Add ResolutionEventListener#downloadMetadataSuccess to communicate long download times to consumers of MavenPomDownloader

rewrite-core/src/main/java/org/openrewrite/ExecutionContext.java

@@ -18,6 +18,8 @@
 import org.jspecify.annotations.Nullable;
 import org.openrewrite.scheduling.RecipeRunCycle;
 
+import java.net.URI;
+import java.time.Duration;
 import java.util.*;
 import java.util.function.BiConsumer;
 import java.util.function.BiFunction;
@@ -100,6 +102,10 @@ default void putCurrentRecipe(Recipe recipe) {
 
     BiConsumer<Throwable, ExecutionContext> getOnTimeout();
 
+    default @Nullable BiConsumer<URI, Duration> getOnDownload() {
+        return null;
+    }
+
     default int getCycle() {
         return getCycleDetails().getCycle();
     }

rewrite-core/src/main/java/org/openrewrite/InMemoryExecutionContext.java

@@ -17,6 +17,7 @@
 
 import org.jspecify.annotations.Nullable;
 
+import java.net.URI;
 import java.time.Duration;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
@@ -27,6 +28,8 @@ public class InMemoryExecutionContext implements ExecutionContext {
     private final Map<String, Object> messages = new ConcurrentHashMap<>();
     private final Consumer<Throwable> onError;
     private final BiConsumer<Throwable, ExecutionContext> onTimeout;
+    @Nullable
+    private final BiConsumer<URI, Duration> onDownload;
 
     public InMemoryExecutionContext() {
         this(
@@ -44,9 +47,19 @@ public InMemoryExecutionContext(Consumer<Throwable> onError, Duration runTimeout
         });
     }
 
-    public InMemoryExecutionContext(Consumer<Throwable> onError, Duration runTimeout, BiConsumer<Throwable, ExecutionContext> onTimeout) {
+    public InMemoryExecutionContext(Consumer<Throwable> onError,
+                                    Duration runTimeout,
+                                    BiConsumer<Throwable, ExecutionContext> onTimeout) {
+        this(onError, runTimeout, onTimeout, null);
+    }
+
+    public InMemoryExecutionContext(Consumer<Throwable> onError,
+                                    Duration runTimeout,
+                                    BiConsumer<Throwable, ExecutionContext> onTimeout,
+                                    @Nullable BiConsumer<URI, Duration> onDownload) {
         this.onError = onError;
         this.onTimeout = onTimeout;
+        this.onDownload = onDownload;
         putMessage(ExecutionContext.RUN_TIMEOUT, runTimeout);
     }
 
@@ -80,4 +93,10 @@ public Consumer<Throwable> getOnError() {
     public BiConsumer<Throwable, ExecutionContext> getOnTimeout() {
         return onTimeout;
     }
+
+    @Override
+    @Nullable
+    public BiConsumer<URI, Duration> getOnDownload() {
+        return onDownload;
+    }
 }

rewrite-core/src/main/java/org/openrewrite/scheduling/WatchableExecutionContext.java

@@ -19,6 +19,8 @@
 import org.jspecify.annotations.Nullable;
 import org.openrewrite.ExecutionContext;
 
+import java.net.URI;
+import java.time.Duration;
 import java.util.function.BiConsumer;
 import java.util.function.Consumer;
 
@@ -64,4 +66,10 @@ public Consumer<Throwable> getOnError() {
     public BiConsumer<Throwable, ExecutionContext> getOnTimeout() {
         return delegate.getOnTimeout();
     }
+
+    @Override
+    @Nullable
+    public BiConsumer<URI, Duration> getOnDownload() {
+        return delegate.getOnDownload();
+    }
 }

rewrite-maven/src/main/java/org/openrewrite/maven/internal/MavenPomDownloader.java

@@ -55,7 +55,6 @@
 import static java.util.Objects.requireNonNull;
 import static java.util.stream.Collectors.toList;
 
-@SuppressWarnings("OptionalAssignedToNull")
 public class MavenPomDownloader {
     private static final RetryPolicy<Object> retryPolicy = RetryPolicy.builder()
             .handle(SocketTimeoutException.class, TimeoutException.class)
@@ -333,7 +332,12 @@ public MavenMetadata downloadMetadata(GroupArtifactVersion gav, @Nullable Resolv
                     .setRepositoryResponses(repositoryResponses);
         }
 
-        sample.stop(timer.tags("outcome", "success").register(Metrics.globalRegistry));
+        long nanos = sample.stop(timer.tags("outcome", "success").register(Metrics.globalRegistry));
+        if (ctx.getOnDownload() != null) {
+            ctx.getOnDownload().accept(
+                    URI.create(attemptedUris.get(attemptedUris.size() - 1)),
+                    Duration.ofNanos(nanos));
+        }
         return mavenMetadata;
     }
 
@@ -604,6 +608,10 @@ public Pom download(GroupArtifactVersion gav,
                         mavenCache.putPom(resolvedGav, pom);
                         ctx.getResolutionListener().downloadSuccess(resolvedGav, containingPom);
                         sample.stop(timer.tags("outcome", "downloaded").register(Metrics.globalRegistry));
+                        long nanos = sample.stop(timer.tags("outcome", "downloaded").register(Metrics.globalRegistry));
+                        if (ctx.getOnDownload() != null) {
+                            ctx.getOnDownload().accept(uri, Duration.ofNanos(nanos));
+                        }
                         return pom;
                     } catch (HttpSenderResponseException e) {
                         repositoryResponses.put(repo, e.getMessage());