Class: PDF::Reader::ObjectHash

Inherits:

Object

• Object
• PDF::Reader::ObjectHash

show all

Includes:

Enumerable

Defined in:

lib/pdf/reader/object_hash.rb

Overview

h = PDF::Reader::ObjectHash.new("somefile.pdf")
h[1]
=> 3469

h[PDF::Reader::Reference.new(1,0)]
=> 3469

Instance Attribute Summary (collapse)

• - (Object) default

  Returns the value of attribute default.

• - (Object) pdf_version readonly

  Returns the value of attribute pdf_version.

• - (Object) trailer readonly

  Returns the value of attribute trailer.

Instance Method Summary (collapse)

• - (Object) [](key)

  Access an object from the PDF.

• - (Object) deref!(key)

  Recursively dereferences the object refered to be key.

• - (Object) each(&block) (also: #each_pair)

  iterate over each key, value.

• - (Object) each_key(&block)

  iterate over each key.

• - (Object) each_value(&block)

  iterate over each value.

• - (Boolean) empty?

  return true if there are no objects in this file.

• - (Boolean) encrypted?
• - (Object) fetch(key, local_default = nil)

  Access an object from the PDF.

• - (Boolean) has_key?(check_key) (also: #include?, #key?, #member?, #value?)

  return true if the specified key exists in the file.

• - (Boolean) has_value?(value)

  return true if the specifiedvalue exists in the file.

• - (ObjectHash) initialize(input, opts = {}) constructor

  Creates a new ObjectHash object.

• - (Object) keys

  return an array of all keys in the file.

• - (Object) obj_type(ref)

  returns the type of object a ref points to.

• - (Object) object(key) (also: #deref)

  If key is a PDF::Reader::Reference object, lookup the corresponding object in the PDF and return it.

• - (Object) page_references

  returns an array of PDF::Reader::References.

• - (Object) size (also: #length)

  return the number of objects in the file.

• - (Boolean) stream?(ref)

  returns true if the supplied references points to an object with a stream.

• - (Object) to_a

  return an array of arrays.

• - (Object) to_s
• - (Object) values

  return an array of all values in the file.

• - (Object) values_at(*ids)

  return an array of all values from the specified keys.

:password - the user password to decrypt the source PDF

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# File 'lib/pdf/reader/object_hash.rb', line 41

def initialize(input, opts = {})
  @io          = extract_io_from(input)
  @pdf_version = read_version
  @xref        = PDF::Reader::XRef.new(@io)
  @trailer     = @xref.trailer
  @cache       = PDF::Reader::ObjectCache.new
  @sec_handler = build_security_handler(opts)
end

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# File 'lib/pdf/reader/object_hash.rb', line 31

def default
  @default
end

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# File 'lib/pdf/reader/object_hash.rb', line 32

def pdf_version
  @pdf_version
end

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# File 'lib/pdf/reader/object_hash.rb', line 32

def trailer
  @trailer
end

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# File 'lib/pdf/reader/object_hash.rb', line 71

def [](key)
  return default if key.to_i <= 0

  unless key.is_a?(PDF::Reader::Reference)
    key = PDF::Reader::Reference.new(key.to_i, 0)
  end

  if @cache.has_key?(key)
    @cache[key]
  elsif xref[key].is_a?(Fixnum)
    buf = new_buffer(xref[key])
    @cache[key] = decrypt(key, Parser.new(buf, self).object(key.id, key.gen))
  elsif xref[key].is_a?(PDF::Reader::Reference)
    container_key = xref[key]
    object_streams[container_key] ||= PDF::Reader::ObjectStream.new(object(container_key))
    @cache[key] = object_streams[container_key][key.id]
  end
rescue InvalidObjectError
  return default
end

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# File 'lib/pdf/reader/object_hash.rb', line 103

def deref!(key)
  case object = deref(key)

    when Hash
      object.each do |key, value|
        object[key] = deref! value
      end

    when PDF::Reader::Stream
      deref! object.hash

    when Array
      object.each_with_index do |value, index|
        object[index] = deref! value
      end

  end

  object
end

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# File 'lib/pdf/reader/object_hash.rb', line 149

def each(&block)
  @xref.each do |ref|
    yield ref, self[ref]
  end
end

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# File 'lib/pdf/reader/object_hash.rb', line 158

def each_key(&block)
  each do |id, obj|
    yield id
  end
end

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# File 'lib/pdf/reader/object_hash.rb', line 166

def each_value(&block)
  each do |id, obj|
    yield obj
  end
end

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# File 'lib/pdf/reader/object_hash.rb', line 181

def empty?
  size == 0 ? true : false
end

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# File 'lib/pdf/reader/object_hash.rb', line 261

def encrypted?
  trailer.has_key?(:Encrypt)
end

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# File 'lib/pdf/reader/object_hash.rb', line 136

def fetch(key, local_default = nil)
  obj = self[key]
  if obj
    return obj
  elsif local_default
    return local_default
  else
    raise IndexError, "#{key} is invalid" if key.to_i <= 0
  end
end

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# File 'lib/pdf/reader/object_hash.rb', line 188

def has_key?(check_key)
  # TODO update from O(n) to O(1)
  each_key do |key|
    if check_key.kind_of?(PDF::Reader::Reference)
      return true if check_key == key
    else
      return true if check_key.to_i == key.id
    end
  end
  return false
end

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# File 'lib/pdf/reader/object_hash.rb', line 205

def has_value?(value)
  # TODO update from O(n) to O(1)
  each_value do |obj|
    return true if obj == value
  end
  return false
end

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# File 'lib/pdf/reader/object_hash.rb', line 220

def keys
  ret = []
  each_key { |k| ret << k }
  ret
end

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# File 'lib/pdf/reader/object_hash.rb', line 51

def obj_type(ref)
  self[ref].class.to_s.to_sym
rescue
  nil
end

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# File 'lib/pdf/reader/object_hash.rb', line 95

def object(key)
  key.is_a?(PDF::Reader::Reference) ? self[key] : key
end

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# File 'lib/pdf/reader/object_hash.rb', line 256

def page_references
  root  = fetch(trailer[:Root])
  @page_references ||= get_page_objects(root[:Pages]).flatten
end

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# File 'lib/pdf/reader/object_hash.rb', line 174

def size
  xref.size
end

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# File 'lib/pdf/reader/object_hash.rb', line 58

def stream?(ref)
  self.has_key?(ref) && self[ref].is_a?(PDF::Reader::Stream)
end

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# File 'lib/pdf/reader/object_hash.rb', line 242

def to_a
  ret = []
  each do |id, obj|
    ret << [id, obj]
  end
  ret
end

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# File 'lib/pdf/reader/object_hash.rb', line 214

def to_s
  "<PDF::Reader::ObjectHash size: #{self.size}>"
end

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# File 'lib/pdf/reader/object_hash.rb', line 228

def values
  ret = []
  each_value { |v| ret << v }
  ret
end

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# File 'lib/pdf/reader/object_hash.rb', line 236

def values_at(*ids)
  ids.map { |id| self[id] }
end