How do serialize and deserialize a `longRunningRecognize` operation to get its result later?

I'm using firebase cloud functions to transcribe user-uploaded audio files with the example code for longRunningRecognize:

// Detects speech in the audio file. This creates a recognition job that you  // can wait for now, or get its result later.  const [operation] = await client.longRunningRecognize(request);    // Get a Promise representation of the final result of the job  const [response] = await operation.promise();  

This code works fine for short audio files that can be transcribed faster than the 9-minute firebase cloud function maximum execution limit, but 1) many of my ~hour-long user-uploaded files don't get transcribed that quickly, and 2) it seems wasteful to have a cloud function getting billed for each tenth of a second it's running just sitting around waiting for an API response.

I think the obvious fix here would be for Google's Speech-to-Text API to support webhooks.

Until that happens, how can I serialize and deserialize the SpeechClient operation so I can get the result of this transcription job later from a scheduled function?

Specifically, I'm looking for something that would work like the made-up SERIALIZE and DESERIALIZE functions in this example:

// start speech recognition job:  const [operation] = await client.longRunningRecognize(request);  const serializedOperation = operation.SERIALIZE();  db.doc("jobs/job1").set(serializedOperation);    // get the result later in a scheduled function:  const snap = await db.doc("jobs/job1").get();  const serializedOperation = snap.data();  const operation = DESERIALIZE(serializedOperation);  const [response] = await operation.promise();  

https://stackoverflow.com/questions/66130631/how-do-serialize-and-deserialize-a-longrunningrecognize-operation-to-get-its-r February 10, 2021 at 11:45AM