pdfminer.six/pdfminer/pdfinterp.py

835 lines
26 KiB
Python

#!/usr/bin/env python2
import sys
import re
try:
from cStringIO import StringIO
except ImportError:
from StringIO import StringIO
from cmapdb import CMapDB, CMap
from psparser import PSException, PSTypeError, PSEOF
from psparser import PSKeyword, literal_name, keyword_name
from psparser import PSStackParser
from psparser import LIT, KWD, STRICT
from pdftypes import PDFException, PDFStream, PDFObjRef
from pdftypes import resolve1
from pdftypes import int_value, float_value, num_value
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 pdfcolor import PDFColorSpace
from pdfcolor import PREDEFINED_COLORSPACE
from pdfcolor import LITERAL_DEVICE_GRAY, LITERAL_DEVICE_RGB
from pdfcolor import LITERAL_DEVICE_CMYK
from utils import choplist
from utils import mult_matrix, MATRIX_IDENTITY
## Exceptions
##
class PDFResourceError(PDFException): pass
class PDFInterpreterError(PDFException): pass
## Constants
##
LITERAL_PDF = LIT('PDF')
LITERAL_TEXT = LIT('Text')
LITERAL_FONT = LIT('Font')
LITERAL_FORM = LIT('Form')
LITERAL_IMAGE = LIT('Image')
## PDFTextState
##
class PDFTextState(object):
def __init__(self):
self.font = None
self.fontsize = 0
self.charspace = 0
self.wordspace = 0
self.scaling = 100
self.leading = 0
self.render = 0
self.rise = 0
self.reset()
# self.matrix is set
# self.linematrix is set
return
def __repr__(self):
return ('<PDFTextState: font=%r, fontsize=%r, charspace=%r, wordspace=%r, '
' scaling=%r, leading=%r, render=%r, rise=%r, '
' matrix=%r, linematrix=%r>' %
(self.font, self.fontsize, self.charspace, self.wordspace,
self.scaling, self.leading, self.render, self.rise,
self.matrix, self.linematrix))
def copy(self):
obj = PDFTextState()
obj.font = self.font
obj.fontsize = self.fontsize
obj.charspace = self.charspace
obj.wordspace = self.wordspace
obj.scaling = self.scaling
obj.leading = self.leading
obj.render = self.render
obj.rise = self.rise
obj.matrix = self.matrix
obj.linematrix = self.linematrix
return obj
def reset(self):
self.matrix = MATRIX_IDENTITY
self.linematrix = (0, 0)
return
## PDFGraphicState
##
class PDFGraphicState(object):
def __init__(self):
self.linewidth = 0
self.linecap = None
self.linejoin = None
self.miterlimit = None
self.dash = None
self.intent = None
self.flatness = None
return
def copy(self):
obj = PDFGraphicState()
obj.linewidth = self.linewidth
obj.linecap = self.linecap
obj.linejoin = self.linejoin
obj.miterlimit = self.miterlimit
obj.dash = self.dash
obj.intent = self.intent
obj.flatness = self.flatness
return obj
def __repr__(self):
return ('<PDFGraphicState: linewidth=%r, linecap=%r, linejoin=%r, '
' miterlimit=%r, dash=%r, intent=%r, flatness=%r>' %
(self.linewidth, self.linecap, self.linejoin,
self.miterlimit, self.dash, self.intent, self.flatness))
## Resource Manager
##
class PDFResourceManager(object):
"""Repository of shared resources.
ResourceManager facilitates reuse of shared resources
such as fonts and images so that large objects are not
allocated multiple times.
"""
debug = 0
def __init__(self, caching=True):
self.caching = caching
self._cached_fonts = {}
return
def get_procset(self, procs):
for proc in procs:
if proc is LITERAL_PDF:
pass
elif proc is LITERAL_TEXT:
pass
else:
#raise PDFResourceError('ProcSet %r is not supported.' % proc)
pass
return
def get_cmap(self, cmapname, strict=False):
try:
return CMapDB.get_cmap(cmapname)
except CMapDB.CMapNotFound:
if strict: raise
return CMap()
def get_font(self, objid, spec):
if objid and objid in self._cached_fonts:
font = self._cached_fonts[objid]
else:
if 2 <= self.debug:
print >>sys.stderr, 'get_font: create: objid=%r, spec=%r' % (objid, spec)
if STRICT:
if spec['Type'] is not LITERAL_FONT:
raise PDFFontError('Type is not /Font')
# Create a Font object.
if 'Subtype' in spec:
subtype = literal_name(spec['Subtype'])
else:
if STRICT:
raise PDFFontError('Font Subtype is not specified.')
subtype = 'Type1'
if subtype in ('Type1', 'MMType1'):
# Type1 Font
font = PDFType1Font(self, spec)
elif subtype == 'TrueType':
# TrueType Font
font = PDFTrueTypeFont(self, spec)
elif subtype == 'Type3':
# Type3 Font
font = PDFType3Font(self, spec)
elif subtype in ('CIDFontType0', 'CIDFontType2'):
# CID Font
font = PDFCIDFont(self, spec)
elif subtype == 'Type0':
# Type0 Font
dfonts = list_value(spec['DescendantFonts'])
assert dfonts
subspec = dict_value(dfonts[0]).copy()
for k in ('Encoding', 'ToUnicode'):
if k in spec:
subspec[k] = resolve1(spec[k])
font = self.get_font(None, subspec)
else:
if STRICT:
raise PDFFontError('Invalid Font spec: %r' % spec)
font = PDFType1Font(self, spec) # this is so wrong!
if objid and self.caching:
self._cached_fonts[objid] = font
return font
## PDFContentParser
##
class PDFContentParser(PSStackParser):
def __init__(self, streams):
self.streams = streams
self.istream = 0
PSStackParser.__init__(self, None)
return
def fillfp(self):
if not self.fp:
if self.istream < len(self.streams):
strm = stream_value(self.streams[self.istream])
self.istream += 1
else:
raise PSEOF('Unexpected EOF, file truncated?')
self.fp = StringIO(strm.get_data())
return
def seek(self, pos):
self.fillfp()
PSStackParser.seek(self, pos)
return
def fillbuf(self):
if self.charpos < len(self.buf): return
while 1:
self.fillfp()
self.bufpos = self.fp.tell()
self.buf = self.fp.read(self.BUFSIZ)
if self.buf: break
self.fp = None
self.charpos = 0
return
def get_inline_data(self, pos, target='EI'):
self.seek(pos)
i = 0
data = ''
while i <= len(target):
self.fillbuf()
if i:
c = self.buf[self.charpos]
data += c
self.charpos += 1
if len(target) <= i and c.isspace():
i += 1
elif i < len(target) and c == target[i]:
i += 1
else:
i = 0
else:
try:
j = self.buf.index(target[0], self.charpos)
#print 'found', (0, self.buf[j:j+10])
data += self.buf[self.charpos:j+1]
self.charpos = j+1
i = 1
except ValueError:
data += self.buf[self.charpos:]
self.charpos = len(self.buf)
data = data[:-(len(target)+1)] # strip the last part
data = re.sub(r'(\x0d\x0a|[\x0d\x0a])$', '', data)
return (pos, data)
def flush(self):
self.add_results(*self.popall())
return
KEYWORD_BI = KWD('BI')
KEYWORD_ID = KWD('ID')
KEYWORD_EI = KWD('EI')
def do_keyword(self, pos, token):
if token is self.KEYWORD_BI:
# inline image within a content stream
self.start_type(pos, 'inline')
elif token is self.KEYWORD_ID:
try:
(_, objs) = self.end_type('inline')
if len(objs) % 2 != 0:
raise PSTypeError('Invalid dictionary construct: %r' % objs)
d = dict( (literal_name(k), v) for (k,v) in choplist(2, objs) )
(pos, data) = self.get_inline_data(pos+len('ID '))
obj = PDFStream(d, data)
self.push((pos, obj))
self.push((pos, self.KEYWORD_EI))
except PSTypeError:
if STRICT: raise
else:
self.push((pos, token))
return
## Interpreter
##
class PDFPageInterpreter(object):
debug = 0
def __init__(self, rsrcmgr, device):
self.rsrcmgr = rsrcmgr
self.device = device
return
def dup(self):
return PDFPageInterpreter(self.rsrcmgr, self.device)
# init_resources(resources):
# Prepare the fonts and XObjects listed in the Resource attribute.
def init_resources(self, resources):
self.resources = resources
self.fontmap = {}
self.xobjmap = {}
self.csmap = PREDEFINED_COLORSPACE.copy()
if not resources: return
def get_colorspace(spec):
if isinstance(spec, list):
name = literal_name(spec[0])
else:
name = literal_name(spec)
if name == 'ICCBased' and isinstance(spec, list) and 2 <= len(spec):
return PDFColorSpace(name, stream_value(spec[1])['N'])
elif name == 'DeviceN' and isinstance(spec, list) and 2 <= len(spec):
return PDFColorSpace(name, len(list_value(spec[1])))
else:
return PREDEFINED_COLORSPACE.get(name)
for (k,v) in dict_value(resources).iteritems():
if 2 <= self.debug:
print >>sys.stderr, 'Resource: %r: %r' % (k,v)
if k == 'Font':
for (fontid,spec) in dict_value(v).iteritems():
objid = None
if isinstance(spec, PDFObjRef):
objid = spec.objid
spec = dict_value(spec)
self.fontmap[fontid] = self.rsrcmgr.get_font(objid, spec)
elif k == 'ColorSpace':
for (csid,spec) in dict_value(v).iteritems():
self.csmap[csid] = get_colorspace(resolve1(spec))
elif k == 'ProcSet':
self.rsrcmgr.get_procset(list_value(v))
elif k == 'XObject':
for (xobjid,xobjstrm) in dict_value(v).iteritems():
self.xobjmap[xobjid] = xobjstrm
return
# init_state(ctm)
# Initialize the text and graphic states for rendering a page.
def init_state(self, ctm):
# gstack: stack for graphical states.
self.gstack = []
self.ctm = ctm
self.device.set_ctm(self.ctm)
self.textstate = PDFTextState()
self.graphicstate = PDFGraphicState()
self.curpath = []
# argstack: stack for command arguments.
self.argstack = []
# set some global states.
self.scs = self.ncs = None
if self.csmap:
self.scs = self.ncs = self.csmap.values()[0]
return
def push(self, obj):
self.argstack.append(obj)
return
def pop(self, n):
if n == 0: return []
x = self.argstack[-n:]
self.argstack = self.argstack[:-n]
return x
def get_current_state(self):
return (self.ctm, self.textstate.copy(), self.graphicstate.copy())
def set_current_state(self, state):
(self.ctm, self.textstate, self.graphicstate) = state
self.device.set_ctm(self.ctm)
return
# gsave
def do_q(self):
self.gstack.append(self.get_current_state())
return
# grestore
def do_Q(self):
if self.gstack:
self.set_current_state(self.gstack.pop())
return
# concat-matrix
def do_cm(self, a1, b1, c1, d1, e1, f1):
self.ctm = mult_matrix((a1,b1,c1,d1,e1,f1), self.ctm)
self.device.set_ctm(self.ctm)
return
# setlinewidth
def do_w(self, linewidth):
self.graphicstate.linewidth = linewidth
return
# setlinecap
def do_J(self, linecap):
self.graphicstate.linecap = linecap
return
# setlinejoin
def do_j(self, linejoin):
self.graphicstate.linejoin = linejoin
return
# setmiterlimit
def do_M(self, miterlimit):
self.graphicstate.miterlimit = miterlimit
return
# setdash
def do_d(self, dash, phase):
self.graphicstate.dash = (dash, phase)
return
# setintent
def do_ri(self, intent):
self.graphicstate.intent = intent
return
# setflatness
def do_i(self, flatness):
self.graphicstate.flatness = flatness
return
# load-gstate
def do_gs(self, name):
#XXX
return
# moveto
def do_m(self, x, y):
self.curpath.append(('m',x,y))
return
# lineto
def do_l(self, x, y):
self.curpath.append(('l',x,y))
return
# curveto
def do_c(self, x1, y1, x2, y2, x3, y3):
self.curpath.append(('c',x1,y1,x2,y2,x3,y3))
return
# urveto
def do_v(self, x2, y2, x3, y3):
self.curpath.append(('v',x2,y2,x3,y3))
return
# rveto
def do_y(self, x1, y1, x3, y3):
self.curpath.append(('y',x1,y1,x3,y3))
return
# closepath
def do_h(self):
self.curpath.append(('h',))
return
# rectangle
def do_re(self, x, y, w, h):
self.curpath.append(('m',x,y))
self.curpath.append(('l',x+w,y))
self.curpath.append(('l',x+w,y+h))
self.curpath.append(('l',x,y+h))
self.curpath.append(('h',))
return
# stroke
def do_S(self):
self.device.paint_path(self.graphicstate, True, False, False, self.curpath)
self.curpath = []
return
# close-and-stroke
def do_s(self):
self.do_h()
self.do_S()
return
# fill
def do_f(self):
self.device.paint_path(self.graphicstate, False, True, False, self.curpath)
self.curpath = []
return
# fill (obsolete)
do_F = do_f
# fill-even-odd
def do_f_a(self):
self.device.paint_path(self.graphicstate, False, True, True, self.curpath)
self.curpath = []
return
# fill-and-stroke
def do_B(self):
self.device.paint_path(self.graphicstate, True, True, False, self.curpath)
self.curpath = []
return
# fill-and-stroke-even-odd
def do_B_a(self):
self.device.paint_path(self.graphicstate, True, True, True, self.curpath)
self.curpath = []
return
# close-fill-and-stroke
def do_b(self):
self.do_h()
self.do_B()
return
# close-fill-and-stroke-even-odd
def do_b_a(self):
self.do_h()
self.do_B_a()
return
# close-only
def do_n(self):
self.curpath = []
return
# clip
def do_W(self): return
# clip-even-odd
def do_W_a(self): return
# setcolorspace-stroking
def do_CS(self, name):
self.scs = self.csmap[literal_name(name)]
return
# setcolorspace-non-strokine
def do_cs(self, name):
self.ncs = self.csmap[literal_name(name)]
return
# setgray-stroking
def do_G(self, gray):
#self.do_CS(LITERAL_DEVICE_GRAY)
return
# setgray-non-stroking
def do_g(self, gray):
#self.do_cs(LITERAL_DEVICE_GRAY)
return
# setrgb-stroking
def do_RG(self, r, g, b):
#self.do_CS(LITERAL_DEVICE_RGB)
return
# setrgb-non-stroking
def do_rg(self, r, g, b):
#self.do_cs(LITERAL_DEVICE_RGB)
return
# setcmyk-stroking
def do_K(self, c, m, y, k):
#self.do_CS(LITERAL_DEVICE_CMYK)
return
# setcmyk-non-stroking
def do_k(self, c, m, y, k):
#self.do_cs(LITERAL_DEVICE_CMYK)
return
# setcolor
def do_SCN(self):
if self.scs:
n = self.scs.ncomponents
else:
if STRICT:
raise PDFInterpreterError('No colorspace specified!')
n = 1
self.pop(n)
return
def do_scn(self):
if self.ncs:
n = self.ncs.ncomponents
else:
if STRICT:
raise PDFInterpreterError('No colorspace specified!')
n = 1
self.pop(n)
return
def do_SC(self):
self.do_SCN()
return
def do_sc(self):
self.do_scn()
return
# sharing-name
def do_sh(self, name): return
# begin-text
def do_BT(self):
self.textstate.reset()
return
# end-text
def do_ET(self):
return
# begin-compat
def do_BX(self): return
# end-compat
def do_EX(self): return
# marked content operators
def do_MP(self, tag):
self.device.do_tag(tag)
return
def do_DP(self, tag, props):
self.device.do_tag(tag, props)
return
def do_BMC(self, tag):
self.device.begin_tag(tag)
return
def do_BDC(self, tag, props):
self.device.begin_tag(tag, props)
return
def do_EMC(self):
self.device.end_tag()
return
# setcharspace
def do_Tc(self, space):
self.textstate.charspace = space
return
# setwordspace
def do_Tw(self, space):
self.textstate.wordspace = space
return
# textscale
def do_Tz(self, scale):
self.textstate.scaling = scale
return
# setleading
def do_TL(self, leading):
self.textstate.leading = -leading
return
# selectfont
def do_Tf(self, fontid, fontsize):
try:
self.textstate.font = self.fontmap[literal_name(fontid)]
except KeyError:
raise
if STRICT:
raise PDFInterpreterError('Undefined Font id: %r' % fontid)
return
self.textstate.fontsize = fontsize
return
# setrendering
def do_Tr(self, render):
self.textstate.render = render
return
# settextrise
def do_Ts(self, rise):
self.textstate.rise = rise
return
# text-move
def do_Td(self, tx, ty):
(a,b,c,d,e,f) = self.textstate.matrix
self.textstate.matrix = (a,b,c,d,tx*a+ty*c+e,tx*b+ty*d+f)
self.textstate.linematrix = (0, 0)
#print >>sys.stderr, 'Td(%r,%r): %r' % (tx,ty,self.textstate)
return
# text-move
def do_TD(self, tx, ty):
(a,b,c,d,e,f) = self.textstate.matrix
self.textstate.matrix = (a,b,c,d,tx*a+ty*c+e,tx*b+ty*d+f)
self.textstate.leading = ty
self.textstate.linematrix = (0, 0)
#print >>sys.stderr, 'TD(%r,%r): %r' % (tx,ty,self.textstate)
return
# textmatrix
def do_Tm(self, a,b,c,d,e,f):
self.textstate.matrix = (a,b,c,d,e,f)
self.textstate.linematrix = (0, 0)
return
# nextline
def do_T_a(self):
(a,b,c,d,e,f) = self.textstate.matrix
self.textstate.matrix = (a,b,c,d,self.textstate.leading*c+e,self.textstate.leading*d+f)
self.textstate.linematrix = (0, 0)
return
# show-pos
def do_TJ(self, seq):
#print >>sys.stderr, 'TJ(%r): %r' % (seq,self.textstate)
if self.textstate.font is None:
if STRICT:
raise PDFInterpreterError('No font specified!')
return
self.device.render_string(self.textstate, seq)
return
# show
def do_Tj(self, s):
self.do_TJ([s])
return
# quote
def do__q(self, s):
self.do_T_a()
self.do_TJ([s])
return
# doublequote
def do__w(self, aw, ac, s):
self.do_Tw(aw)
self.do_Tc(ac)
self.do_TJ([s])
return
# inline image
def do_BI(self): # never called
return
def do_ID(self): # never called
return
def do_EI(self, obj):
if 'W' in obj and 'H' in obj:
iobjid = str(id(obj))
self.device.begin_figure(iobjid, (0,0,1,1), MATRIX_IDENTITY)
self.device.render_image(iobjid, obj)
self.device.end_figure(iobjid)
return
# invoke an XObject
def do_Do(self, xobjid):
xobjid = literal_name(xobjid)
try:
xobj = stream_value(self.xobjmap[xobjid])
except KeyError:
if STRICT:
raise PDFInterpreterError('Undefined xobject id: %r' % xobjid)
return
if 1 <= self.debug:
print >>sys.stderr, 'Processing xobj: %r' % xobj
subtype = xobj.get('Subtype')
if subtype is LITERAL_FORM and 'BBox' in xobj:
interpreter = self.dup()
bbox = list_value(xobj['BBox'])
matrix = list_value(xobj.get('Matrix', MATRIX_IDENTITY))
# According to PDF reference 1.7 section 4.9.1, XObjects in
# earlier PDFs (prior to v1.2) use the page's Resources entry
# instead of having their own Resources entry.
resources = dict_value(xobj.get('Resources')) or self.resources.copy()
self.device.begin_figure(xobjid, bbox, matrix)
interpreter.render_contents(resources, [xobj], ctm=mult_matrix(matrix, self.ctm))
self.device.end_figure(xobjid)
elif subtype is LITERAL_IMAGE and 'Width' in xobj and 'Height' in xobj:
self.device.begin_figure(xobjid, (0,0,1,1), MATRIX_IDENTITY)
self.device.render_image(xobjid, xobj)
self.device.end_figure(xobjid)
else:
# unsupported xobject type.
pass
return
def process_page(self, page):
if 1 <= self.debug:
print >>sys.stderr, 'Processing page: %r' % page
(x0,y0,x1,y1) = page.mediabox
if page.rotate == 90:
ctm = (0,-1,1,0, -y0,x1)
elif page.rotate == 180:
ctm = (-1,0,0,-1, x1,y1)
elif page.rotate == 270:
ctm = (0,1,-1,0, y1,-x0)
else:
ctm = (1,0,0,1, -x0,-y0)
self.device.begin_page(page, ctm)
self.render_contents(page.resources, page.contents, ctm=ctm)
self.device.end_page(page)
return
# render_contents(resources, streams, ctm)
# Render the content streams.
# This method may be called recursively.
def render_contents(self, resources, streams, ctm=MATRIX_IDENTITY):
if 1 <= self.debug:
print >>sys.stderr, ('render_contents: resources=%r, streams=%r, ctm=%r' %
(resources, streams, ctm))
self.init_resources(resources)
self.init_state(ctm)
self.execute(list_value(streams))
return
def execute(self, streams):
try:
parser = PDFContentParser(streams)
except PSEOF:
# empty page
return
while 1:
try:
(_,obj) = parser.nextobject()
except PSEOF:
break
if isinstance(obj, PSKeyword):
name = keyword_name(obj)
method = 'do_%s' % name.replace('*','_a').replace('"','_w').replace("'",'_q')
if hasattr(self, method):
func = getattr(self, method)
nargs = func.func_code.co_argcount-1
if nargs:
args = self.pop(nargs)
if 2 <= self.debug:
print >>sys.stderr, 'exec: %s %r' % (name, args)
if len(args) == nargs:
func(*args)
else:
if 2 <= self.debug:
print >>sys.stderr, 'exec: %s' % (name)
func()
else:
if STRICT:
raise PDFInterpreterError('Unknown operator: %r' % name)
else:
self.push(obj)
return
## process_pdf
##
class PDFTextExtractionNotAllowed(PDFInterpreterError): pass
def process_pdf(rsrcmgr, device, fp, pagenos=None, maxpages=0, password='',
caching=True, check_extractable=True):
# Create a PDF parser object associated with the file object.
parser = PDFParser(fp)
# Create a PDF document object that stores the document structure.
doc = PDFDocument(caching=caching)
# Connect the parser and document objects.
parser.set_document(doc)
doc.set_parser(parser)
# Supply the document password for initialization.
# (If no password is set, give an empty string.)
doc.initialize(password)
# Check if the document allows text extraction. If not, abort.
if check_extractable and not doc.is_extractable:
raise PDFTextExtractionNotAllowed('Text extraction is not allowed: %r' % fp)
# Create a PDF interpreter object.
interpreter = PDFPageInterpreter(rsrcmgr, device)
# Process each page contained in the document.
for (pageno,page) in enumerate(doc.get_pages()):
if pagenos and (pageno not in pagenos): continue
interpreter.process_page(page)
if maxpages and maxpages <= pageno+1: break
return