Method extractDocumentSequences

src/cmap/commands.ts:608–630

* Extracts the document sequences from the command document and returns * a buffer to be added as multiple sections after the initial type 0 * section in the message.

(document: Document)

   * section in the message.
   */
  extractDocumentSequences(document: Document): Uint8Array {
    // Pull out any field in the command document that's value is a document sequence.
    const chunks = [];
    for (const [key, value] of Object.entries(document)) {
      if (value instanceof DocumentSequence) {
        chunks.push(value.toBin());
        // Why are we removing the field from the command? This is because it needs to be
        // removed in the OP_MSG request first section, and DocumentSequence is not a
        // BSON type and is specific to the MongoDB wire protocol so there's nothing
        // our BSON serializer can do about this. Since DocumentSequence is not exposed
        // in the public API and only used internally, we are never mutating an original
        // command provided by the user, just our own, and it's cheaper to delete from
        // our own command than copying it.
        delete document[key];
      }
    }
    if (chunks.length > 0) {
      return ByteUtils.concat(chunks);
    }
    // If we have no document sequences we return an empty buffer for nothing to add
    // to the payload.
    return ByteUtils.allocate(0);
  }

  serializeBson(document: Document): Uint8Array {
    return BSON.serialize(document, {