private void readJournalLine(String line) throws IOException {
    int firstSpace = line.indexOf(' ');
    if (firstSpace == -1) {
      throw new IOException("unexpected journal line: " + line);
    }

    int keyBegin = firstSpace + 1;
    int secondSpace = line.indexOf(' ', keyBegin);
    final String key;
    if (secondSpace == -1) {
      key = line.substring(keyBegin);
      if (firstSpace == REMOVE.length() && line.startsWith(REMOVE)) {
        lruEntries.remove(key);
        return;
      }
    } else {
      key = line.substring(keyBegin, secondSpace);
    }

    Entry entry = lruEntries.get(key);
    if (entry == null) {
      entry = new Entry(key);
      lruEntries.put(key, entry);
    }

    if (secondSpace != -1 && firstSpace == CLEAN.length() && line.startsWith(CLEAN)) {
      String[] parts = line.substring(secondSpace + 1).split(" ");
      entry.readable = true;
      entry.currentEditor = null;
      entry.setLengths(parts);
    } else if (secondSpace == -1 && firstSpace == DIRTY.length() && line.startsWith(DIRTY)) {
      entry.currentEditor = new Editor(entry);
    } else if (secondSpace == -1 && firstSpace == READ.length() && line.startsWith(READ)) {
      // This work was already done by calling lruEntries.get().
    } else {
      throw new IOException("unexpected journal line: " + line);
    }
  }
Opens the cache in {@code directory}, creating a cache if none exists
there.

@param directory a writable directory
@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
core/src/main/java/com/bumptech/glide/disklrucache/DiskLruCache.java