Class: Polipus::Page

Inherits:
Object
  • Object
show all
Defined in:
lib/polipus/page.rb

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(url, params = {}) ⇒ Page

Create a new page



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# File 'lib/polipus/page.rb', line 43

def initialize(url, params = {})
  @url = url.kind_of?(URI) ? url : URI(url)
  @code = params[:code]
  @headers = params[:headers] || {}
  @headers['content-type'] ||= ['']
  @aliases = Array(params[:aka]).compact
  @referer = params[:referer]
  @depth = params[:depth] || 0
  @redirect_to = to_absolute(params[:redirect_to])
  @response_time = params[:response_time]
  @body = params[:body]
  @error = params[:error]
  @fetched = !params[:code].nil?
  @user_data = OpenStruct.new
  @domain_aliases = params[:domain_aliases] ||= []
  @storable = true
  @fetched_at = params[:fetched_at]
end

Instance Attribute Details

#aliases ⇒ Object

Returns the value of attribute aliases.



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# File 'lib/polipus/page.rb', line 30

def aliases
  @aliases
end

#body ⇒ Object (readonly)

The raw HTTP response body of the page



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# File 'lib/polipus/page.rb', line 11

def body
  @body
end

#code ⇒ Object

Integer response code of the page



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# File 'lib/polipus/page.rb', line 19

def code
  @code
end

#depth ⇒ Object

Depth of this page from the root of the crawl. This is not necessarily the shortest path; use PageStore#shortest_paths! to find that value.



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# File 'lib/polipus/page.rb', line 22

def depth
  @depth
end

#domain_aliases ⇒ Object

Returns the value of attribute domain_aliases.



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# File 'lib/polipus/page.rb', line 32

def domain_aliases
  @domain_aliases
end

#error ⇒ Object (readonly)

Exception object, if one was raised during HTTP#fetch_page



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# File 'lib/polipus/page.rb', line 17

def error
  @error
end

#fetched_at ⇒ Object

Returns the value of attribute fetched_at.



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# File 'lib/polipus/page.rb', line 38

def fetched_at
  @fetched_at
end

#headers ⇒ Object (readonly)

Headers of the HTTP response



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# File 'lib/polipus/page.rb', line 13

def headers
  @headers
end

#redirect_to ⇒ Object (readonly)

URL of the page this one redirected to, if any



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# File 'lib/polipus/page.rb', line 15

def redirect_to
  @redirect_to
end

#referer ⇒ Object

URL of the page that brought us to this page



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# File 'lib/polipus/page.rb', line 24

def referer
  @referer
end

#response_time ⇒ Object

Response time of the request for this page in milliseconds



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# File 'lib/polipus/page.rb', line 26

def response_time
  @response_time
end

#storable ⇒ Object

Whether the current page should be stored Default: true



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# File 'lib/polipus/page.rb', line 36

def storable
  @storable
end

#url ⇒ Object (readonly)

The URL of the page



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# File 'lib/polipus/page.rb', line 9

def url
  @url
end

#user_data ⇒ Object

OpenStruct it holds users defined data



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# File 'lib/polipus/page.rb', line 28

def user_data
  @user_data
end

Class Method Details

.from_hash(hash) ⇒ Object 



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# File 'lib/polipus/page.rb', line 220

def self.from_hash(hash)
  page = self.new(URI(hash['url']))
  {
    '@headers'       => hash['headers'] ? Marshal.load(hash['headers']) : {'content-type' => ['']},
    '@body'          => hash['body'],
    '@links'         => hash['links'] ? hash['links'].map { |link| URI(link) } : [],
    '@code'          => hash['code'].to_i,
    '@depth'         => hash['depth'].to_i,
    '@referer'       => hash['referer'],
    '@redirect_to'   => (!!hash['redirect_to'] && !hash['redirect_to'].empty?) ? URI(hash['redirect_to']) : nil,
    '@response_time' => hash['response_time'].to_i,
    '@fetched'       => hash['fetched'],
    '@user_data'     => hash['user_data'] ? OpenStruct.new(hash['user_data']) : nil,
    '@fetched_at'    => hash['fetched_at']
  }.each do |var, value|
    page.instance_variable_set(var, value)
  end
  page
end

.from_json(json) ⇒ Object 



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# File 'lib/polipus/page.rb', line 240

def self.from_json(json)
  hash = JSON.parse json
  self.from_hash hash
end

Instance Method Details

#base ⇒ Object

Base URI from the HTML doc head element www.w3.org/TR/html4/struct/links.html#edef-BASE



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# File 'lib/polipus/page.rb', line 145

def base
  @base = if doc
    href = doc.search('//head/base/@href')
    URI(href.to_s) unless href.nil? rescue nil
  end unless @base
  
  return nil if @base && @base.to_s().empty?
  @base
end

#content_type ⇒ Object

The content-type returned by the HTTP request for this page



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# File 'lib/polipus/page.rb', line 113

def content_type
  headers['content-type'].first
end

#discard_doc! ⇒ Object

Delete the Nokogiri document and response body to conserve memory



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# File 'lib/polipus/page.rb', line 97

def discard_doc!
  links # force parsing of page links before we trash the document
  @doc = @body = nil
end

#discard_links! ⇒ Object

Discard links, a next call of page.links will return an empty array



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# File 'lib/polipus/page.rb', line 90

def discard_links!
  @links = []
end

#doc ⇒ Object

Nokogiri document for the HTML body



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# File 'lib/polipus/page.rb', line 82

def doc
  return @doc if @doc
  @doc = Nokogiri::HTML(@body) if @body && html? rescue nil
end

#expired?(ttl) ⇒ Boolean 



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# File 'lib/polipus/page.rb', line 215

def expired? ttl
  return false if fetched_at.nil?
  (Time.now.to_i - ttl) > fetched_at
end

#fetched? ⇒ Boolean

Was the page successfully fetched? true if the page was fetched with no error, false otherwise.



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# File 'lib/polipus/page.rb', line 106

def fetched?
  @fetched
end

#html? ⇒ Boolean

Returns true if the page is a HTML document, returns false otherwise.



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# File 'lib/polipus/page.rb', line 121

def html?
  !!(content_type =~ %r{^(text/html|application/xhtml+xml)\b})
end

#in_domain?(uri) ⇒ Boolean

Returns true if uri is in the same domain as the page, returns false otherwise



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# File 'lib/polipus/page.rb', line 177

def in_domain?(uri)
  @domain_aliases ||= []
  uri.host == @url.host || @domain_aliases.include?(uri.host)
end

#links ⇒ Object

Array of distinct A tag HREFs from the page



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# File 'lib/polipus/page.rb', line 65

def links
  return @links.to_a unless @links.nil?
  @links = Set.new
  return [] if !doc
  
  doc.search("//a[@href]").each do |a|
    u = a['href']
    next if u.nil? or u.empty?
    abs = to_absolute(u) rescue next
    @links << abs if in_domain?(abs)
  end
  @links.to_a
end

#not_found? ⇒ Boolean

Returns true if the page was not found (returned 404 code), returns false otherwise.



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# File 'lib/polipus/page.rb', line 137

def not_found?
  404 == @code
end

#redirect? ⇒ Boolean

Returns true if the page is a HTTP redirect, returns false otherwise.



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# File 'lib/polipus/page.rb', line 129

def redirect?
  (300..307).include?(@code)
end

#storable? ⇒ Boolean

Returns true if page is marked as storeable false otherwise Default is true



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# File 'lib/polipus/page.rb', line 211

def storable?
  @storable
end

#to_absolute(link) ⇒ Object

Converts relative URL link into an absolute URL based on the location of the page



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# File 'lib/polipus/page.rb', line 159

def to_absolute(link)
  return nil if link.nil?

  # remove anchor
  link = URI.encode(URI.decode(link.to_s.gsub(/#[a-zA-Z0-9_-]*$/,'')))

  relative = URI(link)
  absolute = base ? base.merge(relative) : @url.merge(relative)

  absolute.path = '/' if absolute.path.empty?

  return absolute
end

#to_hash ⇒ Object 



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# File 'lib/polipus/page.rb', line 182

def to_hash
  {
   'url'           => @url.to_s,
   'headers'       => Marshal.dump(@headers),
   'body'          => @body,
   'links'         => links.map(&:to_s), 
   'code'          => @code,
   'depth'         => @depth,
   'referer'       => @referer.to_s,
   'redirect_to'   => @redirect_to.to_s,
   'response_time' => @response_time,
   'fetched'       => @fetched,
   'user_data'     => @user_data.nil? ? {} : @user_data.marshal_dump,
   'fetched_at'    => @fetched_at
 }
end

#to_json ⇒ Object 



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# File 'lib/polipus/page.rb', line 199

def to_json
  th = to_hash.dup
  th.each {|k,v| th.delete(k) if v.nil? || (v.respond_to?(:empty?) && v.empty?)}
  th.delete('headers') if content_type.empty?
  th.to_json
end