Created attachment 27843 [details] patch file This bug report is an extracted abstract from the mail 'SSTRecord.serialize() performance improvement patch for huge hssf output' in the 'dev@poi.apache.org' ML. Please use the 'patch' program to patch the files, such as 'patch -p 0 < HOGE.patch'. I tried to use eclipse to patch them, but I found that any trial will fail. --- This patch provides new two features. The first one is a byte level test method named 'testSSTRecord_DigestCheck()' to investigate a hack correctness. Another one is an enumeration class named 'SerializeFunction' to dispatch various serialization methods of SST record easily. Both of the features are introduced into the org.apache.poi.hssf.record.TestSSTRecord.java. And some trivial accessibility changes of other methods are also contained in this patch. The enum 'SerializeFunction' in default consists of two instances to dispatch the memory output method 'Memory' and the raw-file based output method 'StreamFile'. The test method of 'testSSTRecord_DigestCheck()' proves that there are no differences in the output bytes between the 'Memory' method and 'StreamFile' method and their results are identical to the original results in the message digest of byte. If you want to check by yourself, please run the whole set of unit tests (ant test-all?) in the poi project in which the patch automatically integrates the 'testSSTRecord_DigestCheck()' method.
I'm changing the status to NEEDINFO until my questions in Bug 52986 are answered. Yegor
Created attachment 28362 [details] verification of performance