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Niall Pemberton updated IO-279: ------------------------------- Attachment: IO-279.patch Firstly I don't know why System.currentTimeMillis() is used. What matters is if the files lastModified time compared to its previous lastModified value. I agree with Chris that the lastModified time should be stored after the file is read. > Tailer erroneously considers file as new > ---------------------------------------- > > Key: IO-279 > URL: https://issues.apache.org/jira/browse/IO-279 > Project: Commons IO > Issue Type: Bug > Affects Versions: 2.0.1 > Reporter: Sergio Bossa > Fix For: 2.4 > > Attachments: IO-279.patch > > > Tailer sometimes erroneously considers the tailed file as new, forcing a > repositioning at the start of the file: I'm still unable to reproduce this in > a test case, because it only happens to me with huge log files during Apache > Tomcat startup. > This is the piece of code causing the problem: > {code} > // See if the file needs to be read again > if (length > position) { > // The file has more content than it did last time > last = System.currentTimeMillis(); > position = readLines(reader); > } else if (FileUtils.isFileNewer(file, last)) { > /* This can happen if the file is truncated or overwritten > * with the exact same length of information. In cases like > * this, the file position needs to be reset > */ > position = 0; > reader.seek(position); // cannot be null here > // Now we can read new lines > last = System.currentTimeMillis(); > position = readLines(reader); > } > {code} > What probably happens is that the new file content is about to be written on > disk, the date is already updated but content is still not flushed, so actual > length is untouched and there you go. > In other words, I think there should be some better method to verify the > condition above, rather than relying only on dates: keeping and comparing the > hash code of the latest line may be a solution, but may hurt performances ... > other ideas? -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira