ddl: fix record delete

Before this patch and after introducing sharding info hash cache [1]
calling delete on "_ddl_sharding_info" and "_ddl_sharding_func" spaces
resulted in "attempt to index local 'tuple' (a nil value)" trigger
error. This patch fixes the trigger. If sharding info record is deleted,
corresponding cache section will be deleted as well.

1. 428744d

Closes #310

Author: DifferentialOrange

CHANGELOG.md

@@ -14,6 +14,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ### Fixed
 * Fetching invalid ddl confuguration (sharding key for non-existing space)
   is no longer breaks CRUD requests (#308, PR #309).
+* ddl space record delete no more throws error if crud is used (#310, PR #311).
+* crud sharding metainfo is now updated on ddl record delete (#310, PR #311).
 
 ## [0.12.0] - 28-06-22
 

crud/common/sharding/storage_metadata_cache.lua

@@ -18,16 +18,26 @@ local ddl_space = {
 
 local trigger_stash = stash.get(stash.name.ddl_triggers)
 
-local function update_sharding_func_hash(tuple)
-    local space_name = tuple[utils.SPACE_NAME_FIELDNO]
-    local sharding_func_def = utils.extract_sharding_func_def(tuple)
-    cache_data[FUNC][space_name] = utils.compute_hash(sharding_func_def)
+local function update_sharding_func_hash(old, new)
+    if new ~= nil then
+        local space_name = new[utils.SPACE_NAME_FIELDNO]
+        local sharding_func_def = utils.extract_sharding_func_def(new)
+        cache_data[FUNC][space_name] = utils.compute_hash(sharding_func_def)
+    else
+        local space_name = old[utils.SPACE_NAME_FIELDNO]
+        cache_data[FUNC][space_name] = nil
+    end
 end
 
-local function update_sharding_key_hash(tuple)
-    local space_name = tuple[utils.SPACE_NAME_FIELDNO]
-    local sharding_key_def = tuple[utils.SPACE_SHARDING_KEY_FIELDNO]
-    cache_data[KEY][space_name] = utils.compute_hash(sharding_key_def)
+local function update_sharding_key_hash(old, new)
+    if new ~= nil then
+        local space_name = new[utils.SPACE_NAME_FIELDNO]
+        local sharding_key_def = new[utils.SPACE_SHARDING_KEY_FIELDNO]
+        cache_data[KEY][space_name] = utils.compute_hash(sharding_key_def)
+    else
+        local space_name = old[utils.SPACE_NAME_FIELDNO]
+        cache_data[KEY][space_name] = nil
+    end
 end
 
 local update_hash = {
@@ -49,8 +59,8 @@ local function init_cache(section)
     pcall(space.on_replace, space, nil, trigger_stash[section])
 
     trigger_stash[section] = space:on_replace(
-        function(_, new)
-            return update_hash_func(new)
+        function(old, new)
+            return update_hash_func(old, new)
         end
     )
 
@@ -61,7 +71,7 @@ local function init_cache(section)
         -- It is more like an overcautiousness since the cycle
         -- isn't expected to yield, but let it be here.
         if cache_data[section][space_name] == nil then
-            update_hash_func(tuple)
+            update_hash_func(nil, tuple)
         end
     end
 end

test/integration/ddl_sharding_info_reload_test.lua

@@ -219,6 +219,73 @@ pgroup_storage.test_sharding_func_hash_is_updated_when_ddl_is_updated = function
     t.assert_equals(hash, sharding_utils.compute_hash({body = sharding_func_body}))
 end
 
+pgroup_storage.test_gh_310_ddl_key_record_delete_removes_cache_entry = function(g)
+    local storage = g.cluster:server('s1-master')
+    local space_name = sharding_cases.sharding_key_hash.test_space
+
+    -- Init cache by fetching sharding info.
+    local _, err = get_hash(storage, 'get_sharding_key_hash', space_name)
+    t.assert_equals(err, nil)
+
+    -- Drop space together with sharding info.
+    local _, err = storage:eval([[
+        local space_name = ...
+
+        local current_schema, err = ddl.get_schema()
+        if err ~= nil then
+            error(err)
+        end
+
+        box.space[space_name]:drop()
+        box.space['_ddl_sharding_key']:delete(space_name)
+
+        current_schema.spaces[space_name] = nil
+
+        local _, err = ddl.set_schema(current_schema)
+        if err ~= nil then
+            error(err)
+        end
+    ]], {space_name})
+    t.assert_equals(err, nil)
+
+    local hash, err = get_hash(storage, 'get_sharding_key_hash', space_name)
+    t.assert_equals(err, nil)
+    t.assert_equals(hash, nil)
+end
+
+pgroup_storage.test_gh_310_ddl_func_record_delete_removes_cache_entry = function(g)
+    local storage = g.cluster:server('s1-master')
+    local space_name = sharding_cases.sharding_func_hash.test_space
+
+    -- Init cache by fetching sharding info.
+    local _, err = get_hash(storage, 'get_sharding_func_hash', space_name)
+    t.assert_equals(err, nil)
+
+    -- Drop space together with sharding info.
+    local _, err = storage:eval([[
+        local space_name = ...
+
+        local current_schema, err = ddl.get_schema()
+        if err ~= nil then
+            error(err)
+        end
+
+        box.space[space_name]:drop()
+        box.space['_ddl_sharding_func']:delete(space_name)
+
+        current_schema.spaces[space_name] = nil
+
+        local _, err = ddl.set_schema(current_schema)
+        if err ~= nil then
+            error(err)
+        end
+    ]], {space_name})
+    t.assert_equals(err, nil)
+
+    local hash, err = get_hash(storage, 'get_sharding_func_hash', space_name)
+    t.assert_equals(err, nil)
+    t.assert_equals(hash, nil)
+end
 
 -- Test storage hash metadata mechanisms are ok after code reload.