test/test_seek.py

   1 """Test seeking on files.
   2 """
   3
   4 import io
   5 import rarfile
   6
   7 from nose.tools import *
   8
   9 ARC = 'test/files/seektest.rar'
  10
  11 def do_seek(f, pos, lim):
  12     ofs = pos*4
  13     fsize = lim*4
  14
  15     if ofs < 0:
  16         exp = 0
  17     elif ofs > fsize:
  18         exp = fsize
  19     else:
  20         exp = ofs
  21
  22     f.seek(ofs)
  23
  24     got = f.tell()
  25
  26     eq_(got, exp)
  27     ln = f.read(4)
  28     if got == fsize and ln:
  29         raise Exception('unexpected read')
  30     if not ln and got < fsize:
  31         raise Exception('unexpected read failure')
  32     if ln:
  33         spos = int(ln)
  34         eq_(spos*4, got)
  35
  36 def run_seek(rf, fn):
  37     inf = rf.getinfo(fn)
  38     cnt = int(inf.file_size / 4)
  39     f = rf.open(fn)
  40
  41     do_seek(f, int(cnt/2), cnt)
  42     do_seek(f, 0, cnt)
  43
  44     for i in range(int(cnt/2)):
  45         do_seek(f, i*2, cnt)
  46
  47     for i in range(cnt):
  48         do_seek(f, i*2 - int(cnt / 2), cnt)
  49
  50     for i in range(cnt + 10):
  51         do_seek(f, cnt - i - 5, cnt)
  52
  53     f.close()
  54
  55 def run_arc(arc, desc):
  56     files = ['stest1.txt', 'stest2.txt']
  57     rf = rarfile.RarFile(arc)
  58     for fn in files:
  59         run_seek(rf, fn)
  60
  61 def test_seek_filename():
  62     run_arc(ARC, "fn")
  63
  64 def test_seek_stringio():
  65     data = open(ARC, 'rb').read()
  66
  67     # filelike: cStringIO
  68     try:
  69         import cStringIO
  70         run_arc(cStringIO.StringIO(data), "cStringIO")
  71     except ImportError:
  72         pass
  73
  74     # filelike: StringIO
  75     try:
  76         import StringIO
  77         run_arc(StringIO.StringIO(data), "StringIO")
  78     except ImportError:
  79         pass
  80
  81 def test_seek_bytesio():
  82     # filelike: io.BytesIO, io.open()
  83     data = open(ARC, 'rb').read()
  84     run_arc(io.BytesIO(data), "io.BytesIO")
  85
  86 def test_seek_open():
  87     # filelike: file()
  88     run_arc(open(ARC, 'rb'), "open")
  89
  90 def test_seek_ioopen():
  91     # filelike: io.open()
  92     run_arc(io.open(ARC, 'rb'), "io.open")
  93