core: Don't pre-compute DEADLINE_EXCEEDED message for delayed calls

The main reason I made a change here was to fix the tense from the
deadline "will be exceeded in" to "was exceeded after". But we really
don't want to be doing the string formatting unless the deadline is
actually exceeded. There were a few more changes to make some variables
effectively final.

core/src/main/java/io/grpc/internal/DelayedClientCall.java

@@ -96,15 +96,13 @@ public class DelayedClientCall<ReqT, RespT> extends ClientCall<ReqT, RespT> {
   private ScheduledFuture<?> scheduleDeadlineIfNeeded(
       ScheduledExecutorService scheduler, @Nullable Deadline deadline) {
     Deadline contextDeadline = context.getDeadline();
-    if (deadline == null && contextDeadline == null) {
-      return null;
-    }
-    long remainingNanos = Long.MAX_VALUE;
-    if (deadline != null) {
+    String deadlineName;
+    long remainingNanos;
+    if (deadline != null && isAbeforeB(deadline, contextDeadline)) {
+      deadlineName = "CallOptions";
       remainingNanos = deadline.timeRemaining(NANOSECONDS);
-    }
-
-    if (contextDeadline != null && contextDeadline.timeRemaining(NANOSECONDS) < remainingNanos) {
+    } else if (contextDeadline != null) {
+      deadlineName = "Context";
       remainingNanos = contextDeadline.timeRemaining(NANOSECONDS);
       if (logger.isLoggable(Level.FINE)) {
         StringBuilder builder =
@@ -121,29 +119,29 @@ public class DelayedClientCall<ReqT, RespT> extends ClientCall<ReqT, RespT> {
         }
         logger.fine(builder.toString());
       }
-    }
-
-    long seconds = Math.abs(remainingNanos) / TimeUnit.SECONDS.toNanos(1);
-    long nanos = Math.abs(remainingNanos) % TimeUnit.SECONDS.toNanos(1);
-    final StringBuilder buf = new StringBuilder();
-    String deadlineName = isAbeforeB(contextDeadline, deadline) ? "Context" : "CallOptions";
-    if (remainingNanos < 0) {
-      buf.append("ClientCall started after ");
-      buf.append(deadlineName);
-      buf.append(" deadline was exceeded. Deadline has been exceeded for ");
     } else {
-      buf.append("Deadline ");
-      buf.append(deadlineName);
-      buf.append(" will be exceeded in ");
+      return null;
     }
-    buf.append(seconds);
-    buf.append(String.format(Locale.US, ".%09d", nanos));
-    buf.append("s. ");
 
     /* Cancels the call if deadline exceeded prior to the real call being set. */
     class DeadlineExceededRunnable implements Runnable {
       @Override
       public void run() {
+        long seconds = Math.abs(remainingNanos) / TimeUnit.SECONDS.toNanos(1);
+        long nanos = Math.abs(remainingNanos) % TimeUnit.SECONDS.toNanos(1);
+        StringBuilder buf = new StringBuilder();
+        if (remainingNanos < 0) {
+          buf.append("ClientCall started after ");
+          buf.append(deadlineName);
+          buf.append(" deadline was exceeded. Deadline has been exceeded for ");
+        } else {
+          buf.append("Deadline ");
+          buf.append(deadlineName);
+          buf.append(" was exceeded after ");
+        }
+        buf.append(seconds);
+        buf.append(String.format(Locale.US, ".%09d", nanos));
+        buf.append("s");
         cancel(
             Status.DEADLINE_EXCEEDED.withDescription(buf.toString()),
             // We should not cancel the call if the realCall is set because there could be a

xds/src/test/java/io/grpc/xds/XdsNameResolverTest.java

@@ -2239,7 +2239,7 @@ public class XdsNameResolverTest {
     assertThat(testCall).isNull();
     verifyRpcDelayedThenAborted(observer, 4000L, Status.DEADLINE_EXCEEDED.withDescription(
         "Deadline exceeded after up to 5000 ns of fault-injected delay:"
-            + " Deadline CallOptions will be exceeded in 0.000004000s. "));
+            + " Deadline CallOptions was exceeded after 0.000004000s"));
   }
 
   @Test