Add labels to flamegraph nodes

This replaces using the frame ID for the node label.

src/plugins/profiling/server/routes/flamegraph.ts

@@ -6,8 +6,65 @@
  * Side Public License, v 1.
  */
 
+function getExeFileName(exe: any, type: number) {
+  if (exe.FileName === undefined) {
+    return '';
+  }
+  if (exe.FileName !== '') {
+    return exe.FileName;
+  }
+  switch (type) {
+    case 0:
+      return '<unsymbolized frame>';
+    case 1:
+      return 'Python';
+    case 2:
+      return 'PHP';
+    case 3:
+      return 'Native';
+    case 4:
+      return 'Kernel';
+    case 5:
+      return 'JVM/Hotspot';
+    case 6:
+      return 'Ruby';
+    case 7:
+      return 'Perl';
+    case 8:
+      return 'JavaScript';
+    default:
+      return '';
+  }
+}
+
+function checkIfStringHasParentheses(s: string) {
+  return /\(|\)/.test(s);
+}
+
+function getFunctionName(frame: any) {
+  return frame.FunctionName !== '' && !checkIfStringHasParentheses(frame.FunctionName)
+    ? `${frame.FunctionName}()`
+    : frame.FunctionName;
+}
+
+// Generates the label for a flamegraph node
+//
+// This is slightly modified from the original code in elastic/prodfiler_ui
+function getLabel(frame: any, executable: any, type: number) {
+  if (frame.FunctionName !== '') {
+    return `${getExeFileName(executable, type)}: ${getFunctionName(frame)} in #${frame.LineNumber}`;
+  }
+  return getExeFileName(executable, type);
+}
+
 export class FlameGraph {
-  constructor(events, totalEvents, stackTraces, stackFrames, executables) {
+  events: any;
+  totalEvents: any;
+  stacktraces: any;
+  stackframes: any;
+  executables: any;
+
+  constructor(events: any, totalEvents: any, stackTraces: any, stackFrames: any, executables: any) {
     this.events = events;
     this.totalEvents = totalEvents;
     this.stacktraces = stackTraces;
@@ -16,19 +73,61 @@ export class FlameGraph {
   }
 
   toElastic() {
+    // Create a lookup table for stack frames with an appropriate default if
+    // the corresponding metadata is missing
+    const frameMap = new Map();
+    for (let i = 0; i < this.stackframes.length; i++) {
+      const frame = this.stackframes[i];
+      if (frame.found) {
+        frameMap.set(frame._id, frame._source);
+      } else {
+        frameMap.set(frame._id, {
+          FunctionName: '',
+          LineNumber: 0,
+        });
+      }
+    }
+
+    // Create a lookup table for executables with an appropriate default if
+    // the corresponding metadata is missing
+    const exeMap = new Map();
+    for (let i = 0; i < this.executables.length; i++) {
+      const exe = this.executables[i];
+      if (exe.found) {
+        exeMap.set(exe._id, exe._source);
+      } else {
+        exeMap.set(exe._id, {
+          FileName: '',
+        });
+      }
+    }
+
     let leaves = [];
+
     for (const trace of this.stacktraces) {
       if (trace.found) {
-        const pairs = ['root'].concat(trace._source.FrameID).map((item, i) => [i, item]);
-        const fact = {
-          id: trace._source.FrameID[trace._source.FrameID.length - 1],
+        const path = ['root'];
+        for (let i = 0; i < trace._source.FrameID.length; i++) {
+          const label = getLabel(
+            frameMap.get(trace._source.FrameID[i]),
+            exeMap.get(trace._source.FileID[i]),
+            trace._source.Type[i]);
+          if (label.length === 0) {
+            path.push(trace._source.FrameID[i]);
+          } else {
+            path.push(label);
+          }
+        }
+        const leaf = {
+          id: path[path.length - 1],
           value: 1,
           depth: trace._source.FrameID.length,
-          pathFromRoot: Object.fromEntries(pairs),
+          pathFromRoot: Object.fromEntries(path.map((item, i) => [i, item])),
         };
-        leaves.push(fact);
+        leaves.push(leaf);
       }
     }
+
     return { leaves };
   }