add check before invocation

Author: Fred1155

core/sdk-core/src/main/java/software/amazon/awssdk/core/internal/http/pipeline/stages/AsyncApiCallAttemptMetricCollectionStage.java

@@ -123,6 +123,10 @@ private void reportWriteThroughput(RequestExecutionContext context) {
         long firstByteTime = metrics.firstByteWrittenNanoTime().get();
         if (bytesWritten > 0 && firstByteTime > 0) {
             long lastByteTime = metrics.lastByteWrittenNanoTime().get();
+            // Skip reporting if duration is zero
+            if (firstByteTime == lastByteTime) {
+                return;
+            }
             double writeThroughput = MetricUtils.bytesPerSec(bytesWritten, firstByteTime, lastByteTime);
             context.attemptMetricCollector().reportMetric(CoreMetric.WRITE_THROUGHPUT, writeThroughput);
         }

core/sdk-core/src/main/java/software/amazon/awssdk/core/internal/http/pipeline/stages/HandleResponseStage.java

@@ -85,6 +85,10 @@ private void reportWriteThroughput(RequestExecutionContext context, MetricCollec
         long firstByteTime = metrics.firstByteWrittenNanoTime().get();
         if (bytesWritten > 0 && firstByteTime > 0) {
             long lastByteTime = metrics.lastByteWrittenNanoTime().get();
+            // Skip reporting if duration is zero
+            if (firstByteTime == lastByteTime) {
+                return;
+            }
             double writeThroughput = MetricUtils.bytesPerSec(bytesWritten, firstByteTime, lastByteTime);
             attemptMetricCollector.reportMetric(CoreMetric.WRITE_THROUGHPUT, writeThroughput);
         }

core/sdk-core/src/main/java/software/amazon/awssdk/core/internal/util/MetricUtils.java

@@ -182,9 +182,6 @@ public static OptionalLong responseHeadersReadEndNanoTime(RequestExecutionContex
 
     public static double bytesPerSec(long totalBytes, long nanoStart, long nanoEnd) {
         long duration = nanoEnd - nanoStart;
-        if (duration <= 0) {
-            return 0.0;
-        }
         double bytesPerNs = (double) totalBytes / duration;
         return bytesPerNs * ONE_SEC_IN_NS;
     }

core/sdk-core/src/test/java/software/amazon/awssdk/core/internal/util/MetricUtilsTest.java

@@ -170,13 +170,6 @@ public void reportDuration_completableFuture_doesNotWrapException() {
         }
     }
 
-    @Test
-    public void bytesPerSec_zeroDuration_returnsZero() {
-        long sameTime = System.nanoTime();
-        double result = MetricUtils.bytesPerSec(50, sameTime, sameTime);
-        assertThat(result).isEqualTo(0.0);
-    }
-
     @Test
     public void collectHttpMetrics_collectsAllExpectedMetrics() {
         MetricCollector mockCollector = mock(MetricCollector.class);