private void processJournal() throws IOException {
        deleteIfExists(journalFileTmp);
        for (Iterator<Entry> i = lruEntries.values().iterator(); i.hasNext(); ) {
            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();
            }
        }
    }
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.
app/src/main/java/com/duan/musicoco/cache/DiskLruCache.java