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/**
* Copyright 2017 Pivotal Software, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package io.micrometer.core.instrument;
import io.micrometer.core.annotation.Timed;
import io.micrometer.core.lang.Nullable;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.TimeUnit;
import java.util.function.Consumer;
import java.util.function.Supplier;
/**
* A long task timer is used to track the total duration of all in-flight long-running tasks and the number of
* such tasks.
*
* @author Jon Schneider
*/
public interface LongTaskTimer extends Meter {
static Builder builder(String name) {
return new Builder(name);
}
/**
* Create a timer builder from a {@link Timed} annotation.
*
* @param timed The annotation instance to base a new timer on.
* @return This builder.
*/
static Builder builder(Timed timed) {
if (!timed.longTask()) {
throw new IllegalArgumentException("Cannot build a long task timer from a @Timed annotation that is not marked as a long task");
}
if (timed.value().isEmpty()) {
throw new IllegalArgumentException("Long tasks instrumented with @Timed require the value attribute to be non-empty");
}
return new Builder(timed.value())
.tags(timed.extraTags())
.description(timed.description().isEmpty() ? null : timed.description());
}
/**
* Executes the callable `f` and records the time taken.
*
* @param f Function to execute and measure the execution time.
* @param The return type of the {@link Callable}.
* @return The return value of `f`.
* @throws Exception Any exception bubbling up from the callable.
*/
default T recordCallable(Callable f) throws Exception {
Sample sample = start();
try {
return f.call();
} finally {
sample.stop();
}
}
/**
* Executes the callable `f` and records the time taken.
*
* @param f Function to execute and measure the execution time.
* @param The return type of the {@link Supplier}.
* @return The return value of `f`.
*/
default T record(Supplier f) {
Sample sample = start();
try {
return f.get();
} finally {
sample.stop();
}
}
/**
* Executes the runnable `f` and records the time taken.
*
* @param f Function to execute and measure the execution time with a reference to the
* timer id useful for looking up current duration.
*/
default void record(Consumer f) {
Sample sample = start();
try {
f.accept(sample);
} finally {
sample.stop();
}
}
/**
* Executes the runnable `f` and records the time taken.
*
* @param f Function to execute and measure the execution time.
*/
default void record(Runnable f) {
Sample sample = start();
try {
f.run();
} finally {
sample.stop();
}
}
/**
* Start keeping time for a task.
*
* @return A task id that can be used to look up how long the task has been running.
*/
Sample start();
/**
* Mark a given task as completed.
*
* @param task Id for the task to stop. This should be the value returned from {@link #start()}.
* @return Duration for the task in nanoseconds. A -1 value will be returned for an unknown task.
*/
long stop(long task);
/**
* The current duration for an active task.
*
* @param task Id for the task to stop. This should be the value returned from {@link #start()}.
* @param unit The time unit to scale the duration to.
* @return Duration for the task in nanoseconds. A -1 value will be returned for an unknown task.
*/
double duration(long task, TimeUnit unit);
/**
* @param unit The time unit to scale the duration to.
* @return The cumulative duration of all current tasks in nanoseconds.
*/
double duration(TimeUnit unit);
/**
* @return The current number of tasks being executed.
*/
int activeTasks();
@Override
default Iterable measure() {
return Arrays.asList(
new Measurement(() -> (double) activeTasks(), Statistic.ACTIVE_TASKS),
new Measurement(() -> duration(TimeUnit.NANOSECONDS), Statistic.DURATION)
);
}
class Sample {
private final LongTaskTimer timer;
private final long task;
public Sample(LongTaskTimer timer, long task) {
this.timer = timer;
this.task = task;
}
/**
* Records the duration of the operation
*
* @return The duration that was stop in nanoseconds
*/
public long stop() {
return timer.stop(task);
}
public double duration(TimeUnit unit) {
return timer.duration(task, unit);
}
}
/**
* Fluent builder for long task timers.
*/
class Builder {
private final String name;
private final List tags = new ArrayList<>();
@Nullable
private String description;
private Builder(String name) {
this.name = name;
}
/**
* @param tags Must be an even number of arguments representing key/value pairs of tags.
* @return The long task timer builder with added tags.
*/
public Builder tags(String... tags) {
return tags(Tags.of(tags));
}
/**
* @param tags Tags to add to the eventual long task timer.
* @return The long task timer builder with added tags.
*/
public Builder tags(Iterable tags) {
tags.forEach(this.tags::add);
return this;
}
/**
* @param key The tag key.
* @param value The tag value.
* @return The long task timer builder with a single added tag.
*/
public Builder tag(String key, String value) {
tags.add(Tag.of(key, value));
return this;
}
/**
* @param description Description text of the eventual long task timer.
* @return The long task timer builder with added description.
*/
public Builder description(@Nullable String description) {
this.description = description;
return this;
}
/**
* Add the long task timer to a single registry, or return an existing long task timer in that registry. The returned
* long task timer will be unique for each registry, but each registry is guaranteed to only create one long task timer
* for the same combination of name and tags.
*
* @param registry A registry to add the long task timer to, if it doesn't already exist.
* @return A new or existing long task timer.
*/
public LongTaskTimer register(MeterRegistry registry) {
return registry.more().longTaskTimer(new Meter.Id(name, tags, null, description, Type.LONG_TASK_TIMER));
}
}
}