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()
