tests/test-cache-block-size.sh

   1 #!/usr/bin/env bash
   2 # nbdkit
   3 # Copyright Red Hat
   4 #
   5 # Redistribution and use in source and binary forms, with or without
   6 # modification, are permitted provided that the following conditions are
   7 # met:
   8 #
   9 # * Redistributions of source code must retain the above copyright
  10 # notice, this list of conditions and the following disclaimer.
  11 #
  12 # * Redistributions in binary form must reproduce the above copyright
  13 # notice, this list of conditions and the following disclaimer in the
  14 # documentation and/or other materials provided with the distribution.
  15 #
  16 # * Neither the name of Red Hat nor the names of its contributors may be
  17 # used to endorse or promote products derived from this software without
  18 # specific prior written permission.
  19 #
  20 # THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND
  21 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  22 # THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
  23 # PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR
  24 # CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  25 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  26 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  27 # USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  28 # ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  29 # OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  30 # OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31 # SUCH DAMAGE.
  32
  33 source ./functions.sh
  34 set -e
  35 set -x
  36
  37 requires_filter cache
  38 requires_nbdsh_uri
  39
  40 sock=$(mktemp -u /tmp/nbdkit-test-sock.XXXXXX)
  41 files="cache-block-size.img $sock cache-block-size.pid"
  42 rm -f $files
  43 cleanup_fn rm -f $files
  44
  45 # Create an empty base image.
  46 $TRUNCATE -s 256K cache-block-size.img
  47
  48 # Run nbdkit with the caching filter.
  49 start_nbdkit -P cache-block-size.pid -U $sock --filter=cache \
  50              file cache-block-size.img cache-min-block-size=128K \
  51              cache-on-read=true
  52
  53 nbdsh --connect "nbd+unix://?socket=$sock" \
  54       -c '
  55 # Read half of cache-min-block-size
  56
  57 zero = h.pread(64 * 1024, 0)
  58 assert zero == bytearray(64 * 1024)
  59
  60 buf = b"abcd" * 16 * 1024
  61
  62 # Write past the first read
  63 with open("cache-block-size.img", "wb") as file:
  64     file.seek(64 * 1024)
  65     file.write(buf * 2)
  66     file.truncate(256 * 1024)
  67
  68 # Check that it got written
  69 with open("cache-block-size.img", "rb") as file:
  70     file.seek(64 * 1024)
  71     buf2 = file.read(128 * 1024)
  72     assert (buf * 2) == buf2
  73
  74 # Now read the rest of the cache-min-block-size, it should stay empty
  75 zero = h.pread(64 * 1024, 64 * 1024)
  76 assert zero == bytearray(64 * 1024)
  77
  78 # Read past that, the pattern should be visible there
  79 buf2 = h.pread(64 * 1024, 128 * 1024)
  80 assert buf == buf2
  81 '