Currently on each invocation of `URLClassPath.FileLoader.getResource()`
`normalizedBase` URL is recalculated using same final `baseURL` from parent
class. This can be avoided giving significant improvement in memory
consumption. Consider the benchmark:
@State(Scope.Benchmark)
@BenchmarkMode(Mode.AverageTime)
@OutputTimeUnit(TimeUnit.NANOSECONDS)
@Fork(jvmArgsAppend = {"-Xms2g", "-Xmx2g"})
public class URLClassPathBenchmark {
private final ClassLoader classLoader = getClass().getClassLoader();
@Benchmark
public URL getResource() {
return classLoader.getResource("file:./config/application.properties");
}
}
it demonstrates improvement brought in by this patch:
before
Benchmark Mode Cnt
Score Error Units
URLClassPathBenchmark.getResource avgt 50
2840,746 ± 22,206 ns/op
URLClassPathBenchmark.getResource:·gc.alloc.rate avgt 50
645,313 ± 8,072 MB/sec
URLClassPathBenchmark.getResource:·gc.alloc.rate.norm avgt 50
2403,258 ± 17,639 B/op
URLClassPathBenchmark.getResource:·gc.churn.G1_Eden_Space avgt 50
656,624 ± 116,090 MB/sec
URLClassPathBenchmark.getResource:·gc.churn.G1_Eden_Space.norm avgt 50
2450,175 ± 440,011 B/op
URLClassPathBenchmark.getResource:·gc.churn.G1_Survivor_Space avgt 50
0,123 ± 0,149 MB/sec
URLClassPathBenchmark.getResource:·gc.churn.G1_Survivor_Space.norm avgt 50
0,459 ± 0,556 B/op
URLClassPathBenchmark.getResource:·gc.count avgt 50
67,000 counts
URLClassPathBenchmark.getResource:·gc.time avgt 50
117,000 ms
after
Benchmark Mode Cnt
Score Error Units
URLClassPathBenchmark.getResource avgt 100
2596,719 ± 9,786 ns/op
URLClassPathBenchmark.getResource:·gc.alloc.rate avgt 100
448,780 ± 1,684 MB/sec
URLClassPathBenchmark.getResource:·gc.alloc.rate.norm avgt 100
1528,040 ± 0,005 B/op
URLClassPathBenchmark.getResource:·gc.churn.G1_Eden_Space avgt 100
479,905 ± 23,369 MB/sec
URLClassPathBenchmark.getResource:·gc.churn.G1_Eden_Space.norm avgt 100
1634,314 ± 79,821 B/op
URLClassPathBenchmark.getResource:·gc.churn.G1_Survivor_Space avgt 100
0,101 ± 0,097 MB/sec
URLClassPathBenchmark.getResource:·gc.churn.G1_Survivor_Space.norm avgt 100
0,345 ± 0,329 B/op
URLClassPathBenchmark.getResource:·gc.count avgt 100
98,000 counts
URLClassPathBenchmark.getResource:·gc.time avgt 100
218,000 ms
-------------
Commit messages:
- 8274276: Cache normalizedBase URL in URLClassPath.FileLoader
Changes: https://git.openjdk.java.net/jdk/pull/5677/files
Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=5677&range=00
Issue: https://bugs.openjdk.java.net/browse/JDK-8274276
Stats: 4 lines in 1 file changed: 2 ins; 1 del; 1 mod
Patch: https://git.openjdk.java.net/jdk/pull/5677.diff
Fetch: git fetch https://git.openjdk.java.net/jdk pull/5677/head:pull/5677
PR: https://git.openjdk.java.net/jdk/pull/5677
