Re: [Tarantool-patches] [PATCH 1/9] rlist: move rlist to a new module

[Oleg Babin via Tarantool-patches <tarantool-patches@dev.tarantool.org>]

I've noticed that you've missed to add new file to vshard/CMakeList.txt [1]

It will break the build.


[1] https://github.com/tarantool/vshard/blob/master/vshard/CMakeLists.txt#L9


On 10/02/2021 11:57, Oleg Babin via Tarantool-patches wrote:
> Hi! Thanks for your patch. LGTM.
>
> On 10/02/2021 02:46, Vladislav Shpilevoy wrote:
>> Rlist in storage/init.lua implemented a container similar to rlist
>> in libsmall in Tarantool core. Doubly-linked list.
>>
>> It does not depend on anything in storage/init.lua, and should
>> have been done in a separate module from the beginning.
>>
>> Now init.lua is going to grow even more in scope of map-reduce
>> feature, beyond 3k lines if nothing would be moved out. It was
>> decided (by me) that it crosses the border of when it is time to
>> split init.lua into separate modules.
>>
>> The patch takes the low hanging fruit by moving rlist into its
>> own module.
>> ---
>>   test/unit/rebalancer.result   |  99 -----------------------------
>>   test/unit/rebalancer.test.lua |  27 --------
>>   test/unit/rlist.result        | 114 ++++++++++++++++++++++++++++++++++
>>   test/unit/rlist.test.lua      |  33 ++++++++++
>>   vshard/rlist.lua              |  53 ++++++++++++++++
>>   vshard/storage/init.lua       |  68 +++-----------------
>>   6 files changed, 208 insertions(+), 186 deletions(-)
>>   create mode 100644 test/unit/rlist.result
>>   create mode 100644 test/unit/rlist.test.lua
>>   create mode 100644 vshard/rlist.lua
>>
>> diff --git a/test/unit/rebalancer.result b/test/unit/rebalancer.result
>> index 2fb30e2..19aa480 100644
>> --- a/test/unit/rebalancer.result
>> +++ b/test/unit/rebalancer.result
>> @@ -1008,105 +1008,6 @@ build_routes(replicasets)
>>   -- the latter is a dispenser. It is a structure which hands out
>>   -- destination UUIDs in a round-robin manner to worker fibers.
>>   --
>> -list = rlist.new()
>> ----
>> -...
>> -list
>> ----
>> -- count: 0
>> -...
>> -obj1 = {i = 1}
>> ----
>> -...
>> -rlist.remove(list, obj1)
>> ----
>> -...
>> -list
>> ----
>> -- count: 0
>> -...
>> -rlist.add_tail(list, obj1)
>> ----
>> -...
>> -list
>> ----
>> -- count: 1
>> -  last: &0
>> -    i: 1
>> -  first: *0
>> -...
>> -rlist.remove(list, obj1)
>> ----
>> -...
>> -list
>> ----
>> -- count: 0
>> -...
>> -obj1
>> ----
>> -- i: 1
>> -...
>> -rlist.add_tail(list, obj1)
>> ----
>> -...
>> -obj2 = {i = 2}
>> ----
>> -...
>> -rlist.add_tail(list, obj2)
>> ----
>> -...
>> -list
>> ----
>> -- count: 2
>> -  last: &0
>> -    i: 2
>> -    prev: &1
>> -      i: 1
>> -      next: *0
>> -  first: *1
>> -...
>> -obj3 = {i = 3}
>> ----
>> -...
>> -rlist.add_tail(list, obj3)
>> ----
>> -...
>> -list
>> ----
>> -- count: 3
>> -  last: &0
>> -    i: 3
>> -    prev: &1
>> -      i: 2
>> -      next: *0
>> -      prev: &2
>> -        i: 1
>> -        next: *1
>> -  first: *2
>> -...
>> -rlist.remove(list, obj2)
>> ----
>> -...
>> -list
>> ----
>> -- count: 2
>> -  last: &0
>> -    i: 3
>> -    prev: &1
>> -      i: 1
>> -      next: *0
>> -  first: *1
>> -...
>> -rlist.remove(list, obj1)
>> ----
>> -...
>> -list
>> ----
>> -- count: 1
>> -  last: &0
>> -    i: 3
>> -  first: *0
>> -...
>>   d = dispenser.create({uuid = 15})
>>   ---
>>   ...
>> diff --git a/test/unit/rebalancer.test.lua 
>> b/test/unit/rebalancer.test.lua
>> index a4e18c1..8087d42 100644
>> --- a/test/unit/rebalancer.test.lua
>> +++ b/test/unit/rebalancer.test.lua
>> @@ -246,33 +246,6 @@ build_routes(replicasets)
>>   -- the latter is a dispenser. It is a structure which hands out
>>   -- destination UUIDs in a round-robin manner to worker fibers.
>>   --
>> -list = rlist.new()
>> -list
>> -
>> -obj1 = {i = 1}
>> -rlist.remove(list, obj1)
>> -list
>> -
>> -rlist.add_tail(list, obj1)
>> -list
>> -
>> -rlist.remove(list, obj1)
>> -list
>> -obj1
>> -
>> -rlist.add_tail(list, obj1)
>> -obj2 = {i = 2}
>> -rlist.add_tail(list, obj2)
>> -list
>> -obj3 = {i = 3}
>> -rlist.add_tail(list, obj3)
>> -list
>> -
>> -rlist.remove(list, obj2)
>> -list
>> -rlist.remove(list, obj1)
>> -list
>> -
>>   d = dispenser.create({uuid = 15})
>>   dispenser.pop(d)
>>   for i = 1, 14 do assert(dispenser.pop(d) == 'uuid', i) end
>> diff --git a/test/unit/rlist.result b/test/unit/rlist.result
>> new file mode 100644
>> index 0000000..c8aabc0
>> --- /dev/null
>> +++ b/test/unit/rlist.result
>> @@ -0,0 +1,114 @@
>> +-- test-run result file version 2
>> +--
>> +-- gh-161: parallel rebalancer. One of the most important part of 
>> the latter is
>> +-- a dispenser. It is a structure which hands out destination UUIDs 
>> in a
>> +-- round-robin manner to worker fibers. It uses rlist data structure.
>> +--
>> +rlist = require('vshard.rlist')
>> + | ---
>> + | ...
>> +
>> +list = rlist.new()
>> + | ---
>> + | ...
>> +list
>> + | ---
>> + | - count: 0
>> + | ...
>> +
>> +obj1 = {i = 1}
>> + | ---
>> + | ...
>> +list:remove(obj1)
>> + | ---
>> + | ...
>> +list
>> + | ---
>> + | - count: 0
>> + | ...
>> +
>> +list:add_tail(obj1)
>> + | ---
>> + | ...
>> +list
>> + | ---
>> + | - count: 1
>> + |   last: &0
>> + |     i: 1
>> + |   first: *0
>> + | ...
>> +
>> +list:remove(obj1)
>> + | ---
>> + | ...
>> +list
>> + | ---
>> + | - count: 0
>> + | ...
>> +obj1
>> + | ---
>> + | - i: 1
>> + | ...
>> +
>> +list:add_tail(obj1)
>> + | ---
>> + | ...
>> +obj2 = {i = 2}
>> + | ---
>> + | ...
>> +list:add_tail(obj2)
>> + | ---
>> + | ...
>> +list
>> + | ---
>> + | - count: 2
>> + |   last: &0
>> + |     i: 2
>> + |     prev: &1
>> + |       i: 1
>> + |       next: *0
>> + |   first: *1
>> + | ...
>> +obj3 = {i = 3}
>> + | ---
>> + | ...
>> +list:add_tail(obj3)
>> + | ---
>> + | ...
>> +list
>> + | ---
>> + | - count: 3
>> + |   last: &0
>> + |     i: 3
>> + |     prev: &1
>> + |       i: 2
>> + |       next: *0
>> + |       prev: &2
>> + |         i: 1
>> + |         next: *1
>> + |   first: *2
>> + | ...
>> +
>> +list:remove(obj2)
>> + | ---
>> + | ...
>> +list
>> + | ---
>> + | - count: 2
>> + |   last: &0
>> + |     i: 3
>> + |     prev: &1
>> + |       i: 1
>> + |       next: *0
>> + |   first: *1
>> + | ...
>> +list:remove(obj1)
>> + | ---
>> + | ...
>> +list
>> + | ---
>> + | - count: 1
>> + |   last: &0
>> + |     i: 3
>> + |   first: *0
>> + | ...
>> diff --git a/test/unit/rlist.test.lua b/test/unit/rlist.test.lua
>> new file mode 100644
>> index 0000000..db52955
>> --- /dev/null
>> +++ b/test/unit/rlist.test.lua
>> @@ -0,0 +1,33 @@
>> +--
>> +-- gh-161: parallel rebalancer. One of the most important part of 
>> the latter is
>> +-- a dispenser. It is a structure which hands out destination UUIDs 
>> in a
>> +-- round-robin manner to worker fibers. It uses rlist data structure.
>> +--
>> +rlist = require('vshard.rlist')
>> +
>> +list = rlist.new()
>> +list
>> +
>> +obj1 = {i = 1}
>> +list:remove(obj1)
>> +list
>> +
>> +list:add_tail(obj1)
>> +list
>> +
>> +list:remove(obj1)
>> +list
>> +obj1
>> +
>> +list:add_tail(obj1)
>> +obj2 = {i = 2}
>> +list:add_tail(obj2)
>> +list
>> +obj3 = {i = 3}
>> +list:add_tail(obj3)
>> +list
>> +
>> +list:remove(obj2)
>> +list
>> +list:remove(obj1)
>> +list
>> diff --git a/vshard/rlist.lua b/vshard/rlist.lua
>> new file mode 100644
>> index 0000000..4be5382
>> --- /dev/null
>> +++ b/vshard/rlist.lua
>> @@ -0,0 +1,53 @@
>> +--
>> +-- A subset of rlist methods from the main repository. Rlist is a
>> +-- doubly linked list, and is used here to implement a queue of
>> +-- routes in the parallel rebalancer.
>> +--
>> +local rlist_mt = {}
>> +
>> +function rlist_mt.add_tail(rlist, object)
>> +    local last = rlist.last
>> +    if last then
>> +        last.next = object
>> +        object.prev = last
>> +    else
>> +        rlist.first = object
>> +    end
>> +    rlist.last = object
>> +    rlist.count = rlist.count + 1
>> +end
>> +
>> +function rlist_mt.remove(rlist, object)
>> +    local prev = object.prev
>> +    local next = object.next
>> +    local belongs_to_list = false
>> +    if prev then
>> +        belongs_to_list = true
>> +        prev.next = next
>> +    end
>> +    if next then
>> +        belongs_to_list = true
>> +        next.prev = prev
>> +    end
>> +    object.prev = nil
>> +    object.next = nil
>> +    if rlist.last == object then
>> +        belongs_to_list = true
>> +        rlist.last = prev
>> +    end
>> +    if rlist.first == object then
>> +        belongs_to_list = true
>> +        rlist.first = next
>> +    end
>> +    if belongs_to_list then
>> +        rlist.count = rlist.count - 1
>> +    end
>> +end
>> +
>> +local function rlist_new()
>> +    return setmetatable({count = 0}, {__index = rlist_mt})
>> +end
>> +
>> +return {
>> +    new = rlist_new,
>> +}
>> diff --git a/vshard/storage/init.lua b/vshard/storage/init.lua
>> index 5464824..1b48bf1 100644
>> --- a/vshard/storage/init.lua
>> +++ b/vshard/storage/init.lua
>> @@ -13,12 +13,13 @@ if rawget(_G, MODULE_INTERNALS) then
>>           'vshard.consts', 'vshard.error', 'vshard.cfg',
>>           'vshard.replicaset', 'vshard.util',
>>           'vshard.storage.reload_evolution',
>> -        'vshard.lua_gc',
>> +        'vshard.lua_gc', 'vshard.rlist'
>>       }
>>       for _, module in pairs(vshard_modules) do
>>           package.loaded[module] = nil
>>       end
>>   end
>> +local rlist = require('vshard.rlist')
>>   local consts = require('vshard.consts')
>>   local lerror = require('vshard.error')
>>   local lcfg = require('vshard.cfg')
>> @@ -1786,54 +1787,6 @@ local function 
>> rebalancer_build_routes(replicasets)
>>       return bucket_routes
>>   end
>>   ---
>> --- A subset of rlist methods from the main repository. Rlist is a
>> --- doubly linked list, and is used here to implement a queue of
>> --- routes in the parallel rebalancer.
>> ---
>> -local function rlist_new()
>> -    return {count = 0}
>> -end
>> -
>> -local function rlist_add_tail(rlist, object)
>> -    local last = rlist.last
>> -    if last then
>> -        last.next = object
>> -        object.prev = last
>> -    else
>> -        rlist.first = object
>> -    end
>> -    rlist.last = object
>> -    rlist.count = rlist.count + 1
>> -end
>> -
>> -local function rlist_remove(rlist, object)
>> -    local prev = object.prev
>> -    local next = object.next
>> -    local belongs_to_list = false
>> -    if prev then
>> -        belongs_to_list = true
>> -        prev.next = next
>> -    end
>> -    if next then
>> -        belongs_to_list = true
>> -        next.prev = prev
>> -    end
>> -    object.prev = nil
>> -    object.next = nil
>> -    if rlist.last == object then
>> -        belongs_to_list = true
>> -        rlist.last = prev
>> -    end
>> -    if rlist.first == object then
>> -        belongs_to_list = true
>> -        rlist.first = next
>> -    end
>> -    if belongs_to_list then
>> -        rlist.count = rlist.count - 1
>> -    end
>> -end
>> -
>>   --
>>   -- Dispenser is a container of routes received from the
>>   -- rebalancer. Its task is to hand out the routes to worker fibers
>> @@ -1842,7 +1795,7 @@ end
>>   -- receiver nodes.
>>   --
>>   local function route_dispenser_create(routes)
>> -    local rlist = rlist_new()
>> +    local rlist = rlist.new()
>>       local map = {}
>>       for uuid, bucket_count in pairs(routes) do
>>           local new = {
>> @@ -1873,7 +1826,7 @@ local function route_dispenser_create(routes)
>>           --    the main applier fiber does some analysis on the
>>           --    destinations.
>>           map[uuid] = new
>> -        rlist_add_tail(rlist, new)
>> +        rlist:add_tail(new)
>>       end
>>       return {
>>           rlist = rlist,
>> @@ -1892,7 +1845,7 @@ local function route_dispenser_put(dispenser, 
>> uuid)
>>           local bucket_count = dst.bucket_count + 1
>>           dst.bucket_count = bucket_count
>>           if bucket_count == 1 then
>> -            rlist_add_tail(dispenser.rlist, dst)
>> +            dispenser.rlist:add_tail(dst)
>>           end
>>       end
>>   end
>> @@ -1909,7 +1862,7 @@ local function route_dispenser_skip(dispenser, 
>> uuid)
>>       local dst = map[uuid]
>>       if dst then
>>           map[uuid] = nil
>> -        rlist_remove(dispenser.rlist, dst)
>> +        dispenser.rlist:remove(dst)
>>       end
>>   end
>>   @@ -1952,9 +1905,9 @@ local function route_dispenser_pop(dispenser)
>>       if dst then
>>           local bucket_count = dst.bucket_count - 1
>>           dst.bucket_count = bucket_count
>> -        rlist_remove(rlist, dst)
>> +        rlist:remove(dst)
>>           if bucket_count > 0 then
>> -            rlist_add_tail(rlist, dst)
>> +            rlist:add_tail(dst)
>>           end
>>           return dst.uuid
>>       end
>> @@ -2742,11 +2695,6 @@ M.route_dispenser = {
>>       pop = route_dispenser_pop,
>>       sent = route_dispenser_sent,
>>   }
>> -M.rlist = {
>> -    new = rlist_new,
>> -    add_tail = rlist_add_tail,
>> -    remove = rlist_remove,
>> -}
>>   M.schema_latest_version = schema_latest_version
>>   M.schema_current_version = schema_current_version
>>   M.schema_upgrade_master = schema_upgrade_master