private String descLogsInMemory() {
        final StringBuilder sb = new StringBuilder();
        boolean wasFirst = true;
        for (int i = 0; i < this.logsInMemory.size(); i++) {
            LogEntry logEntry = this.logsInMemory.get(i);
            if (!wasFirst) {
                sb.append(",");
            } else {
                wasFirst = false;
            }
            sb.append("<id:(").append(logEntry.getId().getTerm()).append(",").append(logEntry.getId().getIndex())
                .append("),type:").append(logEntry.getType()).append(">");
        }
        return sb.toString();
    }
Adds event to disk queue, NEVER call it in lock.
@param done
@param type
jraft-core/src/main/java/com/alipay/sofa/jraft/storage/impl/LogManagerImpl.java