io.prometheus.client.Collector Maven / Gradle / Ivy
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package io.prometheus.client;
import java.util.List;
import java.util.regex.Pattern;
/**
* A collector for a set of metrics.
*
* Normal users should use {@link Gauge}, {@link Counter}, {@link Summary} and {@link Histogram}.
*
* Subclasssing Collector is for advanced uses, such as proxying metrics from another monitoring system.
* It is it the responsibility of subclasses to ensure they produce valid metrics.
* @see Exposition formats.
*/
public abstract class Collector {
/**
* Return all of the metrics of this Collector.
*/
public abstract List collect();
public enum Type {
COUNTER,
GAUGE,
SUMMARY,
HISTOGRAM,
UNTYPED,
}
/**
* A metric, and all of its samples.
*/
static public class MetricFamilySamples {
public final String name;
public final Type type;
public final String help;
public final List samples;
public MetricFamilySamples(String name, Type type, String help, List samples) {
this.name = name;
this.type = type;
this.help = help;
this.samples = samples;
}
@Override
public boolean equals(Object obj) {
if (!(obj instanceof MetricFamilySamples)) {
return false;
}
MetricFamilySamples other = (MetricFamilySamples) obj;
return other.name.equals(name) && other.type.equals(type)
&& other.help.equals(help) && other.samples.equals(samples) ;
}
@Override
public int hashCode() {
int hash = 1;
hash = 37 * hash + name.hashCode();
hash = 37 * hash + type.hashCode();
hash = 37 * hash + help.hashCode();
hash = 37 * hash + samples.hashCode();
return hash;
}
@Override
public String toString() {
return "Name: " + name + " Type: " + type + " Help: " + help +
" Samples: " + samples;
}
/**
* A single Sample, with a unique name and set of labels.
*/
public static class Sample {
public final String name;
public final List labelNames;
public final List labelValues; // Must have same length as labelNames.
public final double value;
public Sample(String name, List labelNames, List labelValues, double value) {
this.name = name;
this.labelNames = labelNames;
this.labelValues = labelValues;
this.value = value;
}
@Override
public boolean equals(Object obj) {
if (!(obj instanceof Sample)) {
return false;
}
Sample other = (Sample) obj;
return other.name.equals(name) && other.labelNames.equals(labelNames)
&& other.labelValues.equals(labelValues) && other.value == value;
}
@Override
public int hashCode() {
int hash = 1;
hash = 37 * hash + name.hashCode();
hash = 37 * hash + labelNames.hashCode();
hash = 37 * hash + labelValues.hashCode();
long d = Double.doubleToLongBits(value);
hash = 37 * hash + (int)(d ^ (d >>> 32));
return hash;
}
@Override
public String toString() {
return "Name: " + name + " LabelNames: " + labelNames + " labelValues: " + labelValues +
" Value: " + value;
}
}
}
/**
* Register the Collector with the default registry.
*/
public T register() {
return register(CollectorRegistry.defaultRegistry);
}
/**
* Register the Collector with the given registry.
*/
public T register(CollectorRegistry registry) {
registry.register(this);
return (T)this;
}
public interface Describable {
/**
* Provide a list of metric families this Collector is expected to return.
*
* These should exclude the samples. This is used by the registry to
* detect collisions and duplicate registrations.
*
* Usually custom collectors do not have to implement Describable. If
* Describable is not implemented and the CollectorRegistry was created
* with auto describe enabled (which is the case for the default registry)
* then {@link collect} will be called at registration time instead of
* describe. If this could cause problems, either implement a proper
* describe, or if that's not practical have describe return an empty
* list.
*/
List describe();
}
/* Various utility functions for implementing Collectors. */
/**
* Number of nanoseconds in a second.
*/
public static final double NANOSECONDS_PER_SECOND = 1E9;
/**
* Number of milliseconds in a second.
*/
public static final double MILLISECONDS_PER_SECOND = 1E3;
private static final Pattern METRIC_NAME_RE = Pattern.compile("[a-zA-Z_:][a-zA-Z0-9_:]*");
private static final Pattern METRIC_LABEL_NAME_RE = Pattern.compile("[a-zA-Z_][a-zA-Z0-9_]*");
private static final Pattern RESERVED_METRIC_LABEL_NAME_RE = Pattern.compile("__.*");
/**
* Throw an exception if the metric name is invalid.
*/
protected static void checkMetricName(String name) {
if (!METRIC_NAME_RE.matcher(name).matches()) {
throw new IllegalArgumentException("Invalid metric name: " + name);
}
}
private static final Pattern SANITIZE_PREFIX_PATTERN = Pattern.compile("^[^a-zA-Z_]");
private static final Pattern SANITIZE_BODY_PATTERN = Pattern.compile("[^a-zA-Z0-9_]");
/**
* Sanitize metric name
*/
public static String sanitizeMetricName(String metricName) {
return SANITIZE_BODY_PATTERN.matcher(
SANITIZE_PREFIX_PATTERN.matcher(metricName).replaceFirst("_")
).replaceAll("_");
}
/**
* Throw an exception if the metric label name is invalid.
*/
protected static void checkMetricLabelName(String name) {
if (!METRIC_LABEL_NAME_RE.matcher(name).matches()) {
throw new IllegalArgumentException("Invalid metric label name: " + name);
}
if (RESERVED_METRIC_LABEL_NAME_RE.matcher(name).matches()) {
throw new IllegalArgumentException("Invalid metric label name, reserved for internal use: " + name);
}
}
/**
* Convert a double to its string representation in Go.
*/
public static String doubleToGoString(double d) {
if (d == Double.POSITIVE_INFINITY) {
return "+Inf";
}
if (d == Double.NEGATIVE_INFINITY) {
return "-Inf";
}
if (Double.isNaN(d)) {
return "NaN";
}
return Double.toString(d);
}
}