Attachment 935083 Details for Bug 1138970 – A small python script that reproduces the file corruption

A small python script that reproduces the file corruption

gluster-fuse-client-interleaved-read-write-corruption.py (text/plain), 2.29 KB, created by mike on 2014-09-06 22:29:02 UTC

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Creator: mike

Created: 2014-09-06 22:29:02 UTC

Size: 2.29 KB

patch

obsolete

>#!/usr/bin/python2.7
>
>import os
>import random
>import struct
>import sys
>import time
>import zlib
>
>class RecordIO(object):
>  record_header_format = '!Ii'
>  record_header_size = struct.calcsize(record_header_format)
>  
>  def __init__(self, pfile, key_list=None, attr_list=None, record_type=tuple):
>    self.pfile = pfile
>    
>  def close(self):
>    self.pfile.close()
>
>  def fmt_item(self, data):
>    data_len, checksum = len(data), zlib.adler32(data)
>    header = struct.pack(self.record_header_format, data_len, checksum)
>    return header + data
>    
>class RecordWriter(RecordIO):
>  def write_record(self, data):
>    self.pfile.write(self.fmt_item(data))
>
>class RecordReader(RecordIO):
>  validate_checksum = True
>  follow = True
>  
>  def seek(self, record_offset):
>    self.pfile.seek(record_offset)
>
>  def tell(self):
>    return self.pfile.tell()
>
>  def __iter__(self):
>    return self
>
>  def next(self):
>    record = self.read_record()
>    if record is None:
>      raise StopIteration
>    else:
>      return record
>
>  def _read(self, size):
>    while True:
>      pos = self.tell()
>      raw_data = self.pfile.read(size)
>      if raw_data:
>        return raw_data
>      if not self.follow:
>        return None
>      time.sleep(0.001)
>      self.seek(pos)
>    
>  def read_record(self):
>    pos = self.tell()
>    header_data = self._read(self.record_header_size)
>    if not header_data:
>      return None
>    data_len, checksum = struct.unpack(self.record_header_format, header_data)
>    data = self._read(data_len)
>    new_checksum = zlib.adler32(data)
>    if self.validate_checksum and checksum != new_checksum:
>      raise ValueError('checksum failed', checksum, new_checksum, data_len, repr(data))
>    return data
>
>def run(fname):
>  os.unlink(fname)
>  writer = RecordWriter(open(fname, 'a'))
>  reader = RecordReader(open(fname))
>  x = 100
>  pid = os.fork()
>  if pid == 0:
>    do_writes(writer, x)
>  else:
>    do_reads(reader, x)
>    os.wait()
>
>def do_writes(writer, iterations):
>  for i in xrange(iterations):
>    rec = str(i)
>    writer.write_record(rec)
>    writer.pfile.flush()
>    time.sleep(random.randint(0,10) * 0.001)
>
>def do_reads(reader, iterations):
>  for i in xrange(iterations):
>    rec = reader.next()
>    if str(i) != rec:
>      print 'FAILED: expected record id, i, 'retrieved record id', rec
>      break
>
>run(sys.argv[1])

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Attachments on bug 1138970: 935083 | 935084 | 946342