GcHeapStat.java

net.minecraft.util.profiling.jfr.stats.GcHeapStat

信息

• 全限定名：net.minecraft.util.profiling.jfr.stats.GcHeapStat
• 类型：public record
• 包：net.minecraft.util.profiling.jfr.stats
• 源码路径：src/main/java/net/minecraft/util/profiling/jfr/stats/GcHeapStat.java
• 起始行号：L10
• 职责：

  TODO

字段/常量

• 无

内部类/嵌套类型

• net.minecraft.util.profiling.jfr.stats.GcHeapStat.Summary

  • 类型: record
  • 修饰符: public
  • 源码定位: L39
  • 说明:

    TODO

• net.minecraft.util.profiling.jfr.stats.GcHeapStat.Timing

  • 类型: enum
  • 修饰符: static
  • 源码定位: L45
  • 说明:

    TODO

构造器

• 无

方法

下面的方法块按源码顺序生成。

public static GcHeapStat from(RecordedEvent event) @ L11

• 方法名：from
• 源码定位：L11
• 返回类型：GcHeapStat
• 修饰符：public static

参数:

• event: RecordedEvent

说明:

TODO

public static GcHeapStat.Summary summary(Duration recordingDuration, List<GcHeapStat> heapStats, Duration gcTotalDuration, int totalGCs) @ L19

• 方法名：summary
• 源码定位：L19
• 返回类型：GcHeapStat.Summary
• 修饰符：public static

参数:

• recordingDuration: Duration
• heapStats: List
• gcTotalDuration: Duration
• totalGCs: int

说明:

TODO

private static double calculateAllocationRatePerSecond(List<GcHeapStat> heapStats) @ L23

• 方法名：calculateAllocationRatePerSecond
• 源码定位：L23
• 返回类型：double
• 修饰符：private static

参数:

• heapStats: List

说明:

TODO

代码

public record GcHeapStat(Instant timestamp, long heapUsed, GcHeapStat.Timing timing) {
    public static GcHeapStat from(RecordedEvent event) {
        return new GcHeapStat(
            event.getStartTime(),
            event.getLong("heapUsed"),
            event.getString("when").equalsIgnoreCase("before gc") ? GcHeapStat.Timing.BEFORE_GC : GcHeapStat.Timing.AFTER_GC
        );
    }
 
    public static GcHeapStat.Summary summary(Duration recordingDuration, List<GcHeapStat> heapStats, Duration gcTotalDuration, int totalGCs) {
        return new GcHeapStat.Summary(recordingDuration, gcTotalDuration, totalGCs, calculateAllocationRatePerSecond(heapStats));
    }
 
    private static double calculateAllocationRatePerSecond(List<GcHeapStat> heapStats) {
        long totalAllocations = 0L;
        Map<GcHeapStat.Timing, List<GcHeapStat>> byTiming = heapStats.stream().collect(Collectors.groupingBy(it -> it.timing));
        List<GcHeapStat> beforeGcs = byTiming.get(GcHeapStat.Timing.BEFORE_GC);
        List<GcHeapStat> afterGcs = byTiming.get(GcHeapStat.Timing.AFTER_GC);
 
        for (int i = 1; i < beforeGcs.size(); i++) {
            GcHeapStat beforeGC = beforeGcs.get(i);
            GcHeapStat previousGC = afterGcs.get(i - 1);
            totalAllocations += beforeGC.heapUsed - previousGC.heapUsed;
        }
 
        Duration totalDuration = Duration.between(heapStats.get(1).timestamp, heapStats.get(heapStats.size() - 1).timestamp);
        return (double)totalAllocations / totalDuration.getSeconds();
    }
 
    public record Summary(Duration duration, Duration gcTotalDuration, int totalGCs, double allocationRateBytesPerSecond) {
        public float gcOverHead() {
            return (float)this.gcTotalDuration.toMillis() / (float)this.duration.toMillis();
        }
    }
 
    static enum Timing {
        BEFORE_GC,
        AFTER_GC;
    }
}

引用的其他类

• 无