[hibernate-issues] [Hibernate-JIRA] Commented: (HHH-2122) optimization patch based on pmd rules

[ http://opensource.atlassian.com/projects/hibernate/browse/HHH-2122?page=c... ] Xavier Le Vourch commented on HHH-2122: --------------------------------------- No I did not perform a performance test but I guess you already knew that... My main motivation was to test the new rules and patches for false positives I sent to the PMD project that have been integrated in the current dev version. To do so, I'm running tests on several open source libraries and as a side effect, I'm sending patches to the relevant projects containing fixes for a few of the detected problems. If you look closely, there's no change in the API. It's just avoiding creating temporary objects, avoiding unneeded String objects in the generated byte code or doing checks that are not needed based on the Java specification. Anyway, you can discard the patch if you do not want to integrate it. Below I'll list a short explanation of the perceived advantages I see in the changes. Xavier Double.valueOf(x).doubleValue() -> Double.parseDouble(x) temporary Double is not created append("x") -> append('x') string is not stored in byte code, adding a char is also less complex x != null && x instanceof X -> x instanceof X Java spec list.toArray uses correctly sized array as argument temporary zero sized array not created new String(str) -> str useless copy of immutable object if (expr == false) -> if (!expr) OK, that one is not really needed but the fact that it appears only once means that it's not really a standard construct in your code base append(s1 + s2) -> append(s1).append(s2) temporary StringBuffer object created for "s1 + s2" and then added to the enclosing StringBuffer. loop over array to add to list -> list.addAll(Arrays.asList(<array>)) less complex, less prone to error in loop extra ; removed again appears only once. Depending on context, extra ; can change behavior, not in this case though. name.toLowerCase().equals("rowid") -> name.equalsIgnoreCase("rowid") temporary String object created, appears only once, equalsIgnoreCase() used elsewhere use of System.arraycopy instead of loop arraycopy is native and should be the faster way to copy the array. resulting Java code is also less complex and more maintainable. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://opensource.atlassian.com/projects/hibernate/secure/Administrators.... - For more information on JIRA, see: http://www.atlassian.com/software/jira