Guava

Gauva

Tips

Performance

TypeToken

  • 对性能有一定影响, 谨慎使用
Benchmark Mode Cnt Score Error Units
BenchTypeToken.generic avgt 10 4.001 ± 0.197 ns/op
BenchTypeToken.typeTokenString avgt 10 973.403 ± 13.519 ns/op
BenchTypeToken.typeTokenTwo avgt 10 3289.355 ± 134.182 ns/op
BenchTypeToken.typeTokenVoid avgt 10 1019.551 ± 43.565 ns/op
@State(Scope.Thread)
@OutputTimeUnit(TimeUnit.NANOSECONDS)
@Warmup(iterations = 4)
@Measurement(iterations = 10)
@BenchmarkMode(Mode.AverageTime)
public class BenchTypeToken {
public static void main(String[] args) throws RunnerException {
Options options =
new OptionsBuilder()
.include(BenchTypeToken.class.getSimpleName())
.threads(1)
.forks(1)
.shouldFailOnError(true)
.shouldDoGC(true)
.jvmArgs("-server")
.measurementTime(TimeValue.seconds(2))
.build();
new Runner(options).run();
}
@Benchmark
public void typeTokenString(Blackhole bh) {
bh.consume(new ATyped());
}
@Benchmark
public void typeTokenVoid(Blackhole bh) {
bh.consume(new ATyped());
}
@Benchmark
public void typeTokenTwo(Blackhole bh) {
bh.consume(new ATyped2());
}
@Benchmark
public void generic(Blackhole bh) {
bh.consume(new AGen());
}
static class ATyped extends TypedImpl<Void> {}
static class ATypedS extends TypedImpl<String> {}
static class ATyped2 extends TypedImpl2<Void, Void> {}
static class AGen extends GenImpl<Void> {}
@Getter
@Setter
static class TypedImpl<IN> {
private final TypeToken<IN> in = new TypeToken<IN>(getClass()) {};
}
@Getter
@Setter
static class TypedImpl2<IN, OUT> {
private final TypeToken<IN> in = new TypeToken<IN>(getClass()) {};
private final TypeToken<OUT> out = new TypeToken<OUT>(getClass()) {};
}
@Getter
@Setter
static class GenImpl<IN> {}
}

Immutable

  • 比正常的性能稍微好一点点
Benchmark Mode Cnt Score Error Units
BenchImmutable.immutableList avgt 10 4288.096 ± 97.184 ns/op
BenchImmutable.immutableMap avgt 10 7922.092 ± 368.066 ns/op
BenchImmutable.list avgt 10 4739.961 ± 131.327 ns/op
BenchImmutable.map avgt 10 8779.917 ± 498.843 ns/op
@State(Scope.Thread)
@OutputTimeUnit(TimeUnit.NANOSECONDS)
@Warmup(iterations = 4)
@Measurement(iterations = 10)
@BenchmarkMode(Mode.AverageTime)
public class BenchImmutable {
public static void main(String[] args) throws RunnerException {
Options options =
new OptionsBuilder()
.include(BenchImmutable.class.getSimpleName())
.threads(1)
.forks(1)
.shouldFailOnError(true)
.shouldDoGC(true)
.jvmArgs("-server")
.measurementTime(TimeValue.seconds(8))
.build();
new Runner(options).run();
}
@Benchmark
public void list(Blackhole bh) {
ArrayList<Integer> list = Lists.newArrayList();
for (int i = 0; i < 100; i++) {
list.add(i);
}
for (int i = 0; i < 1000; i++) {
bh.consume(list.get(i % 100));
}
}
@Benchmark
public void immutableList(Blackhole bh) {
Builder<Integer> builder = ImmutableList.builder();
for (int i = 0; i < 100; i++) {
builder.add(i);
}
ImmutableList<Integer> list = builder.build();
for (int i = 0; i < 1000; i++) {
bh.consume(list.get(i % 100));
}
}
@Benchmark
public void map(Blackhole bh) {
HashMap<Integer, Integer> map = Maps.newHashMap();
for (int i = 0; i < 100; i++) {
map.put(i, i);
}
for (int i = 0; i < 1000; i++) {
bh.consume(map.get(i % 100));
}
}
@Benchmark
public void immutableMap(Blackhole bh) {
ImmutableMap.Builder<Integer, Integer> builder = ImmutableMap.builder();
for (int i = 0; i < 100; i++) {
builder.put(i, i);
}
ImmutableMap<Integer, Integer> map = builder.build();
for (int i = 0; i < 1000; i++) {
bh.consume(map.get(i % 100));
}
}
}