Places in code with 6 or more lines that are exactly the same.
Intro
- For duplication, we look at places in code where there are 6 or more lines of code that are exactly the same.
- Before duplication is calculated, the code is cleaned to remove empty lines, comments, and frequently duplicated constructs such as imports.
- You should aim at having as little as possible (<5%) of duplicated code as high-level of duplication can lead to maintenance difficulties, poor factoring, and logical contradictions.
- To learn more about duplications and techniques for eliminating duplication, Sokrates recommends the following resources:
- Avoid Repetition, MartinFlower.com (IEEE Software article)
- Refactoring duplicated code, sourcemaking.com
- Beck Design Rules, MartinFowler.com
- DRY (Don't Repeat Yourself) Principle, Wikipedia
- The Cut-and-Paste Programming Software Development Anti-Pattern, sourcemaking.com
- Code Smells / Duplicated Code, Jeff Atwood, codinghorror.com:
- "Duplicated code is the bane of software development. Stamp out duplication whenever possible. You should always be on the lookout for more subtle cases of near-duplication, too. Don't Repeat Yourself!"
- Reducing Coupling, MartinFlower.com (IEEE Software article):
- "There are several ways to describe coupling, but it boils down to this: If changing one module in a program requires changing another module, then coupling exists. ... Duplication always implies coupling, because changing one piece of duplicate code implies changing the other."
Duplication Overall
- 13% duplication:
- 68,240 cleaned lines of cleaned code (without empty lines, comments, and frequently duplicated constructs such as imports)
- 9,471 duplicated lines
- 1,834 duplicates
Duplication per Extension
Duplication per Component (primary)
Duplication Between Components (50+ lines)
Open 3D force graph...
Show more details on duplication between components...
From Component
--> To Component
Duplicated
Lines
File Pairs
Details
servicetalk-http-api (2%)
--> servicetalk-http-netty (4%)
646
64 file pairs
details...
servicetalk-buffer-api (9%)
--> servicetalk-buffer-netty (8%)
375
4 file pairs
details...
servicetalk-grpc-utils (66%)
--> servicetalk-http-utils (14%)
370
2 file pairs
details...
servicetalk-grpc-api (5%)
--> servicetalk-http-api (1%)
350
33 file pairs
details...
servicetalk-concurrent-api (<1%)
--> servicetalk-http-api (1%)
301
31 file pairs
details...
servicetalk-http-api (1%)
--> servicetalk-transport-api (8%)
233
31 file pairs
details...
servicetalk-http-netty (1%)
--> servicetalk-http-utils (6%)
170
24 file pairs
details...
servicetalk-transport-api (5%)
--> servicetalk-transport-netty-internal (1%)
158
3 file pairs
details...
servicetalk-grpc-api (2%)
--> servicetalk-http-netty (<1%)
150
23 file pairs
details...
servicetalk-client-api (13%)
--> servicetalk-http-api (<1%)
138
31 file pairs
details...
servicetalk-http-api (<1%)
--> servicetalk-http-utils (5%)
132
19 file pairs
details...
servicetalk-grpc-api (1%)
--> servicetalk-transport-api (4%)
112
7 file pairs
details...
servicetalk-http-netty (<1%)
--> servicetalk-transport-api (3%)
103
12 file pairs
details...
servicetalk-grpc-api (1%)
--> servicetalk-http-utils (3%)
88
6 file pairs
details...
servicetalk-http-api (<1%)
--> servicetalk-logging-slf4j-internal (20%)
84
13 file pairs
details...
servicetalk-http-api (<1%)
--> servicetalk-http-security-jersey (24%)
84
13 file pairs
details...
servicetalk-concurrent-internal (4%)
--> servicetalk-http-api (<1%)
84
13 file pairs
details...
servicetalk-concurrent-api (<1%)
--> servicetalk-http-netty (<1%)
81
5 file pairs
details...
servicetalk-concurrent-api (<1%)
--> servicetalk-transport-api (2%)
78
4 file pairs
details...
servicetalk-client-api (7%)
--> servicetalk-concurrent-api (<1%)
78
4 file pairs
details...
servicetalk-grpc-api (1%)
--> servicetalk-opentracing-zipkin-publisher (10%)
72
9 file pairs
details...
servicetalk-concurrent-jdkflow (47%)
--> servicetalk-concurrent-reactivestreams (43%)
69
1 file pair
details...
servicetalk-grpc-api (1%)
--> servicetalk-transport-netty-internal (<1%)
60
3 file pairs
details...
servicetalk-grpc-api (1%)
--> servicetalk-loadbalancer (5%)
60
3 file pairs
details...
servicetalk-grpc-api (1%)
--> servicetalk-http-router-predicate (9%)
60
3 file pairs
details...
servicetalk-concurrent-api (<1%)
--> servicetalk-grpc-api (1%)
60
2 file pairs
details...
servicetalk-http-netty (<1%)
--> servicetalk-opentracing-zipkin-publisher (7%)
54
18 file pairs
details...
servicetalk-http-api (<1%)
--> servicetalk-http-router-jersey (<1%)
52
2 file pairs
details...
servicetalk-http-netty (<1%)
--> servicetalk-transport-netty-internal (<1%)
52
6 file pairs
details...
servicetalk-http-netty (<1%)
--> servicetalk-loadbalancer (4%)
52
6 file pairs
details...
servicetalk-http-api (<1%)
--> servicetalk-serialization-api (6%)
50
4 file pairs
details...
| From Component --> To Component |
Duplicated Lines |
File Pairs | Details |
|---|---|---|---|
| servicetalk-http-api (2%) --> servicetalk-http-netty (4%) |
646 | 64 file pairs | details... |
| servicetalk-buffer-api (9%) --> servicetalk-buffer-netty (8%) |
375 | 4 file pairs | details... |
| servicetalk-grpc-utils (66%) --> servicetalk-http-utils (14%) |
370 | 2 file pairs | details... |
| servicetalk-grpc-api (5%) --> servicetalk-http-api (1%) |
350 | 33 file pairs | details... |
| servicetalk-concurrent-api (<1%) --> servicetalk-http-api (1%) |
301 | 31 file pairs | details... |
| servicetalk-http-api (1%) --> servicetalk-transport-api (8%) |
233 | 31 file pairs | details... |
| servicetalk-http-netty (1%) --> servicetalk-http-utils (6%) |
170 | 24 file pairs | details... |
| servicetalk-transport-api (5%) --> servicetalk-transport-netty-internal (1%) |
158 | 3 file pairs | details... |
| servicetalk-grpc-api (2%) --> servicetalk-http-netty (<1%) |
150 | 23 file pairs | details... |
| servicetalk-client-api (13%) --> servicetalk-http-api (<1%) |
138 | 31 file pairs | details... |
| servicetalk-http-api (<1%) --> servicetalk-http-utils (5%) |
132 | 19 file pairs | details... |
| servicetalk-grpc-api (1%) --> servicetalk-transport-api (4%) |
112 | 7 file pairs | details... |
| servicetalk-http-netty (<1%) --> servicetalk-transport-api (3%) |
103 | 12 file pairs | details... |
| servicetalk-grpc-api (1%) --> servicetalk-http-utils (3%) |
88 | 6 file pairs | details... |
| servicetalk-http-api (<1%) --> servicetalk-logging-slf4j-internal (20%) |
84 | 13 file pairs | details... |
| servicetalk-http-api (<1%) --> servicetalk-http-security-jersey (24%) |
84 | 13 file pairs | details... |
| servicetalk-concurrent-internal (4%) --> servicetalk-http-api (<1%) |
84 | 13 file pairs | details... |
| servicetalk-concurrent-api (<1%) --> servicetalk-http-netty (<1%) |
81 | 5 file pairs | details... |
| servicetalk-concurrent-api (<1%) --> servicetalk-transport-api (2%) |
78 | 4 file pairs | details... |
| servicetalk-client-api (7%) --> servicetalk-concurrent-api (<1%) |
78 | 4 file pairs | details... |
| servicetalk-grpc-api (1%) --> servicetalk-opentracing-zipkin-publisher (10%) |
72 | 9 file pairs | details... |
| servicetalk-concurrent-jdkflow (47%) --> servicetalk-concurrent-reactivestreams (43%) |
69 | 1 file pair | details... |
| servicetalk-grpc-api (1%) --> servicetalk-transport-netty-internal (<1%) |
60 | 3 file pairs | details... |
| servicetalk-grpc-api (1%) --> servicetalk-loadbalancer (5%) |
60 | 3 file pairs | details... |
| servicetalk-grpc-api (1%) --> servicetalk-http-router-predicate (9%) |
60 | 3 file pairs | details... |
| servicetalk-concurrent-api (<1%) --> servicetalk-grpc-api (1%) |
60 | 2 file pairs | details... |
| servicetalk-http-netty (<1%) --> servicetalk-opentracing-zipkin-publisher (7%) |
54 | 18 file pairs | details... |
| servicetalk-http-api (<1%) --> servicetalk-http-router-jersey (<1%) |
52 | 2 file pairs | details... |
| servicetalk-http-netty (<1%) --> servicetalk-transport-netty-internal (<1%) |
52 | 6 file pairs | details... |
| servicetalk-http-netty (<1%) --> servicetalk-loadbalancer (4%) |
52 | 6 file pairs | details... |
| servicetalk-http-api (<1%) --> servicetalk-serialization-api (6%) |
50 | 4 file pairs | details... |
Longest Duplicates
The list of 20 longest duplicates.
| Size | # | Folders | Files | Lines | Code |
|---|---|---|---|---|---|
| 140 | x 2 | servicetalk-buffer-api/s.../servicetalk/buffer/apiservicetalk-buffer-netty...ervicetalk/buffer/netty |  ReadOnlyByteBuffer.javaReadOnlyBuffer.java |
153:384 (50%)81:312 (69%) | view |
| 106 | x 2 | servicetalk-buffer-netty...ervicetalk/buffer/nettyservicetalk-buffer-netty...ervicetalk/buffer/netty | NettyBuffer.javaWrappedBuffer.java |
44:215 (19%)36:207 (21%) | view |
| 66 | x 2 | servicetalk-buffer-netty...ervicetalk/buffer/nettyservicetalk-buffer-netty...ervicetalk/buffer/netty | NettyBuffer.javaWrappedBuffer.java |
542:639 (12%)501:598 (13%) | view |
| 62 | x 2 | servicetalk-buffer-netty...ervicetalk/buffer/nettyservicetalk-buffer-netty...ervicetalk/buffer/netty | NettyBuffer.javaWrappedBuffer.java |
401:502 (11%)367:468 (12%) | view |
| 62 | x 2 | servicetalk-buffer-netty...ervicetalk/buffer/nettyservicetalk-buffer-netty...ervicetalk/buffer/netty | NettyBuffer.javaWrappedBuffer.java |
245:336 (11%)231:322 (12%) | view |
| 59 | x 2 | servicetalk-concurrent-a...vicetalk/concurrent/apiservicetalk-concurrent-a...vicetalk/concurrent/api | CopyOnWriteContextMap.javaCopyOnWriteContextMap.java |
1675:1760 (2%)2177:2262 (2%) | view |
| 41 | x 2 | servicetalk-data-jackson...ervicetalk/data/jacksonservicetalk-data-jackson...ervicetalk/data/jackson | AbstractJacksonDeserializer.javaJacksonStreamingSerializer.java |
176:236 (31%)313:373 (17%) | view |
| 32 | x 2 | servicetalk-http-api/src...io/servicetalk/http/apiservicetalk-http-api/src...io/servicetalk/http/api | DefaultHttpStreamingSerializer.javaDefaultHttpStreamingSerializerDeseria... |
48:98 (74%)45:95 (61%) | view |
| 32 | x 2 | servicetalk-examples/grp...lloworld/src/main/protoservicetalk-examples/grp...-options/src/main/proto | proto helloworld.protohelloworld.proto |
1:37 (100%)1:37 (100%) | view |
| 32 | x 2 | servicetalk-grpc-utils/s.../servicetalk/grpc/utilsservicetalk-http-utils/s.../servicetalk/http/utils | BiGrpcLifecycleObserver.javaBiHttpLifecycleObserver.java |
127:172 (22%)126:171 (23%) | view |
| 28 | x 2 | servicetalk-concurrent-a...vicetalk/concurrent/apiservicetalk-concurrent-a...vicetalk/concurrent/api | CopyOnWriteContextMap.javaCopyOnWriteContextMap.java |
1278:1318 (1%)1676:1716 (1%) | view |
| 28 | x 2 | servicetalk-concurrent-a...vicetalk/concurrent/apiservicetalk-concurrent-a...vicetalk/concurrent/api | CopyOnWriteContextMap.javaCopyOnWriteContextMap.java |
1278:1318 (1%)2178:2218 (1%) | view |
| 27 | x 2 | servicetalk-concurrent-a...vicetalk/concurrent/apiservicetalk-concurrent-a...vicetalk/concurrent/api | CollectingCompletableSubscriber.javaCollectingPublisherSubscriber.java |
49:90 (56%)56:97 (44%) | view |
| 27 | x 2 | servicetalk-http-api/src...io/servicetalk/http/apiservicetalk-http-api/src...io/servicetalk/http/api | DefaultSizeAwareClassHttpSerializer.javaDefaultSizeAwareTypeHttpSerializer.java |
47:82 (75%)47:82 (77%) | view |
| 27 | x 2 | servicetalk-concurrent-a...vicetalk/concurrent/apiservicetalk-concurrent-a...vicetalk/concurrent/api | CancelPropagatingCompletableFuture.javaContextPreservingCompletableFuture.java |
296:336 (11%)276:316 (12%) | view |
| 27 | x 2 | servicetalk-http-api/src...io/servicetalk/http/apiservicetalk-http-api/src...io/servicetalk/http/api | DefaultClassHttpSerializer.javaDefaultTypeHttpSerializer.java |
42:77 (81%)43:78 (81%) | view |
| 25 | x 2 | servicetalk-concurrent-a...vicetalk/concurrent/apiservicetalk-concurrent-a...vicetalk/concurrent/api | ContextPreservingCompletableSubscribe...ContextPreservingSingleSubscriber.java |
88:122 (35%)91:125 (35%) | view |
| 24 | x 2 | servicetalk-concurrent-a...vicetalk/concurrent/apiservicetalk-concurrent-a...vicetalk/concurrent/api | CopyOnWriteContextMap.javaNoopAsyncContextProvider.java |
245:282 (1%)165:202 (16%) | view |
| 24 | x 2 | servicetalk-grpc-utils/s.../servicetalk/grpc/utilsservicetalk-http-utils/s.../servicetalk/http/utils | LoggingGrpcLifecycleObserver.javaLoggingHttpLifecycleObserver.java |
150:181 (19%)140:171 (20%) | view |
| 23 | x 2 | servicetalk-concurrent-a...vicetalk/concurrent/apiservicetalk-concurrent-a...vicetalk/concurrent/api | ContextPreservingCompletableSubscribe...ContextPreservingSubscriber.java |
61:93 (32%)115:147 (25%) | view |
Duplicated Units
The list of top 20 duplicated units.
| Size | # | Folders | Files | Lines | Code |
|---|---|---|---|---|---|
| 26 | x 2 | servicetalk-http-api/src...io/servicetalk/http/apiservicetalk-http-api/src...io/servicetalk/http/api | DefaultHttpStreamingSerializer.javaDefaultHttpStreamingSerializerDeseria... |
67:99 64:96 | view |
| 20 | x 3 | servicetalk-concurrent-a...vicetalk/concurrent/apiservicetalk-concurrent-a...vicetalk/concurrent/apiservicetalk-concurrent-a...vicetalk/concurrent/api | OnErrorMapCompletable.javaOnErrorMapPublisher.javaOnErrorMapSingle.java |
59:80 58:79 60:81 | view |
| 18 | x 2 | servicetalk-concurrent-a...vicetalk/concurrent/apiservicetalk-concurrent-a...vicetalk/concurrent/api | TestPublisher.javaTestSingle.java |
92:110 91:109 | view |
| 14 | x 2 | servicetalk-client-api-i...alk/client/api/internalservicetalk-client-api-i...alk/client/api/internal | RequestConcurrencyControllerMulti.javaReservableRequestConcurrencyControlle... |
37:51 37:51 | view |
| 14 | x 2 | servicetalk-concurrent-a...vicetalk/concurrent/apiservicetalk-concurrent-a...vicetalk/concurrent/api | ContextPreservingCompletableSubscribe...ContextPreservingSingleSubscriber.java |
40:54 43:57 | view |
| 14 | x 2 | servicetalk-concurrent-a...vicetalk/concurrent/apiservicetalk-concurrent-a...vicetalk/concurrent/api | ContextPreservingCompletableSubscribe...ContextPreservingSubscriber.java |
67:81 121:135 | view |
| 14 | x 3 | servicetalk-concurrent-a...vicetalk/concurrent/apiservicetalk-concurrent-a...vicetalk/concurrent/apiservicetalk-concurrent-a...vicetalk/concurrent/api | ContextPreservingCompletableSubscribe...ContextPreservingSingleSubscriber.javaContextPreservingSubscriber.java |
94:108 97:111 94:108 | view |
| 14 | x 2 | servicetalk-concurrent-a...vicetalk/concurrent/apiservicetalk-concurrent-a...vicetalk/concurrent/api | TimeoutCompletable.javaTimeoutSingle.java |
93:114 95:116 | view |
| 13 | x 2 | servicetalk-concurrent-a...vicetalk/concurrent/apiservicetalk-concurrent-a...vicetalk/concurrent/api | OnErrorCompleteCompletable.javaOnErrorCompletePublisher.java |
57:71 57:71 | view |
| 13 | x 2 | servicetalk-concurrent-a...vicetalk/concurrent/apiservicetalk-concurrent-a...vicetalk/concurrent/api | TaskBasedAsyncCompletableOperator.javaTaskBasedAsyncPublisherOperator.java |
100:114 133:147 | view |
| 12 | x 2 | servicetalk-concurrent-a...vicetalk/concurrent/apiservicetalk-concurrent-a...vicetalk/concurrent/api | PublisherFlatMapMerge.javaPublisherFlatMapSingle.java |
471:483 216:228 | view |
| 11 | x 2 | servicetalk-concurrent-a...vicetalk/concurrent/apiservicetalk-concurrent-a...vicetalk/concurrent/api | BeforeFinallyPublisher.javaBeforeFinallySingle.java |
90:101 76:87 | view |
| 11 | x 2 | servicetalk-concurrent-a...vicetalk/concurrent/apiservicetalk-concurrent-a...vicetalk/concurrent/api | CopyOnWriteContextMap.javaCopyOnWriteContextMap.java |
111:122 125:136 | view |
| 11 | x 2 | servicetalk-concurrent-j...talk/concurrent/jdkflowservicetalk-concurrent-r...current/reactivestreams | JdkFlowAdapters.javaReactiveStreamsAdapters.java |
99:111 152:164 | view |
| 10 | x 2 | servicetalk-concurrent-a...vicetalk/concurrent/apiservicetalk-concurrent-a...vicetalk/concurrent/api | TimeoutCompletable.javaTimeoutSingle.java |
117:130 119:132 | view |
| 10 | x 3 | servicetalk-concurrent-a...vicetalk/concurrent/apiservicetalk-concurrent-a...vicetalk/concurrent/apiservicetalk-concurrent-a...vicetalk/concurrent/api | TestCompletable.javaTestPublisher.javaTestSingle.java |
148:158 173:183 151:161 | view |
| 10 | x 2 | servicetalk-http-api/src...io/servicetalk/http/apiservicetalk-http-api/src...io/servicetalk/http/api | AbstractHttpRequesterFilterTest.javaAbstractHttpServiceFilterTest.java |
92:102 61:71 | view |
| 9 | x 3 | servicetalk-concurrent-a...vicetalk/concurrent/apiservicetalk-concurrent-a...vicetalk/concurrent/apiservicetalk-concurrent-a...vicetalk/concurrent/api | BeforeSubscriberCompletable.javaBeforeSubscriberPublisher.javaBeforeSubscriberSingle.java |
66:75 69:78 65:74 | view |
| 9 | x 2 | servicetalk-concurrent-a...vicetalk/concurrent/apiservicetalk-concurrent-a...vicetalk/concurrent/api | Completable.javaSingle.java |
2104:2115 2454:2465 | view |
| 9 | x 2 | servicetalk-concurrent-a...vicetalk/concurrent/apiservicetalk-concurrent-a...vicetalk/concurrent/api | TimeoutCompletable.javaTimeoutSingle.java |
155:166 157:168 | view |