1 /*
2  * Copyright 2017, OpenCensus Authors
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *     http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package io.opencensus.trace;
18 
19 import com.google.auto.value.AutoValue;
20 import io.opencensus.internal.Utils;
21 import java.util.Collections;
22 import java.util.HashMap;
23 import java.util.Map;
24 import javax.annotation.concurrent.Immutable;
25 
26 /**
27  * A text annotation with a set of attributes.
28  *
29  * @since 0.5
30  */
31 @Immutable
32 @AutoValue
33 public abstract class Annotation {
34   private static final Map<String, AttributeValue> EMPTY_ATTRIBUTES =
35       Collections.unmodifiableMap(Collections.<String, AttributeValue>emptyMap());
36 
37   /**
38    * Returns a new {@code Annotation} with the given description.
39    *
40    * @param description the text description of the {@code Annotation}.
41    * @return a new {@code Annotation} with the given description.
42    * @throws NullPointerException if {@code description} is {@code null}.
43    * @since 0.5
44    */
fromDescription(String description)45   public static Annotation fromDescription(String description) {
46     return new AutoValue_Annotation(description, EMPTY_ATTRIBUTES);
47   }
48 
49   /**
50    * Returns a new {@code Annotation} with the given description and set of attributes.
51    *
52    * @param description the text description of the {@code Annotation}.
53    * @param attributes the attributes of the {@code Annotation}.
54    * @return a new {@code Annotation} with the given description and set of attributes.
55    * @throws NullPointerException if {@code description} or {@code attributes} are {@code null}.
56    * @since 0.5
57    */
fromDescriptionAndAttributes( String description, Map<String, AttributeValue> attributes)58   public static Annotation fromDescriptionAndAttributes(
59       String description, Map<String, AttributeValue> attributes) {
60     return new AutoValue_Annotation(
61         description,
62         Collections.unmodifiableMap(
63             new HashMap<String, AttributeValue>(Utils.checkNotNull(attributes, "attributes"))));
64   }
65 
66   /**
67    * Return the description of the {@code Annotation}.
68    *
69    * @return the description of the {@code Annotation}.
70    * @since 0.5
71    */
getDescription()72   public abstract String getDescription();
73 
74   /**
75    * Return the attributes of the {@code Annotation}.
76    *
77    * @return the attributes of the {@code Annotation}.
78    * @since 0.5
79    */
getAttributes()80   public abstract Map<String, AttributeValue> getAttributes();
81 
Annotation()82   Annotation() {}
83 }
84