[IOTDB-1609] Print the actual size of plan when it exceeds the wal_buffer_size

[Cpaulyz]

Contributions:

• Print the actual size of plan when it exceeds the wal_buffer_size
  • Use PhysicalPlan.serialize(DataOutputStream stream) to get actual size of plan after serialization.
  • Print infomation in IOException message
• Add some test in testOverSizedWAL to verify the actual size of plan
  • If wal_buffer_size is less than actual size, it would throw IOException.
  • If wal_buffer_size is more than or equal to actual size, it would not throw IOException.

[coveralls]

Coverage increased (+0.09%) to 66.983% when pulling 6093d10 on Cpaulyz:fix/wal_buffer_size into b5ef4d8 on apache:master.

[JackieTien97]

It seems that there is no need to really do the serialization to get the actual size, maybe you can add a new method like getSerializedSize() in PhysicalPlan, each actual plan class to override that method to calculate its own size. In this way, you can avoid allocate extra memory in this BufferOverflowException situation.

[Cpaulyz]

It seems that there is no need to really do the serialization to get the actual size, maybe you can add a new method like getSerializedSize() in PhysicalPlan, each actual plan class to override that method to calculate its own size. In this way, you can avoid allocate extra memory in this BufferOverflowException situation.

Yes, I totally agree with what you said. In fact, I wanted to do the same thing at first.

However, I noticed that there are quite a lot of classes extends PhysicalPlan. It needs to modify code massively. Considering that getSerializedSize() is only used for this exception and exception may be occurred rarely, I allocate extra memory to get the actual size.

Do you think it's necessary to do what you said? If so, I may need more time to implement getSerializedSize() in each actual plan class.