Bug 1957016 - Move the capturing profile part to recording-utils.sys.mjs r=canaltinova,profiler-reviewers

The capturing profile part is complex enough that we can extract it to
RecordingUtils. Then it's available if other code needs it, including on
Android.

Differential Revision: https://phabricator.services.mozilla.com/D243184

devtools/client/performance-new/shared/background.sys.mjs

@@ -103,35 +103,14 @@ export async function captureProfile(pageContext) {
     return;
   }
 
-  // Pause profiler before we collect the profile, so that we don't capture
-  // more samples while the parent process waits for subprocess profiles.
-  Services.profiler.Pause();
-
-  /**
-   * @type {MockedExports.ProfileGenerationAdditionalInformation | undefined}
-   */
-  let additionalInfo;
-  /**
-   * @type {ProfileCaptureResult}
-   */
-  const profileCaptureResult = await Services.profiler
-    .getProfileDataAsGzippedArrayBuffer()
-    .then(
-      ({ profile, additionalInformation }) => {
-        additionalInfo = additionalInformation;
-        return { type: "SUCCESS", profile };
-      },
-      error => {
-        console.error(error);
-        return { type: "ERROR", error };
-      }
-    );
-
+  const { profileCaptureResult, additionalInformation } = await lazy
+    .RecordingUtils()
+    .getProfileDataAsGzippedArrayBufferThenStop();
   const profilerViewMode = lazy
     .PrefsPresets()
     .getProfilerViewModeForCurrentPreset(pageContext);
-  const sharedLibraries = additionalInfo?.sharedLibraries
-    ? additionalInfo.sharedLibraries
+  const sharedLibraries = additionalInformation?.sharedLibraries
+    ? additionalInformation.sharedLibraries
     : Services.profiler.sharedLibraries;
   const objdirs = lazy.PrefsPresets().getObjdirPrefValue();
 
@@ -148,8 +127,6 @@ export async function captureProfile(pageContext) {
     profileCaptureResult,
     symbolicationService
   );
-
-  Services.profiler.StopProfiler();
 }
 
 /**

devtools/shared/performance-new/recording-utils.sys.mjs

@@ -4,7 +4,8 @@
 // @ts-check
 
 /**
- * @typedef {import("../../client/performance-new/@types/perf").GetActiveBrowserID} GetActiveBrowserID
+ * @typedef {import("perf").GetActiveBrowserID} GetActiveBrowserID
+ * @typedef {import("perf").ProfileCaptureResult} ProfileCaptureResult
  */
 
 /**
@@ -28,8 +29,61 @@ export function getActiveBrowserID() {
   return 0;
 }
 
+/**
+ * @typedef {Object} ProfileCaptureResultAndAdditionalInformation
+ * @property {ProfileCaptureResult} profileCaptureResult
+ * @property {MockedExports.ProfileGenerationAdditionalInformation} [additionalInformation]
+ */
+/**
+ * Fetch the profile data from Firefox, then stop the profiler.
+ *
+ * @returns {Promise<ProfileCaptureResultAndAdditionalInformation>}
+ */
+export async function getProfileDataAsGzippedArrayBufferThenStop() {
+  if (!Services.profiler.IsActive()) {
+    // The profiler is not active, ignore.
+    return {
+      profileCaptureResult: {
+        type: "ERROR",
+        error: new Error("The profiler is not active."),
+      },
+    };
+  }
+  if (Services.profiler.IsPaused()) {
+    // The profiler is already paused for capture, ignore.
+    return {
+      profileCaptureResult: {
+        type: "ERROR",
+        error: new Error("The profiler is already paused."),
+      },
+    };
+  }
+
+  // Pause profiler before we collect the profile, so that we don't capture
+  // more samples while the parent process waits for subprocess profiles.
+  Services.profiler.Pause();
+
+  try {
+    const { profile, additionalInformation } =
+      await Services.profiler.getProfileDataAsGzippedArrayBuffer();
+
+    return {
+      profileCaptureResult: { type: "SUCCESS", profile },
+      additionalInformation,
+    };
+  } catch (unknownError) {
+    const error = /** @type {Error} */ (unknownError);
+    return { profileCaptureResult: { type: "ERROR", error } };
+  } finally {
+    // We're purposefully not using `await`, to minimize the time the user has
+    // to wait until the result is returned.
+    Services.profiler.StopProfiler();
+  }
+}
+
 // This file also exports a named object containing other exports to play well
 // with defineESModuleGetters.
 export const RecordingUtils = {
   getActiveBrowserID,
+  getProfileDataAsGzippedArrayBufferThenStop,
 };