From 99afc1013bba9b67c93240f3080b876c67bd502b Mon Sep 17 00:00:00 2001
From: Pablo Gamito <pablogamito@google.com>
Date: Mon, 22 May 2023 12:15:39 +0000
Subject: [PATCH] Support multiple files for a single trace

Bug: 277181336
Test: npm run build:all && npm run test:all
Change-Id: I7eb981367191c47d3b50b31ee66f147ff1d69431
---
 .../src/app/components/app_component.ts       | 19 +++---
 .../src/app/components/snack_bar_opener.ts    |  2 +-
 .../app/components/upload_traces_component.ts |  7 ++-
 tools/winscope/src/app/trace_info.ts          | 20 +++++++
 tools/winscope/src/app/trace_pipeline.ts      | 29 +++++----
 tools/winscope/src/app/trace_pipeline_test.ts |  3 +-
 tools/winscope/src/parsers/abstract_parser.ts |  6 +-
 tools/winscope/src/parsers/parser_factory.ts  | 37 ++++++------
 tools/winscope/src/test/unit/trace_builder.ts | 11 +++-
 tools/winscope/src/test/unit/utils.ts         | 15 ++++-
 tools/winscope/src/trace/loaded_trace.ts      | 21 +++++++
 tools/winscope/src/trace/parser.ts            |  4 +-
 tools/winscope/src/trace/parser_mock.ts       |  4 ++
 tools/winscope/src/trace/trace.ts             | 60 ++++++++++++++-----
 tools/winscope/src/trace/trace_file.ts        | 12 ++--
 15 files changed, 176 insertions(+), 74 deletions(-)
 create mode 100644 tools/winscope/src/trace/loaded_trace.ts

diff --git a/tools/winscope/src/app/components/app_component.ts b/tools/winscope/src/app/components/app_component.ts
index 6c1d7877b..b47d29e42 100644
--- a/tools/winscope/src/app/components/app_component.ts
+++ b/tools/winscope/src/app/components/app_component.ts
@@ -331,24 +331,23 @@ export class AppComponent implements TraceDataListener {
   private makeActiveTraceFileInfo(view: View): string {
     const traceFile = this.tracePipeline
       .getLoadedTraceFiles()
-      .find((file) => file.type === view.dependencies[0])?.traceFile;
+      .find((file) => file.type === view.dependencies[0]);
 
     if (!traceFile) {
       return '';
     }
 
-    if (!traceFile.parentArchive) {
-      return traceFile.file.name;
-    }
-
-    return `${traceFile.parentArchive.name} - ${traceFile.file.name}`;
+    return `${traceFile.type} (${traceFile.descriptors.join(', ')})`;
   }
 
   private async makeTraceFilesForDownload(): Promise<File[]> {
-    return this.tracePipeline.getLoadedTraceFiles().map((trace) => {
-      const traceType = TRACE_INFO[trace.type].name;
-      const newName = traceType + '/' + FileUtils.removeDirFromFileName(trace.traceFile.file.name);
-      return new File([trace.traceFile.file], newName);
+    const loadedFiles = this.tracePipeline.getLoadedFiles();
+    return [...loadedFiles.keys()].map((traceType) => {
+      const file = loadedFiles.get(traceType)!;
+      const path = TRACE_INFO[traceType].downloadArchiveDir;
+
+      const newName = path + '/' + FileUtils.removeDirFromFileName(file.file.name);
+      return new File([file.file], newName);
     });
   }
 }
diff --git a/tools/winscope/src/app/components/snack_bar_opener.ts b/tools/winscope/src/app/components/snack_bar_opener.ts
index 5b832e678..d9c35c6ee 100644
--- a/tools/winscope/src/app/components/snack_bar_opener.ts
+++ b/tools/winscope/src/app/components/snack_bar_opener.ts
@@ -67,7 +67,7 @@ export class SnackBarOpener implements UserNotificationListener {
   }
 
   private convertErrorToMessage(error: ParserError): string {
-    const fileName = error.trace !== undefined ? error.trace.name : '<no file name>';
+    const fileName = error.trace !== undefined ? error.trace : '<no file name>';
     const traceTypeName =
       error.traceType !== undefined ? TRACE_INFO[error.traceType].name : '<unknown>';
 
diff --git a/tools/winscope/src/app/components/upload_traces_component.ts b/tools/winscope/src/app/components/upload_traces_component.ts
index c9b7c1ee9..2e6da1053 100644
--- a/tools/winscope/src/app/components/upload_traces_component.ts
+++ b/tools/winscope/src/app/components/upload_traces_component.ts
@@ -25,7 +25,7 @@ import {
 import {TRACE_INFO} from 'app/trace_info';
 import {TracePipeline} from 'app/trace_pipeline';
 import {ProgressListener} from 'interfaces/progress_listener';
-import {LoadedTraceFile} from 'trace/trace_file';
+import {LoadedTrace} from 'trace/loaded_trace';
 import {LoadProgressComponent} from './load_progress_component';
 
 @Component({
@@ -63,7 +63,8 @@ import {LoadProgressComponent} from './load_progress_component';
               {{ TRACE_INFO[trace.type].icon }}
             </mat-icon>
 
-            <p matLine>{{ trace.traceFile.file.name }} ({{ TRACE_INFO[trace.type].name }})</p>
+            <p matLine>{{ TRACE_INFO[trace.type].name }}</p>
+            <p matLine *ngFor="let descriptor of trace.descriptors">{{ descriptor }}</p>
 
             <button color="primary" mat-icon-button (click)="onRemoveTrace($event, trace)">
               <mat-icon>close</mat-icon>
@@ -235,7 +236,7 @@ export class UploadTracesComponent implements ProgressListener {
     this.filesUploaded.emit(Array.from(droppedFiles));
   }
 
-  onRemoveTrace(event: MouseEvent, trace: LoadedTraceFile) {
+  onRemoveTrace(event: MouseEvent, trace: LoadedTrace) {
     event.preventDefault();
     event.stopPropagation();
     this.tracePipeline.removeTraceFile(trace.type);
diff --git a/tools/winscope/src/app/trace_info.ts b/tools/winscope/src/app/trace_info.ts
index 7d595cdec..1fc02427f 100644
--- a/tools/winscope/src/app/trace_info.ts
+++ b/tools/winscope/src/app/trace_info.ts
@@ -36,6 +36,7 @@ interface TraceInfoMap {
     name: string;
     icon: string;
     color: string;
+    downloadArchiveDir: string;
   };
 }
 
@@ -44,95 +45,114 @@ export const TRACE_INFO: TraceInfoMap = {
     name: 'Accessibility',
     icon: ACCESSIBILITY_ICON,
     color: '#FF63B8',
+    downloadArchiveDir: 'accessibility',
   },
   [TraceType.WINDOW_MANAGER]: {
     name: 'Window Manager',
     icon: WINDOW_MANAGER_ICON,
     color: '#AF5CF7',
+    downloadArchiveDir: 'wm',
   },
   [TraceType.SURFACE_FLINGER]: {
     name: 'Surface Flinger',
     icon: SURFACE_FLINGER_ICON,
     color: '#4ECDE6',
+    downloadArchiveDir: 'sf',
   },
   [TraceType.SCREEN_RECORDING]: {
     name: 'Screen Recording',
     icon: SCREEN_RECORDING_ICON,
     color: '#8A9CF9',
+    downloadArchiveDir: '',
   },
   [TraceType.TRANSACTIONS]: {
     name: 'Transactions',
     icon: TRANSACTION_ICON,
     color: '#5BB974',
+    downloadArchiveDir: 'sf',
   },
   [TraceType.TRANSACTIONS_LEGACY]: {
     name: 'Transactions Legacy',
     icon: TRANSACTION_ICON,
     color: '#5BB974',
+    downloadArchiveDir: 'sf',
   },
   [TraceType.WAYLAND]: {
     name: 'Wayland',
     icon: WAYLAND_ICON,
     color: '#FDC274',
+    downloadArchiveDir: 'wayland',
   },
   [TraceType.WAYLAND_DUMP]: {
     name: 'Wayland Dump',
     icon: WAYLAND_ICON,
     color: '#D01884',
+    downloadArchiveDir: 'wayland',
   },
   [TraceType.PROTO_LOG]: {
     name: 'ProtoLog',
     icon: PROTO_LOG_ICON,
     color: '#40A58A',
+    downloadArchiveDir: 'protolog',
   },
   [TraceType.SYSTEM_UI]: {
     name: 'System UI',
     icon: SYSTEM_UI_ICON,
     color: '#7A86FF',
+    downloadArchiveDir: 'sysui',
   },
   [TraceType.LAUNCHER]: {
     name: 'Launcher',
     icon: LAUNCHER_ICON,
     color: '#137333',
+    downloadArchiveDir: 'launcher',
   },
   [TraceType.INPUT_METHOD_CLIENTS]: {
     name: 'IME Clients',
     icon: IME_ICON,
     color: '#FA903E',
+    downloadArchiveDir: 'ime',
   },
   [TraceType.INPUT_METHOD_SERVICE]: {
     name: 'IME Service',
     icon: IME_ICON,
     color: '#F29900',
+    downloadArchiveDir: 'ime',
   },
   [TraceType.INPUT_METHOD_MANAGER_SERVICE]: {
     name: 'IME Manager Service',
     icon: IME_ICON,
     color: '#D93025',
+    downloadArchiveDir: 'ime',
   },
   [TraceType.TAG]: {
     name: 'Tag',
     icon: TAG_ICON,
     color: '#4575B4',
+    downloadArchiveDir: '',
   },
   [TraceType.ERROR]: {
     name: 'Error',
     icon: TRACE_ERROR_ICON,
     color: '#D73027',
+    downloadArchiveDir: '',
   },
   [TraceType.EVENT_LOG]: {
     name: 'Event Log',
     icon: EVENT_LOG_ICON,
     color: '#fdd663',
+    downloadArchiveDir: 'eventlog',
   },
   [TraceType.WM_TRANSITION]: {
     name: 'WM Transitions',
     icon: TRANSITION_ICON,
     color: '#EC407A',
+    downloadArchiveDir: 'transition',
   },
   [TraceType.SHELL_TRANSITION]: {
     name: 'Shell Transitions',
     icon: TRANSITION_ICON,
     color: '#EC407A',
+    downloadArchiveDir: 'transition',
   },
 };
diff --git a/tools/winscope/src/app/trace_pipeline.ts b/tools/winscope/src/app/trace_pipeline.ts
index 5620b4c67..eacb15ca4 100644
--- a/tools/winscope/src/app/trace_pipeline.ts
+++ b/tools/winscope/src/app/trace_pipeline.ts
@@ -17,16 +17,18 @@
 import {FunctionUtils, OnProgressUpdateType} from 'common/function_utils';
 import {ParserError, ParserFactory} from 'parsers/parser_factory';
 import {FrameMapper} from 'trace/frame_mapper';
+import {LoadedTrace} from 'trace/loaded_trace';
 import {Parser} from 'trace/parser';
 import {TimestampType} from 'trace/timestamp';
 import {Trace} from 'trace/trace';
 import {Traces} from 'trace/traces';
-import {LoadedTraceFile, TraceFile} from 'trace/trace_file';
+import {TraceFile} from 'trace/trace_file';
 import {TraceType} from 'trace/trace_type';
 
 class TracePipeline {
   private parserFactory = new ParserFactory();
   private parsers: Array<Parser<object>> = [];
+  private files = new Map<TraceType, TraceFile>();
   private traces?: Traces;
   private commonTimestampType?: TimestampType;
 
@@ -38,7 +40,12 @@ class TracePipeline {
       traceFiles,
       onLoadProgressUpdate
     );
-    this.parsers = parsers;
+    this.parsers = parsers.map((it) => it.parser);
+
+    for (const parser of parsers) {
+      this.files.set(parser.parser.getTraceType(), parser.file);
+    }
+
     return parserErrors;
   }
 
@@ -46,9 +53,13 @@ class TracePipeline {
     this.parsers = this.parsers.filter((parser) => parser.getTraceType() !== type);
   }
 
-  getLoadedTraceFiles(): LoadedTraceFile[] {
+  getLoadedFiles(): Map<TraceType, TraceFile> {
+    return this.files;
+  }
+
+  getLoadedTraceFiles(): LoadedTrace[] {
     return this.parsers.map(
-      (parser: Parser<object>) => new LoadedTraceFile(parser.getTraceFile(), parser.getTraceType())
+      (parser: Parser<object>) => new LoadedTrace(parser.getDescriptors(), parser.getTraceType())
     );
   }
 
@@ -57,14 +68,7 @@ class TracePipeline {
 
     this.traces = new Traces();
     this.parsers.forEach((parser) => {
-      const trace = new Trace(
-        parser.getTraceType(),
-        parser.getTraceFile(),
-        undefined,
-        parser,
-        commonTimestampType,
-        {start: 0, end: parser.getLengthEntries()}
-      );
+      const trace = Trace.newUninitializedTrace(parser);
       this.traces?.setTrace(parser.getTraceType(), trace);
     });
     new FrameMapper(this.traces).computeMapping();
@@ -88,6 +92,7 @@ class TracePipeline {
     this.parsers = [];
     this.traces = undefined;
     this.commonTimestampType = undefined;
+    this.files.clear();
   }
 
   private getCommonTimestampType(): TimestampType {
diff --git a/tools/winscope/src/app/trace_pipeline_test.ts b/tools/winscope/src/app/trace_pipeline_test.ts
index 43d29c35a..b00189494 100644
--- a/tools/winscope/src/app/trace_pipeline_test.ts
+++ b/tools/winscope/src/app/trace_pipeline_test.ts
@@ -93,7 +93,8 @@ describe('TracePipeline', () => {
 
     const files = tracePipeline.getLoadedTraceFiles();
     expect(files.length).toEqual(2);
-    expect(files[0].traceFile).toBeTruthy();
+    expect(files[0].descriptors).toBeTruthy();
+    expect(files[0].descriptors.length).toBeGreaterThan(0);
 
     const actualTraceTypes = new Set(files.map((file) => file.type));
     const expectedTraceTypes = new Set([TraceType.SURFACE_FLINGER, TraceType.WINDOW_MANAGER]);
diff --git a/tools/winscope/src/parsers/abstract_parser.ts b/tools/winscope/src/parsers/abstract_parser.ts
index 25d864232..f35950a1a 100644
--- a/tools/winscope/src/parsers/abstract_parser.ts
+++ b/tools/winscope/src/parsers/abstract_parser.ts
@@ -42,7 +42,7 @@ abstract class AbstractParser implements Parser<object> {
         throw TypeError("buffer doesn't contain expected magic number");
       }
     }
-
+     
     this.decodedEntries = this.decodeTrace(traceBuffer).map((it) => this.addDefaultProtoFields(it));
 
     for (const type of [TimestampType.ELAPSED, TimestampType.REAL]) {
@@ -66,8 +66,8 @@ abstract class AbstractParser implements Parser<object> {
 
   abstract getTraceType(): TraceType;
 
-  getTraceFile(): TraceFile {
-    return this.traceFile;
+  getDescriptors(): string[] {
+    return [this.traceFile.getDescriptor()];
   }
 
   getLengthEntries(): number {
diff --git a/tools/winscope/src/parsers/parser_factory.ts b/tools/winscope/src/parsers/parser_factory.ts
index 2c0b18924..95ebb8d0f 100644
--- a/tools/winscope/src/parsers/parser_factory.ts
+++ b/tools/winscope/src/parsers/parser_factory.ts
@@ -56,9 +56,11 @@ export class ParserFactory {
   async createParsers(
     traceFiles: TraceFile[],
     onProgressUpdate: OnProgressUpdateType = FunctionUtils.DO_NOTHING
-  ): Promise<[Array<Parser<object>>, ParserError[]]> {
+  ): Promise<[Array<{file: TraceFile; parser: Parser<object>}>, ParserError[]]> {
     const errors: ParserError[] = [];
 
+    const parsers = new Array<{file: TraceFile; parser: Parser<object>}>();
+
     if (traceFiles.length === 0) {
       errors.push(new ParserError(ParserErrorType.NO_INPUT_FILES));
     }
@@ -73,6 +75,7 @@ export class ParserFactory {
           hasFoundParser = true;
           if (this.shouldUseParser(parser, errors)) {
             this.parsers.set(parser.getTraceType(), parser);
+            parsers.push({file: traceFile, parser});
           }
           break;
         } catch (error) {
@@ -82,37 +85,37 @@ export class ParserFactory {
 
       if (!hasFoundParser) {
         console.log(`Failed to load trace ${traceFile.file.name}`);
-        errors.push(new ParserError(ParserErrorType.UNSUPPORTED_FORMAT, traceFile.file));
+        errors.push(new ParserError(ParserErrorType.UNSUPPORTED_FORMAT, traceFile.getDescriptor()));
       }
 
       onProgressUpdate((100 * (index + 1)) / traceFiles.length);
     }
 
-    return [Array.from(this.parsers.values()), errors];
+    return [parsers, errors];
   }
 
   private shouldUseParser(newParser: Parser<object>, errors: ParserError[]): boolean {
     const oldParser = this.parsers.get(newParser.getTraceType());
     if (!oldParser) {
       console.log(
-        `Loaded trace ${
-          newParser.getTraceFile().file.name
-        } (trace type: ${newParser.getTraceType()})`
+        `Loaded trace ${newParser
+          .getDescriptors()
+          .join()} (trace type: ${newParser.getTraceType()})`
       );
       return true;
     }
 
     if (newParser.getLengthEntries() > oldParser.getLengthEntries()) {
       console.log(
-        `Loaded trace ${
-          newParser.getTraceFile().file.name
-        } (trace type: ${newParser.getTraceType()}).` +
-          ` Replace trace ${oldParser.getTraceFile().file.name}`
+        `Loaded trace ${newParser
+          .getDescriptors()
+          .join()} (trace type: ${newParser.getTraceType()}).` +
+          ` Replace trace ${oldParser.getDescriptors().join()}`
       );
       errors.push(
         new ParserError(
           ParserErrorType.OVERRIDE,
-          oldParser.getTraceFile().file,
+          oldParser.getDescriptors().join(),
           oldParser.getTraceType()
         )
       );
@@ -120,15 +123,15 @@ export class ParserFactory {
     }
 
     console.log(
-      `Skipping trace ${
-        newParser.getTraceFile().file.name
-      } (trace type: ${newParser.getTraceType()}).` +
-        ` Keep trace ${oldParser.getTraceFile().file.name}`
+      `Skipping trace ${newParser
+        .getDescriptors()
+        .join()} (trace type: ${newParser.getTraceType()}).` +
+        ` Keep trace ${oldParser.getDescriptors().join()}`
     );
     errors.push(
       new ParserError(
         ParserErrorType.OVERRIDE,
-        newParser.getTraceFile().file,
+        newParser.getDescriptors().join(),
         newParser.getTraceType()
       )
     );
@@ -145,7 +148,7 @@ export enum ParserErrorType {
 export class ParserError {
   constructor(
     public type: ParserErrorType,
-    public trace: File | undefined = undefined,
+    public trace: string | undefined = undefined,
     public traceType: TraceType | undefined = undefined
   ) {}
 }
diff --git a/tools/winscope/src/test/unit/trace_builder.ts b/tools/winscope/src/test/unit/trace_builder.ts
index 7027882c5..e4edb559c 100644
--- a/tools/winscope/src/test/unit/trace_builder.ts
+++ b/tools/winscope/src/test/unit/trace_builder.ts
@@ -31,6 +31,7 @@ export class TraceBuilder<T> {
   private timestampType = TimestampType.REAL;
   private frameMap?: FrameMap;
   private frameMapBuilder?: FrameMapBuilder;
+  private descriptors: string[] = [];
 
   setType(type: TraceType): TraceBuilder<T> {
     this.type = type;
@@ -73,6 +74,11 @@ export class TraceBuilder<T> {
     return this;
   }
 
+  setDescriptors(descriptors: string[]): TraceBuilder<T> {
+    this.descriptors = descriptors;
+    return this;
+  }
+
   build(): Trace<T> {
     if (!this.parser) {
       this.parser = this.createParser();
@@ -82,11 +88,10 @@ export class TraceBuilder<T> {
       start: 0,
       end: this.parser.getLengthEntries(),
     };
-    const trace = new Trace<T>(
+    const trace = Trace.newInitializedTrace<T>(
       this.type,
-      undefined,
-      undefined,
       this.parser,
+      this.descriptors,
       this.timestampType,
       entriesRange
     );
diff --git a/tools/winscope/src/test/unit/utils.ts b/tools/winscope/src/test/unit/utils.ts
index f51c3e9d5..657531701 100644
--- a/tools/winscope/src/test/unit/utils.ts
+++ b/tools/winscope/src/test/unit/utils.ts
@@ -19,15 +19,28 @@ import {CommonTestUtils} from 'test/common/utils';
 import {LayerTraceEntry, WindowManagerState} from 'trace/flickerlib/common';
 import {Parser} from 'trace/parser';
 import {TimestampType} from 'trace/timestamp';
+import {Trace} from 'trace/trace';
 import {TraceFile} from 'trace/trace_file';
 import {TraceType} from 'trace/trace_type';
 
 class UnitTestUtils extends CommonTestUtils {
+  static async getTraceFromFile(filename: string): Promise<Trace<object>> {
+    const parser = await UnitTestUtils.getParser(filename);
+
+    const trace = Trace.newUninitializedTrace(parser);
+    trace.init(
+      parser.getTimestamps(TimestampType.REAL) !== undefined
+        ? TimestampType.REAL
+        : TimestampType.ELAPSED
+    );
+    return trace;
+  }
+
   static async getParser(filename: string): Promise<Parser<object>> {
     const file = new TraceFile(await CommonTestUtils.getFixtureFile(filename), undefined);
     const [parsers, errors] = await new ParserFactory().createParsers([file]);
     expect(parsers.length).toEqual(1);
-    return parsers[0];
+    return parsers[0].parser;
   }
 
   static async getWindowManagerState(): Promise<WindowManagerState> {
diff --git a/tools/winscope/src/trace/loaded_trace.ts b/tools/winscope/src/trace/loaded_trace.ts
new file mode 100644
index 000000000..eb99b51a7
--- /dev/null
+++ b/tools/winscope/src/trace/loaded_trace.ts
@@ -0,0 +1,21 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import {TraceType} from './trace_type';
+
+export class LoadedTrace {
+  constructor(public descriptors: string[], public type: TraceType) {}
+}
diff --git a/tools/winscope/src/trace/parser.ts b/tools/winscope/src/trace/parser.ts
index 3e78a3bbe..d32861814 100644
--- a/tools/winscope/src/trace/parser.ts
+++ b/tools/winscope/src/trace/parser.ts
@@ -15,13 +15,13 @@
  */
 
 import {Timestamp, TimestampType} from './timestamp';
-import {TraceFile} from './trace_file';
 import {TraceType} from './trace_type';
 
 export interface Parser<T> {
   getTraceType(): TraceType;
-  getTraceFile(): TraceFile;
   getLengthEntries(): number;
   getTimestamps(type: TimestampType): Timestamp[] | undefined;
   getEntry(index: number, timestampType: TimestampType): T;
+
+  getDescriptors(): string[];
 }
diff --git a/tools/winscope/src/trace/parser_mock.ts b/tools/winscope/src/trace/parser_mock.ts
index 4c5fb2861..c87d293e8 100644
--- a/tools/winscope/src/trace/parser_mock.ts
+++ b/tools/winscope/src/trace/parser_mock.ts
@@ -48,4 +48,8 @@ export class ParserMock<T> implements Parser<T> {
   getEntry(index: number): T {
     return this.entries[index];
   }
+
+  getDescriptors(): string[] {
+    return ['MockTrace'];
+  }
 }
diff --git a/tools/winscope/src/trace/trace.ts b/tools/winscope/src/trace/trace.ts
index 942eebe9e..236464859 100644
--- a/tools/winscope/src/trace/trace.ts
+++ b/tools/winscope/src/trace/trace.ts
@@ -72,32 +72,56 @@ export class TraceEntry<T> {
 }
 
 export class Trace<T> {
-  readonly type: TraceType;
   readonly file?: TraceFile;
   readonly lengthEntries: number;
   readonly fullTrace: Trace<T>;
 
-  private readonly parser: Parser<T>;
-  private readonly timestampType: TimestampType;
+  private timestampType: TimestampType | undefined;
   private readonly entriesRange: EntriesRange;
   private frameMap?: FrameMap;
   private framesRange?: FramesRange;
 
-  constructor(
+  static newUninitializedTrace<T>(parser: Parser<T>): Trace<T> {
+    return new Trace(
+      parser.getTraceType(),
+      parser,
+      parser.getDescriptors(),
+      undefined,
+      undefined,
+      undefined
+    );
+  }
+
+  static newInitializedTrace<T>(
     type: TraceType,
-    file: TraceFile | undefined,
-    fullTrace: Trace<T> | undefined,
-    parser: Parser<T>,
+    entryProvider: Parser<T>,
+    descriptors: string[],
     timestampType: TimestampType,
     entriesRange: EntriesRange
-  ) {
-    this.type = type;
-    this.file = file;
-    this.lengthEntries = entriesRange.end - entriesRange.start;
-    this.fullTrace = fullTrace ? fullTrace : this;
-    this.parser = parser;
+  ): Trace<T> {
+    return new Trace(type, entryProvider, descriptors, undefined, timestampType, entriesRange);
+  }
+
+  init(timestampType: TimestampType) {
     this.timestampType = timestampType;
-    this.entriesRange = entriesRange;
+  }
+
+  private constructor(
+    readonly type: TraceType,
+    readonly parser: Parser<T>,
+    readonly descriptors: string[],
+    fullTrace: Trace<T> | undefined,
+    timestampType: TimestampType | undefined,
+    entriesRange: EntriesRange | undefined
+  ) {
+    this.fullTrace = fullTrace ?? this;
+    this.entriesRange = entriesRange ?? {start: 0, end: parser.getLengthEntries()};
+    this.lengthEntries = this.entriesRange.end - this.entriesRange.start;
+    this.timestampType = timestampType;
+  }
+
+  getDescriptors(): string[] {
+    return this.parser.getDescriptors();
   }
 
   setFrameInfo(frameMap: FrameMap, framesRange: FramesRange | undefined) {
@@ -315,6 +339,10 @@ export class Trace<T> {
   }
 
   private getFullTraceTimestamps(): Timestamp[] {
+    if (this.timestampType === undefined) {
+      throw new Error('Forgot to initialize trace?');
+    }
+
     const timestamps = this.parser.getTimestamps(this.timestampType);
     if (!timestamps) {
       throw new Error(`Timestamp type ${this.timestampType} is expected to be available`);
@@ -350,9 +378,9 @@ export class Trace<T> {
 
     const slice = new Trace<T>(
       this.type,
-      this.file,
-      this.fullTrace,
       this.parser,
+      this.descriptors,
+      this.fullTrace,
       this.timestampType,
       entries
     );
diff --git a/tools/winscope/src/trace/trace_file.ts b/tools/winscope/src/trace/trace_file.ts
index dc92f82fc..4f2f6da16 100644
--- a/tools/winscope/src/trace/trace_file.ts
+++ b/tools/winscope/src/trace/trace_file.ts
@@ -14,12 +14,14 @@
  * limitations under the License.
  */
 
-import {TraceType} from './trace_type';
-
 export class TraceFile {
   constructor(public file: File, public parentArchive?: File) {}
-}
 
-export class LoadedTraceFile {
-  constructor(public traceFile: TraceFile, public type: TraceType) {}
+  getDescriptor(): string {
+    let descriptor = this.file.name;
+    if (this.parentArchive?.name !== undefined) {
+      descriptor += ` (${this.parentArchive?.name})`;
+    }
+    return descriptor;
+  }
 }