②onNewBatch
RecordAccumulator
append
MemoryRecords
④recordsBuilder创建recordBuilder
Partitioner
MemoryRecords.builder
①tryAppend 触发abortOnNewBatch
ProducerBatch
tryAppend
BufferPool
getOrCreateDeque
tryAppend-deque中没有batch需要先分配buffer
③分配buffer
new ProducerBatch
KafkaProducer
tryAppend此时deque中还是没有batch
⑤append