Skywalking-08：OAL原理——如何动态生成Class类

OAL 如何动态生成 Class 类

代码入口

在 org.apache.skywalking.oal.rt.OALRuntime#start 方法

    public void start(ClassLoader currentClassLoader) throws ModuleStartException, OALCompileException {
        if (!IS_RT_TEMP_FOLDER_INIT_COMPLETED) {
            prepareRTTempFolder();
            IS_RT_TEMP_FOLDER_INIT_COMPLETED = true;
        }

        this.currentClassLoader = currentClassLoader;
        Reader read;

        try {
            read = ResourceUtils.read(oalDefine.getConfigFile());
        } catch (FileNotFoundException e) {
            throw new ModuleStartException("Can't locate " + oalDefine.getConfigFile(), e);
        }

        OALScripts oalScripts;
        try {
            ScriptParser scriptParser = ScriptParser.createFromFile(read, oalDefine.getSourcePackage());
            // 解析oal脚本，生成OALScripts对象
            oalScripts = scriptParser.parse();
        } catch (IOException e) {
            throw new ModuleStartException("OAL script parse analysis failure.", e);
        }
		// OALScripts对象动态生成需要的类
        this.generateClassAtRuntime(oalScripts);
    }

时序图

OALRuntime-generate-class-at-runtime.sdt 该文件可以在 IDEA 的 Sequence Diagram 插件中打开

案例

启动 OAP 配置中，配置下环境变量 SW_OAL_ENGINE_DEBUG=Y，这样能在工作目录下的 oal-rt 目录下找到生成的 Class 文件。

通过如下目录结构，可以看出有三种 Class ：

• dispatcher ：调度器，将指标对象发送 MetricsStreamProcessor (指标处理器)
• metrics ：指标类，存储指标数据
• StorageBuilder ：存储构造器，实现类 StorageBuilder 接口，提供 map 与 StorageData 之间互转的方法

oal-rt
├── dispatcher
│   ├── ServiceInstanceJVMClassDispatcher.class
│   └── ServiceInstanceJVMThreadDispatcher.class
└── metrics
    ├── InstanceJvmClassLoadedClassCountMetrics.class
    ├── InstanceJvmClassTotalLoadedClassCountMetrics.class
    ├── InstanceJvmClassUnloadedClassCountMetrics.class
    ├── InstanceJvmThreadDaemonCountMetrics.class
    ├── InstanceJvmThreadDeadlockedMetrics.class
    ├── InstanceJvmThreadLiveCountMetrics.class
    └── builder
        ├── InstanceJvmClassLoadedClassCountMetricsBuilder.class
        ├── InstanceJvmClassTotalLoadedClassCountMetricsBuilder.class
        ├── InstanceJvmClassUnloadedClassCountMetricsBuilder.class
        ├── InstanceJvmThreadDaemonCountMetricsBuilder.class
        ├── InstanceJvmThreadDeadlockedMetricsBuilder.class
        └── InstanceJvmThreadLiveCountMetricsBuilder.class

指标类

package org.apache.skywalking.oap.server.core.source.oal.rt.metrics;

import org.apache.skywalking.oap.server.core.analysis.Stream;
import org.apache.skywalking.oap.server.core.analysis.metrics.LongAvgMetrics;
import org.apache.skywalking.oap.server.core.analysis.metrics.Metrics;
import org.apache.skywalking.oap.server.core.analysis.metrics.MetricsMetaInfo;
import org.apache.skywalking.oap.server.core.analysis.metrics.WithMetadata;
import org.apache.skywalking.oap.server.core.analysis.worker.MetricsStreamProcessor;
import org.apache.skywalking.oap.server.core.remote.grpc.proto.RemoteData;
import org.apache.skywalking.oap.server.core.remote.grpc.proto.RemoteData.Builder;
import org.apache.skywalking.oap.server.core.source.oal.rt.metrics.builder.InstanceJvmClassLoadedClassCountMetricsBuilder;
import org.apache.skywalking.oap.server.core.storage.annotation.Column;

@Stream(
    name = "instance_jvm_class_loaded_class_count",
    scopeId = 11000,
    builder = InstanceJvmClassLoadedClassCountMetricsBuilder.class,
    processor = MetricsStreamProcessor.class
)
public class InstanceJvmClassLoadedClassCountMetrics extends LongAvgMetrics implements WithMetadata {
    @Column(
        columnName = "entity_id",
        length = 512
    )
    private String entityId;
    @Column(
        columnName = "service_id",
        length = 256
    )
    private String serviceId;

    public InstanceJvmClassLoadedClassCountMetrics() {
    }

    public String getEntityId() {
        return this.entityId;
    }

    public void setEntityId(String var1) {
        this.entityId = var1;
    }

    public String getServiceId() {
        return this.serviceId;
    }

    public void setServiceId(String var1) {
        this.serviceId = var1;
    }

    public String id() {
        String var1 = String.valueOf(this.getTimeBucket());
        var1 = String.valueOf(var1).concat(String.valueOf("_" + this.entityId));
        return var1;
    }

    public int hashCode() {
        byte var1 = 17;
        int var2 = 31 * var1 + this.entityId.hashCode();
        var2 = 31 * var2 + (int)this.getTimeBucket();
        return var2;
    }

    public int remoteHashCode() {
        byte var1 = 17;
        int var2 = 31 * var1 + this.entityId.hashCode();
        return var2;
    }

    public boolean equals(Object var1) {
        if (this == var1) {
            return true;
        } else if (var1 == null) {
            return false;
        } else if (this.getClass() != var1.getClass()) {
            return false;
        } else {
            InstanceJvmClassLoadedClassCountMetrics var2 = (InstanceJvmClassLoadedClassCountMetrics)var1;
            if (!this.entityId.equals(var2.entityId)) {
                return false;
            } else {
                return this.getTimeBucket() == var2.getTimeBucket();
            }
        }
    }

    public Builder serialize() {
        Builder var1 = RemoteData.newBuilder();
        var1.addDataStrings(this.getEntityId());
        var1.addDataStrings(this.getServiceId());
        var1.addDataLongs(this.getSummation());
        var1.addDataLongs(this.getCount());
        var1.addDataLongs(this.getValue());
        var1.addDataLongs(this.getTimeBucket());
        return var1;
    }

    public void deserialize(RemoteData var1) {
        this.setEntityId(var1.getDataStrings(0));
        this.setServiceId(var1.getDataStrings(1));
        this.setSummation(var1.getDataLongs(0));
        this.setCount(var1.getDataLongs(1));
        this.setValue(var1.getDataLongs(2));
        this.setTimeBucket(var1.getDataLongs(3));
    }

    public MetricsMetaInfo getMeta() {
        return new MetricsMetaInfo("instance_jvm_class_loaded_class_count", 11000, this.entityId);
    }

    public Metrics toHour() {
        InstanceJvmClassLoadedClassCountMetrics var1 = new InstanceJvmClassLoadedClassCountMetrics();
        var1.setEntityId(this.getEntityId());
        var1.setServiceId(this.getServiceId());
        var1.setSummation(this.getSummation());
        var1.setCount(this.getCount());
        var1.setValue(this.getValue());
        var1.setTimeBucket(this.toTimeBucketInHour());
        return var1;
    }

    public Metrics toDay() {
        InstanceJvmClassLoadedClassCountMetrics var1 = new InstanceJvmClassLoadedClassCountMetrics();
        var1.setEntityId(this.getEntityId());
        var1.setServiceId(this.getServiceId());
        var1.setSummation(this.getSummation());
        var1.setCount(this.getCount());
        var1.setValue(this.getValue());
        var1.setTimeBucket(this.toTimeBucketInDay());
        return var1;
    }
}

存储构造器

package org.apache.skywalking.oap.server.core.source.oal.rt.metrics.builder;

import java.util.HashMap;
import java.util.Map;
import org.apache.skywalking.oap.server.core.source.oal.rt.metrics.InstanceJvmClassLoadedClassCountMetrics;
import org.apache.skywalking.oap.server.core.storage.StorageBuilder;
import org.apache.skywalking.oap.server.core.storage.StorageData;

public class InstanceJvmClassLoadedClassCountMetricsBuilder implements StorageBuilder {
    public InstanceJvmClassLoadedClassCountMetricsBuilder() {
    }

    public Map data2Map(StorageData var1) {
        InstanceJvmClassLoadedClassCountMetrics var2 = (InstanceJvmClassLoadedClassCountMetrics)var1;
        HashMap var3 = new HashMap();
        var3.put((Object)"entity_id", var2.getEntityId());
        var3.put((Object)"service_id", var2.getServiceId());
        var3.put((Object)"summation", new Long(var2.getSummation()));
        var3.put((Object)"count", new Long(var2.getCount()));
        var3.put((Object)"value", new Long(var2.getValue()));
        var3.put((Object)"time_bucket", new Long(var2.getTimeBucket()));
        return var3;
    }

    public StorageData map2Data(Map var1) {
        InstanceJvmClassLoadedClassCountMetrics var2 = new InstanceJvmClassLoadedClassCountMetrics();
        var2.setEntityId((String)var1.get("entity_id"));
        var2.setServiceId((String)var1.get("service_id"));
        var2.setSummation(((Number)var1.get("summation")).longValue());
        var2.setCount(((Number)var1.get("count")).longValue());
        var2.setValue(((Number)var1.get("value")).longValue());
        var2.setTimeBucket(((Number)var1.get("time_bucket")).longValue());
        return var2;
    }
}

调度器

package org.apache.skywalking.oap.server.core.source.oal.rt.dispatcher;

import org.apache.skywalking.oap.server.core.analysis.SourceDispatcher;
import org.apache.skywalking.oap.server.core.analysis.worker.MetricsStreamProcessor;
import org.apache.skywalking.oap.server.core.source.ServiceInstanceJVMClass;
import org.apache.skywalking.oap.server.core.source.Source;
import org.apache.skywalking.oap.server.core.source.oal.rt.metrics.InstanceJvmClassLoadedClassCountMetrics;
import org.apache.skywalking.oap.server.core.source.oal.rt.metrics.InstanceJvmClassTotalLoadedClassCountMetrics;
import org.apache.skywalking.oap.server.core.source.oal.rt.metrics.InstanceJvmClassUnloadedClassCountMetrics;

public class ServiceInstanceJVMClassDispatcher implements SourceDispatcher<ServiceInstanceJVMClass> {
    private void doInstanceJvmClassLoadedClassCount(ServiceInstanceJVMClass var1) {
        InstanceJvmClassLoadedClassCountMetrics var2 = new InstanceJvmClassLoadedClassCountMetrics();
        var2.setTimeBucket(var1.getTimeBucket());
        var2.setEntityId(var1.getEntityId());
        var2.setServiceId(var1.getServiceId());
        var2.combine(var1.getLoadedClassCount(), (long)1);
        MetricsStreamProcessor.getInstance().in(var2);
    }

    private void doInstanceJvmClassUnloadedClassCount(ServiceInstanceJVMClass var1) {
        InstanceJvmClassUnloadedClassCountMetrics var2 = new InstanceJvmClassUnloadedClassCountMetrics();
        var2.setTimeBucket(var1.getTimeBucket());
        var2.setEntityId(var1.getEntityId());
        var2.setServiceId(var1.getServiceId());
        var2.combine(var1.getUnloadedClassCount(), (long)1);
        MetricsStreamProcessor.getInstance().in(var2);
    }

    private void doInstanceJvmClassTotalLoadedClassCount(ServiceInstanceJVMClass var1) {
        InstanceJvmClassTotalLoadedClassCountMetrics var2 = new InstanceJvmClassTotalLoadedClassCountMetrics();
        var2.setTimeBucket(var1.getTimeBucket());
        var2.setEntityId(var1.getEntityId());
        var2.setServiceId(var1.getServiceId());
        var2.combine(var1.getTotalLoadedClassCount(), (long)1);
        MetricsStreamProcessor.getInstance().in(var2);
    }

    public void dispatch(Source var1) {
        ServiceInstanceJVMClass var2 = (ServiceInstanceJVMClass)var1;
        this.doInstanceJvmClassLoadedClassCount(var2);
        this.doInstanceJvmClassUnloadedClassCount(var2);
        this.doInstanceJvmClassTotalLoadedClassCount(var2);
    }

    public ServiceInstanceJVMClassDispatcher() {
    }
}

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