Use Iterable instead of Collection.

Author: carlosalberto

api/src/jmh/java/io/opentelemetry/api/trace/propagation/HttpTraceContextExtractBenchmark.java

@@ -9,7 +9,6 @@
 import io.opentelemetry.context.propagation.TextMapPropagator.Getter;
 import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.Collection;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -42,7 +41,7 @@ public class HttpTraceContextExtractBenchmark {
   private final Getter<Map<String, String>> getter =
       new Getter<Map<String, String>>() {
         @Override
-        public Collection<String> keys(Map<String, String> carrier) {
+        public Iterable<String> keys(Map<String, String> carrier) {
           return carrier.keySet();
         }
 

api/src/test/java/io/opentelemetry/api/baggage/propagation/W3CBaggagePropagatorFuzzTest.java

@@ -12,7 +12,6 @@
 import edu.berkeley.cs.jqf.fuzz.JQF;
 import io.opentelemetry.context.Context;
 import io.opentelemetry.context.propagation.TextMapPropagator.Getter;
-import java.util.Collection;
 import java.util.Map;
 import javax.annotation.Nullable;
 import org.junit.runner.RunWith;
@@ -30,7 +29,7 @@ public void safeForRandomInputs(String baggage) {
             ImmutableMap.of("baggage", baggage),
             new Getter<Map<String, String>>() {
               @Override
-              public Collection<String> keys(Map<String, String> carrier) {
+              public Iterable<String> keys(Map<String, String> carrier) {
                 return carrier.keySet();
               }
 

api/src/test/java/io/opentelemetry/api/baggage/propagation/W3CBaggagePropagatorTest.java

@@ -13,7 +13,6 @@
 import io.opentelemetry.api.baggage.EntryMetadata;
 import io.opentelemetry.context.Context;
 import io.opentelemetry.context.propagation.TextMapPropagator.Getter;
-import java.util.Collection;
 import java.util.HashMap;
 import java.util.Map;
 import javax.annotation.Nullable;
@@ -24,7 +23,7 @@ class W3CBaggagePropagatorTest {
   private static final Getter<Map<String, String>> getter =
       new Getter<Map<String, String>>() {
         @Override
-        public Collection<String> keys(Map<String, String> carrier) {
+        public Iterable<String> keys(Map<String, String> carrier) {
           return carrier.keySet();
         }
 

api/src/test/java/io/opentelemetry/api/trace/propagation/HttpTraceContextFuzzTest.java

@@ -12,7 +12,6 @@
 import edu.berkeley.cs.jqf.fuzz.JQF;
 import io.opentelemetry.context.Context;
 import io.opentelemetry.context.propagation.TextMapPropagator.Getter;
-import java.util.Collection;
 import java.util.Map;
 import javax.annotation.Nullable;
 import org.junit.runner.RunWith;
@@ -30,7 +29,7 @@ public void safeForRandomInputs(String traceParentHeader, String traceStateHeade
             ImmutableMap.of("traceparent", traceParentHeader, "tracestate", traceStateHeader),
             new Getter<Map<String, String>>() {
               @Override
-              public Collection<String> keys(Map<String, String> carrier) {
+              public Iterable<String> keys(Map<String, String> carrier) {
                 return carrier.keySet();
               }
 

api/src/test/java/io/opentelemetry/api/trace/propagation/HttpTraceContextTest.java

@@ -19,7 +19,6 @@
 import io.opentelemetry.context.Context;
 import io.opentelemetry.context.propagation.TextMapPropagator.Getter;
 import io.opentelemetry.context.propagation.TextMapPropagator.Setter;
-import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.LinkedHashMap;
@@ -44,7 +43,7 @@ class HttpTraceContextTest {
   private static final Getter<Map<String, String>> getter =
       new Getter<Map<String, String>>() {
         @Override
-        public Collection<String> keys(Map<String, String> carrier) {
+        public Iterable<String> keys(Map<String, String> carrier) {
           return carrier.keySet();
         }
 

context/src/main/java/io/opentelemetry/context/propagation/TextMapPropagator.java

@@ -6,7 +6,6 @@
 package io.opentelemetry.context.propagation;
 
 import io.opentelemetry.context.Context;
-import java.util.Collection;
 import java.util.List;
 import javax.annotation.Nullable;
 import javax.annotation.concurrent.ThreadSafe;
@@ -122,7 +121,7 @@ interface Getter<C> {
      * @param carrier carrier of propagation fields, such as an http request.
      * @since 0.10.0
      */
-    Collection<String> keys(C carrier);
+    Iterable<String> keys(C carrier);
 
     /**
      * Returns the first value of the given propagation {@code key} or returns {@code null}.

context/src/test/java/io/opentelemetry/context/propagation/DefaultPropagatorsTest.java

@@ -10,7 +10,6 @@
 
 import io.opentelemetry.context.Context;
 import io.opentelemetry.context.ContextKey;
-import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
@@ -157,7 +156,7 @@ private static final class MapGetter implements TextMapPropagator.Getter<Map<Str
     private static final MapGetter INSTANCE = new MapGetter();
 
     @Override
-    public Collection<String> keys(Map<String, String> map) {
+    public Iterable<String> keys(Map<String, String> map) {
       return map.keySet();
     }
 

extensions/trace-propagators/src/jmh/java/io/opentelemetry/extensions/trace/propagation/PropagatorContextExtractBenchmark.java

@@ -9,7 +9,6 @@
 import io.opentelemetry.context.Context;
 import io.opentelemetry.context.propagation.TextMapPropagator;
 import java.util.Arrays;
-import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
@@ -96,7 +95,7 @@ public static class JaegerContextExtractBenchmark extends AbstractContextExtract
     private final TextMapPropagator.Getter<Map<String, String>> getter =
         new TextMapPropagator.Getter<Map<String, String>>() {
           @Override
-          public Collection<String> keys(Map<String, String> carrier) {
+          public Iterable<String> keys(Map<String, String> carrier) {
             return carrier.keySet();
           }
 
@@ -144,7 +143,7 @@ public static class JaegerUrlEncodedContextExtractBenchmark
     private final TextMapPropagator.Getter<Map<String, String>> getter =
         new TextMapPropagator.Getter<Map<String, String>>() {
           @Override
-          public Collection<String> keys(Map<String, String> carrier) {
+          public Iterable<String> keys(Map<String, String> carrier) {
             return carrier.keySet();
           }
 
@@ -192,7 +191,7 @@ public static class B3SingleHeaderContextExtractBenchmark
     private final TextMapPropagator.Getter<Map<String, String>> getter =
         new TextMapPropagator.Getter<Map<String, String>>() {
           @Override
-          public Collection<String> keys(Map<String, String> carrier) {
+          public Iterable<String> keys(Map<String, String> carrier) {
             return carrier.keySet();
           }
 
@@ -243,7 +242,7 @@ private static Map<String, String> createHeaders(
     private final TextMapPropagator.Getter<Map<String, String>> getter =
         new TextMapPropagator.Getter<Map<String, String>>() {
           @Override
-          public Collection<String> keys(Map<String, String> carrier) {
+          public Iterable<String> keys(Map<String, String> carrier) {
             return carrier.keySet();
           }
 

extensions/trace-propagators/src/test/java/io/opentelemetry/extensions/trace/propagation/AwsXRayPropagatorTest.java

@@ -14,7 +14,6 @@
 import io.opentelemetry.api.trace.TraceState;
 import io.opentelemetry.context.Context;
 import io.opentelemetry.context.propagation.TextMapPropagator;
-import java.util.Collection;
 import java.util.Collections;
 import java.util.LinkedHashMap;
 import java.util.Map;
@@ -33,7 +32,7 @@ class AwsXRayPropagatorTest {
   private static final TextMapPropagator.Getter<Map<String, String>> getter =
       new TextMapPropagator.Getter<Map<String, String>>() {
         @Override
-        public Collection<String> keys(Map<String, String> carrier) {
+        public Iterable<String> keys(Map<String, String> carrier) {
           return carrier.keySet();
         }
 

extensions/trace-propagators/src/test/java/io/opentelemetry/extensions/trace/propagation/B3PropagatorTest.java

@@ -16,7 +16,6 @@
 import io.opentelemetry.context.Context;
 import io.opentelemetry.context.propagation.TextMapPropagator.Getter;
 import io.opentelemetry.context.propagation.TextMapPropagator.Setter;
-import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.LinkedHashMap;
@@ -41,7 +40,7 @@ class B3PropagatorTest {
   private static final Getter<Map<String, String>> getter =
       new Getter<Map<String, String>>() {
         @Override
-        public Collection<String> keys(Map<String, String> carrier) {
+        public Iterable<String> keys(Map<String, String> carrier) {
           return carrier.keySet();
         }
 

extensions/trace-propagators/src/test/java/io/opentelemetry/extensions/trace/propagation/JaegerPropagatorTest.java

@@ -29,7 +29,6 @@
 import io.opentelemetry.context.propagation.TextMapPropagator.Setter;
 import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.util.Collection;
 import java.util.Collections;
 import java.util.LinkedHashMap;
 import java.util.Map;
@@ -57,7 +56,7 @@ class JaegerPropagatorTest {
   private static final TextMapPropagator.Getter<Map<String, String>> getter =
       new TextMapPropagator.Getter<Map<String, String>>() {
         @Override
-        public Collection<String> keys(Map<String, String> carrier) {
+        public Iterable<String> keys(Map<String, String> carrier) {
           return carrier.keySet();
         }
 

extensions/trace-propagators/src/test/java/io/opentelemetry/extensions/trace/propagation/OtTracerPropagatorTest.java

@@ -16,7 +16,6 @@
 import io.opentelemetry.context.Context;
 import io.opentelemetry.context.propagation.TextMapPropagator.Getter;
 import io.opentelemetry.context.propagation.TextMapPropagator.Setter;
-import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.LinkedHashMap;
@@ -36,7 +35,7 @@ class OtTracerPropagatorTest {
   private static final Getter<Map<String, String>> getter =
       new Getter<Map<String, String>>() {
         @Override
-        public Collection<String> keys(Map<String, String> carrier) {
+        public Iterable<String> keys(Map<String, String> carrier) {
           return carrier.keySet();
         }
 

extensions/trace-propagators/src/test/java/io/opentelemetry/extensions/trace/propagation/TraceMultiPropagatorTest.java

@@ -20,7 +20,6 @@
 import io.opentelemetry.context.Context;
 import io.opentelemetry.context.propagation.TextMapPropagator;
 import java.util.Arrays;
-import java.util.Collection;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -39,7 +38,7 @@ class TraceMultiPropagatorTest {
   private static final TextMapPropagator.Getter<Map<String, String>> getter =
       new TextMapPropagator.Getter<Map<String, String>>() {
         @Override
-        public Collection<String> keys(Map<String, String> carrier) {
+        public Iterable<String> keys(Map<String, String> carrier) {
           return carrier.keySet();
         }
 

integration-tests/tracecontext/src/main/java/io/opentelemetry/Application.java

@@ -14,7 +14,6 @@
 import io.opentelemetry.context.propagation.TextMapPropagator.Getter;
 import io.opentelemetry.context.propagation.TextMapPropagator.Setter;
 import java.util.ArrayList;
-import java.util.Collection;
 import java.util.Collections;
 import java.util.Enumeration;
 import java.util.List;
@@ -69,7 +68,7 @@ public Object handle(Request request, Response response) {
                         request.raw(),
                         new Getter<HttpServletRequest>() {
                           @Override
-                          public Collection<String> keys(HttpServletRequest carrier) {
+                          public Iterable<String> keys(HttpServletRequest carrier) {
                             return Collections.list(carrier.getHeaderNames());
                           }
 

opentracing-shim/src/main/java/io/opentelemetry/opentracingshim/Propagation.java

@@ -11,7 +11,6 @@
 import io.opentelemetry.context.propagation.TextMapPropagator;
 import io.opentracing.propagation.TextMapExtract;
 import io.opentracing.propagation.TextMapInject;
-import java.util.Collection;
 import java.util.HashMap;
 import java.util.Map;
 import javax.annotation.Nullable;
@@ -68,7 +67,7 @@ private TextMapGetter() {}
 
     @Nullable
     @Override
-    public Collection<String> keys(Map<String, String> carrier) {
+    public Iterable<String> keys(Map<String, String> carrier) {
       return carrier.keySet();
     }
 

sdk-extensions/testbed/src/test/java/io/opentelemetry/sdk/extensions/trace/testbed/clientserver/Server.java

@@ -12,7 +12,6 @@
 import io.opentelemetry.context.Context;
 import io.opentelemetry.context.Scope;
 import io.opentelemetry.context.propagation.TextMapPropagator.Getter;
-import java.util.Collection;
 import java.util.concurrent.ArrayBlockingQueue;
 import javax.annotation.Nullable;
 
@@ -35,7 +34,7 @@ private void process(Message message) {
                 message,
                 new Getter<Message>() {
                   @Override
-                  public Collection<String> keys(Message carrier) {
+                  public Iterable<String> keys(Message carrier) {
                     return carrier.keySet();
                   }