Split pdfparser.py and pdfdocument.py.
Yusuke Shinyama
parent
1467fc674c
commit
2221163b94
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@ -0,0 +1,657 @@
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#!/usr/bin/env python2
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import sys
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import re
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import struct
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try:
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import hashlib as md5
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except ImportError:
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import md5
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from psparser import PSEOF
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from psparser import literal_name
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from psparser import LIT, KWD, STRICT
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from pdftypes import PDFException, PDFTypeError, PDFNotImplementedError
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from pdftypes import PDFObjectNotFound, PDFStream
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from pdftypes import resolve1, decipher_all
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from pdftypes import int_value, float_value, num_value
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from pdftypes import str_value, list_value, dict_value, stream_value
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from pdfparser import PDFSyntaxError
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from pdfparser import PDFStreamParser
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from arcfour import Arcfour
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from utils import choplist, nunpack
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from utils import decode_text, ObjIdRange
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## Exceptions
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##
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class PDFNoValidXRef(PDFSyntaxError): pass
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class PDFNoOutlines(PDFException): pass
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class PDFDestinationNotFound(PDFException): pass
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class PDFEncryptionError(PDFException): pass
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class PDFPasswordIncorrect(PDFEncryptionError): pass
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# some predefined literals and keywords.
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LITERAL_OBJSTM = LIT('ObjStm')
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LITERAL_XREF = LIT('XRef')
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LITERAL_PAGE = LIT('Page')
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LITERAL_PAGES = LIT('Pages')
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LITERAL_CATALOG = LIT('Catalog')
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## XRefs
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##
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class PDFBaseXRef(object):
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def get_trailer(self):
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raise NotImplementedError
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def get_objids(self):
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return []
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def get_pos(self, objid):
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raise KeyError(objid)
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## PDFXRef
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##
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class PDFXRef(PDFBaseXRef):
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def __init__(self):
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self.offsets = {}
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self.trailer = {}
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return
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def __repr__(self):
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return '<PDFXRef: offsets=%r>' % (self.offsets.keys())
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def load(self, parser, debug=0):
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while 1:
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try:
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(pos, line) = parser.nextline()
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if not line.strip(): continue
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except PSEOF:
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raise PDFNoValidXRef('Unexpected EOF - file corrupted?')
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if not line:
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raise PDFNoValidXRef('Premature eof: %r' % parser)
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if line.startswith('trailer'):
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parser.seek(pos)
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break
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f = line.strip().split(' ')
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if len(f) != 2:
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raise PDFNoValidXRef('Trailer not found: %r: line=%r' % (parser, line))
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try:
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(start, nobjs) = map(long, f)
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except ValueError:
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raise PDFNoValidXRef('Invalid line: %r: line=%r' % (parser, line))
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for objid in xrange(start, start+nobjs):
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try:
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(_, line) = parser.nextline()
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except PSEOF:
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raise PDFNoValidXRef('Unexpected EOF - file corrupted?')
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f = line.strip().split(' ')
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if len(f) != 3:
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raise PDFNoValidXRef('Invalid XRef format: %r, line=%r' % (parser, line))
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(pos, genno, use) = f
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if use != 'n': continue
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self.offsets[objid] = (int(genno), long(pos))
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if 1 <= debug:
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print >>sys.stderr, 'xref objects:', self.offsets
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self.load_trailer(parser)
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return
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KEYWORD_TRAILER = KWD('trailer')
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def load_trailer(self, parser):
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try:
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(_,kwd) = parser.nexttoken()
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assert kwd is self.KEYWORD_TRAILER
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(_,dic) = parser.nextobject()
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except PSEOF:
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x = parser.pop(1)
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if not x:
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raise PDFNoValidXRef('Unexpected EOF - file corrupted')
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(_,dic) = x[0]
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self.trailer.update(dict_value(dic))
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return
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PDFOBJ_CUE = re.compile(r'^(\d+)\s+(\d+)\s+obj\b')
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def load_fallback(self, parser, debug=0):
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parser.seek(0)
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while 1:
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try:
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(pos, line) = parser.nextline()
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except PSEOF:
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break
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if line.startswith('trailer'):
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parser.seek(pos)
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self.load_trailer(parser)
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if 1 <= debug:
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print >>sys.stderr, 'trailer: %r' % self.get_trailer()
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break
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m = self.PDFOBJ_CUE.match(line)
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if not m: continue
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(objid, genno) = m.groups()
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self.offsets[int(objid)] = (0, pos)
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return
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def get_trailer(self):
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return self.trailer
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def get_objids(self):
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return self.offsets.iterkeys()
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def get_pos(self, objid):
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try:
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(genno, pos) = self.offsets[objid]
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except KeyError:
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raise
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return (None, pos)
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## PDFXRefStream
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##
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class PDFXRefStream(PDFBaseXRef):
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def __init__(self):
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self.data = None
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self.entlen = None
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self.fl1 = self.fl2 = self.fl3 = None
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self.objid_ranges = []
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return
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def __repr__(self):
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return '<PDFXRefStream: fields=%d,%d,%d>' % (self.fl1, self.fl2, self.fl3)
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def load(self, parser, debug=0):
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(_,objid) = parser.nexttoken() # ignored
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(_,genno) = parser.nexttoken() # ignored
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(_,kwd) = parser.nexttoken()
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(_,stream) = parser.nextobject()
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if not isinstance(stream, PDFStream) or stream['Type'] is not LITERAL_XREF:
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raise PDFNoValidXRef('Invalid PDF stream spec.')
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size = stream['Size']
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index_array = stream.get('Index', (0,size))
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if len(index_array) % 2 != 0:
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raise PDFSyntaxError('Invalid index number')
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self.objid_ranges.extend( ObjIdRange(start, nobjs)
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for (start,nobjs) in choplist(2, index_array) )
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(self.fl1, self.fl2, self.fl3) = stream['W']
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self.data = stream.get_data()
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self.entlen = self.fl1+self.fl2+self.fl3
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self.trailer = stream.attrs
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if 1 <= debug:
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print >>sys.stderr, ('xref stream: objid=%s, fields=%d,%d,%d' %
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(', '.join(map(repr, self.objid_ranges)),
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self.fl1, self.fl2, self.fl3))
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return
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def get_trailer(self):
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return self.trailer
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def get_objids(self):
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for objid_range in self.objid_ranges:
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for x in xrange(objid_range.get_start_id(), objid_range.get_end_id()+1):
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yield x
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return
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def get_pos(self, objid):
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offset = 0
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found = False
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for objid_range in self.objid_ranges:
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if objid >= objid_range.get_start_id() and objid <= objid_range.get_end_id():
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offset += objid - objid_range.get_start_id()
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found = True
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break
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else:
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offset += objid_range.get_nobjs()
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if not found: raise KeyError(objid)
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i = self.entlen * offset
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ent = self.data[i:i+self.entlen]
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f1 = nunpack(ent[:self.fl1], 1)
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if f1 == 1:
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pos = nunpack(ent[self.fl1:self.fl1+self.fl2])
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genno = nunpack(ent[self.fl1+self.fl2:])
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return (None, pos)
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elif f1 == 2:
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objid = nunpack(ent[self.fl1:self.fl1+self.fl2])
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index = nunpack(ent[self.fl1+self.fl2:])
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return (objid, index)
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# this is a free object
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raise KeyError(objid)
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## PDFPage
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##
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class PDFPage(object):
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"""An object that holds the information about a page.
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A PDFPage object is merely a convenience class that has a set
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of keys and values, which describe the properties of a page
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and point to its contents.
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Attributes:
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doc: a PDFDocument object.
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pageid: any Python object that can uniquely identify the page.
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attrs: a dictionary of page attributes.
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contents: a list of PDFStream objects that represents the page content.
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lastmod: the last modified time of the page.
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resources: a list of resources used by the page.
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mediabox: the physical size of the page.
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cropbox: the crop rectangle of the page.
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rotate: the page rotation (in degree).
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annots: the page annotations.
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beads: a chain that represents natural reading order.
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"""
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def __init__(self, doc, pageid, attrs):
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"""Initialize a page object.
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doc: a PDFDocument object.
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pageid: any Python object that can uniquely identify the page.
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attrs: a dictionary of page attributes.
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"""
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self.doc = doc
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self.pageid = pageid
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self.attrs = dict_value(attrs)
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self.lastmod = resolve1(self.attrs.get('LastModified'))
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self.resources = resolve1(self.attrs['Resources'])
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self.mediabox = resolve1(self.attrs['MediaBox'])
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if 'CropBox' in self.attrs:
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self.cropbox = resolve1(self.attrs['CropBox'])
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else:
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self.cropbox = self.mediabox
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self.rotate = (self.attrs.get('Rotate', 0)+360) % 360
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self.annots = self.attrs.get('Annots')
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self.beads = self.attrs.get('B')
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if 'Contents' in self.attrs:
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contents = resolve1(self.attrs['Contents'])
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else:
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contents = []
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if not isinstance(contents, list):
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contents = [ contents ]
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self.contents = contents
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return
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def __repr__(self):
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return '<PDFPage: Resources=%r, MediaBox=%r>' % (self.resources, self.mediabox)
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## PDFDocument
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##
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class PDFDocument(object):
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"""PDFDocument object represents a PDF document.
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Since a PDF file can be very big, normally it is not loaded at
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once. So PDF document has to cooperate with a PDF parser in order to
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dynamically import the data as processing goes.
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Typical usage:
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doc = PDFDocument()
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doc.set_parser(parser)
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doc.initialize(password)
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obj = doc.getobj(objid)
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"""
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debug = 0
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def __init__(self, caching=True):
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self.caching = caching
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self.xrefs = []
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self.info = []
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self.catalog = None
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self.encryption = None
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self.decipher = None
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self._parser = None
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self._cached_objs = {}
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self._parsed_objs = {}
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return
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def set_parser(self, parser, fallback=True):
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"Set the document to use a given PDFParser object."
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if self._parser: return
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self._parser = parser
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# Retrieve the information of each header that was appended
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# (maybe multiple times) at the end of the document.
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try:
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self.xrefs = self.read_xref(parser)
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except PDFNoValidXRef:
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fallback = True
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if fallback:
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self.xrefs.extend(self.read_xref(parser, fallback=True))
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for xref in self.xrefs:
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trailer = xref.get_trailer()
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if not trailer: continue
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# If there's an encryption info, remember it.
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if 'Encrypt' in trailer:
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#assert not self.encryption
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self.encryption = (list_value(trailer['ID']),
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dict_value(trailer['Encrypt']))
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if 'Info' in trailer:
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self.info.append(dict_value(trailer['Info']))
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if 'Root' in trailer:
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# Every PDF file must have exactly one /Root dictionary.
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self.catalog = dict_value(trailer['Root'])
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break
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else:
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raise PDFSyntaxError('No /Root object! - Is this really a PDF?')
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if self.catalog.get('Type') is not LITERAL_CATALOG:
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if STRICT:
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raise PDFSyntaxError('Catalog not found!')
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return
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# initialize(password='')
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# Perform the initialization with a given password.
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# This step is mandatory even if there's no password associated
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# with the document.
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PASSWORD_PADDING = '(\xbfN^Nu\x8aAd\x00NV\xff\xfa\x01\x08..\x00\xb6\xd0h>\x80/\x0c\xa9\xfedSiz'
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def initialize(self, password=''):
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if not self.encryption:
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self.is_printable = self.is_modifiable = self.is_extractable = True
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return
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(docid, param) = self.encryption
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if literal_name(param.get('Filter')) != 'Standard':
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raise PDFEncryptionError('Unknown filter: param=%r' % param)
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V = int_value(param.get('V', 0))
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if not (V == 1 or V == 2):
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raise PDFEncryptionError('Unknown algorithm: param=%r' % param)
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length = int_value(param.get('Length', 40)) # Key length (bits)
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O = str_value(param['O'])
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R = int_value(param['R']) # Revision
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if 5 <= R:
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raise PDFEncryptionError('Unknown revision: %r' % R)
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U = str_value(param['U'])
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P = int_value(param['P'])
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self.is_printable = bool(P & 4)
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self.is_modifiable = bool(P & 8)
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self.is_extractable = bool(P & 16)
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# Algorithm 3.2
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password = (password+self.PASSWORD_PADDING)[:32] # 1
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hash = md5.md5(password) # 2
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hash.update(O) # 3
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hash.update(struct.pack('<l', P)) # 4
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hash.update(docid[0]) # 5
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if 4 <= R:
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# 6
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raise PDFNotImplementedError('Revision 4 encryption is currently unsupported')
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if 3 <= R:
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# 8
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for _ in xrange(50):
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hash = md5.md5(hash.digest()[:length/8])
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key = hash.digest()[:length/8]
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if R == 2:
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# Algorithm 3.4
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u1 = Arcfour(key).process(self.PASSWORD_PADDING)
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elif R == 3:
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# Algorithm 3.5
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hash = md5.md5(self.PASSWORD_PADDING) # 2
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hash.update(docid[0]) # 3
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x = Arcfour(key).process(hash.digest()[:16]) # 4
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for i in xrange(1,19+1):
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k = ''.join( chr(ord(c) ^ i) for c in key )
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x = Arcfour(k).process(x)
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u1 = x+x # 32bytes total
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if R == 2:
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is_authenticated = (u1 == U)
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else:
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is_authenticated = (u1[:16] == U[:16])
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if not is_authenticated:
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raise PDFPasswordIncorrect
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self.decrypt_key = key
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self.decipher = self.decrypt_rc4 # XXX may be AES
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return
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def decrypt_rc4(self, objid, genno, data):
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key = self.decrypt_key + struct.pack('<L',objid)[:3]+struct.pack('<L',genno)[:2]
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hash = md5.md5(key)
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key = hash.digest()[:min(len(key),16)]
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return Arcfour(key).process(data)
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KEYWORD_OBJ = KWD('obj')
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# can raise PDFObjectNotFound
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def getobj(self, objid):
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if not self.xrefs:
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raise PDFException('PDFDocument is not initialized')
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if 2 <= self.debug:
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print >>sys.stderr, 'getobj: objid=%r' % (objid)
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if objid in self._cached_objs:
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genno = 0
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obj = self._cached_objs[objid]
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else:
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for xref in self.xrefs:
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try:
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(strmid, index) = xref.get_pos(objid)
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break
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except KeyError:
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pass
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else:
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raise PDFObjectNotFound(objid)
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if strmid:
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stream = stream_value(self.getobj(strmid))
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if stream.get('Type') is not LITERAL_OBJSTM:
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if STRICT:
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raise PDFSyntaxError('Not a stream object: %r' % stream)
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try:
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n = stream['N']
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except KeyError:
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if STRICT:
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raise PDFSyntaxError('N is not defined: %r' % stream)
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n = 0
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if strmid in self._parsed_objs:
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objs = self._parsed_objs[strmid]
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else:
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parser = PDFStreamParser(stream.get_data())
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parser.set_document(self)
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objs = []
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try:
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while 1:
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(_,obj) = parser.nextobject()
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objs.append(obj)
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except PSEOF:
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pass
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if self.caching:
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self._parsed_objs[strmid] = objs
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genno = 0
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i = n*2+index
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try:
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obj = objs[i]
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except IndexError:
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raise PDFObjectNotFound(objid)
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if isinstance(obj, PDFStream):
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obj.set_objid(objid, 0)
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else:
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self._parser.seek(index)
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try:
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(_,objid1) = self._parser.nexttoken() # objid
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(_,genno) = self._parser.nexttoken() # genno
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(_,kwd) = self._parser.nexttoken()
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# #### hack around malformed pdf files
|
||||
#assert objid1 == objid, (objid, objid1)
|
||||
if objid1 != objid:
|
||||
x = []
|
||||
while kwd is not self.KEYWORD_OBJ:
|
||||
(_,kwd) = self._parser.nexttoken()
|
||||
x.append(kwd)
|
||||
if x:
|
||||
objid1 = x[-2]
|
||||
genno = x[-1]
|
||||
# #### end hack around malformed pdf files
|
||||
if kwd is not self.KEYWORD_OBJ:
|
||||
raise PDFSyntaxError('Invalid object spec: offset=%r' % index)
|
||||
(_,obj) = self._parser.nextobject()
|
||||
if isinstance(obj, PDFStream):
|
||||
obj.set_objid(objid, genno)
|
||||
except PSEOF:
|
||||
raise PDFObjectNotFound(objid)
|
||||
if 2 <= self.debug:
|
||||
print >>sys.stderr, 'register: objid=%r: %r' % (objid, obj)
|
||||
if self.caching:
|
||||
self._cached_objs[objid] = obj
|
||||
if self.decipher:
|
||||
obj = decipher_all(self.decipher, objid, genno, obj)
|
||||
return obj
|
||||
|
||||
INHERITABLE_ATTRS = set(['Resources', 'MediaBox', 'CropBox', 'Rotate'])
|
||||
def get_pages(self):
|
||||
if not self.xrefs:
|
||||
raise PDFException('PDFDocument is not initialized')
|
||||
def search(obj, parent):
|
||||
if isinstance(obj, int):
|
||||
objid = obj
|
||||
tree = dict_value(self.getobj(objid)).copy()
|
||||
else:
|
||||
objid = obj.objid
|
||||
tree = dict_value(obj).copy()
|
||||
for (k,v) in parent.iteritems():
|
||||
if k in self.INHERITABLE_ATTRS and k not in tree:
|
||||
tree[k] = v
|
||||
if tree.get('Type') is LITERAL_PAGES and 'Kids' in tree:
|
||||
if 1 <= self.debug:
|
||||
print >>sys.stderr, 'Pages: Kids=%r' % tree['Kids']
|
||||
for c in list_value(tree['Kids']):
|
||||
for x in search(c, tree):
|
||||
yield x
|
||||
elif tree.get('Type') is LITERAL_PAGE:
|
||||
if 1 <= self.debug:
|
||||
print >>sys.stderr, 'Page: %r' % tree
|
||||
yield (objid, tree)
|
||||
pages = False
|
||||
if 'Pages' in self.catalog:
|
||||
for (objid,tree) in search(self.catalog['Pages'], self.catalog):
|
||||
yield PDFPage(self, objid, tree)
|
||||
pages = True
|
||||
if not pages:
|
||||
# fallback when /Pages is missing.
|
||||
for xref in self.xrefs:
|
||||
for objid in xref.get_objids():
|
||||
try:
|
||||
obj = self.getobj(objid)
|
||||
if isinstance(obj, dict) and obj.get('Type') is LITERAL_PAGE:
|
||||
yield PDFPage(self, objid, obj)
|
||||
except PDFObjectNotFound:
|
||||
pass
|
||||
return
|
||||
|
||||
def get_outlines(self):
|
||||
if 'Outlines' not in self.catalog:
|
||||
raise PDFNoOutlines
|
||||
def search(entry, level):
|
||||
entry = dict_value(entry)
|
||||
if 'Title' in entry:
|
||||
if 'A' in entry or 'Dest' in entry:
|
||||
title = decode_text(str_value(entry['Title']))
|
||||
dest = entry.get('Dest')
|
||||
action = entry.get('A')
|
||||
se = entry.get('SE')
|
||||
yield (level, title, dest, action, se)
|
||||
if 'First' in entry and 'Last' in entry:
|
||||
for x in search(entry['First'], level+1):
|
||||
yield x
|
||||
if 'Next' in entry:
|
||||
for x in search(entry['Next'], level):
|
||||
yield x
|
||||
return
|
||||
return search(self.catalog['Outlines'], 0)
|
||||
|
||||
def lookup_name(self, cat, key):
|
||||
try:
|
||||
names = dict_value(self.catalog['Names'])
|
||||
except (PDFTypeError, KeyError):
|
||||
raise KeyError((cat,key))
|
||||
# may raise KeyError
|
||||
d0 = dict_value(names[cat])
|
||||
def lookup(d):
|
||||
if 'Limits' in d:
|
||||
(k1,k2) = list_value(d['Limits'])
|
||||
if key < k1 or k2 < key: return None
|
||||
if 'Names' in d:
|
||||
objs = list_value(d['Names'])
|
||||
names = dict(choplist(2, objs))
|
||||
return names[key]
|
||||
if 'Kids' in d:
|
||||
for c in list_value(d['Kids']):
|
||||
v = lookup(dict_value(c))
|
||||
if v: return v
|
||||
raise KeyError((cat,key))
|
||||
return lookup(d0)
|
||||
|
||||
def get_dest(self, name):
|
||||
try:
|
||||
# PDF-1.2 or later
|
||||
obj = self.lookup_name('Dests', name)
|
||||
except KeyError:
|
||||
# PDF-1.1 or prior
|
||||
if 'Dests' not in self.catalog:
|
||||
raise PDFDestinationNotFound(name)
|
||||
d0 = dict_value(self.catalog['Dests'])
|
||||
if name not in d0:
|
||||
raise PDFDestinationNotFound(name)
|
||||
obj = d0[name]
|
||||
return obj
|
||||
|
||||
# find_xref
|
||||
def find_xref(self, parser):
|
||||
"""Internal function used to locate the first XRef."""
|
||||
# search the last xref table by scanning the file backwards.
|
||||
prev = None
|
||||
for line in parser.revreadlines():
|
||||
line = line.strip()
|
||||
if 2 <= self.debug:
|
||||
print >>sys.stderr, 'find_xref: %r' % line
|
||||
if line == 'startxref': break
|
||||
if line:
|
||||
prev = line
|
||||
else:
|
||||
raise PDFNoValidXRef('Unexpected EOF')
|
||||
if 1 <= self.debug:
|
||||
print >>sys.stderr, 'xref found: pos=%r' % prev
|
||||
return long(prev)
|
||||
|
||||
# read xref table
|
||||
def read_xref_from(self, parser, start, xrefs):
|
||||
"""Reads XRefs from the given location."""
|
||||
parser.seek(start)
|
||||
parser.reset()
|
||||
try:
|
||||
(pos, token) = parser.nexttoken()
|
||||
except PSEOF:
|
||||
raise PDFNoValidXRef('Unexpected EOF')
|
||||
if 2 <= self.debug:
|
||||
print >>sys.stderr, 'read_xref_from: start=%d, token=%r' % (start, token)
|
||||
if isinstance(token, int):
|
||||
# XRefStream: PDF-1.5
|
||||
parser.seek(pos)
|
||||
parser.reset()
|
||||
xref = PDFXRefStream()
|
||||
xref.load(parser, debug=self.debug)
|
||||
else:
|
||||
if token is parser.KEYWORD_XREF:
|
||||
parser.nextline()
|
||||
xref = PDFXRef()
|
||||
xref.load(parser, debug=self.debug)
|
||||
xrefs.append(xref)
|
||||
trailer = xref.get_trailer()
|
||||
if 1 <= self.debug:
|
||||
print >>sys.stderr, 'trailer: %r' % trailer
|
||||
if 'XRefStm' in trailer:
|
||||
pos = int_value(trailer['XRefStm'])
|
||||
self.read_xref_from(parser, pos, xrefs)
|
||||
if 'Prev' in trailer:
|
||||
# find previous xref
|
||||
pos = int_value(trailer['Prev'])
|
||||
self.read_xref_from(parser, pos, xrefs)
|
||||
return
|
||||
|
||||
# read xref tables and trailers
|
||||
def read_xref(self, parser, fallback=False):
|
||||
"""Reads all the XRefs in the PDF file and returns them."""
|
||||
xrefs = []
|
||||
parser.fallback = fallback
|
||||
if parser.fallback:
|
||||
xref = PDFXRef()
|
||||
xref.load_fallback(parser)
|
||||
xrefs.append(xref)
|
||||
else:
|
||||
pos = self.find_xref(parser)
|
||||
self.read_xref_from(parser, pos, xrefs)
|
||||
return xrefs
|
||||
|
|
@ -17,8 +17,9 @@ from pdftypes import str_value, list_value, dict_value, stream_value
|
|||
from pdffont import PDFFontError
|
||||
from pdffont import PDFType1Font, PDFTrueTypeFont, PDFType3Font
|
||||
from pdffont import PDFCIDFont
|
||||
from pdfparser import PDFDocument, PDFParser
|
||||
from pdfparser import PDFPasswordIncorrect
|
||||
from pdfparser import PDFParser
|
||||
from pdfdocument import PDFDocument
|
||||
from pdfdocument import PDFPasswordIncorrect
|
||||
from pdfcolor import PDFColorSpace
|
||||
from pdfcolor import PREDEFINED_COLORSPACE
|
||||
from pdfcolor import LITERAL_DEVICE_GRAY, LITERAL_DEVICE_RGB
|
||||
|
|
|
|||
|
|
@ -1,597 +1,21 @@
|
|||
#!/usr/bin/env python2
|
||||
import sys
|
||||
import re
|
||||
import struct
|
||||
try:
|
||||
import hashlib as md5
|
||||
except ImportError:
|
||||
import md5
|
||||
try:
|
||||
from cStringIO import StringIO
|
||||
except ImportError:
|
||||
from StringIO import StringIO
|
||||
from psparser import PSStackParser
|
||||
from psparser import PSSyntaxError, PSEOF
|
||||
from psparser import literal_name
|
||||
from psparser import LIT, KWD, STRICT
|
||||
from pdftypes import PDFException, PDFTypeError, PDFNotImplementedError
|
||||
from pdftypes import PDFObjectNotFound, PDFStream, PDFObjRef
|
||||
from pdftypes import resolve1, decipher_all
|
||||
from psparser import KWD, STRICT
|
||||
from pdftypes import PDFException
|
||||
from pdftypes import PDFStream, PDFObjRef
|
||||
from pdftypes import int_value, float_value, num_value
|
||||
from pdftypes import str_value, list_value, dict_value, stream_value
|
||||
from arcfour import Arcfour
|
||||
from utils import choplist, nunpack
|
||||
from utils import decode_text, ObjIdRange
|
||||
|
||||
|
||||
## Exceptions
|
||||
##
|
||||
class PDFSyntaxError(PDFException): pass
|
||||
class PDFNoValidXRef(PDFSyntaxError): pass
|
||||
class PDFNoOutlines(PDFException): pass
|
||||
class PDFDestinationNotFound(PDFException): pass
|
||||
class PDFEncryptionError(PDFException): pass
|
||||
class PDFPasswordIncorrect(PDFEncryptionError): pass
|
||||
|
||||
# some predefined literals and keywords.
|
||||
LITERAL_OBJSTM = LIT('ObjStm')
|
||||
LITERAL_XREF = LIT('XRef')
|
||||
LITERAL_PAGE = LIT('Page')
|
||||
LITERAL_PAGES = LIT('Pages')
|
||||
LITERAL_CATALOG = LIT('Catalog')
|
||||
|
||||
|
||||
## XRefs
|
||||
##
|
||||
class PDFBaseXRef(object):
|
||||
|
||||
def get_trailer(self):
|
||||
raise NotImplementedError
|
||||
|
||||
def get_objids(self):
|
||||
return []
|
||||
|
||||
def get_pos(self, objid):
|
||||
raise KeyError(objid)
|
||||
|
||||
|
||||
## PDFXRef
|
||||
##
|
||||
class PDFXRef(PDFBaseXRef):
|
||||
|
||||
def __init__(self):
|
||||
self.offsets = {}
|
||||
self.trailer = {}
|
||||
return
|
||||
|
||||
def __repr__(self):
|
||||
return '<PDFXRef: offsets=%r>' % (self.offsets.keys())
|
||||
|
||||
def load(self, parser, debug=0):
|
||||
while 1:
|
||||
try:
|
||||
(pos, line) = parser.nextline()
|
||||
if not line.strip(): continue
|
||||
except PSEOF:
|
||||
raise PDFNoValidXRef('Unexpected EOF - file corrupted?')
|
||||
if not line:
|
||||
raise PDFNoValidXRef('Premature eof: %r' % parser)
|
||||
if line.startswith('trailer'):
|
||||
parser.seek(pos)
|
||||
break
|
||||
f = line.strip().split(' ')
|
||||
if len(f) != 2:
|
||||
raise PDFNoValidXRef('Trailer not found: %r: line=%r' % (parser, line))
|
||||
try:
|
||||
(start, nobjs) = map(long, f)
|
||||
except ValueError:
|
||||
raise PDFNoValidXRef('Invalid line: %r: line=%r' % (parser, line))
|
||||
for objid in xrange(start, start+nobjs):
|
||||
try:
|
||||
(_, line) = parser.nextline()
|
||||
except PSEOF:
|
||||
raise PDFNoValidXRef('Unexpected EOF - file corrupted?')
|
||||
f = line.strip().split(' ')
|
||||
if len(f) != 3:
|
||||
raise PDFNoValidXRef('Invalid XRef format: %r, line=%r' % (parser, line))
|
||||
(pos, genno, use) = f
|
||||
if use != 'n': continue
|
||||
self.offsets[objid] = (int(genno), long(pos))
|
||||
if 1 <= debug:
|
||||
print >>sys.stderr, 'xref objects:', self.offsets
|
||||
self.load_trailer(parser)
|
||||
return
|
||||
|
||||
KEYWORD_TRAILER = KWD('trailer')
|
||||
def load_trailer(self, parser):
|
||||
try:
|
||||
(_,kwd) = parser.nexttoken()
|
||||
assert kwd is self.KEYWORD_TRAILER
|
||||
(_,dic) = parser.nextobject()
|
||||
except PSEOF:
|
||||
x = parser.pop(1)
|
||||
if not x:
|
||||
raise PDFNoValidXRef('Unexpected EOF - file corrupted')
|
||||
(_,dic) = x[0]
|
||||
self.trailer.update(dict_value(dic))
|
||||
return
|
||||
|
||||
PDFOBJ_CUE = re.compile(r'^(\d+)\s+(\d+)\s+obj\b')
|
||||
def load_fallback(self, parser, debug=0):
|
||||
parser.seek(0)
|
||||
while 1:
|
||||
try:
|
||||
(pos, line) = parser.nextline()
|
||||
except PSEOF:
|
||||
break
|
||||
if line.startswith('trailer'):
|
||||
parser.seek(pos)
|
||||
self.load_trailer(parser)
|
||||
if 1 <= debug:
|
||||
print >>sys.stderr, 'trailer: %r' % self.get_trailer()
|
||||
break
|
||||
m = self.PDFOBJ_CUE.match(line)
|
||||
if not m: continue
|
||||
(objid, genno) = m.groups()
|
||||
self.offsets[int(objid)] = (0, pos)
|
||||
return
|
||||
|
||||
def get_trailer(self):
|
||||
return self.trailer
|
||||
|
||||
def get_objids(self):
|
||||
return self.offsets.iterkeys()
|
||||
|
||||
def get_pos(self, objid):
|
||||
try:
|
||||
(genno, pos) = self.offsets[objid]
|
||||
except KeyError:
|
||||
raise
|
||||
return (None, pos)
|
||||
|
||||
|
||||
## PDFXRefStream
|
||||
##
|
||||
class PDFXRefStream(PDFBaseXRef):
|
||||
|
||||
def __init__(self):
|
||||
self.data = None
|
||||
self.entlen = None
|
||||
self.fl1 = self.fl2 = self.fl3 = None
|
||||
self.objid_ranges = []
|
||||
return
|
||||
|
||||
def __repr__(self):
|
||||
return '<PDFXRefStream: fields=%d,%d,%d>' % (self.fl1, self.fl2, self.fl3)
|
||||
|
||||
def load(self, parser, debug=0):
|
||||
(_,objid) = parser.nexttoken() # ignored
|
||||
(_,genno) = parser.nexttoken() # ignored
|
||||
(_,kwd) = parser.nexttoken()
|
||||
(_,stream) = parser.nextobject()
|
||||
if not isinstance(stream, PDFStream) or stream['Type'] is not LITERAL_XREF:
|
||||
raise PDFNoValidXRef('Invalid PDF stream spec.')
|
||||
size = stream['Size']
|
||||
index_array = stream.get('Index', (0,size))
|
||||
if len(index_array) % 2 != 0:
|
||||
raise PDFSyntaxError('Invalid index number')
|
||||
self.objid_ranges.extend( ObjIdRange(start, nobjs)
|
||||
for (start,nobjs) in choplist(2, index_array) )
|
||||
(self.fl1, self.fl2, self.fl3) = stream['W']
|
||||
self.data = stream.get_data()
|
||||
self.entlen = self.fl1+self.fl2+self.fl3
|
||||
self.trailer = stream.attrs
|
||||
if 1 <= debug:
|
||||
print >>sys.stderr, ('xref stream: objid=%s, fields=%d,%d,%d' %
|
||||
(', '.join(map(repr, self.objid_ranges)),
|
||||
self.fl1, self.fl2, self.fl3))
|
||||
return
|
||||
|
||||
def get_trailer(self):
|
||||
return self.trailer
|
||||
|
||||
def get_objids(self):
|
||||
for objid_range in self.objid_ranges:
|
||||
for x in xrange(objid_range.get_start_id(), objid_range.get_end_id()+1):
|
||||
yield x
|
||||
return
|
||||
|
||||
def get_pos(self, objid):
|
||||
offset = 0
|
||||
found = False
|
||||
for objid_range in self.objid_ranges:
|
||||
if objid >= objid_range.get_start_id() and objid <= objid_range.get_end_id():
|
||||
offset += objid - objid_range.get_start_id()
|
||||
found = True
|
||||
break
|
||||
else:
|
||||
offset += objid_range.get_nobjs()
|
||||
if not found: raise KeyError(objid)
|
||||
i = self.entlen * offset
|
||||
ent = self.data[i:i+self.entlen]
|
||||
f1 = nunpack(ent[:self.fl1], 1)
|
||||
if f1 == 1:
|
||||
pos = nunpack(ent[self.fl1:self.fl1+self.fl2])
|
||||
genno = nunpack(ent[self.fl1+self.fl2:])
|
||||
return (None, pos)
|
||||
elif f1 == 2:
|
||||
objid = nunpack(ent[self.fl1:self.fl1+self.fl2])
|
||||
index = nunpack(ent[self.fl1+self.fl2:])
|
||||
return (objid, index)
|
||||
# this is a free object
|
||||
raise KeyError(objid)
|
||||
|
||||
|
||||
## PDFPage
|
||||
##
|
||||
class PDFPage(object):
|
||||
|
||||
"""An object that holds the information about a page.
|
||||
|
||||
A PDFPage object is merely a convenience class that has a set
|
||||
of keys and values, which describe the properties of a page
|
||||
and point to its contents.
|
||||
|
||||
Attributes:
|
||||
doc: a PDFDocument object.
|
||||
pageid: any Python object that can uniquely identify the page.
|
||||
attrs: a dictionary of page attributes.
|
||||
contents: a list of PDFStream objects that represents the page content.
|
||||
lastmod: the last modified time of the page.
|
||||
resources: a list of resources used by the page.
|
||||
mediabox: the physical size of the page.
|
||||
cropbox: the crop rectangle of the page.
|
||||
rotate: the page rotation (in degree).
|
||||
annots: the page annotations.
|
||||
beads: a chain that represents natural reading order.
|
||||
"""
|
||||
|
||||
def __init__(self, doc, pageid, attrs):
|
||||
"""Initialize a page object.
|
||||
|
||||
doc: a PDFDocument object.
|
||||
pageid: any Python object that can uniquely identify the page.
|
||||
attrs: a dictionary of page attributes.
|
||||
"""
|
||||
self.doc = doc
|
||||
self.pageid = pageid
|
||||
self.attrs = dict_value(attrs)
|
||||
self.lastmod = resolve1(self.attrs.get('LastModified'))
|
||||
self.resources = resolve1(self.attrs['Resources'])
|
||||
self.mediabox = resolve1(self.attrs['MediaBox'])
|
||||
if 'CropBox' in self.attrs:
|
||||
self.cropbox = resolve1(self.attrs['CropBox'])
|
||||
else:
|
||||
self.cropbox = self.mediabox
|
||||
self.rotate = (self.attrs.get('Rotate', 0)+360) % 360
|
||||
self.annots = self.attrs.get('Annots')
|
||||
self.beads = self.attrs.get('B')
|
||||
if 'Contents' in self.attrs:
|
||||
contents = resolve1(self.attrs['Contents'])
|
||||
else:
|
||||
contents = []
|
||||
if not isinstance(contents, list):
|
||||
contents = [ contents ]
|
||||
self.contents = contents
|
||||
return
|
||||
|
||||
def __repr__(self):
|
||||
return '<PDFPage: Resources=%r, MediaBox=%r>' % (self.resources, self.mediabox)
|
||||
|
||||
|
||||
## PDFDocument
|
||||
##
|
||||
class PDFDocument(object):
|
||||
|
||||
"""PDFDocument object represents a PDF document.
|
||||
|
||||
Since a PDF file can be very big, normally it is not loaded at
|
||||
once. So PDF document has to cooperate with a PDF parser in order to
|
||||
dynamically import the data as processing goes.
|
||||
|
||||
Typical usage:
|
||||
doc = PDFDocument()
|
||||
doc.set_parser(parser)
|
||||
doc.initialize(password)
|
||||
obj = doc.getobj(objid)
|
||||
|
||||
"""
|
||||
|
||||
debug = 0
|
||||
|
||||
def __init__(self, caching=True):
|
||||
self.caching = caching
|
||||
self.xrefs = []
|
||||
self.info = []
|
||||
self.catalog = None
|
||||
self.encryption = None
|
||||
self.decipher = None
|
||||
self._parser = None
|
||||
self._cached_objs = {}
|
||||
self._parsed_objs = {}
|
||||
return
|
||||
|
||||
def set_parser(self, parser, fallback=True):
|
||||
"Set the document to use a given PDFParser object."
|
||||
if self._parser: return
|
||||
self._parser = parser
|
||||
# Retrieve the information of each header that was appended
|
||||
# (maybe multiple times) at the end of the document.
|
||||
try:
|
||||
self.xrefs = parser.read_xref()
|
||||
except PDFNoValidXRef:
|
||||
fallback = True
|
||||
if fallback:
|
||||
self.xrefs.extend(parser.read_xref(fallback=True))
|
||||
for xref in self.xrefs:
|
||||
trailer = xref.get_trailer()
|
||||
if not trailer: continue
|
||||
# If there's an encryption info, remember it.
|
||||
if 'Encrypt' in trailer:
|
||||
#assert not self.encryption
|
||||
self.encryption = (list_value(trailer['ID']),
|
||||
dict_value(trailer['Encrypt']))
|
||||
if 'Info' in trailer:
|
||||
self.info.append(dict_value(trailer['Info']))
|
||||
if 'Root' in trailer:
|
||||
# Every PDF file must have exactly one /Root dictionary.
|
||||
self.catalog = dict_value(trailer['Root'])
|
||||
break
|
||||
else:
|
||||
raise PDFSyntaxError('No /Root object! - Is this really a PDF?')
|
||||
if self.catalog.get('Type') is not LITERAL_CATALOG:
|
||||
if STRICT:
|
||||
raise PDFSyntaxError('Catalog not found!')
|
||||
return
|
||||
|
||||
# initialize(password='')
|
||||
# Perform the initialization with a given password.
|
||||
# This step is mandatory even if there's no password associated
|
||||
# with the document.
|
||||
PASSWORD_PADDING = '(\xbfN^Nu\x8aAd\x00NV\xff\xfa\x01\x08..\x00\xb6\xd0h>\x80/\x0c\xa9\xfedSiz'
|
||||
def initialize(self, password=''):
|
||||
if not self.encryption:
|
||||
self.is_printable = self.is_modifiable = self.is_extractable = True
|
||||
return
|
||||
(docid, param) = self.encryption
|
||||
if literal_name(param.get('Filter')) != 'Standard':
|
||||
raise PDFEncryptionError('Unknown filter: param=%r' % param)
|
||||
V = int_value(param.get('V', 0))
|
||||
if not (V == 1 or V == 2):
|
||||
raise PDFEncryptionError('Unknown algorithm: param=%r' % param)
|
||||
length = int_value(param.get('Length', 40)) # Key length (bits)
|
||||
O = str_value(param['O'])
|
||||
R = int_value(param['R']) # Revision
|
||||
if 5 <= R:
|
||||
raise PDFEncryptionError('Unknown revision: %r' % R)
|
||||
U = str_value(param['U'])
|
||||
P = int_value(param['P'])
|
||||
self.is_printable = bool(P & 4)
|
||||
self.is_modifiable = bool(P & 8)
|
||||
self.is_extractable = bool(P & 16)
|
||||
# Algorithm 3.2
|
||||
password = (password+self.PASSWORD_PADDING)[:32] # 1
|
||||
hash = md5.md5(password) # 2
|
||||
hash.update(O) # 3
|
||||
hash.update(struct.pack('<l', P)) # 4
|
||||
hash.update(docid[0]) # 5
|
||||
if 4 <= R:
|
||||
# 6
|
||||
raise PDFNotImplementedError('Revision 4 encryption is currently unsupported')
|
||||
if 3 <= R:
|
||||
# 8
|
||||
for _ in xrange(50):
|
||||
hash = md5.md5(hash.digest()[:length/8])
|
||||
key = hash.digest()[:length/8]
|
||||
if R == 2:
|
||||
# Algorithm 3.4
|
||||
u1 = Arcfour(key).process(self.PASSWORD_PADDING)
|
||||
elif R == 3:
|
||||
# Algorithm 3.5
|
||||
hash = md5.md5(self.PASSWORD_PADDING) # 2
|
||||
hash.update(docid[0]) # 3
|
||||
x = Arcfour(key).process(hash.digest()[:16]) # 4
|
||||
for i in xrange(1,19+1):
|
||||
k = ''.join( chr(ord(c) ^ i) for c in key )
|
||||
x = Arcfour(k).process(x)
|
||||
u1 = x+x # 32bytes total
|
||||
if R == 2:
|
||||
is_authenticated = (u1 == U)
|
||||
else:
|
||||
is_authenticated = (u1[:16] == U[:16])
|
||||
if not is_authenticated:
|
||||
raise PDFPasswordIncorrect
|
||||
self.decrypt_key = key
|
||||
self.decipher = self.decrypt_rc4 # XXX may be AES
|
||||
return
|
||||
|
||||
def decrypt_rc4(self, objid, genno, data):
|
||||
key = self.decrypt_key + struct.pack('<L',objid)[:3]+struct.pack('<L',genno)[:2]
|
||||
hash = md5.md5(key)
|
||||
key = hash.digest()[:min(len(key),16)]
|
||||
return Arcfour(key).process(data)
|
||||
|
||||
KEYWORD_OBJ = KWD('obj')
|
||||
# can raise PDFObjectNotFound
|
||||
def getobj(self, objid):
|
||||
if not self.xrefs:
|
||||
raise PDFException('PDFDocument is not initialized')
|
||||
if 2 <= self.debug:
|
||||
print >>sys.stderr, 'getobj: objid=%r' % (objid)
|
||||
if objid in self._cached_objs:
|
||||
genno = 0
|
||||
obj = self._cached_objs[objid]
|
||||
else:
|
||||
for xref in self.xrefs:
|
||||
try:
|
||||
(strmid, index) = xref.get_pos(objid)
|
||||
break
|
||||
except KeyError:
|
||||
pass
|
||||
else:
|
||||
raise PDFObjectNotFound(objid)
|
||||
if strmid:
|
||||
stream = stream_value(self.getobj(strmid))
|
||||
if stream.get('Type') is not LITERAL_OBJSTM:
|
||||
if STRICT:
|
||||
raise PDFSyntaxError('Not a stream object: %r' % stream)
|
||||
try:
|
||||
n = stream['N']
|
||||
except KeyError:
|
||||
if STRICT:
|
||||
raise PDFSyntaxError('N is not defined: %r' % stream)
|
||||
n = 0
|
||||
if strmid in self._parsed_objs:
|
||||
objs = self._parsed_objs[strmid]
|
||||
else:
|
||||
parser = PDFStreamParser(stream.get_data())
|
||||
parser.set_document(self)
|
||||
objs = []
|
||||
try:
|
||||
while 1:
|
||||
(_,obj) = parser.nextobject()
|
||||
objs.append(obj)
|
||||
except PSEOF:
|
||||
pass
|
||||
if self.caching:
|
||||
self._parsed_objs[strmid] = objs
|
||||
genno = 0
|
||||
i = n*2+index
|
||||
try:
|
||||
obj = objs[i]
|
||||
except IndexError:
|
||||
raise PDFObjectNotFound(objid)
|
||||
if isinstance(obj, PDFStream):
|
||||
obj.set_objid(objid, 0)
|
||||
else:
|
||||
self._parser.seek(index)
|
||||
try:
|
||||
(_,objid1) = self._parser.nexttoken() # objid
|
||||
(_,genno) = self._parser.nexttoken() # genno
|
||||
(_,kwd) = self._parser.nexttoken()
|
||||
# #### hack around malformed pdf files
|
||||
#assert objid1 == objid, (objid, objid1)
|
||||
if objid1 != objid:
|
||||
x = []
|
||||
while kwd is not self.KEYWORD_OBJ:
|
||||
(_,kwd) = self._parser.nexttoken()
|
||||
x.append(kwd)
|
||||
if x:
|
||||
objid1 = x[-2]
|
||||
genno = x[-1]
|
||||
# #### end hack around malformed pdf files
|
||||
if kwd is not self.KEYWORD_OBJ:
|
||||
raise PDFSyntaxError('Invalid object spec: offset=%r' % index)
|
||||
(_,obj) = self._parser.nextobject()
|
||||
if isinstance(obj, PDFStream):
|
||||
obj.set_objid(objid, genno)
|
||||
except PSEOF:
|
||||
raise PDFObjectNotFound(objid)
|
||||
if 2 <= self.debug:
|
||||
print >>sys.stderr, 'register: objid=%r: %r' % (objid, obj)
|
||||
if self.caching:
|
||||
self._cached_objs[objid] = obj
|
||||
if self.decipher:
|
||||
obj = decipher_all(self.decipher, objid, genno, obj)
|
||||
return obj
|
||||
|
||||
INHERITABLE_ATTRS = set(['Resources', 'MediaBox', 'CropBox', 'Rotate'])
|
||||
def get_pages(self):
|
||||
if not self.xrefs:
|
||||
raise PDFException('PDFDocument is not initialized')
|
||||
def search(obj, parent):
|
||||
if isinstance(obj, int):
|
||||
objid = obj
|
||||
tree = dict_value(self.getobj(objid)).copy()
|
||||
else:
|
||||
objid = obj.objid
|
||||
tree = dict_value(obj).copy()
|
||||
for (k,v) in parent.iteritems():
|
||||
if k in self.INHERITABLE_ATTRS and k not in tree:
|
||||
tree[k] = v
|
||||
if tree.get('Type') is LITERAL_PAGES and 'Kids' in tree:
|
||||
if 1 <= self.debug:
|
||||
print >>sys.stderr, 'Pages: Kids=%r' % tree['Kids']
|
||||
for c in list_value(tree['Kids']):
|
||||
for x in search(c, tree):
|
||||
yield x
|
||||
elif tree.get('Type') is LITERAL_PAGE:
|
||||
if 1 <= self.debug:
|
||||
print >>sys.stderr, 'Page: %r' % tree
|
||||
yield (objid, tree)
|
||||
pages = False
|
||||
if 'Pages' in self.catalog:
|
||||
for (objid,tree) in search(self.catalog['Pages'], self.catalog):
|
||||
yield PDFPage(self, objid, tree)
|
||||
pages = True
|
||||
if not pages:
|
||||
# fallback when /Pages is missing.
|
||||
for xref in self.xrefs:
|
||||
for objid in xref.get_objids():
|
||||
try:
|
||||
obj = self.getobj(objid)
|
||||
if isinstance(obj, dict) and obj.get('Type') is LITERAL_PAGE:
|
||||
yield PDFPage(self, objid, obj)
|
||||
except PDFObjectNotFound:
|
||||
pass
|
||||
return
|
||||
|
||||
def get_outlines(self):
|
||||
if 'Outlines' not in self.catalog:
|
||||
raise PDFNoOutlines
|
||||
def search(entry, level):
|
||||
entry = dict_value(entry)
|
||||
if 'Title' in entry:
|
||||
if 'A' in entry or 'Dest' in entry:
|
||||
title = decode_text(str_value(entry['Title']))
|
||||
dest = entry.get('Dest')
|
||||
action = entry.get('A')
|
||||
se = entry.get('SE')
|
||||
yield (level, title, dest, action, se)
|
||||
if 'First' in entry and 'Last' in entry:
|
||||
for x in search(entry['First'], level+1):
|
||||
yield x
|
||||
if 'Next' in entry:
|
||||
for x in search(entry['Next'], level):
|
||||
yield x
|
||||
return
|
||||
return search(self.catalog['Outlines'], 0)
|
||||
|
||||
def lookup_name(self, cat, key):
|
||||
try:
|
||||
names = dict_value(self.catalog['Names'])
|
||||
except (PDFTypeError, KeyError):
|
||||
raise KeyError((cat,key))
|
||||
# may raise KeyError
|
||||
d0 = dict_value(names[cat])
|
||||
def lookup(d):
|
||||
if 'Limits' in d:
|
||||
(k1,k2) = list_value(d['Limits'])
|
||||
if key < k1 or k2 < key: return None
|
||||
if 'Names' in d:
|
||||
objs = list_value(d['Names'])
|
||||
names = dict(choplist(2, objs))
|
||||
return names[key]
|
||||
if 'Kids' in d:
|
||||
for c in list_value(d['Kids']):
|
||||
v = lookup(dict_value(c))
|
||||
if v: return v
|
||||
raise KeyError((cat,key))
|
||||
return lookup(d0)
|
||||
|
||||
def get_dest(self, name):
|
||||
try:
|
||||
# PDF-1.2 or later
|
||||
obj = self.lookup_name('Dests', name)
|
||||
except KeyError:
|
||||
# PDF-1.1 or prior
|
||||
if 'Dests' not in self.catalog:
|
||||
raise PDFDestinationNotFound(name)
|
||||
d0 = dict_value(self.catalog['Dests'])
|
||||
if name not in d0:
|
||||
raise PDFDestinationNotFound(name)
|
||||
obj = d0[name]
|
||||
return obj
|
||||
|
||||
|
||||
## PDFParser
|
||||
|
|
@ -704,72 +128,6 @@ class PDFParser(PSStackParser):
|
|||
|
||||
return
|
||||
|
||||
def find_xref(self):
|
||||
"""Internal function used to locate the first XRef."""
|
||||
# search the last xref table by scanning the file backwards.
|
||||
prev = None
|
||||
for line in self.revreadlines():
|
||||
line = line.strip()
|
||||
if 2 <= self.debug:
|
||||
print >>sys.stderr, 'find_xref: %r' % line
|
||||
if line == 'startxref': break
|
||||
if line:
|
||||
prev = line
|
||||
else:
|
||||
raise PDFNoValidXRef('Unexpected EOF')
|
||||
if 1 <= self.debug:
|
||||
print >>sys.stderr, 'xref found: pos=%r' % prev
|
||||
return long(prev)
|
||||
|
||||
# read xref table
|
||||
def read_xref_from(self, start, xrefs):
|
||||
"""Reads XRefs from the given location."""
|
||||
self.seek(start)
|
||||
self.reset()
|
||||
try:
|
||||
(pos, token) = self.nexttoken()
|
||||
except PSEOF:
|
||||
raise PDFNoValidXRef('Unexpected EOF')
|
||||
if 2 <= self.debug:
|
||||
print >>sys.stderr, 'read_xref_from: start=%d, token=%r' % (start, token)
|
||||
if isinstance(token, int):
|
||||
# XRefStream: PDF-1.5
|
||||
self.seek(pos)
|
||||
self.reset()
|
||||
xref = PDFXRefStream()
|
||||
xref.load(self, debug=self.debug)
|
||||
else:
|
||||
if token is self.KEYWORD_XREF:
|
||||
self.nextline()
|
||||
xref = PDFXRef()
|
||||
xref.load(self, debug=self.debug)
|
||||
xrefs.append(xref)
|
||||
trailer = xref.get_trailer()
|
||||
if 1 <= self.debug:
|
||||
print >>sys.stderr, 'trailer: %r' % trailer
|
||||
if 'XRefStm' in trailer:
|
||||
pos = int_value(trailer['XRefStm'])
|
||||
self.read_xref_from(pos, xrefs)
|
||||
if 'Prev' in trailer:
|
||||
# find previous xref
|
||||
pos = int_value(trailer['Prev'])
|
||||
self.read_xref_from(pos, xrefs)
|
||||
return
|
||||
|
||||
# read xref tables and trailers
|
||||
def read_xref(self, fallback=False):
|
||||
"""Reads all the XRefs in the PDF file and returns them."""
|
||||
xrefs = []
|
||||
self.fallback = fallback
|
||||
if self.fallback:
|
||||
xref = PDFXRef()
|
||||
xref.load_fallback(self)
|
||||
xrefs.append(xref)
|
||||
else:
|
||||
pos = self.find_xref()
|
||||
self.read_xref_from(pos, xrefs)
|
||||
return xrefs
|
||||
|
||||
|
||||
## PDFStreamParser
|
||||
##
|
||||
|
|
|
|||
|
|
@ -8,7 +8,8 @@
|
|||
#
|
||||
import sys, re
|
||||
from pdfminer.psparser import PSKeyword, PSLiteral
|
||||
from pdfminer.pdfparser import PDFDocument, PDFParser, PDFNoOutlines
|
||||
from pdfminer.pdfparser import PDFParser
|
||||
from pdfminer.pdfdocument import PDFDocument, PDFNoOutlines
|
||||
from pdfminer.pdftypes import PDFObjectNotFound
|
||||
from pdfminer.pdftypes import PDFStream, PDFObjRef, resolve1, stream_value
|
||||
|
||||
|
|
|
|||
|
|
@ -1,6 +1,7 @@
|
|||
#!/usr/bin/env python2
|
||||
import sys
|
||||
from pdfminer.pdfparser import PDFDocument, PDFParser
|
||||
from pdfminer.pdfdocument import PDFDocument
|
||||
from pdfminer.pdfparser import PDFParser
|
||||
from pdfminer.pdfinterp import PDFResourceManager, PDFPageInterpreter, process_pdf
|
||||
from pdfminer.pdfdevice import PDFDevice, TagExtractor
|
||||
from pdfminer.converter import XMLConverter, HTMLConverter, TextConverter
|
||||
|
|
|
|||
Loading…
Reference in New Issue