Class: Origami::Parser

Inherits:
Object
  • Object
show all
Defined in:
lib/origami/parser.rb

Overview

:nodoc:

Defined Under Namespace

Classes: ParsingError

Constant Summary collapse

VERBOSE_QUIET =

Do not output debug information.

0
VERBOSE_INFO =

Output some useful information.

1
VERBOSE_DEBUG =

Output debug information.

2
VERBOSE_TRACE =

Output every objects read

3

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options = {}) ⇒ Parser

:nodoc:



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# File 'lib/origami/parser.rb', line 51

def initialize(options = {}) # :nodoc:
  # Type information for indirect objects.
  @deferred_casts = {}

  # Default options values
  @options =
    {
      verbosity: VERBOSE_INFO, # Verbose level.
      ignore_errors: true,     # Try to keep on parsing when errors occur.
      callback: proc {},   # Callback procedure whenever a structure is read.
      logger: $stderr,          # Where to output parser messages.
      colorize_log: true       # Colorize parser output?
    }

  @options.update(options)
  @logger = @options[:logger]
  @data = nil
end

Instance Attribute Details

#options ⇒ Object

Returns the value of attribute options.



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# File 'lib/origami/parser.rb', line 49

def options
  @options
end

Class Method Details

.init_scanner(stream) ⇒ Object 



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# File 'lib/origami/parser.rb', line 205

def self.init_scanner(stream)
  if stream.is_a?(StringScanner)
    stream
  elsif stream.respond_to?(:to_str)
    StringScanner.new(stream.to_str)
  else
    raise TypeError, "Cannot initialize scanner from #{stream.class}"
  end
end

Instance Method Details

#debug(msg = "") ⇒ Object

:nodoc:



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# File 'lib/origami/parser.rb', line 197

def debug(msg = "") # :nodoc:
  log(VERBOSE_DEBUG, 'debug', :magenta, msg)
end

#defer_type_cast(reference, type) ⇒ Object

:nodoc:



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# File 'lib/origami/parser.rb', line 169

def defer_type_cast(reference, type) # :nodoc:
  @deferred_casts[reference] = type
end

#error(msg = "") ⇒ Object

:nodoc:



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# File 'lib/origami/parser.rb', line 185

def error(msg = "") # :nodoc:
  log(VERBOSE_QUIET, 'error', :red, msg)
end

#info(msg = "") ⇒ Object

:nodoc:



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# File 'lib/origami/parser.rb', line 193

def info(msg = "") # :nodoc:
  log(VERBOSE_INFO, 'info ', :green, msg)
end

#parse(stream) ⇒ Object 



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# File 'lib/origami/parser.rb', line 82

def parse(stream)
  data =
    if stream.respond_to? :read
      StringScanner.new(stream.read.force_encoding('binary'))
    elsif stream.is_a? ::String
      @filename = stream
      StringScanner.new(File.binread(@filename))
    elsif stream.is_a? StringScanner
      stream
    else
      raise TypeError
    end

  @data = data
  @data.pos = 0
end

#parse_object(pos = @data.pos) ⇒ Object

:nodoc:



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# File 'lib/origami/parser.rb', line 99

def parse_object(pos = @data.pos) # :nodoc:
  @data.pos = pos

  begin
    obj = Object.parse(@data, self)
    return if obj.nil?

    obj = try_object_promotion(obj)
    trace "Read #{obj.type} object, #{obj.reference}"

    @options[:callback].call(obj)
    obj
  rescue UnterminatedObjectError
    error $!.message
    obj = $!.obj

    Object.skip_until_next_obj(@data)
    @options[:callback].call(obj)
    obj
  rescue
    error "Breaking on: #{(@data.peek(10) + "...").inspect} at offset 0x#{@data.pos.to_s(16)}"
    error "Last exception: [#{$!.class}] #{$!.message}"
    if !@options[:ignore_errors]
      error "Manually fix the file or set :ignore_errors parameter."
      raise
    end

    debug 'Skipping this indirect object.'
    raise if !Object.skip_until_next_obj(@data)

    retry
  end
end

#parse_trailer(pos = @data.pos) ⇒ Object

:nodoc:



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# File 'lib/origami/parser.rb', line 152

def parse_trailer(pos = @data.pos) # :nodoc:
  @data.pos = pos

  begin
    info "...Parsing trailer..."
    trailer = Trailer.parse(@data, self)

    @options[:callback].call(trailer)
    trailer
  rescue
    debug "Exception caught while parsing trailer : " + $!.message
    warn "Unable to parse trailer!"

    raise
  end
end

#parse_xreftable(pos = @data.pos) ⇒ Object

:nodoc:



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# File 'lib/origami/parser.rb', line 133

def parse_xreftable(pos = @data.pos) # :nodoc:
  @data.pos = pos

  begin
    info "...Parsing xref table..."
    xreftable = XRef::Section.parse(@data)
    @options[:callback].call(xreftable)

    xreftable
  rescue
    debug "Exception caught while parsing xref table : " + $!.message
    warn "Unable to parse xref table! Xrefs might be stored into an XRef stream."

    @data.pos -= 'trailer'.length unless @data.skip_until(/trailer/).nil?

    nil
  end
end

#pos ⇒ Object 



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# File 'lib/origami/parser.rb', line 70

def pos
  raise "Cannot get position, parser has no loaded data." if @data.nil?

  @data.pos
end

#pos=(offset) ⇒ Object 



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# File 'lib/origami/parser.rb', line 76

def pos=(offset)
  raise "Cannot set position, parser has no loaded data." if @data.nil?

  @data.pos = offset
end

#target_data ⇒ Object 



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# File 'lib/origami/parser.rb', line 181

def target_data
  @data.string.dup if @data
end

#target_filename ⇒ Object 



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# File 'lib/origami/parser.rb', line 173

def target_filename
  @filename
end

#target_filesize ⇒ Object 



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# File 'lib/origami/parser.rb', line 177

def target_filesize
  @data&.string&.size
end

#trace(msg = "") ⇒ Object

:nodoc:



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# File 'lib/origami/parser.rb', line 201

def trace(msg = "") # :nodoc:
  log(VERBOSE_TRACE, 'trace', :cyan, msg)
end

#warn(msg = "") ⇒ Object

:nodoc:



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# File 'lib/origami/parser.rb', line 189

def warn(msg = "") # :nodoc:
  log(VERBOSE_INFO, 'warn ', :yellow, msg)
end