#!/usr/bin/env python # A part of pdfrw (pdfrw.googlecode.com) # Copyright (C) 2006-2009 Patrick Maupin, Austin, Texas # MIT license -- See LICENSE.txt for details ''' The PdfWriter class writes an entire PDF file out to disk. The writing process is not at all optimized or organized. An instance of the PdfWriter class has two methods: addpage(page) and write(fname) addpage() assumes that the pages are part of a valid tree/forest of PDF objects. ''' try: set except NameError: from sets import Set as set from pdfobjects import PdfName, PdfArray, PdfDict, IndirectPdfDict, PdfObject, PdfString from pdfcompress import compress debug = False class FormatObjects(object): ''' FormatObjects performs the actual formatting and disk write. ''' def add(self, obj, visited): ''' Add an object to our list, if it's an indirect object. Just format it if not. ''' # Can't hash dicts, so just hash the object ID objid = id(obj) # Automatically set stream objects to indirect if isinstance(obj, PdfDict): indirect = obj.indirect or (obj.stream is not None) else: indirect = getattr(obj, 'indirect', False) if not indirect: assert objid not in visited, \ 'Circular reference encountered in non-indirect object %s' % repr(obj) visited.add(objid) result = self.format_obj(obj, visited) visited.remove(objid) return result objnum = self.indirect_dict.get(objid) # If we haven't seen the object yet, we need to # add it to the indirect object list. if objnum is None: objlist = self.objlist objnum = len(objlist) + 1 if debug: print ' Object', objnum, '\r', objlist.append(None) self.indirect_dict[objid] = objnum objlist[objnum-1] = self.format_obj(obj) return '%s 0 R' % objnum def format_array(myarray, formatter): # Format array data into semi-readable ASCII if sum([len(x) for x in myarray]) <= 70: return formatter % ' '.join(myarray) bigarray = [] count = 1000000 for x in myarray: lenx = len(x) if lenx + count > 70: subarray = [] bigarray.append(subarray) count = 0 count += lenx + 1 subarray.append(x) return formatter % '\n '.join([' '.join(x) for x in bigarray]) format_array = staticmethod(format_array) def format_obj(self, obj, visited=None): ''' format PDF object data into semi-readable ASCII. May mutually recurse with add() -- add() will return references for indirect objects, and add the indirect object to the list. ''' if visited is None: visited = set() if isinstance(obj, PdfArray): myarray = [self.add(x, visited) for x in obj] return self.format_array(myarray, '[%s]') elif isinstance(obj, PdfDict): if self.compress and obj.stream: compress([obj]) myarray = [] # Jython 2.2.1 has a bug which segfaults when # sorting subclassed strings, so we un-subclass them. dictkeys = [str(x) for x in obj.iterkeys()] dictkeys.sort() for key in dictkeys: myarray.append(key) myarray.append(self.add(obj[key], visited)) result = self.format_array(myarray, '<<%s>>') stream = obj.stream if stream is not None: result = '%s\nstream\n%s\nendstream' % (result, stream) return result elif isinstance(obj, basestring) and not hasattr(obj, 'indirect'): return PdfString.encode(obj) else: return str(obj) def dump(cls, f, trailer, version='1.3', compress=True): self = cls() self.compress = compress self.indirect_dict = {} self.objlist = [] # The first format of trailer gets all the information, # but we throw away the actual trailer formatting. self.format_obj(trailer) # Now we know the size, so we update the trailer dict # and get the formatted data. trailer.Size = PdfObject(len(self.objlist) + 1) trailer = self.format_obj(trailer) # Now we have all the pieces to write out to the file. # Keep careful track of the counts while we do it so # we can correctly build the cross-reference. header = '%%PDF-%s\n%%\xe2\xe3\xcf\xd3\n' % version f.write(header) offset = len(header) offsets = [(0, 65535, 'f')] for i, x in enumerate(self.objlist): objstr = '%s 0 obj\n%s\nendobj\n' % (i + 1, x) offsets.append((offset, 0, 'n')) offset += len(objstr) f.write(objstr) f.write('xref\n0 %s\n' % len(offsets)) for x in offsets: f.write('%010d %05d %s\r\n' % x) f.write('trailer\n\n%s\nstartxref\n%s\n%%%%EOF\n' % (trailer, offset)) dump = classmethod(dump) class PdfWriter(object): _trailer = None def __init__(self, version='1.3', compress=True): self.pagearray = PdfArray() self.compress = compress self.version = version def addpage(self, page): self._trailer = None assert page.Type == PdfName.Page inheritable = page.inheritable # searches for resources self.pagearray.append( IndirectPdfDict( page, Resources = inheritable.Resources, MediaBox = inheritable.MediaBox, CropBox = inheritable.CropBox, Rotate = inheritable.Rotate, ) ) return self addPage = addpage # for compatibility with pyPdf def addpages(self, pagelist): for page in pagelist: self.addpage(page) return self def _get_trailer(self): trailer = self._trailer if trailer is not None: return trailer # Create the basic object structure of the PDF file trailer = PdfDict( Root = IndirectPdfDict( Type = PdfName.Catalog, Pages = IndirectPdfDict( Type = PdfName.Pages, Count = PdfObject(len(self.pagearray)), Kids = self.pagearray ) ) ) # Make all the pages point back to the page dictionary pagedict = trailer.Root.Pages for page in pagedict.Kids: page.Parent = pagedict self._trailer = trailer return trailer def _set_trailer(self, trailer): self._trailer = trailer trailer = property(_get_trailer, _set_trailer) def write(self, fname, trailer=None): trailer = trailer or self.trailer # Dump the data. We either have a filename or a preexisting # file object. preexisting = hasattr(fname, 'write') f = preexisting and fname or open(fname, 'wb') FormatObjects.dump(f, trailer, self.version, self.compress) if not preexisting: f.close() if __name__ == '__main__': debug = True import pdfreader x = pdfreader.PdfReader('source.pdf') y = PdfWriter() for i, page in enumerate(x.pages): print ' Adding page', i+1, '\r', y.addpage(page) print y.write('result.pdf') print