Tsz Wo (Nicholas), SZE created HDFS-5285: --------------------------------------------
Summary: 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 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)