com.palantir.dialogue.core.DialogueNodeselectionMetrics Maven / Gradle / Ivy

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There is a newer version: 5.4.0
package com.palantir.dialogue.core;

import com.codahale.metrics.Meter;
import com.google.errorprone.annotations.CheckReturnValue;
import com.palantir.logsafe.Preconditions;
import com.palantir.logsafe.Safe;
import com.palantir.tritium.metrics.registry.MetricName;
import com.palantir.tritium.metrics.registry.TaggedMetricRegistry;

/**
 * Instrumentation for which node selection strategy is used
 */
final class DialogueNodeselectionMetrics {
    private static final String JAVA_VERSION = System.getProperty("java.version", "unknown");

    private static final String LIBRARY_NAME = "dialogue";

    private static final String LIBRARY_VERSION = "4.7.0";

    private final TaggedMetricRegistry registry;

    private DialogueNodeselectionMetrics(TaggedMetricRegistry registry) {
        this.registry = registry;
    }

    static DialogueNodeselectionMetrics of(TaggedMetricRegistry registry) {
        return new DialogueNodeselectionMetrics(Preconditions.checkNotNull(registry, "TaggedMetricRegistry"));
    }

    /**
     * Marked every time the node selection strategy changes
     */
    @CheckReturnValue
    StrategyBuilderChannelNameStage strategy() {
        return new StrategyBuilder();
    }

    @Override
    public String toString() {
        return "DialogueNodeselectionMetrics{registry=" + registry + '}';
    }

    interface StrategyBuildStage {
        @CheckReturnValue
        Meter build();

        @CheckReturnValue
        MetricName buildMetricName();
    }

    interface StrategyBuilderChannelNameStage {
        @CheckReturnValue
        StrategyBuilderStrategyStage channelName(@Safe String channelName);
    }

    interface StrategyBuilderStrategyStage {
        @CheckReturnValue
        StrategyBuildStage strategy(@Safe String strategy);
    }

    private final class StrategyBuilder
            implements StrategyBuilderChannelNameStage, StrategyBuilderStrategyStage, StrategyBuildStage {
        private String channelName;

        private String strategy;

        @Override
        public StrategyBuilder channelName(@Safe String channelName) {
            Preconditions.checkState(this.channelName == null, "channel-name is already set");
            this.channelName = Preconditions.checkNotNull(channelName, "channel-name is required");
            return this;
        }

        @Override
        public StrategyBuilder strategy(@Safe String strategy) {
            Preconditions.checkState(this.strategy == null, "strategy is already set");
            this.strategy = Preconditions.checkNotNull(strategy, "strategy is required");
            return this;
        }

        @Override
        public Meter build() {
            return registry.meter(buildMetricName());
        }

        @Override
        public MetricName buildMetricName() {
            return MetricName.builder()
                    .safeName("dialogue.nodeselection.strategy")
                    .putSafeTags("channel-name", channelName)
                    .putSafeTags("strategy", strategy)
                    .putSafeTags("libraryName", LIBRARY_NAME)
                    .putSafeTags("libraryVersion", LIBRARY_VERSION)
                    .putSafeTags("javaVersion", JAVA_VERSION)
                    .build();
        }
    }
}