#!/usr/bin/env bash
# nbdkit
# Copyright Red Hat
#
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# modification, are permitted provided that the following conditions are
# met:
#
# * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
#
# * Redistributions in binary form must reproduce the above copyright
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# documentation and/or other materials provided with the distribution.
#
# * Neither the name of Red Hat nor the names of its contributors may be
# used to endorse or promote products derived from this software without
# specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
# THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
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# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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# OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.

source ./functions.sh
set -e
set -x

requires_filter cow
requires_nbdsh_uri

# On Windows, calling ftruncate in the cow filter fails with:
# nbdkit: memory[1]: error: ftruncate: File too large
if is_windows; then
   echo "$0: the cow filter needs to be fixed to work on Windows"
   exit 77
fi

sock=$(mktemp -u /tmp/nbdkit-test-sock.XXXXXX)
files="$sock cow-on-read.pid"
rm -f $files
cleanup_fn rm -f $files

# Run nbdkit with the cow filter and cow-on-read.
start_nbdkit -P cow-on-read.pid -U $sock \
             --filter=cow \
             memory 128K cow-on-read=true

nbdsh --connect "nbd+unix://?socket=$sock" \
      -c '
# Write some pattern data to the overlay and check it reads back OK.
buf = b"abcd" * 16384
h.pwrite(buf, 32768)
zero = h.pread(32768, 0)
assert zero == bytearray(32768)
buf2 = h.pread(65536, 32768)
assert buf == buf2
'
