Class: CSS::Native::Cascade

Inherits:
Cascade
  • Object
show all
Defined in:
lib/css/native.rb

Overview

Subclass of CSS::Cascade that uses the native matcher for the inner rule-matching loop. Selectors are pre-compiled at construction —those that can’t be compiled (pseudo-classes etc.) fall through to the pure-Ruby matcher, so behavior is identical to CSS::Cascade.

Requires a Nokogiri document at construction; the snapshot is built once and reused for every resolve(). Mutate the DOM and you must construct a fresh CSS::Native::Cascade.

Constant Summary

Constants inherited from Cascade

Cascade::TRANSPARENT_AT_RULES

Instance Method Summary collapse

Constructor Details

#initialize(stylesheet, document, context: CSS::MediaQueries::Context.default) ⇒ Cascade

Returns a new instance of Cascade.



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# File 'lib/css/native.rb', line 83

def initialize(stylesheet, document, context: CSS::MediaQueries::Context.default)
  super(stylesheet, context: context)

  @snapshot        = Snapshot.from_document(document)
  @compiled_by_ast = {}.compare_by_identity

  @entries.each do |entry|
    entry.selector_pairs.each {|ast, _spec|
      @compiled_by_ast[ast] = Native.compile_or_nil(ast)
    }
  end
end

Instance Method Details

#resolve(element, inline_style: nil, state: nil) ⇒ Object

Override: batch every candidate’s compiled selectors into one FFI hop per resolve (GVL released), then merge in any Ruby-fallback matches. Cuts per-resolve FFI cost from O(candidates) to O(1).



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# File 'lib/css/native.rb', line 99

def resolve(element, inline_style: nil, state: nil)
  cache        = {}
  candidates   = collect_candidate_indexes(element, cache)
  order        = 0
  matches      = []
  native_state = state && @snapshot.compile_state(state)

  best_by_entry = native_pass(element, candidates, native_state)
  ruby_fallback_pass(element, candidates, best_by_entry, cache, state)

  candidates.each do |entry_idx|
    spec = best_by_entry[entry_idx] or next

    @entries[entry_idx].declarations.each {|decl|
      order += 1
      matches << CSS::Cascade::Match.new(declaration: decl, specificity: spec, inline: false, order: order)
    }
  end

  if inline_style
    inline_declarations(inline_style).each {|decl|
      order += 1
      matches << CSS::Cascade::Match.new(
        declaration: decl,
        specificity: CSS::Selectors::Specificity::ZERO,
        inline:      true,
        order:       order
      )
    }
  end

  pick_winners(matches)
end