87 lines
2.3 KiB
Ruby
87 lines
2.3 KiB
Ruby
# frozen_string_literal: true
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module Gitlab
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module Pagination
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module Keyset
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class RequestContext
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attr_reader :request
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DEFAULT_SORT_DIRECTION = :desc
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PRIMARY_KEY = :id
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# A tie breaker is added as an additional order-by column
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# to establish a well-defined order. We use the primary key
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# column here.
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TIE_BREAKER = { PRIMARY_KEY => DEFAULT_SORT_DIRECTION }.freeze
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def initialize(request)
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@request = request
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end
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# extracts Paging information from request parameters
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def page
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@page ||= Page.new(order_by: order_by, per_page: params[:per_page])
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end
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def apply_headers(next_page)
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request.header('Links', pagination_links(next_page))
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end
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private
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def order_by
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return TIE_BREAKER.dup unless params[:order_by]
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order_by = { params[:order_by].to_sym => params[:sort]&.to_sym || DEFAULT_SORT_DIRECTION }
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# Order by an additional unique key, we use the primary key here
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order_by = order_by.merge(TIE_BREAKER) unless order_by[PRIMARY_KEY]
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order_by
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end
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def params
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@params ||= request.params
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end
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def lower_bounds_params(page)
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page.lower_bounds.each_with_object({}) do |(column, value), params|
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filter = filter_with_comparator(page, column)
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params[filter] = value
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end
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end
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def filter_with_comparator(page, column)
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direction = page.order_by[column]
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if direction&.to_sym == :desc
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"#{column}_before"
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else
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"#{column}_after"
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end
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end
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def page_href(page)
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base_request_uri.tap do |uri|
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uri.query = query_params_for(page).to_query
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end.to_s
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end
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def pagination_links(next_page)
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%(<#{page_href(next_page)}>; rel="next")
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end
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def base_request_uri
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@base_request_uri ||= URI.parse(request.request.url).tap do |uri|
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uri.host = Gitlab.config.gitlab.host
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uri.port = Gitlab.config.gitlab.port
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end
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end
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def query_params_for(page)
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request.params.merge(lower_bounds_params(page))
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end
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end
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end
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end
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end
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