Method readStreamAsJSON

ui/media/js/engine.js:129–179

(jsonStr, throwOnError)

            } while (!done && (this.#response.ok || this.#response.status === 425))
        }
        *readStreamAsJSON(jsonStr, throwOnError) {
            if (typeof jsonStr !== "string") {
                throw new Error("jsonStr is not a string.")
            }
            do {
                if (this.#bufferedString.length > 0) {
                    // Append new data when required
                    if (jsonStr.length > 0) {
                        jsonStr = this.#bufferedString + jsonStr
                    } else {
                        jsonStr = this.#bufferedString
                    }
                    this.#bufferedString = ""
                }
                if (!jsonStr) {
                    return
                }
                // Find next delimiter
                let lastChunkIdx = jsonStr.indexOf("}{")
                if (lastChunkIdx >= 0) {
                    this.#bufferedString = jsonStr.substring(0, lastChunkIdx + 1)
                    jsonStr = jsonStr.substring(lastChunkIdx + 1)
                } else {
                    this.#bufferedString = jsonStr
                    jsonStr = ""
                }
                if (this.#bufferedString.length <= 0) {
                    return
                }
                // hack for a middleman buffering all the streaming updates, and unleashing them on the poor browser in one shot.
                // this results in having to parse JSON like {"step": 1}{"step": 2}{"step": 3}{"ste...
                // which is obviously invalid and can happen at any point while rendering.
                // So we need to extract only the next {} section
                try {
                    // Try to parse
                    const jsonObj = JSON.parse(this.#bufferedString)
                    this.#bufferedString = jsonStr
                    jsonStr = ""
                    yield jsonObj
                } catch (e) {
                    if (throwOnError) {
                        console.error(`Parsing: "${this.#bufferedString}", Buffer: "${jsonStr}"`)
                    }
                    this.#bufferedString += jsonStr
                    if (e instanceof SyntaxError && !throwOnError) {
                        return
                    }
                    throw e
                }
            } while (this.#bufferedString.length > 0 && this.#bufferedString.indexOf("}") >= 0)
        }
    }

    const EVENT_IDLE = "idle"