com.google.appengine.repackaged.io.opencensus.tags.TagKey Maven / Gradle / Ivy
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API for Google App Engine standard environment with some of the dependencies shaded (repackaged)
/*
* 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.tags;
import com.google.auto.value.AutoValue;
import io.opencensus.internal.StringUtils;
import io.opencensus.internal.Utils;
import javax.annotation.concurrent.Immutable;
/**
* A key to a value stored in a {@link TagContext}.
*
* Each {@code TagKey} has a {@code String} name. Names have a maximum length of {@link
* #MAX_LENGTH} and contain only printable ASCII characters.
*
*
{@code TagKey}s are designed to be used as constants. Declaring each key as a constant
* prevents key names from being validated multiple times.
*
* @since 0.8
*/
@Immutable
@AutoValue
public abstract class TagKey {
/**
* The maximum length for a tag key name. The value is {@value #MAX_LENGTH}.
*
* @since 0.8
*/
public static final int MAX_LENGTH = 255;
TagKey() {}
/**
* Constructs a {@code TagKey} with the given name.
*
*
The name must meet the following requirements:
*
*
* - It cannot be longer than {@link #MAX_LENGTH}.
*
- It can only contain printable ASCII characters.
*
*
* @param name the name of the key.
* @return a {@code TagKey} with the given name.
* @throws IllegalArgumentException if the name is not valid.
* @since 0.8
*/
public static TagKey create(String name) {
Utils.checkArgument(isValid(name), "Invalid TagKey name: %s", name);
return new AutoValue_TagKey(name);
}
/**
* Returns the name of the key.
*
* @return the name of the key.
* @since 0.8
*/
public abstract String getName();
/**
* Determines whether the given {@code String} is a valid tag key.
*
* @param name the tag key name to be validated.
* @return whether the name is valid.
*/
private static boolean isValid(String name) {
return !name.isEmpty() && name.length() <= MAX_LENGTH && StringUtils.isPrintableString(name);
}
}