1 files changed, 97 insertions, 0 deletions
diff --git a/src/com/google/testing/littlemock/AppDataDirGuesser.java b/src/com/google/testing/littlemock/AppDataDirGuesser.java
new file mode 100644
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+++ b/src/com/google/testing/littlemock/AppDataDirGuesser.java
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+/*
+ * Copyright (C) 2011 Google Inc.
+ *
+ * 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.google.testing.littlemock;
+
+import java.io.File;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Utility class for helping guess the application data directory.
+ */
+public class AppDataDirGuesser {
+
+  /** A single default instance of app data dir guesser, for overriding if you really need to. */
+  private static volatile AppDataDirGuesser sInjectableInstance = new AppDataDirGuesser();
+
+  public static void setInstance(AppDataDirGuesser instance) {
+    sInjectableInstance = instance;
+  }
+
+  public static AppDataDirGuesser getsInstance() {
+    return sInjectableInstance;
+  }
+
+  public File guessSuitableDirectoryForGeneratedClasses() {
+    try {
+      ClassLoader classLoader = AppDataDirGuesser.class.getClassLoader();
+      // Check that we have an instance of the PathClassLoader.
+      Class<?> clazz = Class.forName("dalvik.system.PathClassLoader");
+      clazz.cast(classLoader);
+      // Use the toString() method to calculate the data directory.
+      String pathFromThisClassLoader = getPathFromThisClassLoader(classLoader);
+      File[] results = guessPath(pathFromThisClassLoader);
+      if (results.length > 0) {
+        return results[0];
+      }
+    } catch (ClassCastException e) {
+      // Fall through, we will return null.
+    } catch (ClassNotFoundException e) {
+      // Fall through, we will return null.
+    }
+    return null;
+  }
+
+  private String getPathFromThisClassLoader(ClassLoader classLoader) {
+    // Parsing toString() method: yuck.  But no other way to get the path.
+    // Strip out the bit between angle brackets, that's our path.
+    String result = classLoader.toString();
+    int index = result.lastIndexOf('[');
+    result = (index == -1) ? result : result.substring(index + 1);
+    index = result.indexOf(']');
+    return (index == -1) ? result : result.substring(0, index);
+  }
+
+  // @VisibleForTesting
+  File[] guessPath(String input) {
+    List<File> results = new ArrayList<File>();
+    for (String potential : input.split(":")) {
+      if (!potential.startsWith("/data/app/")) {
+        continue;
+      }
+      int start = "/data/app/".length();
+      int end = potential.lastIndexOf(".apk");
+      if (end != potential.length() - 4) {
+        continue;
+      }
+      int dash = potential.indexOf("-");
+      if (dash != -1) {
+        end = dash;
+      }
+      File file = new File("/data/data/" + potential.substring(start, end) + "/cache");
+      if (isWriteableDirectory(file)) {
+        results.add(file);
+      }
+    }
+    return results.toArray(new File[results.size()]);
+  }
+
+  // @VisibleForTesting
+  boolean isWriteableDirectory(File file) {
+    return file.isDirectory() && file.canWrite();
+  }
+}