Eleven: rebrand step 1: update paths

Change-Id: Iab35e4024e20c48e7439e78d1c6efe0ef4f730ca

1 files changed, 969 insertions, 0 deletions

diff --git a/src/org/lineageos/eleven/cache/DiskLruCache.java b/src/org/lineageos/eleven/cache/DiskLruCache.java
new file mode 100644
index 0000000..0e33afb
--- /dev/null
+++ b/src/org/lineageos/eleven/cache/DiskLruCache.java
@@ -0,0 +1,969 @@
+/*
+ * Copyright (C) 2011 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.cyanogenmod.eleven.cache;
+
+import java.io.BufferedInputStream;
+import java.io.BufferedWriter;
+import java.io.Closeable;
+import java.io.EOFException;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.FileWriter;
+import java.io.FilterOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.OutputStream;
+import java.io.OutputStreamWriter;
+import java.io.Reader;
+import java.io.StringWriter;
+import java.io.Writer;
+import java.lang.reflect.Array;
+import java.nio.charset.Charset;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.concurrent.Callable;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.LinkedBlockingQueue;
+import java.util.concurrent.ThreadPoolExecutor;
+import java.util.concurrent.TimeUnit;
+
+/**
+ ****************************************************************************** Taken from the JB source code, can be found in:
+ * libcore/luni/src/main/java/libcore/io/DiskLruCache.java or direct link:
+ * https:
+ * //android.googlesource.com/platform/libcore/+/android-4.1.1_r1/luni/src/
+ * main/java/libcore/io/DiskLruCache.java A cache that uses a bounded amount of
+ * space on a filesystem. Each cache entry has a string key and a fixed number
+ * of values. Values are byte sequences, accessible as streams or files. Each
+ * value must be between {@code 0} and {@code Integer.MAX_VALUE} bytes in
+ * length.
+ * <p>
+ * The cache stores its data in a directory on the filesystem. This directory
+ * must be exclusive to the cache; the cache may delete or overwrite files from
+ * its directory. It is an error for multiple processes to use the same cache
+ * directory at the same time.
+ * <p>
+ * This cache limits the number of bytes that it will store on the filesystem.
+ * When the number of stored bytes exceeds the limit, the cache will remove
+ * entries in the background until the limit is satisfied. The limit is not
+ * strict: the cache may temporarily exceed it while waiting for files to be
+ * deleted. The limit does not include filesystem overhead or the cache journal
+ * so space-sensitive applications should set a conservative limit.
+ * <p>
+ * Clients call {@link #edit} to create or update the values of an entry. An
+ * entry may have only one editor at one time; if a value is not available to be
+ * edited then {@link #edit} will return null.
+ * <ul>
+ * <li>When an entry is being <strong>created</strong> it is necessary to supply
+ * a full set of values; the empty value should be used as a placeholder if
+ * necessary.
+ * <li>When an entry is being <strong>edited</strong>, it is not necessary to
+ * supply data for every value; values default to their previous value.
+ * </ul>
+ * Every {@link #edit} call must be matched by a call to {@link Editor#commit}
+ * or {@link Editor#abort}. Committing is atomic: a read observes the full set
+ * of values as they were before or after the commit, but never a mix of values.
+ * <p>
+ * Clients call {@link #get} to read a snapshot of an entry. The read will
+ * observe the value at the time that {@link #get} was called. Updates and
+ * removals after the call do not impact ongoing reads.
+ * <p>
+ * This class is tolerant of some I/O errors. If files are missing from the
+ * filesystem, the corresponding entries will be dropped from the cache. If an
+ * error occurs while writing a cache value, the edit will fail silently.
+ * Callers should handle other problems by catching {@code IOException} and
+ * responding appropriately.
+ */
+public final class DiskLruCache implements Closeable {
+    static final String JOURNAL_FILE = "journal";
+
+    static final String JOURNAL_FILE_TMP = "journal.tmp";
+
+    static final String MAGIC = "libcore.io.DiskLruCache";
+
+    static final String VERSION_1 = "1";
+
+    static final long ANY_SEQUENCE_NUMBER = -1;
+
+    private static final String CLEAN = "CLEAN";
+
+    private static final String DIRTY = "DIRTY";
+
+    private static final String REMOVE = "REMOVE";
+
+    private static final String READ = "READ";
+
+    private static final Charset UTF_8 = Charset.forName("UTF-8");
+
+    private static final int IO_BUFFER_SIZE = 8 * 1024;
+
+    /*
+     * This cache uses a journal file named "journal". A typical journal file
+     * looks like this: libcore.io.DiskLruCache 1 100 2 CLEAN
+     * 3400330d1dfc7f3f7f4b8d4d803dfcf6 832 21054 DIRTY
+     * 335c4c6028171cfddfbaae1a9c313c52 CLEAN 335c4c6028171cfddfbaae1a9c313c52
+     * 3934 2342 REMOVE 335c4c6028171cfddfbaae1a9c313c52 DIRTY
+     * 1ab96a171faeeee38496d8b330771a7a CLEAN 1ab96a171faeeee38496d8b330771a7a
+     * 1600 234 READ 335c4c6028171cfddfbaae1a9c313c52 READ
+     * 3400330d1dfc7f3f7f4b8d4d803dfcf6 The first five lines of the journal form
+     * its header. They are the constant string "libcore.io.DiskLruCache", the
+     * disk cache's version, the application's version, the value count, and a
+     * blank line. Each of the subsequent lines in the file is a record of the
+     * state of a cache entry. Each line contains space-separated values: a
+     * state, a key, and optional state-specific values. o DIRTY lines track
+     * that an entry is actively being created or updated. Every successful
+     * DIRTY action should be followed by a CLEAN or REMOVE action. DIRTY lines
+     * without a matching CLEAN or REMOVE indicate that temporary files may need
+     * to be deleted. o CLEAN lines track a cache entry that has been
+     * successfully published and may be read. A publish line is followed by the
+     * lengths of each of its values. o READ lines track accesses for LRU. o
+     * REMOVE lines track entries that have been deleted. The journal file is
+     * appended to as cache operations occur. The journal may occasionally be
+     * compacted by dropping redundant lines. A temporary file named
+     * "journal.tmp" will be used during compaction; that file should be deleted
+     * if it exists when the cache is opened.
+     */
+
+    private final File directory;
+
+    private final File journalFile;
+
+    private final File journalFileTmp;
+
+    private final int appVersion;
+
+    private final long maxSize;
+
+    private final int valueCount;
+
+    private long size = 0;
+
+    private Writer journalWriter;
+
+    private final LinkedHashMap<String, Entry> lruEntries = new LinkedHashMap<String, Entry>(0,
+            0.75f, true);
+
+    private int redundantOpCount;
+
+    /**
+     * To differentiate between old and current snapshots, each entry is given a
+     * sequence number each time an edit is committed. A snapshot is stale if
+     * its sequence number is not equal to its entry's sequence number.
+     */
+    private long nextSequenceNumber = 0;
+
+    /* From java.util.Arrays */
+    @SuppressWarnings("unchecked")
+    private static <T> T[] copyOfRange(final T[] original, final int start, final int end) {
+        final int originalLength = original.length; // For exception priority
+                                                    // compatibility.
+        if (start > end) {
+            throw new IllegalArgumentException();
+        }
+        if (start < 0 || start > originalLength) {
+            throw new ArrayIndexOutOfBoundsException();
+        }
+        final int resultLength = end - start;
+        final int copyLength = Math.min(resultLength, originalLength - start);
+        final T[] result = (T[])Array.newInstance(original.getClass().getComponentType(),
+                resultLength);
+        System.arraycopy(original, start, result, 0, copyLength);
+        return result;
+    }
+
+    /**
+     * Returns the remainder of 'reader' as a string, closing it when done.
+     */
+    public static String readFully(final Reader reader) throws IOException {
+        try {
+            final StringWriter writer = new StringWriter();
+            final char[] buffer = new char[1024];
+            int count;
+            while ((count = reader.read(buffer)) != -1) {
+                writer.write(buffer, 0, count);
+            }
+            return writer.toString();
+        } finally {
+            reader.close();
+        }
+    }
+
+    /**
+     * Returns the ASCII characters up to but not including the next "\r\n", or
+     * "\n".
+     *
+     * @throws java.io.EOFException if the stream is exhausted before the next
+     *             newline character.
+     */
+    public static String readAsciiLine(final InputStream in) throws IOException {
+        // TODO: support UTF-8 here instead
+
+        final StringBuilder result = new StringBuilder(80);
+        while (true) {
+            final int c = in.read();
+            if (c == -1) {
+                throw new EOFException();
+            } else if (c == '\n') {
+                break;
+            }
+
+            result.append((char)c);
+        }
+        final int length = result.length();
+        if (length > 0 && result.charAt(length - 1) == '\r') {
+            result.setLength(length - 1);
+        }
+        return result.toString();
+    }
+
+    /**
+     * Closes 'closeable', ignoring any checked exceptions. Does nothing if
+     * 'closeable' is null.
+     */
+    public static void closeQuietly(final Closeable closeable) {
+        if (closeable != null) {
+            try {
+                closeable.close();
+            } catch (final RuntimeException rethrown) {
+                throw rethrown;
+            } catch (final Exception ignored) {
+            }
+        }
+    }
+
+    /**
+     * Recursively delete everything in {@code dir}.
+     */
+    // TODO: this should specify paths as Strings rather than as Files
+    public static void deleteContents(final File dir) throws IOException {
+        final File[] files = dir.listFiles();
+        if (files == null) {
+            throw new IllegalArgumentException("not a directory: " + dir);
+        }
+        for (final File file : files) {
+            if (file.isDirectory()) {
+                deleteContents(file);
+            }
+            if (!file.delete()) {
+                throw new IOException("failed to delete file: " + file);
+            }
+        }
+    }
+
+    /** This cache uses a single background thread to evict entries. */
+    private final ExecutorService executorService = new ThreadPoolExecutor(0, 1, 60L,
+            TimeUnit.SECONDS, new LinkedBlockingQueue<Runnable>());
+
+    private final Callable<Void> cleanupCallable = new Callable<Void>() {
+        @Override
+        public Void call() throws Exception {
+            synchronized (DiskLruCache.this) {
+                if (journalWriter == null) {
+                    return null; // closed
+                }
+                trimToSize();
+                if (journalRebuildRequired()) {
+                    rebuildJournal();
+                    redundantOpCount = 0;
+                }
+            }
+            return null;
+        }
+    };
+
+    private DiskLruCache(final File directory, final int appVersion, final int valueCount,
+            final long maxSize) {
+        this.directory = directory;
+        this.appVersion = appVersion;
+        journalFile = new File(directory, JOURNAL_FILE);
+        journalFileTmp = new File(directory, JOURNAL_FILE_TMP);
+        this.valueCount = valueCount;
+        this.maxSize = maxSize;
+    }
+
+    /**
+     * Opens the cache in {@code directory}, creating a cache if none exists
+     * there.
+     *
+     * @param directory a writable directory
+     * @param appVersion
+     * @param valueCount the number of values per cache entry. Must be positive.
+     * @param maxSize the maximum number of bytes this cache should use to store
+     * @throws IOException if reading or writing the cache directory fails
+     */
+    public static DiskLruCache open(final File directory, final int appVersion,
+            final int valueCount, final long maxSize) throws IOException {
+        if (maxSize <= 0) {
+            throw new IllegalArgumentException("maxSize <= 0");
+        }
+        if (valueCount <= 0) {
+            throw new IllegalArgumentException("valueCount <= 0");
+        }
+
+        // prefer to pick up where we left off
+        DiskLruCache cache = new DiskLruCache(directory, appVersion, valueCount, maxSize);
+        if (cache.journalFile.exists()) {
+            try {
+                cache.readJournal();
+                cache.processJournal();
+                cache.journalWriter = new BufferedWriter(new FileWriter(cache.journalFile, true),
+                        IO_BUFFER_SIZE);
+                return cache;
+            } catch (final IOException journalIsCorrupt) {
+                // System.logW("DiskLruCache " + directory + " is corrupt: "
+                // + journalIsCorrupt.getMessage() + ", removing");
+                cache.delete();
+            }
+        }
+
+        // create a new empty cache
+        directory.mkdirs();
+        cache = new DiskLruCache(directory, appVersion, valueCount, maxSize);
+        cache.rebuildJournal();
+        return cache;
+    }
+
+    private void readJournal() throws IOException {
+        final InputStream in = new BufferedInputStream(new FileInputStream(journalFile),
+                IO_BUFFER_SIZE);
+        try {
+            final String magic = readAsciiLine(in);
+            final String version = readAsciiLine(in);
+            final String appVersionString = readAsciiLine(in);
+            final String valueCountString = readAsciiLine(in);
+            final String blank = readAsciiLine(in);
+            if (!MAGIC.equals(magic) || !VERSION_1.equals(version)
+                    || !Integer.toString(appVersion).equals(appVersionString)
+                    || !Integer.toString(valueCount).equals(valueCountString) || !"".equals(blank)) {
+                throw new IOException("unexpected journal header: [" + magic + ", " + version
+                        + ", " + valueCountString + ", " + blank + "]");
+            }
+
+            while (true) {
+                try {
+                    readJournalLine(readAsciiLine(in));
+                } catch (final EOFException endOfJournal) {
+                    break;
+                }
+            }
+        } finally {
+            closeQuietly(in);
+        }
+    }
+
+    private void readJournalLine(final String line) throws IOException {
+        final String[] parts = line.split(" ");
+        if (parts.length < 2) {
+            throw new IOException("unexpected journal line: " + line);
+        }
+
+        final String key = parts[1];
+        if (parts[0].equals(REMOVE) && parts.length == 2) {
+            lruEntries.remove(key);
+            return;
+        }
+
+        Entry entry = lruEntries.get(key);
+        if (entry == null) {
+            entry = new Entry(key);
+            lruEntries.put(key, entry);
+        }
+
+        if (parts[0].equals(CLEAN) && parts.length == 2 + valueCount) {
+            entry.readable = true;
+            entry.currentEditor = null;
+            entry.setLengths(copyOfRange(parts, 2, parts.length));
+        } else if (parts[0].equals(DIRTY) && parts.length == 2) {
+            entry.currentEditor = new Editor(entry);
+        } else if (parts[0].equals(READ) && parts.length == 2) {
+            // this work was already done by calling lruEntries.get()
+        } else {
+            throw new IOException("unexpected journal line: " + line);
+        }
+    }
+
+    /**
+     * Computes the initial size and collects garbage as a part of opening the
+     * cache. Dirty entries are assumed to be inconsistent and will be deleted.
+     */
+    private void processJournal() throws IOException {
+        deleteIfExists(journalFileTmp);
+        for (final Iterator<Entry> i = lruEntries.values().iterator(); i.hasNext();) {
+            final Entry entry = i.next();
+            if (entry.currentEditor == null) {
+                for (int t = 0; t < valueCount; t++) {
+                    size += entry.lengths[t];
+                }
+            } else {
+                entry.currentEditor = null;
+                for (int t = 0; t < valueCount; t++) {
+                    deleteIfExists(entry.getCleanFile(t));
+                    deleteIfExists(entry.getDirtyFile(t));
+                }
+                i.remove();
+            }
+        }
+    }
+
+    /**
+     * Creates a new journal that omits redundant information. This replaces the
+     * current journal if it exists.
+     */
+    private synchronized void rebuildJournal() throws IOException {
+        if (journalWriter != null) {
+            journalWriter.close();
+        }
+
+        final Writer writer = new BufferedWriter(new FileWriter(journalFileTmp), IO_BUFFER_SIZE);
+        writer.write(MAGIC);
+        writer.write("\n");
+        writer.write(VERSION_1);
+        writer.write("\n");
+        writer.write(Integer.toString(appVersion));
+        writer.write("\n");
+        writer.write(Integer.toString(valueCount));
+        writer.write("\n");
+        writer.write("\n");
+
+        for (final Entry entry : lruEntries.values()) {
+            if (entry.currentEditor != null) {
+                writer.write(DIRTY + ' ' + entry.key + '\n');
+            } else {
+                writer.write(CLEAN + ' ' + entry.key + entry.getLengths() + '\n');
+            }
+        }
+
+        writer.close();
+        journalFileTmp.renameTo(journalFile);
+        journalWriter = new BufferedWriter(new FileWriter(journalFile, true), IO_BUFFER_SIZE);
+    }
+
+    private static void deleteIfExists(final File file) throws IOException {
+        // try {
+        // Libcore.os.remove(file.getPath());
+        // } catch (ErrnoException errnoException) {
+        // if (errnoException.errno != OsConstants.ENOENT) {
+        // throw errnoException.rethrowAsIOException();
+        // }
+        // }
+        if (file.exists() && !file.delete()) {
+            throw new IOException();
+        }
+    }
+
+    /**
+     * Returns a snapshot of the entry named {@code key}, or null if it doesn't
+     * exist is not currently readable. If a value is returned, it is moved to
+     * the head of the LRU queue.
+     */
+    public synchronized Snapshot get(final String key) throws IOException {
+        checkNotClosed();
+        validateKey(key);
+        final Entry entry = lruEntries.get(key);
+        if (entry == null) {
+            return null;
+        }
+
+        if (!entry.readable) {
+            return null;
+        }
+
+        /*
+         * Open all streams eagerly to guarantee that we see a single published
+         * snapshot. If we opened streams lazily then the streams could come
+         * from different edits.
+         */
+        final InputStream[] ins = new InputStream[valueCount];
+        try {
+            for (int i = 0; i < valueCount; i++) {
+                ins[i] = new FileInputStream(entry.getCleanFile(i));
+            }
+        } catch (final FileNotFoundException e) {
+            // a file must have been deleted manually!
+            return null;
+        }
+
+        redundantOpCount++;
+        journalWriter.append(READ + ' ').append(key).append('\n');
+        if (journalRebuildRequired()) {
+            executorService.submit(cleanupCallable);
+        }
+
+        return new Snapshot(key, entry.sequenceNumber, ins);
+    }
+
+    /**
+     * Returns an editor for the entry named {@code key}, or null if another
+     * edit is in progress.
+     */
+    public Editor edit(final String key) throws IOException {
+        return edit(key, ANY_SEQUENCE_NUMBER);
+    }
+
+    private synchronized Editor edit(final String key, final long expectedSequenceNumber)
+            throws IOException {
+        checkNotClosed();
+        validateKey(key);
+        Entry entry = lruEntries.get(key);
+        if (expectedSequenceNumber != ANY_SEQUENCE_NUMBER
+                && (entry == null || entry.sequenceNumber != expectedSequenceNumber)) {
+            return null; // snapshot is stale
+        }
+        if (entry == null) {
+            entry = new Entry(key);
+            lruEntries.put(key, entry);
+        } else if (entry.currentEditor != null) {
+            return null; // another edit is in progress
+        }
+
+        final Editor editor = new Editor(entry);
+        entry.currentEditor = editor;
+
+        // flush the journal before creating files to prevent file leaks
+        journalWriter.write(DIRTY + ' ' + key + '\n');
+        journalWriter.flush();
+        return editor;
+    }
+
+    /**
+     * Returns the directory where this cache stores its data.
+     */
+    public File getDirectory() {
+        return directory;
+    }
+
+    /**
+     * Returns the maximum number of bytes that this cache should use to store
+     * its data.
+     */
+    public long maxSize() {
+        return maxSize;
+    }
+
+    /**
+     * Returns the number of bytes currently being used to store the values in
+     * this cache. This may be greater than the max size if a background
+     * deletion is pending.
+     */
+    public synchronized long size() {
+        return size;
+    }
+
+    private synchronized void completeEdit(final Editor editor, final boolean success)
+            throws IOException {
+        final Entry entry = editor.entry;
+        if (entry.currentEditor != editor) {
+            throw new IllegalStateException();
+        }
+
+        // if this edit is creating the entry for the first time, every index
+        // must have a value
+        if (success && !entry.readable) {
+            for (int i = 0; i < valueCount; i++) {
+                if (!entry.getDirtyFile(i).exists()) {
+                    editor.abort();
+                    throw new IllegalStateException("edit didn't create file " + i);
+                }
+            }
+        }
+
+        for (int i = 0; i < valueCount; i++) {
+            final File dirty = entry.getDirtyFile(i);
+            if (success) {
+                if (dirty.exists()) {
+                    final File clean = entry.getCleanFile(i);
+                    dirty.renameTo(clean);
+                    final long oldLength = entry.lengths[i];
+                    final long newLength = clean.length();
+                    entry.lengths[i] = newLength;
+                    size = size - oldLength + newLength;
+                }
+            } else {
+                deleteIfExists(dirty);
+            }
+        }
+
+        redundantOpCount++;
+        entry.currentEditor = null;
+        if (entry.readable | success) {
+            entry.readable = true;
+            journalWriter.write(CLEAN + ' ' + entry.key + entry.getLengths() + '\n');
+            if (success) {
+                entry.sequenceNumber = nextSequenceNumber++;
+            }
+        } else {
+            lruEntries.remove(entry.key);
+            journalWriter.write(REMOVE + ' ' + entry.key + '\n');
+        }
+
+        if (size > maxSize || journalRebuildRequired()) {
+            executorService.submit(cleanupCallable);
+        }
+    }
+
+    /**
+     * We only rebuild the journal when it will halve the size of the journal
+     * and eliminate at least 2000 ops.
+     */
+    private boolean journalRebuildRequired() {
+        final int REDUNDANT_OP_COMPACT_THRESHOLD = 2000;
+        return redundantOpCount >= REDUNDANT_OP_COMPACT_THRESHOLD
+                && redundantOpCount >= lruEntries.size();
+    }
+
+    /**
+     * Drops the entry for {@code key} if it exists and can be removed. Entries
+     * actively being edited cannot be removed.
+     *
+     * @return true if an entry was removed.
+     */
+    public synchronized boolean remove(final String key) throws IOException {
+        checkNotClosed();
+        validateKey(key);
+        final Entry entry = lruEntries.get(key);
+        if (entry == null || entry.currentEditor != null) {
+            return false;
+        }
+
+        for (int i = 0; i < valueCount; i++) {
+            final File file = entry.getCleanFile(i);
+            if (!file.delete()) {
+                throw new IOException("failed to delete " + file);
+            }
+            size -= entry.lengths[i];
+            entry.lengths[i] = 0;
+        }
+
+        redundantOpCount++;
+        journalWriter.append(REMOVE + ' ').append(key).append('\n');
+        lruEntries.remove(key);
+
+        if (journalRebuildRequired()) {
+            executorService.submit(cleanupCallable);
+        }
+
+        return true;
+    }
+
+    /**
+     * Returns true if this cache has been closed.
+     */
+    public boolean isClosed() {
+        return journalWriter == null;
+    }
+
+    private void checkNotClosed() {
+        if (journalWriter == null) {
+            throw new IllegalStateException("cache is closed");
+        }
+    }
+
+    /**
+     * Force buffered operations to the filesystem.
+     */
+    public synchronized void flush() throws IOException {
+        checkNotClosed();
+        trimToSize();
+        journalWriter.flush();
+    }
+
+    /**
+     * Closes this cache. Stored values will remain on the filesystem.
+     */
+    @Override
+    public synchronized void close() throws IOException {
+        if (journalWriter == null) {
+            return; // already closed
+        }
+        for (final Entry entry : new ArrayList<Entry>(lruEntries.values())) {
+            if (entry.currentEditor != null) {
+                entry.currentEditor.abort();
+            }
+        }
+        trimToSize();
+        journalWriter.close();
+        journalWriter = null;
+    }
+
+    private void trimToSize() throws IOException {
+        while (size > maxSize) {
+            // Map.Entry<String, Entry> toEvict = lruEntries.eldest();
+            final Map.Entry<String, Entry> toEvict = lruEntries.entrySet().iterator().next();
+            remove(toEvict.getKey());
+        }
+    }
+
+    /**
+     * Closes the cache and deletes all of its stored values. This will delete
+     * all files in the cache directory including files that weren't created by
+     * the cache.
+     */
+    public void delete() throws IOException {
+        close();
+        deleteContents(directory);
+    }
+
+    private void validateKey(final String key) {
+        if (key.contains(" ") || key.contains("\n") || key.contains("\r")) {
+            throw new IllegalArgumentException("keys must not contain spaces or newlines: \"" + key
+                    + "\"");
+        }
+    }
+
+    private static String inputStreamToString(final InputStream in) throws IOException {
+        return readFully(new InputStreamReader(in, UTF_8));
+    }
+
+    /**
+     * A snapshot of the values for an entry.
+     */
+    public final class Snapshot implements Closeable {
+        private final String key;
+
+        private final long sequenceNumber;
+
+        private final InputStream[] ins;
+
+        private Snapshot(final String key, final long sequenceNumber, final InputStream[] ins) {
+            this.key = key;
+            this.sequenceNumber = sequenceNumber;
+            this.ins = ins;
+        }
+
+        /**
+         * Returns an editor for this snapshot's entry, or null if either the
+         * entry has changed since this snapshot was created or if another edit
+         * is in progress.
+         */
+        public Editor edit() throws IOException {
+            return DiskLruCache.this.edit(key, sequenceNumber);
+        }
+
+        /**
+         * Returns the unbuffered stream with the value for {@code index}.
+         */
+        public InputStream getInputStream(final int index) {
+            return ins[index];
+        }
+
+        /**
+         * Returns the string value for {@code index}.
+         */
+        public String getString(final int index) throws IOException {
+            return inputStreamToString(getInputStream(index));
+        }
+
+        @Override
+        public void close() {
+            for (final InputStream in : ins) {
+                closeQuietly(in);
+            }
+        }
+    }
+
+    /**
+     * Edits the values for an entry.
+     */
+    public final class Editor {
+        private final Entry entry;
+
+        private boolean hasErrors;
+
+        private Editor(final Entry entry) {
+            this.entry = entry;
+        }
+
+        /**
+         * Returns an unbuffered input stream to read the last committed value,
+         * or null if no value has been committed.
+         */
+        public InputStream newInputStream(final int index) throws IOException {
+            synchronized (DiskLruCache.this) {
+                if (entry.currentEditor != this) {
+                    throw new IllegalStateException();
+                }
+                if (!entry.readable) {
+                    return null;
+                }
+                return new FileInputStream(entry.getCleanFile(index));
+            }
+        }
+
+        /**
+         * Returns the last committed value as a string, or null if no value has
+         * been committed.
+         */
+        public String getString(final int index) throws IOException {
+            final InputStream in = newInputStream(index);
+            return in != null ? inputStreamToString(in) : null;
+        }
+
+        /**
+         * Returns a new unbuffered output stream to write the value at
+         * {@code index}. If the underlying output stream encounters errors when
+         * writing to the filesystem, this edit will be aborted when
+         * {@link #commit} is called. The returned output stream does not throw
+         * IOExceptions.
+         */
+        public OutputStream newOutputStream(final int index) throws IOException {
+            synchronized (DiskLruCache.this) {
+                if (entry.currentEditor != this) {
+                    throw new IllegalStateException();
+                }
+                return new FaultHidingOutputStream(new FileOutputStream(entry.getDirtyFile(index)));
+            }
+        }
+
+        /**
+         * Sets the value at {@code index} to {@code value}.
+         */
+        public void set(final int index, final String value) throws IOException {
+            Writer writer = null;
+            try {
+                writer = new OutputStreamWriter(newOutputStream(index), UTF_8);
+                writer.write(value);
+            } finally {
+                closeQuietly(writer);
+            }
+        }
+
+        /**
+         * Commits this edit so it is visible to readers. This releases the edit
+         * lock so another edit may be started on the same key.
+         */
+        public void commit() throws IOException {
+            if (hasErrors) {
+                completeEdit(this, false);
+                remove(entry.key); // the previous entry is stale
+            } else {
+                completeEdit(this, true);
+            }
+        }
+
+        /**
+         * Aborts this edit. This releases the edit lock so another edit may be
+         * started on the same key.
+         */
+        public void abort() throws IOException {
+            completeEdit(this, false);
+        }
+
+        private class FaultHidingOutputStream extends FilterOutputStream {
+            private FaultHidingOutputStream(final OutputStream out) {
+                super(out);
+            }
+
+            @Override
+            public void write(final int oneByte) {
+                try {
+                    out.write(oneByte);
+                } catch (final IOException e) {
+                    hasErrors = true;
+                }
+            }
+
+            @Override
+            public void write(final byte[] buffer, final int offset, final int length) {
+                try {
+                    out.write(buffer, offset, length);
+                } catch (final IOException e) {
+                    hasErrors = true;
+                }
+            }
+
+            @Override
+            public void close() {
+                try {
+                    out.close();
+                } catch (final IOException e) {
+                    hasErrors = true;
+                }
+            }
+
+            @Override
+            public void flush() {
+                try {
+                    out.flush();
+                } catch (final IOException e) {
+                    hasErrors = true;
+                }
+            }
+        }
+    }
+
+    private final class Entry {
+        private final String key;
+
+        /** Lengths of this entry's files. */
+        private final long[] lengths;
+
+        /** True if this entry has ever been published */
+        private boolean readable;
+
+        /** The ongoing edit or null if this entry is not being edited. */
+        private Editor currentEditor;
+
+        /**
+         * The sequence number of the most recently committed edit to this
+         * entry.
+         */
+        private long sequenceNumber;
+
+        private Entry(final String key) {
+            this.key = key;
+            lengths = new long[valueCount];
+        }
+
+        public String getLengths() throws IOException {
+            final StringBuilder result = new StringBuilder();
+            for (final long size : lengths) {
+                result.append(' ').append(size);
+            }
+            return result.toString();
+        }
+
+        /**
+         * Set lengths using decimal numbers like "10123".
+         */
+        private void setLengths(final String[] strings) throws IOException {
+            if (strings.length != valueCount) {
+                throw invalidLengths(strings);
+            }
+
+            try {
+                for (int i = 0; i < strings.length; i++) {
+                    lengths[i] = Long.parseLong(strings[i]);
+                }
+            } catch (final NumberFormatException e) {
+                throw invalidLengths(strings);
+            }
+        }
+
+        private IOException invalidLengths(final String[] strings) throws IOException {
+            throw new IOException("unexpected journal line: " + Arrays.toString(strings));
+        }
+
+        public File getCleanFile(final int i) {
+            return new File(directory, key + "." + i);
+        }
+
+        public File getDirtyFile(final int i) {
+            return new File(directory, key + "." + i + ".tmp");
+        }
+    }
+}