75 lines
1.8 KiB
Ruby
75 lines
1.8 KiB
Ruby
# frozen_string_literal: true
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module Gitlab
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module Diff
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class CharDiff
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include Gitlab::Utils::StrongMemoize
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def initialize(old_string, new_string)
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@old_string = old_string.to_s
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@new_string = new_string.to_s
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@changes = []
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end
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def generate_diff
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@changes = diff_match_patch.diff_main(@old_string, @new_string)
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diff_match_patch.diff_cleanupSemantic(@changes)
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@changes
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end
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def changed_ranges(offset: 0)
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old_diffs = []
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new_diffs = []
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new_pointer = old_pointer = offset
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generate_diff.each do |(action, content)|
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content_size = content.size
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if action == :equal
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new_pointer += content_size
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old_pointer += content_size
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end
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if action == :delete
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old_diffs << MarkerRange.new(old_pointer, old_pointer + content_size - 1, mode: MarkerRange::DELETION)
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old_pointer += content_size
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end
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if action == :insert
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new_diffs << MarkerRange.new(new_pointer, new_pointer + content_size - 1, mode: MarkerRange::ADDITION)
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new_pointer += content_size
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end
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end
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[old_diffs, new_diffs]
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end
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def to_html
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@changes.map do |op, text|
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%{<span class="#{html_class_names(op)}">#{ERB::Util.html_escape(text)}</span>}
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end.join.html_safe
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end
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private
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def diff_match_patch
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strong_memoize(:diff_match_patch) { DiffMatchPatch.new }
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end
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def html_class_names(operation)
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class_names = ['idiff']
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case operation
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when :insert
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class_names << 'addition'
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when :delete
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class_names << 'deletion'
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end
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class_names.join(' ')
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end
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end
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end
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end
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