ruby – 确定两个Nokogiri节点是否相同

Ruby 2020-09-06
想象一下,你有Nokogiri节点代表< a>.以下两个文件中的元素： 

<r xmlns:x="foo"><a foo="bar" jim="jam" x:oh="no"><x:b>Hello</x:b></a></r>
<r xmlns:i="foo"><a jim="jam" i:oh="no" foo="bar"><i:b>Hello</i:b></a></r>

从DOM的角度来看,这两者是等价的.我想有效地检测到这一点,但Nokogiri :: XML :: Node#==只检查对象相等性.由于Nokogiri 1.5.0还没有规范化的支持,我不能只是序列化节点并比较字符串.

比较两个节点以确保其名称,属性和内容在规范上等效的最快方法是什么？

如果需要,答案可能依赖于Ruby 1.9.2中仅提供的功能.

测试用例

ORIG1 = "<a>
  <a1><a1a/><a1b/><a1c/></a1>
  <a2><a2a/><a2b foo='bar' jim='jam'/><a2c/></a2>
  <a3><a3a/><a3b/><a3c>foo</a3c></a3>
</a>"
ORIG2 = "<a>
  <a1><a1a/><a1b/><a1c/></a1>
  <a2><a2a/><a2b jim='jam' foo='bar'/><a2c/></a2>
  <a3><a3a/><a3b/><a3c>foo</a3c></a3>
</a>"
NOTEXT = "<a>
  <a1><a1a/><a1b/><a1c/></a1>
  <a2><a2a/><a2b foo='bar' jim='jam'/><a2c/></a2>
  <a3><a3a/><a3b/><a3c/></a3>
</a>"
EXTRATEXT1 = "<a>
  <a1><a1a/><a1b/><a1c/></a1>
  <a2><a2a/><a2b foo='bar' jim='jam'/><a2c/></a2>
  <a3><a3a/><a3b/><a3c>foobar</a3c></a3>
</a>"
EXTRATEXT2 = "<a>
  <a1><a1a/><a1b/><a1c/></a1>
  <a2><a2a/><a2b foo='bar' jim='jam'/><a2c/></a2>
  <a3><a3a/><a3b>hi</a3b><a3c>foo</a3c></a3>
</a>"
MISSINGNODE = "<a>
  <a1><a1a/><a1b/><a1c/></a1>
  <a2><a2a/><a2b foo='bar' jim='jam'/><a2c/></a2>
  <a3><a3a/><a3b/></a3>
</a>"
EXTRANODE = "<a>
  <a1><a1a/><a1b/><a1c/></a1>
  <a2><a2a/><a2b foo='bar' jim='jam'/><a2c/></a2>
  <a3><a3a/><a3b/><a3c>foo</a3c><a3d/></a3>
</a>"
SWAPNODE = "<a>
  <a1><a1a/><a1b/><a1c/></a1>
  <a2><a2a/><a2b foo='bar' jim='jam'/><a2c/></a2>
  <a3><a3x/><a3b/><a3c>foo</a3c></a3>
</a>"
MISSINGATTRIB = "<a>
  <a1><a1a/><a1b/><a1c/></a1>
  <a2><a2a/><a2b jim='jam'/><a2c/></a2>
  <a3><a3a/><a3b/><a3c>foo</a3c></a3>
</a>"
EXTRAATTRIB1 = "<a>
  <a1><a1a/><a1b/><a1c/></a1>
  <a2><a2a/><a2b foo='bar' jim='jam' kits='meow'/><a2c/></a2>
  <a3><a3a/><a3b/><a3c>foo</a3c></a3>
</a>"
EXTRAATTRIB2 = "<a>
  <a1><a1a/><a1b/><a1c kits='meow'/></a1>
  <a2><a2a/><a2b foo='bar' jim='jam'/><a2c/></a2>
  <a3><a3a/><a3b/><a3c>foo</a3c></a3>
</a>"
SWAPATTRIB1 = "<a>
  <a1><a1a/><a1b/><a1c/></a1>
  <a2><a2a/><a2b foo='bar' jim='zzz'/><a2c/></a2>
  <a3><a3a/><a3b/><a3c>foo</a3c></a3>
</a>"
SWAPATTRIB2 = "<a>
  <a1><a1a/><a1b/><a1c/></a1>
  <a2><a2a/><a2b foo='bar' zzz='jam'/><a2c/></a2>
  <a3><a3a/><a3b/><a3c>foo</a3c></a3>
</a>"
NAMESPACE1 = "<a xmlns:x='foo'>
  <a1><a1a/><a1b/><a1c/></a1>
  <a2><a2a/><a2b foo='bar' jim='jam'/><a2c/></a2>
  <a3><x:a3a/><a3b/><a3c>foo</a3c></a3>
</a>"
NAMESPACE1B = "<a xmlns:z='foo'>
  <a1><a1a/><a1b/><a1c/></a1>
  <a2><a2a/><a2b foo='bar' jim='jam'/><a2c/></a2>
  <a3><z:a3a/><a3b/><a3c>foo</a3c></a3>
</a>"
NAMESPACE1C = "<a xmlns:x='bar'>
  <a1><a1a/><a1b/><a1c/></a1>
  <a2><a2a/><a2b foo='bar' jim='jam'/><a2c/></a2>
  <a3><x:a3a/><a3b/><a3c>foo</a3c></a3>
</a>"
NAMESPACE2 = "<a xmlns:x='foo'>
  <a1><a1a/><a1b/><a1c/></a1>
  <a2><a2a/><a2b foo='bar' x:jim='jam'/><a2c/></a2>
  <a3><a3a/><a3b/><a3c>foo</a3c></a3>
</a>"
NAMESPACE2B= "<a xmlns:z='foo'>
  <a1><a1a/><a1b/><a1c/></a1>
  <a2><a2a/><a2b foo='bar' z:jim='jam'/><a2c/></a2>
  <a3><a3a/><a3b/><a3c>foo</a3c></a3>
</a>"
NAMESPACE2C= "<a xmlns:x='bar'>
  <a1><a1a/><a1b/><a1c/></a1>
  <a2><a2a/><a2b foo='bar' x:jim='jam'/><a2c/></a2>
  <a3><a3a/><a3b/><a3c>foo</a3c></a3>
</a>"


require 'nokogiri'
require 'minitest/autorun'
class NodeEquivalence < MiniTest::Unit::TestCase
  def setup
    @o1 = Nokogiri::XML(ORIG1,&:noblanks).root
  end
  def test_equivalence
    o2 = Nokogiri::XML(ORIG2,&:noblanks).root
    assert @o1 =~ o2,"Equivalent nodes should be equivalent"
    assert o2 =~ @o1,"Equivalent nodes should be equivalent"
  end
  def test_textnodes
    no_text = Nokogiri::XML(NOTEXT,&:noblanks).root
    extra1  = Nokogiri::XML(EXTRATEXT1,&:noblanks).root
    extra2  = Nokogiri::XML(EXTRATEXT2,&:noblanks).root
    refute @o1 =~ no_text,"Notice missing text node child"
    refute no_text =~ @o1,"Notice missing text node child"
    refute @o1 =~ extra1,"Notice different text in text node"
    refute extra1 =~ @o1,"Notice different text in text node"
    refute @o1 =~ extra2,"Notice extra text node"
    refute extra2 =~ @o1,"Notice extra text node"
  end
  def test_nodes
    missing = Nokogiri::XML(MISSINGNODE,&:noblanks).root
    extra   = Nokogiri::XML(EXTRANODE,&:noblanks).root
    changed = Nokogiri::XML(SWAPNODE,&:noblanks).root
    refute @o1 =~ missing,"Notice missing node"
    refute missing =~ @o1,"Notice missing node"
    refute @o1 =~ extra,"Notice extra node"
    refute extra =~ @o1,"Notice extra node"
    refute @o1 =~ changed,"Notice renamed node"
    refute changed =~ @o1,"Notice renamed node"
  end
  def test_attributes
    missing = Nokogiri::XML(MISSINGATTRIB,&:noblanks).root
    extra1  = Nokogiri::XML(EXTRAATTRIB1,&:noblanks).root
    extra2  = Nokogiri::XML(EXTRAATTRIB2,&:noblanks).root
    swap1   = Nokogiri::XML(SWAPATTRIB1,&:noblanks).root
    swap2   = Nokogiri::XML(SWAPATTRIB2,"Notice missing attribute"
    refute missing =~ @o1,"Notice missing attribute"
    refute @o1 =~ extra1,"Notice extra attribute"
    refute extra1 =~ @o1,"Notice extra attribute"
    refute @o1 =~ extra2,"Notice new attribute"
    refute extra2 =~ @o1,"Notice new attribute"
    refute @o1 =~ swap1,"Notice changed attribute value"
    refute swap1 =~ @o1,"Notice changed attribute value"
    refute @o1 =~ swap2,"Notice changed attribute name"
    refute swap2 =~ @o1,"Notice changed attribute name"
  end
  def test_namespaces
    ns1  = Nokogiri::XML(NAMESPACE1,&:noblanks).root
    ns2  = Nokogiri::XML(NAMESPACE2,&:noblanks).root
    ns1b = Nokogiri::XML(NAMESPACE1B,&:noblanks).root
    ns2b = Nokogiri::XML(NAMESPACE2B,&:noblanks).root
    ns1c = Nokogiri::XML(NAMESPACE1C,&:noblanks).root
    ns2c = Nokogiri::XML(NAMESPACE2C,&:noblanks).root
    refute @o1 =~ ns1,"Notice added node namespace"
    refute ns1 =~ @o1,"Notice removed node namespace"
    refute @o1 =~ ns2,"Notice added attribute namespace"
    refute ns2 =~ @o1,"Notice removed attribute namespace"
    assert ns1 =~ ns1b,"Different namespace names on nodes don't matter"
    assert ns2 =~ ns2b,"Different namespace names on attributes don't matter"
    refute ns1 =~ ns1c,"Notice different namespace hrefs on nodes"
    refute ns2 =~ ns2c,"Notice different namespace hrefs on attributes"
  end
end

解决方法

这是我目前的实施.它现在不知道名称空间： 

class Nokogiri::XML::Node
  # Return true if this node is content-equivalent to other,false otherwise
  def =~(other)
    return true if self == other
    return false unless name == other.name
    stype = node_type; otype = other.node_type
    return false unless stype == otype
    sa = attributes; oa = other.attributes
    return false unless sa.length == oa.length
    sa = sa.sort.map{ |n,a| [n,a.value,a.namespace && a.namespace.href] }
    oa = oa.sort.map{ |n,a.namespace && a.namespace.href] }
    return false unless sa == oa
    skids = children; okids = other.children
    return false unless skids.length == okids.length
    return false if stype == TEXT_NODE && (content != other.content)
    sns = namespace; ons = other.namespace
    return false if !sns ^ !ons
    return false if sns && (sns.href != ons.href)
    skids.to_enum.with_index.all?{ |ski,i| ski =~ okids[i] }
  end
end

这是我的基准代码(使用上面测试用例中的常量)：

require 'benchmark'
Benchmark.bm(10) do |x|
  N = 1000
  NODES = [
    ORIG1,ORIG2,NOTEXT,EXTRATEXT1,EXTRATEXT2,MISSINGNODE,EXTRANODE,SWAPNODE,MISSINGATTRIB,EXTRAATTRIB1,EXTRAATTRIB2,SWAPATTRIB1,SWAPATTRIB2,NAMESPACE1,NAMESPACE2
  ].map{ |xml| Nokogiri::XML(xml,&:noblanks).root }
  MAIN = NODES.shift
  x.report("Phrogz"){ N.times{
    NODES.each{ |other| MAIN =~ other }
  }}
end

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