sharding func: fix specifying vshard sharding funcs

Starting from 0.11.0 user can specify sharding func to
calculate bucket_id with sharding func definition as a part of
DDL schema or insert manually to the space `_ddl_sharding_func`.

Right now ddl fails with setting schema with vshard sharding function.
But even if this bug is fixed, there is also a bug on CRUD side.
Inserting manually to the space `_ddl_sharding_func` showed
that CRUD search vshard sharding func in `_G` but this
approach doesn't work with vshard case.

This patch allows to specify `vshard` sharding func
inserting manually to the space `_ddl_sharding_func`.

Closes #314

CHANGELOG.md

@@ -13,6 +13,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ### Fixed
 
+- Fix specifying `vshard` sharding funcs (#314).
+
 ## [0.12.1] - 21-07-22
 
 ### Fixed

crud/common/sharding/sharding_func.lua

@@ -9,6 +9,10 @@ local ShardingFuncError = errors.new_class('ShardingFuncError',  {capture_stack
 
 local sharding_func_module = {}
 
+local sharding_module_names = {
+    ['vshard'] = true,
+}
+
 local function is_callable(object)
     if type(object) == 'function' then
         return true
@@ -43,13 +47,25 @@ end
 local function get_function_from_G(func_name)
     local chunks = string.split(func_name, '.')
     local sharding_func = _G
+    local sharding_module = false
+
+    if sharding_module_names[chunks[1]] then
+        sharding_func = require(chunks[1])
+        sharding_module = true
+        table.remove(chunks, 1)
+    end
 
     -- check is the each chunk an identifier
     for _, chunk in pairs(chunks) do
         if not utils.check_name_isident(chunk) or sharding_func == nil then
             return nil
         end
-        sharding_func = rawget(sharding_func, chunk)
+
+        if sharding_module then
+            sharding_func = sharding_func[chunk]
+        else
+            sharding_func = rawget(sharding_func, chunk)
+        end
     end
 
     return sharding_func

test/entrypoint/srv_ddl.lua

@@ -161,6 +161,8 @@ package.preload['customers-storage'] = function()
             local customers_G_func_schema = table.deepcopy(customers_id_key_schema)
             customers_G_func_schema.sharding_func = 'some_module.sharding_func'
 
+            local customers_vshard_func_schema = table.deepcopy(customers_id_key_schema)
+
             local schema = {
                 spaces = {
                     customers = customers_id_schema,
@@ -173,6 +175,7 @@ package.preload['customers-storage'] = function()
                     customers_name_age_key_three_fields_index = customers_name_age_key_three_fields_index_schema,
                     customers_G_func = customers_G_func_schema,
                     customers_body_func = customers_body_func_schema,
+                    customers_vshard_func = customers_vshard_func_schema,
                 }
             }
 
@@ -188,7 +191,9 @@ package.preload['customers-storage'] = function()
                 box.space['_ddl_sharding_key']:update(space_name, {{'=', fieldno_sharding_key, sharding_key_def}})
             end)
             rawset(_G, 'set_sharding_func', function(space_name, fieldno_sharding_func, sharding_func_def)
-                box.space['_ddl_sharding_func']:update(space_name, {{'=', fieldno_sharding_func, sharding_func_def}})
+                local record = {space_name, box.NULL, box.NULL}
+                record[fieldno_sharding_func] = sharding_func_def
+                box.space['_ddl_sharding_func']:replace(record)
             end)
         end,
     }

test/integration/ddl_sharding_func_test.lua

@@ -75,6 +75,7 @@ cache_group.after_all(function(g) helpers.stop_cluster(g.cluster) end)
 cache_group.before_each(function(g)
     helpers.truncate_space_on_cluster(g.cluster, 'customers_G_func')
     helpers.truncate_space_on_cluster(g.cluster, 'customers_body_func')
+    helpers.truncate_space_on_cluster(g.cluster, 'customers_vshard_func')
 end)
 
 pgroup.test_insert_object = function(g)
@@ -938,3 +939,68 @@ pgroup.test_gh_278_count_with_explicit_bucket_id_and_ddl = function(g)
     t.assert_is_not(obj, nil)
     t.assert_equals(obj, 1)
 end
+
+local vshard_cases = {
+    mpcrc32 = {
+        sharding_func_name = 'vshard.router.bucket_id_mpcrc32',
+        bucket_id = 1614,
+        srv_with_data = 's1-master',
+        srv_without_data = 's2-master',
+    },
+    strcrc32 = {
+        sharding_func_name = 'vshard.router.bucket_id_strcrc32',
+        bucket_id = 477,
+        srv_with_data = 's2-master',
+        srv_without_data = 's1-master',
+    }
+}
+
+for name, case in pairs(vshard_cases) do
+    local test_name = ('test_vshard_%s_sharding_func'):format(name)
+
+    cache_group[test_name] = function(g)
+        local fieldno_sharding_func_name = 2
+        local space_name = 'customers_vshard_func'
+
+        helpers.call_on_servers(g.cluster, {'s1-master', 's2-master'}, function(server)
+            server.net_box:call('set_sharding_func',
+                    {space_name, fieldno_sharding_func_name, case.sharding_func_name})
+        end)
+
+        local record_exist, err = helpers.update_sharding_func_cache(g.cluster, space_name)
+        t.assert_equals(err, nil)
+        t.assert_equals(record_exist, true)
+
+        -- Insert a tuple.
+        local result, err = g.cluster.main_server.net_box:call(
+                'crud.insert', {space_name, {1, box.NULL, 'Ivan', 25}})
+        t.assert_equals(err, nil)
+        t.assert_equals(result.metadata, {
+            {is_nullable = false, name = 'id', type = 'unsigned'},
+            {is_nullable = false, name = 'bucket_id', type = 'unsigned'},
+            {is_nullable = false, name = 'name', type = 'string'},
+            {is_nullable = false, name = 'age', type = 'number'},
+        })
+        t.assert_equals(#result.rows, 1)
+        t.assert_equals(result.rows[1], {1, case.bucket_id, 'Ivan', 25})
+
+        -- There is a tuple on server that we inserted before using crud.insert().
+        local conn_srv_with_data = g.cluster:server(case.srv_with_data).net_box
+        local result = conn_srv_with_data.space[space_name]:get({1})
+        t.assert_equals(result, {1, case.bucket_id, 'Ivan', 25})
+
+        -- There is no tuple on server that we inserted before using crud.insert().
+        local conn_srv_without_data = g.cluster:server(case.srv_without_data).net_box
+        local result = conn_srv_without_data.space[space_name]:get({1})
+        t.assert_equals(result, nil)
+
+        local conditions = {{'==', 'id', 1}}
+        local result, err = g.cluster.main_server.net_box:call('crud.select', {
+            space_name, conditions,
+        })
+
+        t.assert_equals(err, nil)
+        t.assert_equals(#result.rows, 1)
+        t.assert_equals(result.rows[1], {1, case.bucket_id, 'Ivan', 25})
+    end
+end

test/integration/ddl_sharding_key_test.lua

@@ -898,6 +898,7 @@ pgroup.test_update_cache_with_incorrect_key = function(g)
         customers = {parts = {{fieldno = 1}}},
         customers_G_func = {parts = {{fieldno = 1}}},
         customers_body_func = {parts = {{fieldno = 1}}},
+        customers_vshard_func = {parts = {{fieldno = 1}}},
         customers_age_key = {parts = {{fieldno = 4}}},
         customers_name_age_key_different_indexes = {parts = {{fieldno = 3}, {fieldno = 4}}},
         customers_name_age_key_three_fields_index = {parts = {{fieldno = 3}, {fieldno = 4}}},
@@ -925,6 +926,7 @@ pgroup.test_update_cache_with_incorrect_key = function(g)
         customers = {parts = {{fieldno = 1}}},
         customers_G_func = {parts = {{fieldno = 1}}},
         customers_body_func = {parts = {{fieldno = 1}}},
+        customers_vshard_func = {parts = {{fieldno = 1}}},
         customers_age_key = {parts = {{fieldno = 4}}},
         customers_name_age_key_different_indexes = {parts = {{fieldno = 3}, {fieldno = 4}}},
         customers_name_age_key_three_fields_index = {parts = {{fieldno = 3}, {fieldno = 4}}},
@@ -951,6 +953,7 @@ pgroup.test_update_cache_with_incorrect_key = function(g)
         customers = {parts = {{fieldno = 1}}},
         customers_G_func = {parts = {{fieldno = 1}}},
         customers_body_func = {parts = {{fieldno = 1}}},
+        customers_vshard_func = {parts = {{fieldno = 1}}},
         customers_age_key = {parts = {{fieldno = 4}}},
         customers_name_age_key_different_indexes = {parts = {{fieldno = 3}, {fieldno = 4}}},
         customers_name_age_key_three_fields_index = {parts = {{fieldno = 3}, {fieldno = 4}}},