upstream/mercurial-mirror Files · contrib/bdiff-torture.py

worker: Use buffered input from the pickle stream...

worker: Use buffered input from the pickle stream On Python 3, "pickle.load" will raise an exception ("_pickle.UnpicklingError: pickle data was truncated") when it gets a short read, i.e. it receives fewer bytes than it requested. On our build machine, Mercurial seems to frequently hit this problem while updating a mozilla-central clone iff it gets scheduled in batch mode. It is easy to trigger with: #wipe the workdir rm -rf * hg update null chrt -b 0 hg update default I've also written the following program, which demonstrates the core problem: from __future__ import print_function import io import os import pickle import time obj = {"a": 1, "b": 2} obj_data = pickle.dumps(obj) assert len(obj_data) > 10 rfd, wfd = os.pipe() pid = os.fork() if pid == 0: os.close(rfd) for _ in range(4): time.sleep(0.5) print("First write") os.write(wfd, obj_data[:10]) time.sleep(0.5) print("Second write") os.write(wfd, obj_data[10:]) os._exit(0) try: os.close(wfd) rfile = os.fdopen(rfd, "rb", 0) print("Reading") while True: try: obj_copy = pickle.load(rfile) assert obj == obj_copy except EOFError: break print("Success") finally: os.kill(pid, 15) The program reliably fails with Python 3.8 and succeeds with Python 2.7. Providing the unpickler with a buffered reader fixes the issue, so let "os.fdopen" create one. https://bugzilla.mozilla.org/show_bug.cgi?id=1604486 Differential Revision: https://phab.mercurial-scm.org/D8051

Augie Fackler - - Load All Authors

File last commit:

r43346:2372284d default


                r44718:cb52e619

stable

Download file

             bdiff-torture.py
        
                    108 lines
            
             | 2.1 KiB
            
                | text/x-python
            
             |
                PythonLexer
            
             / contrib / bdiff-torture.py
          
                    History
                
                 |
                  Annotation
                 | Raw
                 |Copy content
                 |Copy permalink

      # Randomized torture test generation for bdiff

      from __future__ import absolute_import, print_function

      import random

      import sys

      from mercurial import (

          mdiff,

          pycompat,

      )

      def reducetest(a, b):

          tries = 0

          reductions = 0

          print("reducing...")

          while tries < 1000:

              a2 = (

                  "\n".join(l for l in a.splitlines() if random.randint(0, 100) > 0)

                  + "\n"

              )

              b2 = (

                  "\n".join(l for l in b.splitlines() if random.randint(0, 100) > 0)

                  + "\n"

              )

              if a2 == a and b2 == b:

                  continue

              if a2 == b2:

                  continue

              tries += 1

              try:

                  test1(a, b)

              except Exception:

                  reductions += 1

                  tries = 0

                  a = a2

                  b = b2

          print("reduced:", reductions, len(a) + len(b), repr(a), repr(b))

          try:

              test1(a, b)

          except Exception as inst:

              print("failed:", inst)

          sys.exit(0)

      def test1(a, b):

          d = mdiff.textdiff(a, b)

          if not d:

              raise ValueError("empty")

          c = mdiff.patches(a, [d])

          if c != b:

              raise ValueError("bad")

      def testwrap(a, b):

          try:

              test1(a, b)

              return

          except Exception as inst:

              print("exception:", inst)

          reducetest(a, b)

      def test(a, b):

          testwrap(a, b)

          testwrap(b, a)

      def rndtest(size, noise):

          a = []

          src = "                aaaaaaaabbbbccd"

          for x in pycompat.xrange(size):

              a.append(src[random.randint(0, len(src) - 1)])

          while True:

              b = [c for c in a if random.randint(0, 99) > noise]

              b2 = []

              for c in b:

                  b2.append(c)

                  while random.randint(0, 99) < noise:

                      b2.append(src[random.randint(0, len(src) - 1)])

              if b2 != a:

                  break

          a = "\n".join(a) + "\n"

          b = "\n".join(b2) + "\n"

          test(a, b)

      maxvol = 10000

      startsize = 2

      while True:

          size = startsize

          count = 0

          while size < maxvol:

              print(size)

              volume = 0

              while volume < maxvol:

                  rndtest(size, 2)

                  volume += size

                  count += 2

              size *= 2

          maxvol *= 4

          startsize *= 4

	Site-wide shortcuts
/	Use quick search box
g h	Goto home page
g g	Goto my private gists page
g G	Goto my public gists page
g 0-9	Goto bookmarked items from 0-9
n r	New repository page
n g	New gist page

	Repositories
g s	Goto summary page
g c	Goto changelog page
g f	Goto files page
g F	Goto files page with file search activated
g p	Goto pull requests page
g o	Goto repository settings
g O	Goto repository access permissions settings
t s	Toggle sidebar on some pages

				# Randomized torture test generation for bdiff

				from __future__ import absolute_import, print_function
				import random
				import sys

				from mercurial import (
				mdiff,
				pycompat,
				)


				def reducetest(a, b):
				tries = 0
				reductions = 0
				print("reducing...")
				while tries < 1000:
				a2 = (
				"\n".join(l for l in a.splitlines() if random.randint(0, 100) > 0)
				+ "\n"
				)
				b2 = (
				"\n".join(l for l in b.splitlines() if random.randint(0, 100) > 0)
				+ "\n"
				)
				if a2 == a and b2 == b:
				continue
				if a2 == b2:
				continue
				tries += 1

				try:
				test1(a, b)
				except Exception:
				reductions += 1
				tries = 0
				a = a2
				b = b2

				print("reduced:", reductions, len(a) + len(b), repr(a), repr(b))
				try:
				test1(a, b)
				except Exception as inst:
				print("failed:", inst)

				sys.exit(0)


				def test1(a, b):
				d = mdiff.textdiff(a, b)
				if not d:
				raise ValueError("empty")
				c = mdiff.patches(a, [d])
				if c != b:
				raise ValueError("bad")


				def testwrap(a, b):
				try:
				test1(a, b)
				return
				except Exception as inst:
				print("exception:", inst)
				reducetest(a, b)


				def test(a, b):
				testwrap(a, b)
				testwrap(b, a)


				def rndtest(size, noise):
				a = []
				src = " aaaaaaaabbbbccd"
				for x in pycompat.xrange(size):
				a.append(src[random.randint(0, len(src) - 1)])

				while True:
				b = [c for c in a if random.randint(0, 99) > noise]
				b2 = []
				for c in b:
				b2.append(c)
				while random.randint(0, 99) < noise:
				b2.append(src[random.randint(0, len(src) - 1)])
				if b2 != a:
				break

				a = "\n".join(a) + "\n"
				b = "\n".join(b2) + "\n"

				test(a, b)


				maxvol = 10000
				startsize = 2
				while True:
				size = startsize
				count = 0
				while size < maxvol:
				print(size)
				volume = 0
				while volume < maxvol:
				rndtest(size, 2)
				volume += size
				count += 2
				size *= 2
				maxvol *= 4
				startsize *= 4