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Add a hook to get early access to trace object before loading #169

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Merged
cdamus merged 1 commit into from
Mar 6, 2026
Merged

Add a hook to get early access to trace object before loading #169

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125 changes: 111 additions & 14 deletions ui/src/core/app_impl.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -31,7 +31,10 @@ import {CommandInvocation, CommandManagerImpl} from './command_manager';
import {embedderContext} from './embedder';
import {featureFlags} from './feature_flags';
import {loadTrace} from './load_trace';
import {HierarchicalOmniboxManager, OmniboxManagerImpl} from './omnibox_manager';
import {
HierarchicalOmniboxManager,
OmniboxManagerImpl,
} from './omnibox_manager';
import {PageManagerImpl} from './page_manager';
import {PerfManager} from './perf_manager';
import {PluginManagerImpl} from './plugin_manager';
Expand Down Expand Up @@ -282,34 +285,128 @@ export class AppImpl implements App {
};
}

openTraceFromFile(file: File) {
return this.openTrace({type: 'FILE', file});
openTraceFromFile(file: File): Promise<TraceImpl>;
openTraceFromFile(
file: File,
/**
* An optional call-back to be notified of the identity of the new trace as soon as it is created
* and before loading begins. Be careful how this is used: it may only be used for its identity
* because it is in an uninitialized state and loading it may yet fail.
*/
onTraceCreated?: (newTrace: TraceImpl) => void,
): Promise<TraceImpl>;
openTraceFromFile(
file: File,
onTraceCreated?: (newTrace: TraceImpl) => void,
) {
return this.openTrace({type: 'FILE', file}, onTraceCreated);
}

openTraceFromMultipleFiles(files: ReadonlyArray<File>) {
return this.openTrace({type: 'MULTIPLE_FILES', files});
openTraceFromMultipleFiles(files: ReadonlyArray<File>): Promise<TraceImpl>;
openTraceFromMultipleFiles(
files: ReadonlyArray<File>,
/**
* An optional call-back to be notified of the identity of the new trace as soon as it is created
* and before loading begins. Be careful how this is used: it may only be used for its identity
* because it is in an uninitialized state and loading it may yet fail.
*/
onTraceCreated?: (newTrace: TraceImpl) => void,
): Promise<TraceImpl>;
openTraceFromMultipleFiles(
files: ReadonlyArray<File>,
onTraceCreated?: (newTrace: TraceImpl) => void,
) {
return this.openTrace({type: 'MULTIPLE_FILES', files}, onTraceCreated);
}

openTraceFromUrl(url: string, serializedAppState?: SerializedAppState) {
return this.openTrace({type: 'URL', url, serializedAppState});
openTraceFromUrl(
url: string,
serializedAppState?: SerializedAppState,
): Promise<TraceImpl>;
openTraceFromUrl(
url: string,
serializedAppState?: SerializedAppState,
/**
* An optional call-back to be notified of the identity of the new trace as soon as it is created
* and before loading begins. Be careful how this is used: it may only be used for its identity
* because it is in an uninitialized state and loading it may yet fail.
*/
onTraceCreated?: (newTrace: TraceImpl) => void,
): Promise<TraceImpl>;
openTraceFromUrl(
url: string,
serializedAppState?: SerializedAppState,
onTraceCreated?: (newTrace: TraceImpl) => void,
) {
return this.openTrace(
{type: 'URL', url, serializedAppState},
onTraceCreated,
);
}

openTraceFromStream(stream: TraceStream) {
return this.openTrace({type: 'STREAM', stream});
openTraceFromStream(stream: TraceStream): Promise<TraceImpl>;
openTraceFromStream(
stream: TraceStream,
/**
* An optional call-back to be notified of the identity of the new trace as soon as it is created
* and before loading begins. Be careful how this is used: it may only be used for its identity
* because it is in an uninitialized state and loading it may yet fail.
*/
onTraceCreated?: (newTrace: TraceImpl) => void,
): Promise<TraceImpl>;
openTraceFromStream(
stream: TraceStream,
onTraceCreated?: (newTrace: TraceImpl) => void,
) {
return this.openTrace({type: 'STREAM', stream}, onTraceCreated);
}

openTraceFromBuffer(
args: OpenTraceArrayBufArgs,
serializedAppState?: SerializedAppState,
): Promise<TraceImpl>;
openTraceFromBuffer(
args: OpenTraceArrayBufArgs,
serializedAppState?: SerializedAppState,
/**
* An optional call-back to be notified of the identity of the new trace as soon as it is created
* and before loading begins. Be careful how this is used: it may only be used for its identity
* because it is in an uninitialized state and loading it may yet fail.
*/
onTraceCreated?: (newTrace: TraceImpl) => void,
): Promise<TraceImpl>;
openTraceFromBuffer(
args: OpenTraceArrayBufArgs,
serializedAppState?: SerializedAppState,
onTraceCreated?: (newTrace: TraceImpl) => void,
) {
return this.openTrace({...args, type: 'ARRAY_BUFFER', serializedAppState});
return this.openTrace(
{...args, type: 'ARRAY_BUFFER', serializedAppState},
onTraceCreated,
);
}

openTraceFromHttpRpc(port?: string) {
return this.openTrace({type: 'HTTP_RPC', port});
openTraceFromHttpRpc(port?: string): Promise<TraceImpl>;
openTraceFromHttpRpc(
port?: string,
/**
* An optional call-back to be notified of the identity of the new trace as soon as it is created
* and before loading begins. Be careful how this is used: it may only be used for its identity
* because it is in an uninitialized state and loading it may yet fail.
*/
onTraceCreated?: (newTrace: TraceImpl) => void,
): Promise<TraceImpl>;
openTraceFromHttpRpc(
port?: string,
onTraceCreated?: (newTrace: TraceImpl) => void,
) {
return this.openTrace({type: 'HTTP_RPC', port}, onTraceCreated);
}

private async openTrace(src: TraceSource): Promise<TraceImpl> {
private async openTrace(
src: TraceSource,
onTraceCreated?: (newTrace: TraceImpl) => void,
): Promise<TraceImpl> {
if (src.type === 'ARRAY_BUFFER' && src.buffer instanceof Uint8Array) {
// Even though the type of `buffer` is ArrayBuffer, it's possible to
// accidentally pass a Uint8Array here, because the interface of
Expand Down Expand Up @@ -351,7 +448,7 @@ export class AppImpl implements App {
// - Call AppImpl.setActiveTrace(TraceImpl)
// - Continue with the trace loading logic (track decider, plugins, etc)
// - Resolve the promise when everything is done.
const trace = await loadTrace(this, src);
const trace = await loadTrace(this, src, onTraceCreated);
this.omnibox.childFor(src).reset(/* focus= */ false);
// loadTrace() internally will call setActiveTrace() and change our
// _currentTrace in the middle of its execution. We cannot wait for
Expand Down
10 changes: 9 additions & 1 deletion ui/src/core/load_trace.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -127,11 +127,17 @@ let lastEngineId = 0;
export async function loadTrace(
app: AppImpl,
traceSource: TraceSource,
/**
* An optional call-back to be notified of the identity of the new trace as soon as it is created
* and before loading begins. Be careful how this is used: it may only be used for its identity
* because it is in an uninitialized state and loading it may yet fail.
*/
onTraceCreated?: (newTrace: TraceImpl) => void,
): Promise<TraceImpl> {
updateStatus(traceSource, app, 'Opening trace');
const engineId = `${++lastEngineId}`;
const engine = await createEngine(app, engineId, traceSource);
return await loadTraceIntoEngine(app, traceSource, engine);
return await loadTraceIntoEngine(app, traceSource, engine, onTraceCreated);
}

async function createEngine(
Expand Down Expand Up @@ -183,6 +189,7 @@ async function loadTraceIntoEngine(
app: AppImpl,
traceSource: TraceSource,
engine: EngineBase,
onTraceCreated?: (newTrace: TraceImpl) => void,
): Promise<TraceImpl> {
let traceStream: TraceStream | undefined;
let serializedAppState = traceSource.serializedAppState;
Expand Down Expand Up @@ -238,6 +245,7 @@ async function loadTraceIntoEngine(

const traceDetails = await getTraceInfo(engine, app, traceSource);
const trace = new TraceImpl(app, engine, traceDetails);
onTraceCreated?.(trace);
app.setActiveTrace(trace);

const visibleTimeSpan = await computeVisibleTime(
Expand Down