[HDFS-608] BlockReceiver:receivePacket(): packet's header parsing logic is complicated. Refactoring will help w/ testing efforts

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Duplicate
• Assignee: Konstantin I Boudnik
• Reporter: Konstantin I Boudnik
• Created: 09/Sep/09 22:23
• Updated: 22/May/10 00:51
• Resolved: 22/May/10 00:51

Description

Current logic of getting an information from a packet header is kinda complicated with all shifting along the internal data buffer back and forth.
Besides, an absence of clear API to access a packet header's information makes pipeline testing effort (even with aspects' application) to be a very complicated or even impossible.

It'd be very nice to have a separate data container which will keep all the information about a packet header within and will initialized once when a new packet is acquired.

In order to speed-up pipeline testing needed for append (HDFS-265) this modification might implemented in three different states:

• introduce new header structure and refactor receivePacket()
• refactor readNextPacket so it it will acquire next packet in initialize its header
• refactor the sender side to use the packet's header structure as the receiver does.

Issue Links

• is related to: HDFS-881 Refactor DataNode Packet header into DataTransferProtocol