Class: Origami::PDF::LazyParser

Inherits:
Parser show all
Defined in:
lib/origami/parsers/pdf/lazy.rb

Overview

Create a new PDF lazy Parser.

Constant Summary

Constants inherited from Origami::Parser

Origami::Parser::VERBOSE_DEBUG, Origami::Parser::VERBOSE_INFO, Origami::Parser::VERBOSE_QUIET, Origami::Parser::VERBOSE_TRACE

Instance Attribute Summary

Attributes inherited from Origami::Parser

#options

Instance Method Summary collapse

Methods inherited from Parser

#initialize

Methods inherited from Origami::Parser

#debug, #defer_type_cast, #error, #info, init_scanner, #initialize, #parse_object, #parse_trailer, #parse_xreftable, #pos, #pos=, #target_data, #target_filename, #target_filesize, #trace, #warn

Constructor Details

This class inherits a constructor from Origami::PDF::Parser

Instance Method Details

#parse(stream) ⇒ Object 



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# File 'lib/origami/parsers/pdf/lazy.rb', line 29

def parse(stream)
  super

  pdf = parse_initialize
  revisions = []

  # Locate the last xref offset at the end of the file.
  xref_offset = locate_last_xref_offset

  while xref_offset && (xref_offset != 0)

    # Create a new revision based on the xref section offset.
    revision = parse_revision(pdf, xref_offset)

    # Locate the previous xref section.
    xref_offset = if revision.xrefstm? && revision.xrefstm[:Prev].is_a?(Integer)
      revision.xrefstm[:Prev].to_i
    elsif revision.trailer[:Prev].is_a?(Integer)
      revision.trailer[:Prev].to_i
    end

    # Prepend the revision.
    revisions.unshift(revision)
  end

  pdf.revisions.clear
  revisions.each do |rev|
    pdf.revisions.push(rev)
    pdf.insert(rev.xrefstm) if rev.xrefstm?
  end

  parse_finalize(pdf)

  pdf
end