Module: Sdp::Pagination

Defined in:
lib/sdp/pagination.rb

Overview

Lazy enumeration over SDP list endpoints.

Two modes, keyed on whether the caller pinned a page:

  • No :page in the query — auto-paginate. The enumerator fetches the first page on first consumption and follows meta.hasMore, requesting the next page only when iteration runs past the rows already fetched (so ‘enum.take(3)` against a 20-row first page performs exactly one request). Filters are re-sent on every page request.

  • Explicit :page — single page. The enumerator yields exactly that page’s rows and never fetches another, even when meta.hasMore is true.

:pageSize is clamped client-side to MAX_PAGE_SIZE — SDP rejects larger values, and a clamped request is more useful than a guaranteed 400.

Non-paginated list endpoints (GET /v1/wallets at v0.28) flow through the same helper: their meta carries no hasMore, so enumeration stops after a single fetch — and they pick up auto-pagination for free if SDP paginates them in a later version.

Constant Summary collapse

MAX_PAGE_SIZE =

SDP’s pageSize ceiling (v0.28)

100
MAX_PAGES =

defensive ceiling; empty-page + hasMore guards are the primary stop

10_000

Class Method Summary collapse

Class Method Details

.enumerate(client, path, query = {}, &mapper) ⇒ Object

client — anything exposing #get(path, query:) → Client::Response query — wire-shaped (camelCase keys), nils allowed (compacted here) mapper — called once per page with the Response; returns that page’s rows



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# File 'lib/sdp/pagination.rb', line 30

def self.enumerate(client, path, query = {}, &mapper)
  query = query.compact
  query[:pageSize] = [ query[:pageSize].to_i, MAX_PAGE_SIZE ].min if query.key?(:pageSize)
  single_page = query.key?(:page)

  Enumerator.new do |yielder|
    page = query[:page]
    loop do
      request_query = page ? query.merge(page: page) : query
      response = client.get(path, query: request_query)
      rows = mapper.call(response)
      rows.each { |row| yielder << row }

      break if single_page

      meta = response.meta || {}
      # An empty page also stops: hasMore with zero rows would loop forever.
      break if rows.empty? || !meta[:has_more]

      # Advance a LOCAL counter the client owns; ignore meta[:page] so a
      # server that echoes the wrong page number cannot cause an infinite
      # loop or a TypeError (string "1" + 1).
      page = (page || 1) + 1
      break if page > MAX_PAGES
    end
  end
end