[Profiling] Simplify query post-processing and flamegraph response (#141729)

* Replace non-null assertion with nullish coalescing

* Remove createFrameGroup

* Remove callers

* Use adjacency list representation for tree

* Move frame type map outside function

* Inline frame group name

* Replace FrameGroupID with ID

* Create columnar view model in client

x-pack/plugins/profiling/server/routes/flamechart.ts

@@ -8,12 +8,8 @@
 import { schema } from '@kbn/config-schema';
 import { RouteRegisterParameters } from '.';
 import { getRoutePaths } from '../../common';
-import { createCallerCalleeGraph } from '../../common/callercallee';
-import {
-  createColumnarCallerCallee,
-  createFlameGraph,
-  ElasticFlameGraph,
-} from '../../common/flamegraph';
+import { createCalleeTree } from '../../common/callee';
+import { createFlameGraph } from '../../common/flamegraph';
 import { createProfilingEsClient } from '../utils/create_profiling_es_client';
 import { withProfilingSpan } from '../utils/with_profiling_span';
 import { getClient } from './compat';
@@ -46,55 +42,57 @@ export function registerFlameChartSearchRoute({ router, logger }: RouteRegisterP
         });
         const totalSeconds = timeTo - timeFrom;
 
-        const { stackTraces, executables, stackFrames, eventsIndex, totalCount, stackTraceEvents } =
-          await getExecutablesAndStackTraces({
-            logger,
-            client: createProfilingEsClient({ request, esClient }),
-            filter,
-            sampleSize: targetSampleSize,
-          });
+        const {
+          stackTraces,
+          executables,
+          stackFrames,
+          eventsIndex,
+          totalCount,
+          totalFrames,
+          stackTraceEvents,
+        } = await getExecutablesAndStackTraces({
+          logger,
+          client: createProfilingEsClient({ request, esClient }),
+          filter,
+          sampleSize: targetSampleSize,
+        });
 
         const flamegraph = await withProfilingSpan('create_flamegraph', async () => {
           const t0 = Date.now();
-          const graph = createCallerCalleeGraph(
+          const tree = createCalleeTree(
             stackTraceEvents,
             stackTraces,
             stackFrames,
-            executables
+            executables,
+            totalFrames
           );
-          logger.info(`creating caller-callee graph took ${Date.now() - t0} ms`);
+          logger.info(`creating callee tree took ${Date.now() - t0} ms`);
+
+          // sampleRate is 1/5^N, with N being the downsampled index the events were fetched from.
+          // N=0: full events table (sampleRate is 1)
+          // N=1: downsampled by 5 (sampleRate is 0.2)
+          // ...
+
+          // totalCount is the sum(Count) of all events in the filter range in the
+          // downsampled index we were looking at.
+          // To estimate how many events we have in the full events index: totalCount / sampleRate.
+          // Do the same for single entries in the events array.
 
           const t1 = Date.now();
-          const columnar = createColumnarCallerCallee(graph);
-          logger.info(`creating columnar caller-callee graph took ${Date.now() - t1} ms`);
-
-          const t2 = Date.now();
-          const fg = createFlameGraph(columnar);
-          logger.info(`creating flamegraph took ${Date.now() - t2} ms`);
+          const fg = createFlameGraph(
+            tree,
+            totalSeconds,
+            Math.floor(totalCount / eventsIndex.sampleRate),
+            totalCount
+          );
+          logger.info(`creating flamegraph took ${Date.now() - t1} ms`);
 
           return fg;
         });
 
-        // sampleRate is 1/5^N, with N being the downsampled index the events were fetched from.
-        // N=0: full events table (sampleRate is 1)
-        // N=1: downsampled by 5 (sampleRate is 0.2)
-        // ...
-
-        // totalCount is the sum(Count) of all events in the filter range in the
-        // downsampled index we were looking at.
-        // To estimate how many events we have in the full events index: totalCount / sampleRate.
-        // Do the same for single entries in the events array.
-
-        const body: ElasticFlameGraph = {
-          ...flamegraph,
-          TotalSeconds: totalSeconds,
-          TotalTraces: Math.floor(totalCount / eventsIndex.sampleRate),
-          SampledTraces: totalCount,
-        };
-
         logger.info('returning payload response to client');
 
-        return response.ok({ body });
+        return response.ok({ body: flamegraph });
       } catch (e) {
         logger.error(e);
         return response.customError({

x-pack/plugins/profiling/server/routes/get_executables_and_stacktraces.ts

@@ -68,7 +68,7 @@ export async function getExecutablesAndStackTraces({
       stackTraceEvents.set(id, Math.floor(count / (eventsIndex.sampleRate * p)));
     }
 
-    const { stackTraces, stackFrameDocIDs, executableDocIDs } = await mgetStackTraces({
+    const { stackTraces, totalFrames, stackFrameDocIDs, executableDocIDs } = await mgetStackTraces({
       logger,
       client,
       events: stackTraceEvents,
@@ -86,6 +86,7 @@ export async function getExecutablesAndStackTraces({
         stackFrames,
         stackTraceEvents,
         totalCount,
+        totalFrames,
         eventsIndex,
       };
     });

x-pack/plugins/profiling/server/routes/stacktrace.ts

@@ -18,6 +18,8 @@ import {
   ProfilingStackTrace,
 } from '../../common/elasticsearch';
 import {
+  emptyExecutable,
+  emptyStackFrame,
   Executable,
   FileID,
   StackFrame,
@@ -310,7 +312,7 @@ export async function mgetStackTraces({
     );
   }
 
-  return { stackTraces, stackFrameDocIDs, executableDocIDs };
+  return { stackTraces, totalFrames, stackFrameDocIDs, executableDocIDs };
 }
 
 export async function mgetStackFrames({
@@ -352,13 +354,7 @@ export async function mgetStackFrames({
       });
       framesFound++;
     } else {
-      stackFrames.set(frame._id, {
-        FileName: '',
-        FunctionName: '',
-        FunctionOffset: 0,
-        LineNumber: 0,
-        SourceType: 0,
-      });
+      stackFrames.set(frame._id, emptyStackFrame);
     }
   }
   logger.info(`processing data took ${Date.now() - t0} ms`);
@@ -403,9 +399,7 @@ export async function mgetExecutables({
       });
       exeFound++;
     } else {
-      executables.set(exe._id, {
-        FileName: '',
-      });
+      executables.set(exe._id, emptyExecutable);
     }
   }
   logger.info(`processing data took ${Date.now() - t0} ms`);