Function parseEnvelope

packages/core/src/utils/envelope.ts:145–177

(env: string | Uint8Array)

 * Parses an envelope
 */
export function parseEnvelope(env: string | Uint8Array): Envelope {
  let buffer = typeof env === 'string' ? encodeUTF8(env) : env;

  function readBinary(length: number): Uint8Array {
    const bin = buffer.subarray(0, length);
    // Replace the buffer with the remaining data excluding trailing newline
    buffer = buffer.subarray(length + 1);
    return bin;
  }

  function readJson<T>(): T {
    let i = buffer.indexOf(0xa);
    // If we couldn't find a newline, we must have found the end of the buffer
    if (i < 0) {
      i = buffer.length;
    }

    return JSON.parse(decodeUTF8(readBinary(i))) as T;
  }

  const envelopeHeader = readJson<BaseEnvelopeHeaders>();
  // eslint-disable-next-line @typescript-eslint/no-explicit-any
  const items: [any, any][] = [];

  while (buffer.length) {
    const itemHeader = readJson<BaseEnvelopeItemHeaders>();
    const binaryLength = typeof itemHeader.length === 'number' ? itemHeader.length : undefined;

    items.push([itemHeader, binaryLength ? readBinary(binaryLength) : readJson()]);
  }

  return [envelopeHeader, items];
}

/**
 * Creates envelope item for a single span