optimize line probe without condition (#9787)

In case of a line probe without condition we can move the sampling is
currently done in LogProbe::evaluate to LogProbe::isReadToCapture.
This way if the sample fails we return false on isReadyTocapture
and no CapturedContext is created and nothing captured.
If we sample the execution the CapturedContext will be created,
we capture the context and serialize the result, but we are sure that
we are not doing for nothing.

Author: jpbempel

dd-java-agent/agent-debugger/src/main/java/com/datadog/debugger/probe/LogProbe.java

@@ -485,6 +485,10 @@ public InstrumentationResult.Status instrument(
 
   @Override
   public boolean isReadyToCapture() {
+    if (isLineProbe() && !hasCondition()) {
+      // we are sampling here to avoid creating CapturedContext when the sampling result is negative
+      return ProbeRateLimiter.tryProbe(id);
+    }
     return true;
   }
 
@@ -494,9 +498,14 @@ public void evaluate(
     if (!(status instanceof LogStatus)) {
       throw new IllegalStateException("Invalid status: " + status.getClass());
     }
-
     LogStatus logStatus = (LogStatus) status;
-    if (!hasCondition()) {
+    if (isLineProbe() && !hasCondition()) {
+      // sampling was already done in isReadToCapture so we assume that if we are executing the
+      // current method it means the status should be sampled
+      if (!logStatus.getDebugSessionStatus().isDisabled()) {
+        logStatus.setSampled(true);
+      }
+    } else if (!hasCondition()) {
       // sample when no condition associated
       sample(logStatus, methodLocation);
     }

dd-java-agent/agent-debugger/src/test/java/com/datadog/debugger/probe/LogProbeTest.java

@@ -342,6 +342,7 @@ private Builder createLog(String template) {
     return LogProbe.builder()
         .language(LANGUAGE)
         .probeId(PROBE_ID)
+        .where("String.java", 42)
         .template(template, parseTemplate(template));
   }