# Some more complex uses of mount tables and mounts
#
# TODO - list the examples and any issues.

cache off

root
set root_h=$_
eval $root_h
set root=$MT_NAME

set NAMESPACE_ROOT=$root
mt tl/a
set m=$_
set mt_a_h=$m
eval $m
eval $m
set mt_a_name=$MT_NAME
set mt_a_addr=$MT_ADDR

mt tl/b
set m=$_
set mt_b_h=$m
eval $m
eval $m
set mt_b_name=$MT_NAME
set mt_b_addr=$MT_ADDR

setRoots $root

#
# Using glob 'correctly' takes some care. There are (at least?) three
# forms that you need to consider...
#

# ls ... finds all of the mount points, as relative names
ls ...
set l=$_
eval $l
assert $RN 3
wait $l

# ls /... is meaningless, finds nothing
ls /...
set l=$_
eval $l
assert $RN 0
wait $l

# a rooted glob finds all of the mount points, include an entry for the root
# itself. It returns rooted names.
ls $root/...
set l=$_
eval $l
assert $RN 4
wait $l

resolve tl/a
set r=$_
eval $r
assert $RN 1
eval $r
assert $R0 $mt_a_name
wait $r

#
# Now, let's run some echo servers, invoke rpc's on them, see what
# glob and resolve do.
#

# run an echo server on tl.
echoServer "E1" tl
set es_E1=$_
read $es_E1
eval $es_E1
set es_E1_addr=$ADDR

# the echo server above, obscures the mount tables below it.
# each of the ls (i.e. glob) calls below will lead to 'ipc:unknown method'
# errors generated by the echo server.
ls ...
set l=$_
eval $l
assert $RN 1

ls $root/...
set l=$_
eval $l
assert $RN 2

echoClient tl test
read $_ o
assert $o "E1: test"

# resolve will find the address of the echo server.
resolve tl
set r=$_
eval $r
assert $RN 1
eval $r
assert $R0 /$es_E1_addr//

# let's have the echo server shut down
stop $es_E1

# and now, we can see the mount tables again.
ls ...
set l=$_
eval $l
assert $RN 3
wait $l

resolve tl/a
set r=$_
eval $r
assert $RN 1
eval $r
assert $R0 $mt_a_name

# run an echo server on tl/a
echoServer "E2" tl/a
set es_E2=$_
read $es_E2
eval $es_E2
read $es_E2
set es_E2_addr=$ADDR

# we can invoke the echo server 'E2' just fine, probably because
# we just get lucky and get the most recently mounted address back first.
echoClient "tl/a" bar
read $_ o
assert $o "E2: bar"

# but, when we resolve it's name, we get back two servers, one for the
# mount table and another for the server!
resolve tl/a
set r=$_
eval $r
assert $RN 2
eval $r
assert $R0 /$es_E2_addr//
eval $r
assert $R1 $mt_a_name

# resolveMT correctly returns the root's address.
resolveMT tl/a
set r=$_
eval $r
assert $RN 1
eval $r
assert $R0 $root//tl/a

#
# NOTE: I propose to fix the above ambiguity by having resolve only
# ever return non-mountpoint servers. To do so, requires that the mount table
# can tell them apart, which requires the separate Mount and MountMT calls.
#

# Mount the same server somewhere else
mount tl/a/c /$es_E2_addr// 1h
wait $_

ls ...
wait $_

# this leads to 1 call of ResolveStep for //c on the echo server.
resolve tl/a/c
wait $_

# this leads to 2 calls of ResolveStep for //c on the echo server.
echoClient tl/a/c baz
read $_ o
assert $o "E2: baz"

#
# Can the spurious calls to ResolveStep above be avoided??
#

# Mount the same server with a really long name.
set long_name=tl/b/x/y/z/really/long
mount $long_name /$es_E2_addr// 1h
wait $_

echoClient $long_name "long baz"
read $_ o
assert $o "E2: long baz"

# This example just creates a 'pointer' into the Echo servers name space.
# NOTE: do we really need this functionality?
#
# ResolveStep is again called on the server for //tl/b/x/y/z/really/long
mount tl/b/short1 /$es_E2_addr/$long_name 1h
wait $_

echoClient tl/b/short1 "short baz"
read $_ o
assert $o E2.${long_name}": short baz"

# Create a mount table with a 'long' name
set long_name=tl/b/some/deep/name/that/is/a/mount/table
mt $long_name
set m=$_
eval $m
eval $m
set mt_l_name=$MT_NAME
set mt_l_addr=$MT_ADDR


# Create a second mount table with a 'long' name
set second_long_name=tl/a/some/deep/name/that/is/a/mount/table
mt $second_long_name
set m=$_
eval $m
eval $m
set mt_l2_name=$MT_NAME
set mt_l2_addr=$MT_ADDR

# Run an echo server that uses that mount table
echoServer "E3" $long_name/echo
set es_E3=$_
read $es_E3
eval $es_E3
set es_E3_addr=$ADDR

echoClient $long_name/echo "long E3"
read $_ o
assert $o "E3: long E3"

# make sure that the mount table is the one we expect.
resolveMT $long_name/echo
set r=$_
eval $r
assert $RN 1
eval $r
assert $R0 /$mt_l_addr//echo

# Now, use mount directly to create a 'symlink'
set symlink_target=some/deep/name/that/is/a/mount
mount tl/b/symlink /$mt_b_addr/$symlink_target 1h
wait $_

ls -l tl/b/symlink
wait $_

resolve tl/b/symlink
set r=$_
eval $r
# returns nothing since symlink is an 'interior' node.
assert $RN 0
# don't close or wait for this command since it'll error out.


# resolveMT will return the original mount point
resolveMT tl/b/symlink
set r=$_
eval $r
assert $RN 1
eval $r
assert $R0 /$mt_b_addr//$symlink_target

stop $es_E3
stop $es_E2

quit