[NUTCH-676] MapWritable is written inefficiently and confusingly

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 0.9.0
• Fix Version/s: 1.0.0
• Assignee: Dogacan Guney
• Reporter: Todd Lipcon
• Created: 30/Dec/08 20:56
• Updated: 10/Apr/09 12:29
• Resolved: 21/Jan/09 19:26

Description

The MapWritable implemention in o.a.n.crawl is written confusingly - it maintains its own internal linked list which I think may have a bug somewhere (I'm getting an NPE in certain cases in the code, though it's hard to track down)

Can anyone comment as to why MapWritable is written the way it is, rather than just using a HashMap or a LinkedHashMap if consistent ordering is important? I imagine that would improve performance.

What about just using the Hadoop MapWritable? Obviously that would break some backwards compatibility but it may be a good idea at some point to reduce confusion (I didn't realize that Nutch had its own impl until a few minutes ago)