.

src/collapse/perf.rs

@@ -24,10 +24,10 @@ mod logging {
 }
 
 #[derive(PartialEq)]
-enum SkipStackOpt {
-    DontSkip,
-    Entirely,
-    Partially,
+enum StackFilter {
+    Keep,
+    Skip,
+    SkipRemaining,
 }
 
 /// `perf` folder configuration options.
@@ -124,7 +124,7 @@ pub struct Folder {
     pname: String,
 
     /// Whether to skip stack lines in this event.
-    skip_stack: SkipStackOpt,
+    stack_filter: StackFilter,
 
     /// Function entries on the stack in this entry thus far.
     stack: VecDeque<String>,
@@ -145,7 +145,7 @@ impl From<Options> for Folder {
             in_event: false,
             nstacks_per_job: common::DEFAULT_NSTACKS_PER_JOB,
             pname: String::default(),
-            skip_stack: SkipStackOpt::DontSkip,
+            stack_filter: StackFilter::Keep,
             stack: VecDeque::default(),
             opt,
         }
@@ -202,7 +202,7 @@ impl CollapsePrivate for Folder {
 
         // Reset state...
         self.in_event = false;
-        self.skip_stack = SkipStackOpt::DontSkip;
+        self.stack_filter = StackFilter::Keep;
         self.stack.clear();
         Ok(())
     }
@@ -259,7 +259,7 @@ impl CollapsePrivate for Folder {
             in_event: false,
             nstacks_per_job: self.nstacks_per_job,
             pname: String::new(),
-            skip_stack: SkipStackOpt::DontSkip,
+            stack_filter: StackFilter::Keep,
             stack: VecDeque::default(),
             opt: self.opt.clone(),
         }
@@ -380,7 +380,7 @@ impl Folder {
             if let Some(event) = event {
                 if let Some(ref event_filter) = self.event_filter {
                     if event != event_filter {
-                        self.skip_stack = SkipStackOpt::Entirely;
+                        self.stack_filter = StackFilter::Skip;
                         return;
                     }
                 } else {
@@ -478,7 +478,11 @@ impl Folder {
     //     7f53389994d0 [unknown] ([unknown])
     //                0 [unknown] ([unknown])
     fn on_stack_line(&mut self, line: &str) {
-        if self.skip_stack == SkipStackOpt::Entirely || self.skip_stack == SkipStackOpt::Partially {
+        let should_omit = matches!(
+            self.stack_filter,
+            StackFilter::Skip | StackFilter::SkipRemaining
+        );
+        if should_omit {
             return;
         }
 
@@ -546,8 +550,8 @@ impl Folder {
             }
 
             if let Some(skip_after) = &self.opt.skip_after {
-                if rawfunc.eq(skip_after) {
-                    self.skip_stack = SkipStackOpt::Partially;
+                if rawfunc == *skip_after {
+                    self.stack_filter = StackFilter::SkipRemaining;
                 }
             }
         } else {
@@ -557,7 +561,7 @@ impl Folder {
 
     fn after_event(&mut self, occurrences: &mut Occurrences) {
         // end of stack, so emit stack entry
-        if self.skip_stack == SkipStackOpt::Partially || self.skip_stack == SkipStackOpt::DontSkip {
+        if !self.stack.is_empty() {
             // allocate a string that is long enough to hold the entire stack string
             let mut stack_str = String::with_capacity(
                 self.pname.len() + self.stack.iter().fold(0, |a, s| a + s.len() + 1),
@@ -577,7 +581,7 @@ impl Folder {
 
         // reset for the next event
         self.in_event = false;
-        self.skip_stack = SkipStackOpt::DontSkip;
+        self.stack_filter = StackFilter::Keep;
         self.stack.clear();
     }
 }
@@ -790,6 +794,9 @@ mod tests {
         let mut buf_actual = Vec::new();
         <Folder as Collapse>::collapse(&mut folder, &bytes[..], &mut buf_actual)?;
         let lines = std::str::from_utf8(&buf_actual[..]).unwrap().lines();
+
+        // without `skip_after` some collapsed lines would look like:
+        // go;[unknown];x_cgo_notify_runtime_init_done;runtime.main;main.init;...
         for line in lines {
             if line.contains("main.init") {
                 assert!(line.contains("go;main.init;")); // we removed the frames above "main.init"