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package org.apache.kafka.common.metrics;

public interface Monitorable {

    /**
     * Set the PluginMetrics instance from the component that instantiates the plugin.
     * Plugins can register and unregister metrics using the given PluginMetrics
     * at any point in their lifecycle prior to their close method being called.
     *
     * Plugin must call the close() method on this PluginMetrics instance in their close()
     * method to clear all metrics they registered.
     */
    void withPluginMetrics(PluginMetrics metrics);

}

/**
 * Implementations are thread safe so plugins may use the PluginMetrics instance from multiple threads
 */
public interface PluginMetrics extends Closeable {

    /**
     * Create a {@link MetricName} with the given name, description and tags. The group will be set to "plugins"
     * Tags to uniquely identify the plugins are automatically added to the provided tags
     *
     * @param name        The name of the metric
     * @param description A human-readable description to include in the metric
     * @param tags        additional key/value attributes of the metric
     */
    MetricName metricName(String name, String description, Map<String, String> tags);

    /**
     * Add a metric to monitor an object that implements {@link MetricValueProvider}. This metric won't be associated with any
     * sensor. This is a way to expose existing values as metrics.
     *
     * @param metricName The name of the metric
     * @param metricValueProvider The metric value provider associated with this metric
     * @throws IllegalArgumentException if a metric with same name already exists.
     */
    void addMetric(MetricName metricName, MetricValueProvider<?> metricValueProvider);

    /**
     * Remove a metric if it exists.
     *
     * @param metricName The name of the metric
     * @throws IllegalArgumentException if the plugin has not already created a metric with this name
     */
    void removeMetric(MetricName metricName);

    /**
     * Create a sensor with the given unique name. The name must only be unique for the plugin, so different plugins can use the same names.
     *
     * @param name The sensor name
     * @return The sensor
     * @throws IllegalArgumentException if a sensor with same name already exists for this plugin
     */
    Sensor sensor(String name);

    /**
     * Remove a sensor (if it exists) and its associated metrics.
     *
     * @param name The name of the sensor to be removed
     * @throws IllegalArgumentException if the plugin has not already created a sensor with this name
     */
    void removeSensor(String name);
}