Add tracepoint grouping helper for probe manager

2 files changed, 108 insertions, 0 deletions

diff --git a/internal/probemanager/grouping.go b/internal/probemanager/grouping.go
new file mode 100644
index 0000000..aa4f133
--- /dev/null
+++ b/internal/probemanager/grouping.go
@@ -0,0 +1,53 @@
+package probemanager
+
+import "strings"
+
+const (
+	sysEnterPrefix = "sys_enter_"
+	sysExitPrefix  = "sys_exit_"
+)
+
+// TracepointPair holds enter/exit tracepoint names for one syscall.
+type TracepointPair struct {
+	Enter string
+	Exit  string
+}
+
+// GroupTracepoints groups syscall tracepoint names by base syscall name.
+// Input names must be in sys_enter_<name> / sys_exit_<name> format.
+func GroupTracepoints(names []string) map[string]TracepointPair {
+	out := make(map[string]TracepointPair, len(names)/2)
+	for _, name := range names {
+		base, isEnter, ok := parseSyscallTracepoint(name)
+		if !ok {
+			continue
+		}
+
+		pair := out[base]
+		if isEnter {
+			pair.Enter = name
+		} else {
+			pair.Exit = name
+		}
+		out[base] = pair
+	}
+	return out
+}
+
+func parseSyscallTracepoint(name string) (base string, isEnter bool, ok bool) {
+	if strings.HasPrefix(name, sysEnterPrefix) {
+		base = strings.TrimPrefix(name, sysEnterPrefix)
+		if base == "" {
+			return "", false, false
+		}
+		return base, true, true
+	}
+	if strings.HasPrefix(name, sysExitPrefix) {
+		base = strings.TrimPrefix(name, sysExitPrefix)
+		if base == "" {
+			return "", false, false
+		}
+		return base, false, true
+	}
+	return "", false, false
+}
diff --git a/internal/probemanager/grouping_test.go b/internal/probemanager/grouping_test.go
new file mode 100644
index 0000000..3e838d5
--- /dev/null
+++ b/internal/probemanager/grouping_test.go
@@ -0,0 +1,55 @@
+package probemanager
+
+import "testing"
+
+func TestGroupTracepointsPairsEnterAndExit(t *testing.T) {
+	got := GroupTracepoints([]string{
+		"sys_enter_read",
+		"sys_exit_read",
+		"sys_enter_openat",
+		"sys_exit_openat",
+	})
+
+	if len(got) != 2 {
+		t.Fatalf("expected 2 grouped syscalls, got %d", len(got))
+	}
+
+	read := got["read"]
+	if read.Enter != "sys_enter_read" || read.Exit != "sys_exit_read" {
+		t.Fatalf("unexpected read pair: %+v", read)
+	}
+
+	openat := got["openat"]
+	if openat.Enter != "sys_enter_openat" || openat.Exit != "sys_exit_openat" {
+		t.Fatalf("unexpected openat pair: %+v", openat)
+	}
+}
+
+func TestGroupTracepointsAllowsPartialPairs(t *testing.T) {
+	got := GroupTracepoints([]string{
+		"sys_enter_ioctl",
+		"sys_exit_fcntl",
+	})
+
+	ioctl := got["ioctl"]
+	if ioctl.Enter != "sys_enter_ioctl" || ioctl.Exit != "" {
+		t.Fatalf("unexpected ioctl pair: %+v", ioctl)
+	}
+
+	fcntl := got["fcntl"]
+	if fcntl.Enter != "" || fcntl.Exit != "sys_exit_fcntl" {
+		t.Fatalf("unexpected fcntl pair: %+v", fcntl)
+	}
+}
+
+func TestGroupTracepointsIgnoresInvalidNames(t *testing.T) {
+	got := GroupTracepoints([]string{
+		"sys_enter_",
+		"sys_exit_",
+		"random_name",
+		"syscalls:sys_enter_read",
+	})
+	if len(got) != 0 {
+		t.Fatalf("expected no grouped entries, got %+v", got)
+	}
+}