1 files changed, 259 insertions, 0 deletions
diff --git a/mobile/android/geckoview/src/main/java/org/mozilla/gecko/util/FileUtils.java b/mobile/android/geckoview/src/main/java/org/mozilla/gecko/util/FileUtils.java
new file mode 100644
index 000000000..01cdd42bb
--- /dev/null
+++ b/mobile/android/geckoview/src/main/java/org/mozilla/gecko/util/FileUtils.java
@@ -0,0 +1,259 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.util;
+
+import android.util.Log;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.FilenameFilter;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.OutputStream;
+import java.io.OutputStreamWriter;
+import java.nio.charset.Charset;
+import java.util.Comparator;
+import java.util.Set;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+import org.mozilla.gecko.annotation.RobocopTarget;
+
+public class FileUtils {
+    private static final String LOGTAG = "GeckoFileUtils";
+
+    /*
+    * A basic Filter for checking a filename and age.
+    **/
+    static public class NameAndAgeFilter implements FilenameFilter {
+        final private String mName;
+        final private double mMaxAge;
+
+        public NameAndAgeFilter(String name, double age) {
+            mName = name;
+            mMaxAge = age;
+        }
+
+        @Override
+        public boolean accept(File dir, String filename) {
+            if (mName == null || mName.matches(filename)) {
+                File f = new File(dir, filename);
+
+                if (mMaxAge < 0 || System.currentTimeMillis() - f.lastModified() > mMaxAge) {
+                    return true;
+                }
+            }
+
+            return false;
+        }
+    }
+
+    @RobocopTarget
+    public static void delTree(File dir, FilenameFilter filter, boolean recurse) {
+        String[] files = null;
+
+        if (filter != null) {
+          files = dir.list(filter);
+        } else {
+          files = dir.list();
+        }
+
+        if (files == null) {
+          return;
+        }
+
+        for (String file : files) {
+            File f = new File(dir, file);
+            delete(f, recurse);
+        }
+    }
+
+    public static boolean delete(File file) throws IOException {
+        return delete(file, true);
+    }
+
+    public static boolean delete(File file, boolean recurse) {
+        if (file.isDirectory() && recurse) {
+            // If the quick delete failed and this is a dir, recursively delete the contents of the dir
+            String files[] = file.list();
+            for (String temp : files) {
+                File fileDelete = new File(file, temp);
+                try {
+                    delete(fileDelete);
+                } catch (IOException ex) {
+                    Log.i(LOGTAG, "Error deleting " + fileDelete.getPath(), ex);
+                }
+            }
+        }
+
+        // Even if this is a dir, it should now be empty and delete should work
+        return file.delete();
+    }
+
+    /**
+     * A generic solution to read a JSONObject from a file. See
+     * {@link #readStringFromFile(File)} for more details.
+     *
+     * @throws IOException if the file is empty, or another IOException occurs
+     * @throws JSONException if the file could not be converted to a JSONObject.
+     */
+    public static JSONObject readJSONObjectFromFile(final File file) throws IOException, JSONException {
+        if (file.length() == 0) {
+            // Redirect this exception so it's clearer than when the JSON parser catches it.
+            throw new IOException("Given file is empty - the JSON parser cannot create an object from an empty file");
+        }
+        return new JSONObject(readStringFromFile(file));
+    }
+
+    /**
+     * A generic solution to read from a file. For more details,
+     * see {@link #readStringFromInputStreamAndCloseStream(InputStream, int)}.
+     *
+     * This method loads the entire file into memory so will have the expected performance impact.
+     * If you're trying to read a large file, you should be handling your own reading to avoid
+     * out-of-memory errors.
+     */
+    public static String readStringFromFile(final File file) throws IOException {
+        // FileInputStream will throw FileNotFoundException if the file does not exist, but
+        // File.length will return 0 if the file does not exist so we catch it sooner.
+        if (!file.exists()) {
+            throw new FileNotFoundException("Given file, " + file + ", does not exist");
+        } else if (file.length() == 0) {
+            return "";
+        }
+        final int len = (int) file.length(); // includes potential EOF character.
+        return readStringFromInputStreamAndCloseStream(new FileInputStream(file), len);
+    }
+
+    /**
+     * A generic solution to read from an input stream in UTF-8. This function will read from the stream until it
+     * is finished and close the stream - this is necessary to close the wrapping resources.
+     *
+     * For a higher-level method, see {@link #readStringFromFile(File)}.
+     *
+     * Since this is generic, it may not be the most performant for your use case.
+     *
+     * @param bufferSize Size of the underlying buffer for read optimizations - must be > 0.
+     */
+    public static String readStringFromInputStreamAndCloseStream(final InputStream inputStream, final int bufferSize)
+            throws IOException {
+        if (bufferSize <= 0) {
+            // Safe close: it's more important to alert the programmer of
+            // their error than to let them catch and continue on their way.
+            IOUtils.safeStreamClose(inputStream);
+            throw new IllegalArgumentException("Expected buffer size larger than 0. Got: " + bufferSize);
+        }
+
+        final StringBuilder stringBuilder = new StringBuilder(bufferSize);
+        final InputStreamReader reader = new InputStreamReader(inputStream, Charset.forName("UTF-8"));
+        try {
+            int charsRead;
+            final char[] buffer = new char[bufferSize];
+            while ((charsRead = reader.read(buffer, 0, bufferSize)) != -1) {
+                stringBuilder.append(buffer, 0, charsRead);
+            }
+        } finally {
+            reader.close();
+        }
+        return stringBuilder.toString();
+    }
+
+    /**
+     * A generic solution to write a JSONObject to a file.
+     * See {@link #writeStringToFile(File, String)} for more details.
+     */
+    public static void writeJSONObjectToFile(final File file, final JSONObject obj) throws IOException {
+        writeStringToFile(file, obj.toString());
+    }
+
+    /**
+     * A generic solution to write to a File - the given file will be overwritten. If it does not exist yet, it will
+     * be created. See {@link #writeStringToOutputStreamAndCloseStream(OutputStream, String)} for more details.
+     */
+    public static void writeStringToFile(final File file, final String str) throws IOException {
+        writeStringToOutputStreamAndCloseStream(new FileOutputStream(file, false), str);
+    }
+
+    /**
+     * A generic solution to write to an output stream in UTF-8. The stream will be closed at the
+     * completion of this method - it's necessary in order to close the wrapping resources.
+     *
+     * For a higher-level method, see {@link #writeStringToFile(File, String)}.
+     *
+     * Since this is generic, it may not be the most performant for your use case.
+     */
+    public static void writeStringToOutputStreamAndCloseStream(final OutputStream outputStream, final String str)
+            throws IOException {
+        try {
+            final OutputStreamWriter writer = new OutputStreamWriter(outputStream, Charset.forName("UTF-8"));
+            try {
+                writer.write(str);
+            } finally {
+                writer.close();
+            }
+        } finally {
+            // OutputStreamWriter.close can throw before closing the
+            // underlying stream. For safety, we close here too.
+            outputStream.close();
+        }
+    }
+
+    public static class FilenameWhitelistFilter implements FilenameFilter {
+        private final Set<String> mFilenameWhitelist;
+
+        public FilenameWhitelistFilter(final Set<String> filenameWhitelist) {
+            mFilenameWhitelist = filenameWhitelist;
+        }
+
+        @Override
+        public boolean accept(final File dir, final String filename) {
+            return mFilenameWhitelist.contains(filename);
+        }
+    }
+
+    public static class FilenameRegexFilter implements FilenameFilter {
+        private final Pattern mPattern;
+
+        // Each time `Pattern.matcher` is called, a new matcher is created. We can avoid the excessive object creation
+        // by caching the returned matcher and calling `Matcher.reset` on it. Since Matcher's are not thread safe,
+        // this assumes `FilenameFilter.accept` is not run in parallel (which, according to the source, it is not).
+        private Matcher mCachedMatcher;
+
+        public FilenameRegexFilter(final Pattern pattern) {
+            mPattern = pattern;
+        }
+
+        @Override
+        public boolean accept(final File dir, final String filename) {
+            if (mCachedMatcher == null) {
+                mCachedMatcher = mPattern.matcher(filename);
+            } else {
+                mCachedMatcher.reset(filename);
+            }
+            return mCachedMatcher.matches();
+        }
+    }
+
+    public static class FileLastModifiedComparator implements Comparator<File> {
+        @Override
+        public int compare(final File lhs, final File rhs) {
+            // Long.compare is API 19+.
+            final long lhsModified = lhs.lastModified();
+            final long rhsModified = rhs.lastModified();
+            if (lhsModified < rhsModified) {
+                return -1;
+            } else if (lhsModified == rhsModified) {
+                return 0;
+            } else {
+                return 1;
+            }
+        }
+    }
+}