[tarantool-patches] Re: [PATCH] Cache find_sharded_spaces result

[Vladislav Shpilevoy <v.shpilevoy@tarantool.org>]

Pushed.

On 04/06/2018 15:52, AKhatskevich wrote:
> `find_sharded_spaces` result is cached.
> Cache result is updated only when `schema_version` changes.
> 
> User-visible `sharded_spaces` function returns a deep copy of the cached
> result and user cannot affect a result of a future call to the function.
> 
> Closes: #111
> ---
> Branch: https://github.com/tarantool/vshard/tree/kh/gh-111-cache_spaces
> Issue: https://github.com/tarantool/vshard/issues/111
> 
>   test/unit/garbage.result   | 24 ++++++++++++++++++++++--
>   test/unit/garbage.test.lua |  9 +++++++++
>   vshard/storage/init.lua    | 15 +++++++++++++--
>   3 files changed, 44 insertions(+), 4 deletions(-)
> 
> diff --git a/test/unit/garbage.result b/test/unit/garbage.result
> index 270949c..0da8ee1 100644
> --- a/test/unit/garbage.result
> +++ b/test/unit/garbage.result
> @@ -106,8 +106,8 @@ sk2 = s2:create_index('bucket_id', {parts = {{2, 'unsigned'}}, unique = false})
>   ...
>   show_sharded_spaces()
>   ---
> -- - test2
> -  - test
> +- - test
> +  - test2
>   ...
>   s:drop()
>   ---
> @@ -116,6 +116,26 @@ s2:drop()
>   ---
>   ...
>   --
> +-- gh-111: cache sharded spaces based on schema version
> +--
> +cached_spaces = vshard.storage.internal.cached_find_sharded_spaces()
> +---
> +...
> +cached_spaces == vshard.storage.internal.cached_find_sharded_spaces()
> +---
> +- true
> +...
> +s = box.schema.create_space('test')
> +---
> +...
> +cached_spaces == vshard.storage.internal.cached_find_sharded_spaces()
> +---
> +- false
> +...
> +s:drop()
> +---
> +...
> +--
>   -- Test garbage buckets detection.
>   --
>   find_garbage = vshard.storage.internal.find_garbage_bucket
> diff --git a/test/unit/garbage.test.lua b/test/unit/garbage.test.lua
> index 12a59c5..db7821f 100644
> --- a/test/unit/garbage.test.lua
> +++ b/test/unit/garbage.test.lua
> @@ -58,6 +58,15 @@ show_sharded_spaces()
>   s:drop()
>   s2:drop()
>   
> +--
> +-- gh-111: cache sharded spaces based on schema version
> +--
> +cached_spaces = vshard.storage.internal.cached_find_sharded_spaces()
> +cached_spaces == vshard.storage.internal.cached_find_sharded_spaces()
> +s = box.schema.create_space('test')
> +cached_spaces == vshard.storage.internal.cached_find_sharded_spaces()
> +s:drop()
> +
>   --
>   -- Test garbage buckets detection.
>   --
> diff --git a/vshard/storage/init.lua b/vshard/storage/init.lua
> index f3f1bab..d5e7b57 100644
> --- a/vshard/storage/init.lua
> +++ b/vshard/storage/init.lua
> @@ -552,10 +552,16 @@ local function bucket_recv(bucket_id, from, data)
>   end
>   
>   --
> --- Find spaces with index having the specified name.
> +-- Find spaces with index having the specified (in cfg) name.
> +-- The function result is cached using `schema_version`.
>   -- @retval Map of type {space_id = <space object>}.
>   --
> +local sharded_spaces_cache_schema_version = nil
> +local sharded_spaces_cache = nil
>   local function find_sharded_spaces()
> +    if sharded_spaces_cache_schema_version == box.internal.schema_version() then
> +        return sharded_spaces_cache
> +    end
>       local spaces = {}
>       local idx = M.shard_index
>       for k, space in pairs(box.space) do
> @@ -567,6 +573,8 @@ local function find_sharded_spaces()
>               end
>           end
>       end
> +    sharded_spaces_cache_schema_version = box.internal.schema_version()
> +    sharded_spaces_cache = spaces
>       return spaces
>   end
>   
> @@ -1817,6 +1825,7 @@ M.collect_garbage_step = collect_garbage_step
>   M.collect_garbage_f = collect_garbage_f
>   M.rebalancer_build_routes = rebalancer_build_routes
>   M.rebalancer_calculate_metrics = rebalancer_calculate_metrics
> +M.cached_find_sharded_spaces = find_sharded_spaces
>   
>   if not rawget(_G, '__module_vshard_storage') then
>       rawset(_G, '__module_vshard_storage', M)
> @@ -1853,6 +1862,8 @@ return {
>       internal = M,
>       on_master_enable = on_master_enable,
>       on_master_disable = on_master_disable,
> -    sharded_spaces = find_sharded_spaces,
> +    sharded_spaces = function()
> +        return table.deepcopy(find_sharded_spaces())
> +    end,
>       module_version = function() return M.module_version end,
>   }
>