| /* |
| * Copyright 2017, OpenCensus Authors |
| * |
| * 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.opencensus.trace.samplers; |
| |
| import io.opencensus.trace.Sampler; |
| import io.opencensus.trace.Span; |
| |
| /** |
| * Static class to access a set of pre-defined {@link Sampler Samplers}. |
| * |
| * @since 0.5 |
| */ |
| public final class Samplers { |
| private static final Sampler ALWAYS_SAMPLE = new AlwaysSampleSampler(); |
| private static final Sampler NEVER_SAMPLE = new NeverSampleSampler(); |
| |
| // No instance of this class. |
| private Samplers() {} |
| |
| /** |
| * Returns a {@link Sampler} that always makes a "yes" decision on {@link Span} sampling. |
| * |
| * @return a {@code Sampler} that always makes a "yes" decision on {@code Span} sampling. |
| * @since 0.5 |
| */ |
| public static Sampler alwaysSample() { |
| return ALWAYS_SAMPLE; |
| } |
| |
| /** |
| * Returns a {@link Sampler} that always makes a "no" decision on {@link Span} sampling. |
| * |
| * @return a {@code Sampler} that always makes a "no" decision on {@code Span} sampling. |
| * @since 0.5 |
| */ |
| public static Sampler neverSample() { |
| return NEVER_SAMPLE; |
| } |
| |
| /** |
| * Returns a {@link Sampler} that makes a "yes" decision with a given probability. |
| * |
| * @param probability The desired probability of sampling. Must be within [0.0, 1.0]. |
| * @return a {@code Sampler} that makes a "yes" decision with a given probability. |
| * @throws IllegalArgumentException if {@code probability} is out of range |
| * @since 0.5 |
| */ |
| public static Sampler probabilitySampler(double probability) { |
| return ProbabilitySampler.create(probability); |
| } |
| } |