Resolve space name in statistics

`crud.len` supports using space id instead of name. After this patch,
stats wrapper support mapping id to name.

Part of #224

crud/stats/module.lua

@@ -118,6 +118,8 @@ local function wrap_tail(space_name, op, opts, start_time, call_status, ...)
     end
 
     local context_stats = utils.get_context_section('router_stats')
+    -- Describe local variables to use `goto`.
+    local space_not_found_msg, space
 
     -- If space not exists, do not build a separate collector for it.
     -- Call request for non-existing space will always result in error.
@@ -127,7 +129,7 @@ local function wrap_tail(space_name, op, opts, start_time, call_status, ...)
     -- it is treated as unknown as well.
     if status == 'error' and registry.is_unknown_space(space_name) then
         if type(err) == 'table' and type(err.err) == 'string' then
-            local space_not_found_msg = utils.space_doesnt_exist_msg(space_name)
+            space_not_found_msg = utils.space_doesnt_exist_msg(space_name)
             if string.find(err.err, space_not_found_msg) ~= nil then
                 registry.observe_space_not_found()
                 goto return_values
@@ -137,13 +139,22 @@ local function wrap_tail(space_name, op, opts, start_time, call_status, ...)
         -- We can't rely only on parsing error value because space existence
         -- is not always the first check in request validation.
         -- Check explicitly if space do not exist.
-        local space = utils.get_space(space_name, vshard.router.routeall())
+        space = utils.get_space(space_name, vshard.router.routeall())
         if space == nil then
             registry.observe_space_not_found()
             goto return_values
         end
     end
 
+    -- If space id is provided instead of name, resolve name.
+    if type(space_name) ~= 'string' then
+        if space == nil then
+            space = utils.get_space(space_name, vshard.router.routeall())
+        end
+
+        space_name = space.name
+    end
+
     registry.observe(latency, space_name, op, status)
 
     if context_stats ~= nil then

test/entrypoint/srv_select.lua

@@ -24,6 +24,7 @@ package.preload['customers-storage'] = function()
                 },
                 if_not_exists = true,
                 engine = engine,
+                id = 542,
             })
             -- primary index
             customers_space:create_index('id_index', {

test/entrypoint/srv_simple_operations.lua

@@ -21,6 +21,7 @@ package.preload['customers-storage'] = function()
                 },
                 if_not_exists = true,
                 engine = engine,
+                id = 542,
             })
             customers_space:create_index('id', {
                 parts = { {field = 'id'} },

test/integration/stats_test.lua

@@ -7,6 +7,7 @@ local stats_registry_common = require('crud.stats.registry_common')
 local g = t.group('stats_integration')
 local helpers = require('test.helper')
 
+local space_id = 542
 local space_name = 'customers'
 local unknown_space_name = 'non_existing_space'
 
@@ -559,3 +560,11 @@ for name, case in pairs(select_cases) do
             'Expected count of map reduces planned')
     end
 end
+
+g.test_resolve_name_from_id = function(g)
+    local op = 'len'
+    g.router:call('crud.len', { space_id })
+
+    local stats = g:get_stats(space_name)
+    t.assert_not_equals(stats[op], nil, "Statistics is filled by name")
+end

test/unit/stats_test.lua

@@ -9,6 +9,7 @@ local utils = require('crud.common.utils')
 local g = t.group('stats_unit')
 local helpers = require('test.helper')
 
+local space_id = 542
 local space_name = 'customers'
 local unknown_space_name = 'non_existing_space'
 
@@ -496,3 +497,11 @@ g.test_disable_stats_after_fetch_callback_get_do_not_break_call = function(g)
 
     t.success('No unexpected errors')
 end
+
+g.test_resolve_name_from_id = function(g)
+    local op = stats_module.op.LEN
+    g.router:eval(call_wrapped, { 'return_true', stats_module.op.LEN, {}, space_id })
+
+    local stats = g:get_stats(space_name)
+    t.assert_not_equals(stats[op], nil, "Statistics is filled by name")
+end