carterkozak commented on a change in pull request #555:
URL: https://github.com/apache/logging-log4j2/pull/555#discussion_r682075572
##########
File path:
log4j-core/src/main/java/org/apache/logging/log4j/core/pattern/NameAbbreviator.java
##########
@@ -285,40 +285,40 @@ public PatternAbbreviatorFragment(
/**
* Abbreviate element of name.
*
- * @param buf buffer to receive element.
- * @param startPos starting index of name element.
- * @return starting index of next element.
+ * @param input input string which is being written to the output
{@code buf}.
+ * @param inputIndex starting index of name element in the {@code
input} string.
+ * @param buf buffer to receive element.
+ * @return starting index of next element.
*/
- public int abbreviate(final StringBuilder buf, final int startPos) {
- final int start = (startPos < 0) ? 0 : startPos;
- final int max = buf.length();
- int nextDot = -1;
- for (int i = start; i < max; i++) {
- if (buf.charAt(i) == '.') {
- nextDot = i;
- break;
- }
+ int abbreviate(final String input, final int inputIndex, final
StringBuilder buf) {
+ // ckozak: indexOf with a string is intentional. indexOf(String,
int) appears to
+ // have optimizations that don't apply to indexOf(char, int)
+ // which result in a >10% performance improvement in some
+ // NamePatternConverterBenchmark cases. This should be
re-evaluated with
+ // future java releases.
+ int nextDot = input.indexOf(".", inputIndex);
Review comment:
This performance change was _wild_:
```diff
- int nextDot = input.indexOf('.', inputIndex);
+ int nextDot = input.indexOf(".", inputIndex);
```
@garydgregory Any chance you have ideas that might explain this? It threw me
for a loop because the character-based indexOf underperforms compared to the
old implementation, while the string-based indexOf has an advantage and much
lower variance.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: notifications-unsubscr...@logging.apache.org
For queries about this service, please contact Infrastructure at:
us...@infra.apache.org
