tests/python-export-name.py

   1 # nbdkit
   2 # Copyright (C) 2018-2020 Red Hat Inc.
   3 #
   4 # Redistribution and use in source and binary forms, with or without
   5 # modification, are permitted provided that the following conditions are
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   9 # notice, this list of conditions and the following disclaimer.
  10 #
  11 # * Redistributions in binary form must reproduce the above copyright
  12 # notice, this list of conditions and the following disclaimer in the
  13 # documentation and/or other materials provided with the distribution.
  14 #
  15 # * Neither the name of Red Hat nor the names of its contributors may be
  16 # used to endorse or promote products derived from this software without
  17 # specific prior written permission.
  18 #
  19 # THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND
  20 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  21 # THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
  22 # PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR
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  29 # OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30 # SUCH DAMAGE.
  31
  32 # Create an nbdkit sh plugin which reflects the export name back to
  33 # the caller in the virtual device data and size.
  34
  35 import nbdkit
  36
  37
  38 def open(readonly):
  39     # The export name is a Unicode string, but to return this to the
  40     # client we have to convert it to bytes.
  41     name = nbdkit.export_name()
  42     nbdkit.debug("export name = '%s'" % name)
  43     return {'name': str.encode(name)}
  44
  45
  46 def get_size(h):
  47     return len(h['name'])
  48
  49
  50 def pread(h, count, offset):
  51     end = offset + count
  52     return h['name'][offset:end]