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30990006a9
This reduces chances of errors where consumers of strings mutate inputs and reduces memory usage of the app. Test suite passes now, but there may be some stuff left, so we will run a few sites on a branch prior to merging
57 lines
1.1 KiB
Ruby
57 lines
1.1 KiB
Ruby
# frozen_string_literal: true
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#
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# This is used for finding the gaps between a subset of elements in an array
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# and the original layout. We use this in Discourse to find gaps between posts.
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#
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# Note that we will only return a gap as 'before' or 'after', not both. We only
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# want to display the gap once.
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#
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class Gaps
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attr_reader :before, :after
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def initialize(subset, original)
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@before = {}
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@after = {}
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@subset = subset
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@original = original
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find_gaps
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end
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def empty?
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@before.size == 0 && @after.size == 0
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end
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def find_gaps
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return if @subset.nil? || @original.nil?
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i = j = 0
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gaps = {}
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current_gap = []
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while
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e1 = @subset[i]
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e2 = @original[j]
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if (e1 == e2)
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if current_gap.size > 0
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@before[e1] = current_gap.dup
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current_gap = []
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end
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i = i + 1
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else
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current_gap << e2
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end
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j = j + 1
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break if (i == @subset.size) || (j == @original.size)
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end
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@after[@subset[i - 1]] = @original[j..-1] if j < @original.size
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end
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end
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