Override
+  protected String createMessage(@Nonnull String description) {
+    return description + " already exists";
   }
 }
diff --git a/sched/src/com/android/sched/util/file/NoSuchFileException.java b/sched/src/com/android/sched/util/file/NoSuchFileException.java
index 16926e4..abaaf0c 100644
--- a/sched/src/com/android/sched/util/file/NoSuchFileException.java
+++ b/sched/src/com/android/sched/util/file/NoSuchFileException.java
@@ -16,24 +16,36 @@
 
 package com.android.sched.util.file;
 
+import com.android.sched.util.location.HasLocation;
 import com.android.sched.util.location.Location;
 
-import java.io.IOException;
-
 import javax.annotation.CheckForNull;
 import javax.annotation.Nonnull;
 
 /**
  * Exception when a file or directory does not exist.
  */
-public class NoSuchFileException extends IOException {
+public class NoSuchFileException extends WithLocationException {
   private static final long serialVersionUID = 1L;
 
   public NoSuchFileException(@Nonnull Location location) {
-    this(location, null);
+    super(location, null);
   }
 
   public NoSuchFileException(@Nonnull Location location, @CheckForNull Throwable cause) {
-    super(location.getDescription() + " does not exist", cause);
+    super(location, cause);
+  }
+
+  public NoSuchFileException(@Nonnull HasLocation locationProvider) {
+    super(locationProvider, null);
+  }
+
+  public NoSuchFileException(@Nonnull HasLocation location, @CheckForNull Throwable cause) {
+    super(location, cause);
+  }
+
+  @Override
+  protected String createMessage(@Nonnull String description) {
+    return description + " does not exist";
   }
 }
diff --git a/sched/src/com/android/sched/util/file/NotDirectoryException.java b/sched/src/com/android/sched/util/file/NotDirectoryException.java
index c47ff69..a0c3dab 100644
--- a/sched/src/com/android/sched/util/file/NotDirectoryException.java
+++ b/sched/src/com/android/sched/util/file/NotDirectoryException.java
@@ -16,6 +16,7 @@
 
 package com.android.sched.util.file;
 
+import com.android.sched.util.location.HasLocation;
 import com.android.sched.util.location.Location;
 
 import javax.annotation.CheckForNull;
@@ -27,11 +28,24 @@ import javax.annotation.Nonnull;
 public class NotDirectoryException extends NotFileOrDirectoryException {
   private static final long serialVersionUID = 1L;
 
-  public NotDirectoryException(@Nonnull Location expected) {
-    this(expected, null);
+  public NotDirectoryException(@Nonnull Location location) {
+    super(location, null);
   }
 
-  public NotDirectoryException(@Nonnull Location expected, @CheckForNull Throwable cause) {
-    super(expected.getDescription() + " is not actually a directory", cause);
+  public NotDirectoryException(@Nonnull Location location, @CheckForNull Throwable cause) {
+    super(location, cause);
+  }
+
+  public NotDirectoryException(@Nonnull HasLocation locationProvider) {
+    super(locationProvider, null);
+  }
+
+  public NotDirectoryException(@Nonnull HasLocation location, @CheckForNull Throwable cause) {
+    super(location, cause);
+  }
+
+  @Override
+  protected String createMessage(@Nonnull String description) {
+    return description + " is not actually a directory";
   }
 }
diff --git a/sched/src/com/android/sched/util/file/NotFileException.java b/sched/src/com/android/sched/util/file/NotFileException.java
index 87a8578..9d5cfc5 100644
--- a/sched/src/com/android/sched/util/file/NotFileException.java
+++ b/sched/src/com/android/sched/util/file/NotFileException.java
@@ -16,6 +16,7 @@
 
 package com.android.sched.util.file;
 
+import com.android.sched.util.location.HasLocation;
 import com.android.sched.util.location.Location;
 
 import javax.annotation.CheckForNull;
@@ -27,11 +28,24 @@ import javax.annotation.Nonnull;
 public class NotFileException extends NotFileOrDirectoryException {
   private static final long serialVersionUID = 1L;
 
-  public NotFileException(@Nonnull Location expected) {
-    this(expected, null);
+  public NotFileException(@Nonnull Location location) {
+    super(location, null);
   }
 
-  public NotFileException(@Nonnull Location expected, @CheckForNull Throwable cause) {
-    super(expected.getDescription() + " is not actually a file", cause);
+  public NotFileException(@Nonnull Location location, @CheckForNull Throwable cause) {
+    super(location, cause);
+  }
+
+  public NotFileException(@Nonnull HasLocation locationProvider) {
+    super(locationProvider, null);
+  }
+
+  public NotFileException(@Nonnull HasLocation location, @CheckForNull Throwable cause) {
+    super(location, cause);
+  }
+
+  @Override
+  protected String createMessage(@Nonnull String description) {
+    return description + " is not actually a file";
   }
 }
diff --git a/sched/src/com/android/sched/util/file/NotFileOrDirectoryException.java b/sched/src/com/android/sched/util/file/NotFileOrDirectoryException.java
index 37b0899..43e55b4 100644
--- a/sched/src/com/android/sched/util/file/NotFileOrDirectoryException.java
+++ b/sched/src/com/android/sched/util/file/NotFileOrDirectoryException.java
@@ -16,7 +16,8 @@
 
 package com.android.sched.util.file;
 
-import java.io.IOException;
+import com.android.sched.util.location.HasLocation;
+import com.android.sched.util.location.Location;
 
 import javax.annotation.CheckForNull;
 import javax.annotation.Nonnull;
@@ -24,14 +25,15 @@ import javax.annotation.Nonnull;
 /**
  * Exception when a path is not from the expected file or directory kind.
  */
-public abstract class NotFileOrDirectoryException extends IOException {
+public abstract class NotFileOrDirectoryException extends WithLocationException {
   private static final long serialVersionUID = 1L;
 
-  public NotFileOrDirectoryException(@Nonnull String string) {
-    super(string);
+  public NotFileOrDirectoryException(@Nonnull Location location, @CheckForNull Throwable cause) {
+    super(location, cause);
   }
 
-  public NotFileOrDirectoryException(@Nonnull String string, @CheckForNull Throwable cause) {
-    super(string, cause);
+  public NotFileOrDirectoryException(@Nonnull HasLocation locationProvider,
+      @CheckForNull Throwable cause) {
+    super(locationProvider, cause);
   }
 }
diff --git a/sched/src/com/android/sched/util/file/WithLocationException.java b/sched/src/com/android/sched/util/file/WithLocationException.java
new file mode 100644
index 0000000..4d5a08f
--- /dev/null
+++ b/sched/src/com/android/sched/util/file/WithLocationException.java
@@ -0,0 +1,67 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * 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.android.sched.util.file;
+
+import com.android.sched.util.location.HasLocation;
+import com.android.sched.util.location.Location;
+
+import java.io.IOException;
+
+import javax.annotation.CheckForNull;
+import javax.annotation.Nonnull;
+
+/**
+ * Common superclass for exceptions which are related to a specific location.
+ */
+public abstract class WithLocationException extends IOException {
+  private static final long serialVersionUID = 1L;
+
+  @CheckForNull
+  private final Location location;
+  @CheckForNull
+  private final HasLocation locationProvider;
+
+  @Nonnull
+  protected abstract String createMessage(@Nonnull String description);
+
+  protected WithLocationException(@Nonnull Location location, @CheckForNull Throwable cause) {
+    super("", cause);
+    assert location != null;
+    this.location = location;
+    this.locationProvider = null;
+  }
+
+  protected WithLocationException(@Nonnull HasLocation locationProvider,
+      @CheckForNull Throwable cause) {
+    super("", cause);
+    assert locationProvider != null;
+    this.location = null;
+    this.locationProvider = locationProvider;
+  }
+
+  @Override
+  @Nonnull
+  public String getMessage() {
+    if (location != null) {
+      return createMessage(location.getDescription());
+    }
+    if (locationProvider != null) {
+      return createMessage(locationProvider.getLocation().getDescription());
+    }
+    throw new AssertionError();
+  }
+}
diff --git a/sched/src/com/android/sched/util/file/WrongPermissionException.java b/sched/src/com/android/sched/util/file/WrongPermissionException.java
index e4faea0..f046d90 100644
--- a/sched/src/com/android/sched/util/file/WrongPermissionException.java
+++ b/sched/src/com/android/sched/util/file/WrongPermissionException.java
@@ -17,28 +17,47 @@
 package com.android.sched.util.file;
 
 import com.android.sched.util.file.FileOrDirectory.Permission;
+import com.android.sched.util.location.HasLocation;
 import com.android.sched.util.location.Location;
 
-import java.io.IOException;
-
 import javax.annotation.CheckForNull;
 import javax.annotation.Nonnull;
 
 /**
  * Exception when a file or directory have not the expected permission.
  */
-public class WrongPermissionException extends IOException {
+public class WrongPermissionException extends WithLocationException {
   private static final long serialVersionUID = 1L;
 
+  private final int permission;
+
   public WrongPermissionException(@Nonnull Location location, int permission) {
-    this(location, permission, null);
+    super(location, null);
+    this.permission = permission;
   }
 
   public WrongPermissionException(@Nonnull Location location, int permission,
       @CheckForNull Throwable cause) {
-    super(location.getDescription() + " is not " +
-      ((permission == Permission.READ)    ? "readable" :
-      ((permission == Permission.WRITE)   ? "writable" :
-      ((permission == Permission.EXECUTE) ? "executable" : "???"))), cause);
+    super(location, cause);
+    this.permission = permission;
+  }
+
+  public WrongPermissionException(@Nonnull HasLocation locationProvider, int permission) {
+    super(locationProvider, null);
+    this.permission = permission;
+  }
+
+  public WrongPermissionException(@Nonnull HasLocation location, int permission,
+      @CheckForNull Throwable cause) {
+    super(location, cause);
+    this.permission = permission;
+  }
+
+  @Override
+  protected String createMessage(@Nonnull String description) {
+    return description + " is not " +
+        ((permission == Permission.READ)    ? "readable" :
+        ((permission == Permission.WRITE)   ? "writable" :
+        ((permission == Permission.EXECUTE) ? "executable" : "???")));
   }
 }
diff --git a/sched/src/com/android/sched/vfs/CachedDirectFS.java b/sched/src/com/android/sched/vfs/CachedDirectFS.java
index de2deee..83512be 100644
--- a/sched/src/com/android/sched/vfs/CachedDirectFS.java
+++ b/sched/src/com/android/sched/vfs/CachedDirectFS.java
@@ -288,7 +288,7 @@ public class CachedDirectFS extends BaseVFS<CachedParentVDir, CachedParentVFile>
 
     File path = getNativeFile(file.getPath());
     if (!path.delete() || path.exists()) {
-      throw new CannotDeleteFileException(file.getLocation());
+      throw new CannotDeleteFileException(file);
     }
 
     file.deleteFromCache();
@@ -297,8 +297,8 @@ public class CachedDirectFS extends BaseVFS<CachedParentVDir, CachedParentVFile>
 
   @Override
   @Nonnull
-  synchronized CachedParentVFile createVFile(@Nonnull CachedParentVDir parent, @Nonnull String name)
-      throws CannotCreateFileException {
+  synchronized CachedParentVFile createVFile(@Nonnull CachedParentVDir parent,
+      @Nonnull String name) throws CannotCreateFileException {
     assert !isClosed();
 
     try {
@@ -324,7 +324,8 @@ public class CachedDirectFS extends BaseVFS<CachedParentVDir, CachedParentVFile>
 
   @Override
   @Nonnull
-  synchronized CachedParentVDir createVDir(@Nonnull CachedParentVDir parent, @Nonnull String name)
+  synchronized CachedParentVDir createVDir(@Nonnull CachedParentVDir parent,
+      @Nonnull String name)
       throws CannotCreateFileException {
     assert !isClosed();
 
diff --git a/sched/src/com/android/sched/vfs/CaseInsensitiveFS.java b/sched/src/com/android/sched/vfs/CaseInsensitiveFS.java
index 1188bf4..1c81dfa 100644
--- a/sched/src/com/android/sched/vfs/CaseInsensitiveFS.java
+++ b/sched/src/com/android/sched/vfs/CaseInsensitiveFS.java
@@ -379,11 +379,11 @@ public class CaseInsensitiveFS extends BaseVFS<CaseInsensitiveVDir, CaseInsensit
       BaseVFile encoded = vfs.getRootDir().getVFile(encode(file.getPath()));
       vfs.delete(encoded);
     } catch (NotDirectoryException e) {
-      throw new CannotDeleteFileException(file.getLocation());
+      throw new CannotDeleteFileException(file);
     } catch (NotFileException e) {
-      throw new CannotDeleteFileException(file.getLocation());
+      throw new CannotDeleteFileException(file);
     } catch (NoSuchFileException e) {
-      throw new CannotDeleteFileException(file.getLocation());
+      throw new CannotDeleteFileException(file);
     }
   }
 
diff --git a/sched/src/com/android/sched/vfs/DirectFS.java b/sched/src/com/android/sched/vfs/DirectFS.java
index a9537f6..b280a40 100644
--- a/sched/src/com/android/sched/vfs/DirectFS.java
+++ b/sched/src/com/android/sched/vfs/DirectFS.java
@@ -223,7 +223,7 @@ public class DirectFS extends BaseVFS<ParentVDir, ParentVFile> implements VFS {
 
     File path = getNativeFile(file.getPath());
     if (!path.delete() || path.exists()) {
-      throw new CannotDeleteFileException(file.getLocation());
+      throw new CannotDeleteFileException(file);
     }
   }
 
diff --git a/sched/src/com/android/sched/vfs/InMemoryVDir.java b/sched/src/com/android/sched/vfs/InMemoryVDir.java
index 4ace1fc..ad6f186 100644
--- a/sched/src/com/android/sched/vfs/InMemoryVDir.java
+++ b/sched/src/com/android/sched/vfs/InMemoryVDir.java
@@ -83,7 +83,8 @@ abstract class InMemoryVDir extends BaseVDir {
 
   @Override
   @Nonnull
-  public synchronized BaseVDir createVDir(@Nonnull String name) throws CannotCreateFileException {
+  public synchronized BaseVDir createVDir(@Nonnull String name)
+      throws CannotCreateFileException {
     try {
       return getVDir(name);
     } catch (NoSuchFileException e) {
@@ -98,7 +99,8 @@ abstract class InMemoryVDir extends BaseVDir {
 
   @Override
   @Nonnull
-  public synchronized BaseVFile createVFile(@Nonnull String name) throws CannotCreateFileException {
+  public synchronized BaseVFile createVFile(@Nonnull String name)
+      throws CannotCreateFileException {
     try {
       return getVFile(name);
     } catch (NoSuchFileException e) {
diff --git a/sched/src/com/android/sched/vfs/MessageDigestFS.java b/sched/src/com/android/sched/vfs/MessageDigestFS.java
index 294eb6d..d01c1e0 100644
--- a/sched/src/com/android/sched/vfs/MessageDigestFS.java
+++ b/sched/src/com/android/sched/vfs/MessageDigestFS.java
@@ -197,7 +197,7 @@ public class MessageDigestFS extends BaseVFS<BaseVDir, MessageDigestVFile> imple
         }
       } catch (IOException e) {
         throw new WrongVFSFormatException(this, vfs.getLocation(), new CannotReadException(
-            digestFile.getLocation()));
+            digestFile));
       }
     } finally {
       if (in != null) {