def test_evil_page_deletion(resources, outdir): # str needed for py<3.6 copy(str(resources / 'sandwich.pdf'), str(outdir / 'sandwich.pdf')) src = Pdf.open(outdir / 'sandwich.pdf') pdf = Pdf.open(resources / 'graph.pdf') assert refcount(src) == 2 pdf.pages.append(src.pages[0]) assert refcount(src) == 3 del src.pages[0] gc.collect() assert refcount(src) == 3 with suppress(PermissionError): # Fails on Windows (outdir / 'sandwich.pdf').unlink() pdf.save(outdir / 'out.pdf') del pdf.pages[0] pdf.save(outdir / 'out2.pdf') del pdf.pages[0] pdf.save(outdir / 'out_nopages.pdf') del pdf gc.collect()
def test_evil_page_deletion(resources, outdir): copy(resources / 'sandwich.pdf', outdir / 'sandwich.pdf') src = Pdf.open(outdir / 'sandwich.pdf') # no with clause pdf = Pdf.open(resources / 'graph.pdf') assert refcount(src) == 2 pdf.pages.append(src.pages[0]) assert refcount(src) == 2 del src.pages[0] gc.collect() assert refcount(src) == 2 with suppress(PermissionError): # Fails on Windows (outdir / 'sandwich.pdf').unlink() pdf.save(outdir / 'out.pdf') del pdf.pages[0] pdf.save(outdir / 'out2.pdf') del pdf.pages[0] pdf.save(outdir / 'out_nopages.pdf') del pdf gc.collect()
def test_access_image(resources): pdf = Pdf.open(resources / 'congress.pdf') assert refcount(pdf) == 2 # refcount is always +1 im0 = pdf.pages[0].Resources.XObject['/Im0'] assert refcount(pdf) == 3, "didn't acquire a reference to owner" del pdf gc.collect() im0.read_raw_bytes()
def check_refcount(thing, count): "Test that the reference count of thing is exactly 'count' in caller" try: from sys import refcount # pypy doesn't haven't refcount except ImportError: return True # ...so for pypy say it's okay # count + 1 because this function holds a reference, and its caller holds # a reference, and we're writing this from the caller's perspective return refcount(thing) == count + 1
def test_remove_pdf_and_all_pages(resources): pdf = Pdf.open(resources / 'graph.pdf') page0 = pdf.pages[0] contents = page0.Contents assert refcount(pdf) == 4, "stream didn't acquire reference to owner" del pdf del page0 gc.collect() contents.read_raw_bytes() del contents gc.collect()
def test_access_page(resources): pdf = Pdf.open(resources / 'graph.pdf') page0 = pdf.pages[0] also_page0 = pdf.pages.p(1) assert refcount(pdf) == 4, "didn't acquire a reference to owner" del pdf gc.collect() page0.Contents.read_raw_bytes() del page0 gc.collect() also_page0.Contents.read_raw_bytes()
def test_transfer_page(resources): pdf = Pdf.open(resources / 'graph.pdf') page0 = pdf.pages[0] before = page0.Contents.read_bytes() assert refcount(pdf) == 3 # this, pdf, page0->pdf assert refcount(page0) == 2 pdf2 = Pdf.open(resources / 'fourpages.pdf') pdf2.pages.insert(2, page0) p2p2 = pdf2.pages[2] assert refcount(pdf) == 3 # this, pdf, page0->pdf assert refcount(p2p2) == 2 del pdf del page0 assert refcount(p2p2) == 2 del pdf2.pages[2] assert before == p2p2.Contents.read_bytes()
self.w2=None self.w3=None def set_all(self,*args): self.w1 = weakref.ref(args[0]) self.w2 = weakref.ref(args[1]) self.w3 = weakref.ref(args[2]) def get_all(self): # print 'id: ', id(a), '=> ', refcount(a) print self.w1() print self.w2() print self.w3() a = Dummy() b = Dummy() c = Dummy() #wr = weakref.ref(a) #print wr vlist = VirtualList() vlist.set_all(a,b,c) print 'id: ', id(a), '=> ', refcount(a) print 'id: ', id(b), '=> ', refcount(b) # print gc.get_referents(a, b) # print gc.get_referrers(a) print '=================================' del b, c vlist.get_all()