[FileEncap9] Extract ResearchLogDirectory class

Previously used a monotonically increasing int.  Now uses uuid and nanoseconds.

squashed in:
    [FileEncap11] Read preference from ResearchSettings
    Change-Id: Ic779e0a69db6b16e92c6f4b63dbe7b7add566ab6

    [FileEncap12] Simplify directory cleanup invocation
    Change-Id: I688047409c0343d32b11447fb625dfb726c731ec

    [FileEncap14] Change log filename syntax
    Change-Id: I9243b20b2eb392f81ab8c5c3d19315211240e0bc

Change-Id: I5c9d70e0cb7b0965158e17dd71dfab796bd9a440

1 files changed, 111 insertions, 0 deletions

diff --git a/java/src/com/android/inputmethod/research/ResearchLogDirectory.java b/java/src/com/android/inputmethod/research/ResearchLogDirectory.java
new file mode 100644
index 000000000..291dea5d0
--- /dev/null
+++ b/java/src/com/android/inputmethod/research/ResearchLogDirectory.java
@@ -0,0 +1,111 @@
+/*
+ * Copyright (C) 2013 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.inputmethod.research;
+
+import android.content.Context;
+import android.util.Log;
+
+import java.io.File;
+import java.io.FileFilter;
+
+/**
+ * Manages log files.
+ *
+ * This class handles all aspects where and how research log data is stored.  This includes
+ * generating log filenames in the correct place with the correct names, and cleaning up log files
+ * under this directory.
+ */
+public class ResearchLogDirectory {
+    public static final String TAG = ResearchLogDirectory.class.getSimpleName();
+    /* package */ static final String LOG_FILENAME_PREFIX = "researchLog";
+    private static final String FILENAME_SUFFIX = ".txt";
+    private static final String USER_RECORDING_FILENAME_PREFIX = "recording";
+
+    private static final ReadOnlyLogFileFilter sUploadableLogFileFilter =
+            new ReadOnlyLogFileFilter();
+
+    private final File mFilesDir;
+
+    static class ReadOnlyLogFileFilter implements FileFilter {
+        @Override
+        public boolean accept(final File pathname) {
+            return pathname.getName().startsWith(ResearchLogDirectory.LOG_FILENAME_PREFIX)
+                    && !pathname.canWrite();
+        }
+    }
+
+    /**
+     * Creates a new ResearchLogDirectory, creating the storage directory if it does not exist.
+     */
+    public ResearchLogDirectory(final Context context) {
+        mFilesDir = getLoggingDirectory(context);
+        if (mFilesDir == null) {
+            throw new NullPointerException("No files directory specified");
+        }
+        if (!mFilesDir.exists()) {
+            mFilesDir.mkdirs();
+        }
+    }
+
+    private File getLoggingDirectory(final Context context) {
+        // TODO: Switch to using a subdirectory of getFilesDir().
+        return context.getFilesDir();
+    }
+
+    /**
+     * Get an array of log files that are ready for uploading.
+     *
+     * A file is ready for uploading if it is marked as read-only.
+     *
+     * @return the array of uploadable files
+     */
+    public File[] getUploadableLogFiles() {
+        try {
+            return mFilesDir.listFiles(sUploadableLogFileFilter);
+        } catch (final SecurityException e) {
+            Log.e(TAG, "Could not cleanup log directory, permission denied", e);
+            return new File[0];
+        }
+    }
+
+    public void cleanupLogFilesOlderThan(final long time) {
+        try {
+            for (final File file : mFilesDir.listFiles()) {
+                final String filename = file.getName();
+                if ((filename.startsWith(LOG_FILENAME_PREFIX)
+                        || filename.startsWith(USER_RECORDING_FILENAME_PREFIX))
+                        && (file.lastModified() < time)) {
+                    file.delete();
+                }
+            }
+        } catch (final SecurityException e) {
+            Log.e(TAG, "Could not cleanup log directory, permission denied", e);
+        }
+    }
+
+    public File getLogFilePath(final long time) {
+        return new File(mFilesDir, getUniqueFilename(LOG_FILENAME_PREFIX, time));
+    }
+
+    public File getUserRecordingFilePath(final long time) {
+        return new File(mFilesDir, getUniqueFilename(USER_RECORDING_FILENAME_PREFIX, time));
+    }
+
+    private static String getUniqueFilename(final String prefix, final long time) {
+        return prefix + "-" + time + FILENAME_SUFFIX;
+    }
+}