fix: avoid transferring traces to JS (#5139)

Author: agostbiro

.changeset/wicked-walls-itch.md

@@ -0,0 +1,5 @@
+---
+"@nomicfoundation/ed": patch
+---
+
+fix: avoid transferring traces to JS if there are no plugins that need them to improve performance

crates/tools/js/benchmark/index.js

@@ -215,8 +215,15 @@ function numIterations(scenarioName) {
   // Run fast scenarios repeatedly to get more reliable results
   if (scenarioName.includes("safe-contracts")) {
     return 15;
-  } else if (scenarioName.includes("seaport")) {
+  } else if (
+    scenarioName.includes("seaport") ||
+    scenarioName.includes("openzeppelin") ||
+    scenarioName.includes("rocketpool") ||
+    scenarioName.includes("uniswap")
+  ) {
     return 5;
+  } else if (scenarioName.includes("neptune-mutual")) {
+    return 3;
   } else {
     return 1;
   }

packages/hardhat-core/src/internal/hardhat-network/provider/provider.ts

@@ -368,41 +368,49 @@ export class EdrProviderWrapper
     );
     const response = JSON.parse(responseObject.json);
 
-    const rawTraces = responseObject.traces;
-    for (const rawTrace of rawTraces) {
-      const trace = rawTrace.trace();
-      for (const traceItem of trace) {
-        if ("pc" in traceItem) {
-          if (this._node._vm.evm.events.listenerCount("step") > 0) {
-            this._node._vm.evm.events.emit(
-              "step",
-              edrTracingStepToMinimalInterpreterStep(traceItem)
-            );
-          }
-          if (this._rawTraceCallbacks.onStep !== undefined) {
-            await this._rawTraceCallbacks.onStep(traceItem);
-          }
-        } else if ("executionResult" in traceItem) {
-          if (this._node._vm.evm.events.listenerCount("afterMessage") > 0) {
-            this._node._vm.evm.events.emit(
-              "afterMessage",
-              edrTracingMessageResultToMinimalEVMResult(traceItem)
-            );
-          }
-          if (this._rawTraceCallbacks.onAfterMessage !== undefined) {
-            await this._rawTraceCallbacks.onAfterMessage(
-              traceItem.executionResult
-            );
-          }
-        } else {
-          if (this._node._vm.evm.events.listenerCount("beforeMessage") > 0) {
-            this._node._vm.evm.events.emit(
-              "beforeMessage",
-              edrTracingMessageToMinimalMessage(traceItem)
-            );
-          }
-          if (this._rawTraceCallbacks.onBeforeMessage !== undefined) {
-            await this._rawTraceCallbacks.onBeforeMessage(traceItem);
+    const needsTraces =
+      this._node._vm.evm.events.eventNames().length > 0 ||
+      this._rawTraceCallbacks.onStep !== undefined ||
+      this._rawTraceCallbacks.onAfterMessage !== undefined ||
+      this._rawTraceCallbacks.onBeforeMessage !== undefined;
+
+    if (needsTraces) {
+      const rawTraces = responseObject.traces;
+      for (const rawTrace of rawTraces) {
+        const trace = rawTrace.trace();
+        for (const traceItem of trace) {
+          if ("pc" in traceItem) {
+            if (this._node._vm.evm.events.listenerCount("step") > 0) {
+              this._node._vm.evm.events.emit(
+                "step",
+                edrTracingStepToMinimalInterpreterStep(traceItem)
+              );
+            }
+            if (this._rawTraceCallbacks.onStep !== undefined) {
+              await this._rawTraceCallbacks.onStep(traceItem);
+            }
+          } else if ("executionResult" in traceItem) {
+            if (this._node._vm.evm.events.listenerCount("afterMessage") > 0) {
+              this._node._vm.evm.events.emit(
+                "afterMessage",
+                edrTracingMessageResultToMinimalEVMResult(traceItem)
+              );
+            }
+            if (this._rawTraceCallbacks.onAfterMessage !== undefined) {
+              await this._rawTraceCallbacks.onAfterMessage(
+                traceItem.executionResult
+              );
+            }
+          } else {
+            if (this._node._vm.evm.events.listenerCount("beforeMessage") > 0) {
+              this._node._vm.evm.events.emit(
+                "beforeMessage",
+                edrTracingMessageToMinimalMessage(traceItem)
+              );
+            }
+            if (this._rawTraceCallbacks.onBeforeMessage !== undefined) {
+              await this._rawTraceCallbacks.onBeforeMessage(traceItem);
+            }
           }
         }
       }