add next_key field to results of get_table_rows to better support pagination

[arhag]

Other RPC calls in chain API that allow pagination have a more field that can support the same type as the lower_bound and upper_bound fields of the request. This enables nodeos to include the key that would need to be passed into the lower_bound on a subsequent call to continue retrieving the remaining results from the initial request (ignoring any state changes since that time).

However, the get_table_rows RPC was implemented using the old pattern of providing a boolean more which does not convey enough information to allow a client to generally handle pagination.

So a new string field next_key should be added to get_table_rows_result which is kept as the empty string when more == false, otherwise the string will be set to the key of the next row that wasn't returned in the response in the same format that was expected for the lower_bound and upper_bound fields of the request.

[heipacker]

sounds good

[andresberrios]

Why would you call it more2 instead of something meaningful like next_key or something?

[arhag]

Why would you call it more2 instead of something meaningful like next_key or something?

Sure. That sounds good.

[mharrisb1]

@lparisc tagging you and labeling documentation because work is done for this but it is not documented. Please add new next_key field to get_table_rows documentation https://developers.eos.io/manuals/eos/latest/nodeos/plugins/chain_api_plugin/api-reference/index#operation/get_table_rows