#!/bin/sh
#
# Written by Dridi Boukelmoune <dridi.boukelmoune@gmail.com>
#
# This file is in the public domain.
#
# 4.2.  Maximum Table Size
#
#    Protocols that use HPACK determine the maximum size that the encoder
#    is permitted to use for the dynamic table.  In HTTP/2, this value is
#    determined by the SETTINGS_HEADER_TABLE_SIZE setting (see
#    Section 6.5.2 of [HTTP2]).
#
#    An encoder can choose to use less capacity than this maximum size
#    (see Section 6.3), but the chosen size MUST stay lower than or equal
#    to the maximum set by the protocol.
#
#    A change in the maximum size of the dynamic table is signaled via a
#    dynamic table size update (see Section 6.3).  This dynamic table size
#    update MUST occur at the beginning of the first header block
#    following the change to the dynamic table size.  In HTTP/2, this
#    follows a settings acknowledgment (see Section 6.5.3 of [HTTP2]).
#
#    Multiple updates to the maximum table size can occur between the
#    transmission of two header blocks.  In the case that this size is
#    changed more than once in this interval, the smallest maximum table
#    size that occurs in that interval MUST be signaled in a dynamic table
#    size update.  The final maximum size is always signaled, resulting in
#    at most two dynamic table size updates.  This ensures that the
#    decoder is able to perform eviction based on reductions in dynamic
#    table size (see Section 4.3).
#
#    This mechanism can be used to completely clear entries from the
#    dynamic table by setting a maximum size of 0, which can subsequently
#    be restored.

. "$(dirname "$0")"/common.sh

_ ---------------------------------------
_ Encoder can choose to use less capacity
_ ---------------------------------------

mk_hex <<EOF
# update table size to 0
20

# dynamic field "name: value"
4004 6e61 6d65 0576 616c 7565           | @.name.value
EOF

mk_msg <<EOF
name: value
EOF

mk_tbl </dev/null

mk_enc <<EOF
update 0
dynamic str name str value
EOF

tst_decode
tst_encode

_ ----------------------------
_ Resize followed by an update
_ ----------------------------

mk_hex <<EOF
# dynamic field "name: value"
4004 6e61 6d65 0576 616c 7565           | @.name.value

# table update to 20
34                                      | 4

# literal field "name: value"
0004 6e61 6d65 0576 616c 7565           | ..name.value
EOF

mk_msg <<EOF
name: value
name: value
EOF

mk_tbl </dev/null

mk_enc <<EOF
dynamic str name str value
send

resize 20

# cashpack automatically sends the update
literal str name str value
EOF

tst_decode --decoding-spec d12,r20,
tst_encode

_ -----------------------------------------------------
_ Table resized multiple times between two HPACK blocks
_ -----------------------------------------------------

mk_hex <<EOF
# dynamic field "name: value"
4004 6e61 6d65 0576 616c 7565           | @.name.value

# table update to 0
20                                      |  

# table update back to 4096
3fe1 1f                                 | ?..

# literal field "name: value"
0004 6e61 6d65 0576 616c 7565           | ..name.value
EOF

mk_enc <<EOF
dynamic str name str value
send

resize 0
resize 4096

# cashpack automatically sends both updates
literal str name str value
EOF

tst_decode --decoding-spec d12,r0,r4096,
tst_encode

_ ----------------------------------------------------------
_ Table resized more than two times between two HPACK blocks
_ ----------------------------------------------------------

mk_enc <<EOF
dynamic str name str value
send

# the first resize will be ignored leading to the same
# HPACK blocks as the previous test case
resize 20
resize 0
resize 4096

# cashpack automatically sends the two relevant updates
literal str name str value
EOF

tst_decode --decoding-spec d12,r20,r0,r4096,
tst_encode

_ ---------------------------------------------------------
_ Use less capacity for the last update of multiple resizes
_ ---------------------------------------------------------

mk_hex <<EOF
# dynamic field "name: value"
4004 6e61 6d65 0576 616c 7565           | @.name.value

# table update to 0
20                                      |  

# table update to only 2048
3fe1 08                                 | ?..

# literal field "name: value"
0004 6e61 6d65 0576 616c 7565           | ..name.value
EOF

tst_decode --decoding-spec d12,r0,r4096,
# XXX: not testable yet for encoding

_ ---------------------------
_ Missing update after resize
_ ---------------------------

mk_hex <<EOF
# dynamic field "name: value"
4004 6e61 6d65 0576 616c 7565           | @.name.value

# literal field "name: value"
0004 6e61 6d65 0576 616c 7565           | ..name.value
EOF

tst_decode --decoding-spec d12,r0, --expect-error RSZ

_ ------------------------------------
_ Omit the minimum of multiple resizes
_ ------------------------------------

mk_hex <<EOF
# dynamic field "name: value"
4004 6e61 6d65 0576 616c 7565           | @.name.value

# table update to 4096
3fe1 1f                                 | ?..
EOF

tst_decode --decoding-spec d12,r0,r4096, --expect-error UPD

_ -------------------------------------
_ Update too big after multiple resizes
_ -------------------------------------

mk_hex <<EOF
# dynamic field "name: value"
4004 6e61 6d65 0576 616c 7565           | @.name.value

# table update to 0
20                                      |  

# table update over 9000
3f8a 46                                 | ?.F
EOF

tst_decode --decoding-spec d12,r0,r4096, --expect-error UPD

_ -------------------------------------------------------
_ Table size update not at the begining of an HPACK block
_ -------------------------------------------------------

mk_msg </dev/null
mk_tbl </dev/null

mk_bin <<EOF
10000100 | pick ":path: /" from the 4th static entry
00111111 | 001 (table update) and 31 (5-bit prefix)
01110111 | 0 (end of int) and 119 (total: 150)
EOF

tst_decode --expect-error UPD

_ ---------------------------------------------
_ No more than two updates can occur in a block
_ ---------------------------------------------

mk_hex <<EOF
# dynamic field "name: value"
4004 6e61 6d65 0576 616c 7565           | @.name.value

# table update to 0
20                                      |  

# table update back to 4096
3fe1 1f                                 | ?..

# table update to 20
34                                      | 4
EOF

HDECODE=hdecode # XXX: nghttp2 1.7.1 fails this test
tst_decode --decoding-spec d12,r0,r4096, --expect-error UPD

_ ----------------------------------
_ Set a limit above the maximum size
_ ----------------------------------

mk_hex <<EOF
# no update received
4004 6e61 6d65 0576 616c 7565 4005 6f74 | @.name.value@.ot
6865 7205 6669 656c 64                  | her.field
EOF

mk_tbl <<EOF
[  1] (s =  42) other: field
      Table size:  42
EOF

mk_enc <<EOF
update 4096
dynamic str name str value
dynamic str other str field
EOF

tst_encode --table-size 42

# the same test with the limit set during allocation
mk_enc <<EOF
dynamic str name str value
dynamic str other str field
EOF

tst_encode --table-limit 4096 --table-size 42

_ ---------------------------------------
_ Resize above the limit after it was set
_ ---------------------------------------

mk_hex <<EOF
# no update, yet
4004 6e61 6d65 0576 616c 7565 4005 6f74 | @.name.value@.ot
6865 7205 6669 656c 64                  | her.field

# table update to 0
20

# table update to 4096
3fe1 1f

4004 6e61 6d65 0576 616c 7565 4005 6f74 | @.name.value@.ot
6865 7205 6669 656c 64                  | her.field
EOF

mk_tbl <<EOF
[  1] (s =  42) other: field
[  2] (s =  41) name: value
      Table size:  83
EOF

mk_enc <<EOF
update 4096
dynamic str name str value
dynamic str other str field
send

resize 0
resize 8192
dynamic str name str value
dynamic str other str field
EOF

tst_encode

# the same test with the limit set during allocation
mk_enc <<EOF
dynamic str name str value
dynamic str other str field
send

resize 0
resize 8192
dynamic str name str value
dynamic str other str field
EOF

tst_encode --table-limit 4096

_ ----------------------
_ Resize below the limit
_ ----------------------

mk_hex <<EOF
# table update to 4096
3fe1 1f

4004 6e61 6d65 0576 616c 7565 4005 6f74 | @.name.value@.ot
6865 7205 6669 656c 64                  | her.field
EOF

mk_tbl <<EOF
[  1] (s =  42) other: field
[  2] (s =  41) name: value
      Table size:  83
EOF

mk_enc <<EOF
update 8192
resize 4096
dynamic str name str value
dynamic str other str field
EOF

tst_encode --table-size 42

# the same test with the limit set during allocation
mk_enc <<EOF
resize 4096
dynamic str name str value
dynamic str other str field
EOF

tst_encode --table-limit 8192 --table-size 42