Practical Microservices

Augmenting the Message Store for $any and $all

Technically, we don’t have to do anything to support $any, since we did that backhere when we wrote the subscribe functionality’s handleMessage function. That was too good of a header to pass up though.

Let’s jump into the Message Store’s read functionality to provide messages for $all:

debugging-components/src/message-store/read.js

const getAllMessagesSql = `
  SELECT
    id::varchar,
    stream_name::varchar,
    type::varchar,
    position::bigint,
    global_position::bigint,
    data::varchar,
    metadata::varchar,
    time::timestamp
  FROM
    messages
  WHERE
    global_position > $1
  LIMIT $2`
  function read (streamName, fromPosition = 0, maxMessages = 1000) {
    let