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Tsz Wo (Nicholas), SZE commented on HDFS-5285: ---------------------------------------------- Vinay, thanks for taking a look. > I can see INodeFileWithSnapshot still in the hierarchy which extends > INodeFile. You intentionally left it as it is ..? My patch is not completed yet. Will remove INodeFileWithSnapshot and the other INodeFile subclasses. > Flatten INodeFile hierarchy > --------------------------- > > Key: HDFS-5285 > URL: https://issues.apache.org/jira/browse/HDFS-5285 > Project: Hadoop HDFS > Issue Type: Sub-task > Components: namenode > Reporter: Tsz Wo (Nicholas), SZE > Assignee: Tsz Wo (Nicholas), SZE > Attachments: h5285_20131001.patch, h5285_20131002.patch, > h5285_20131118.patch > > > For files, there are INodeFile, INodeFileUnderConstruction, > INodeFileWithSnapshot and INodeFileUnderConstructionWithSnapshot for > representing whether a file is under construction or whether it is in some > snapshot. The following are two major problems of the current approach: > - Java class does not support multiple inheritances so that > INodeFileUnderConstructionWithSnapshot cannot extend both > INodeFileUnderConstruction and INodeFileWithSnapshot. > - The number of classes is exponential to the number of features. Currently, > there are only two features, UnderConstruction and WithSnapshot. The number > of classes is 2^2 = 4. It is hard to add one more feature since the number > of classes will become 2^3 = 8. -- This message was sent by Atlassian JIRA (v6.1#6144)