Is your feature request related to a problem?
Yes, when trying to enter a Context, the call method doesn't work well with non-throwing Callables, such as lambdas. For example:
Integer theAnswer = Context.current().fork().call(() -> 42);
To fix this, I believe adding a Supplier overload to Context would solve this, since it doesn't declare a checked exception.
Describe the solution you'd like
diff --git a/api/src/context/java/io/grpc/Context.java b/api/src/context/java/io/grpc/Context.java
index c19d2db9d..374c42b35 100644
--- a/api/src/context/java/io/grpc/Context.java
+++ b/api/src/context/java/io/grpc/Context.java
@@ -27,6 +27,7 @@ import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.atomic.AtomicReference;
+import java.util.function.Supplier;
import java.util.logging.Level;
import java.util.logging.Logger;
@@ -554,6 +555,22 @@ public class Context {
}
}
+ /**
+ * Immediately supply a value from a {@link Supplier} with this context as the
+ * {@link #current} context.
+ * @param supplier {@link Supplier} to use to produce the value.
+ * @return result of supplier.
+ */
+ @CanIgnoreReturnValue
+ public <V> V supply(Supplier<V> supplier) {
+ Context previous = attach();
+ try {
+ return supplier.get();
+ } finally {
+ detach(previous);
+ }
+ }
+Additional context
Supplier is a Java 8 class, and only present in Android 24, which appears to be above the minimum support level for gRPC Java. I checked that there are some uses of Java8 classes like Duration, and they can be desugared correctly according to the Android docs. It appears the @IgnoreJRERequirement annotation can be used to avoid the animal sniffer warnings, but that lives in the api/main source, not the api/context one. Otherwise, this GitHub issue would have been a Pull Request.
I'm creating this issue to look for help on how to proceed.
Is your feature request related to a problem?
Yes, when trying to enter a Context, the
callmethod doesn't work well with non-throwing Callables, such as lambdas. For example:To fix this, I believe adding a
Supplieroverload to Context would solve this, since it doesn't declare a checked exception.Describe the solution you'd like
Additional context
Supplier is a Java 8 class, and only present in Android 24, which appears to be above the minimum support level for gRPC Java. I checked that there are some uses of Java8 classes like
Duration, and they can be desugared correctly according to the Android docs. It appears the@IgnoreJRERequirementannotation can be used to avoid the animal sniffer warnings, but that lives in the api/main source, not the api/context one. Otherwise, this GitHub issue would have been a Pull Request.I'm creating this issue to look for help on how to proceed.