1+ /**
2+ * Copyright 2017 VMware, Inc.
3+ * <p>
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+ * <p>
8+ * https://www.apache.org/licenses/LICENSE-2.0
9+ * <p>
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+ package io .micrometer .prometheus ;
17+
18+ import io .micrometer .core .instrument .Meter ;
19+ import io .micrometer .core .instrument .Tag ;
20+ import io .micrometer .core .instrument .config .NamingConvention ;
21+ import io .prometheus .client .Collector ;
22+
23+ import java .util .*;
24+ import java .util .concurrent .ConcurrentHashMap ;
25+ import java .util .stream .Stream ;
26+
27+ import static java .util .stream .Collectors .toList ;
28+
29+ /**
30+ * {@link Collector} for Micrometer.
31+ *
32+ * @author Jon Schneider
33+ * @author Johnny Lim
34+ */
35+ class MutatedMicrometerCollector extends Collector implements Collector .Describable {
36+
37+ static final class TagsHolder {
38+ final List <String > keys ;
39+ final List <String > values ;
40+
41+ private TagsHolder (List <String > keys , List <String > values ) {
42+ this .keys = keys ;
43+ this .values = values ;
44+ }
45+
46+ static TagsHolder from (List <Tag > tags ) {
47+ Objects .requireNonNull (tags , "tags" );
48+
49+ List <String > keys = new ArrayList <>(tags .size ());
50+ List <String > values = new ArrayList <>(tags .size ());
51+
52+ for (Tag tag : tags ) {
53+ keys .add (tag .getKey ());
54+ values .add (tag .getValue ());
55+ }
56+
57+ return new TagsHolder (
58+ Collections .unmodifiableList (keys ),
59+ Collections .unmodifiableList (values )
60+ );
61+ }
62+
63+ public List <String > getKeys () {
64+ return keys ;
65+ }
66+
67+ public List <String > getValues () {
68+ return values ;
69+ }
70+
71+ @ Override
72+ public boolean equals (Object o ) {
73+ if (this == o ) return true ;
74+ if (o == null || getClass () != o .getClass ()) return false ;
75+ TagsHolder that = (TagsHolder ) o ;
76+ return keys .equals (that .keys ) && values .equals (that .values );
77+ }
78+
79+ @ Override
80+ public int hashCode () {
81+ return Objects .hash (keys , values );
82+ }
83+ }
84+
85+ private final Meter .Id id ;
86+ private final Map <TagsHolder , Child > children = new ConcurrentHashMap <>();
87+ private final String conventionName ;
88+ private final String help ;
89+
90+ public MutatedMicrometerCollector (Meter .Id id , NamingConvention convention , PrometheusConfig config ) {
91+ this .id = id ;
92+ this .conventionName = id .getConventionName (convention );
93+ this .help = config .descriptions () ? Optional .ofNullable (id .getDescription ()).orElse (" " ) : " " ;
94+ }
95+
96+ public void add (List <Tag > tags , Child child ) {
97+ children .put (TagsHolder .from (tags ), child );
98+ }
99+
100+ public void remove (List <Tag > tags ) {
101+ children .remove (TagsHolder .from (tags ));
102+ }
103+
104+ public boolean isEmpty () {
105+ return children .isEmpty ();
106+ }
107+
108+ @ Override
109+ public List <MetricFamilySamples > collect () {
110+ Map <String , Family > families = new HashMap <>();
111+
112+ for (Map .Entry <TagsHolder , Child > e : children .entrySet ()) {
113+ TagsHolder tags = e .getKey ();
114+ Child child = e .getValue ();
115+
116+ child .samples (conventionName , tags ).forEach (family -> {
117+ families .compute (family .getConventionName (), (name , matchingFamily ) -> matchingFamily != null ?
118+ matchingFamily .addSamples (family .samples ) : family );
119+ });
120+ }
121+
122+ return families .values ().stream ()
123+ .map (family -> new MetricFamilySamples (family .conventionName , family .type , help , family .samples ))
124+ .collect (toList ());
125+ }
126+
127+ @ Override
128+ public List <MetricFamilySamples > describe () {
129+ switch (id .getType ()) {
130+ case COUNTER :
131+ return Collections .singletonList (
132+ new MetricFamilySamples (conventionName , Type .COUNTER , help , Collections .emptyList ()));
133+
134+ case GAUGE :
135+ return Collections .singletonList (
136+ new MetricFamilySamples (conventionName , Type .GAUGE , help , Collections .emptyList ()));
137+
138+ case TIMER :
139+ case DISTRIBUTION_SUMMARY :
140+ return Arrays .asList (
141+ new MetricFamilySamples (conventionName , Type .HISTOGRAM , help , Collections .emptyList ()),
142+ new MetricFamilySamples (conventionName + "_max" , Type .GAUGE , help , Collections .emptyList ()));
143+
144+ case LONG_TASK_TIMER :
145+ return Arrays .asList (
146+ new MetricFamilySamples (conventionName , Type .HISTOGRAM , help , Collections .emptyList ()),
147+ new MetricFamilySamples (conventionName , Type .UNKNOWN , help , Collections .emptyList ()));
148+
149+ default :
150+ return Collections .singletonList (
151+ new MetricFamilySamples (conventionName , Type .UNKNOWN , help , Collections .emptyList ()));
152+ }
153+ }
154+
155+ interface Child {
156+ Stream <Family > samples (String conventionName , TagsHolder tags );
157+ }
158+
159+ static class Family {
160+ final Type type ;
161+ final String conventionName ;
162+ final List <MetricFamilySamples .Sample > samples = new ArrayList <>();
163+
164+ Family (Type type , String conventionName , MetricFamilySamples .Sample ... samples ) {
165+ this .type = type ;
166+ this .conventionName = conventionName ;
167+ Collections .addAll (this .samples , samples );
168+ }
169+
170+ Family (Type type , String conventionName , Stream <MetricFamilySamples .Sample > samples ) {
171+ this .type = type ;
172+ this .conventionName = conventionName ;
173+ samples .forEach (this .samples ::add );
174+ }
175+
176+ String getConventionName () {
177+ return conventionName ;
178+ }
179+
180+ Family addSamples (Collection <MetricFamilySamples .Sample > samples ) {
181+ this .samples .addAll (samples );
182+ return this ;
183+ }
184+ }
185+ }
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