111 lines
3.3 KiB
Python
111 lines
3.3 KiB
Python
# -*- coding: utf-8 -*-
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from .polyglotpdfzip import PolyglotPdfZip
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import logging
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import tempfile
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from ZipFileTransformer import ZipFile
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from ZipFileTransformer import Zip
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from PdfFileTransformer import Pdf
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'''
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|-----------------------------------| -
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|--------- ZIP Data[0] = -----------| |
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|- PDF Header + PDF Obj[0] Header --| |
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|-----------------------------------| | K2
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|------- PDF Obj[0] stream = ------| |
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|--------- ZIP Data LF [1:] --------| |
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|-----------------------------------| -
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|------ Original PDF Ojbects -------| |
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|-----------------------------------| |
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|------------ Xref Table -----------| |
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|-----------------------------------| | J2
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|------------- Trailer -------------| |
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|-----------------------------------| -
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|---------- End Zip Data -----------|
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|-----------------------------------|
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'''
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class PolyglotSZipPdf(PolyglotPdfZip):
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def __init__(self, Pdf, Zip):
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super().__init__(Pdf, Zip)
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def get_rebuild_zip_first_part_size(self):
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zo_path = tempfile.mkstemp()[1]
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logging.info("use tmp file zip: " + zo_path)
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zo = ZipFile(zo_path, 'a')
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zi = ZipFile(self.zip.filename, 'r')
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for zipinfo in zi.infolist():
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zo.writestr(zipinfo, zi.read(zipinfo))
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zi.close()
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zo.close()
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rebuild_zip = Zip(zo_path)
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p = rebuild_zip.end_of_data
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k2_stream = rebuild_zip.buffer[:p]
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size_k2_stream = len(k2_stream)
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return size_k2_stream
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def get_pdf_header(self):
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return self.pdf.get_file_header()
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def generate_zip_with_pdf_part(self, filename, pdf_data):
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zo = ZipFile(filename, 'a')
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zi = ZipFile(self.zip.filename, 'r')
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zo.writestr(' ', pdf_data, 0)
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for zipinfo in zi.infolist():
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zo.writestr(zipinfo, zi.read(zipinfo))
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zi.close()
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zo.close()
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def get_rebuild_pdf(self, zo_path, offset):
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'''
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Generate polyglot with final zip.
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'''
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new_zip = Zip(zo_path)
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new_pdf = Pdf(self.pdf.filename)
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p1 = new_zip.end_of_first_local_file_header
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p2 = new_zip.end_of_data
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k2_stream = new_zip.buffer[p1:p2]
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size_k2_stream = len(k2_stream)
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new_pdf.insert_new_obj_stream_at_start(k2_stream)
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k2_stream_offset = new_pdf.get_first_stream_offset()
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new_pdf.file_offset = offset
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pdf_buffer = new_pdf.get_build_buffer()
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j2 = pdf_buffer[k2_stream_offset + size_k2_stream:]
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new_zip.add_data_to_file(b'', j2, True)
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return new_zip.buffer
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def get_pdf_offset(self, zipfile):
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f = open(zipfile, "rb")
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data = f.read()
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return data.find(b"%PDF")
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def generate(self):
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zip_stream_size = self.get_rebuild_zip_first_part_size()
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pdf_header = self.get_pdf_header()
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pdf_header = (pdf_header +
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b'1 0 obj\n<<\n/Filter /FlateDecode\n/Length ' +
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str(zip_stream_size).encode("utf-8") +
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b'\n>>\nstream\n')
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filename = tempfile.mkstemp()[1]
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logging.info("use tmp file for new zip: " + filename)
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self.generate_zip_with_pdf_part(filename, pdf_header)
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pdf_offset = self.get_pdf_offset(filename)
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self.buffer = self.get_rebuild_pdf(filename, pdf_offset)
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