[Tarantool-patches] [PATCH v8 10/12] log/lua: allow to specify logging level as a string

[Cyrill Gorcunov <gorcunov@gmail.com>]

Allow to specify logging level as a string in log.cfg() call.

@TarantoolBot document
Title: Module log

The `log.cfg({level='string'})` accepts not only number but
symbolic representation of loglevels such as: `fatal`, `syserror`,
`error`, `crit`, `warn`, `info`, `verbose` and `debug`.

Part-of #689

Suggested-by: Oleg Babin <olegrok@tarantool.org>
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
---
 src/lua/log.lua              | 36 ++++++++++++++++++++++++++++++++++--
 test/app-tap/logger.test.lua | 29 ++++++++++++++++++++++++++++-
 2 files changed, 62 insertions(+), 3 deletions(-)

diff --git a/src/lua/log.lua b/src/lua/log.lua
index 33f7a5892..50c96a8d2 100644
--- a/src/lua/log.lua
+++ b/src/lua/log.lua
@@ -140,6 +140,26 @@ local function update_box_cfg(k)
     end
 end
 
+-- Logging levels symbolic representation.
+local log_level_keys = {
+    ['fatal']       = ffi.C.S_FATAL,
+    ['syserror']    = ffi.C.S_SYSERROR,
+    ['error']       = ffi.C.S_ERROR,
+    ['crit']        = ffi.C.S_CRIT,
+    ['warn']        = ffi.C.S_WARN,
+    ['info']        = ffi.C.S_INFO,
+    ['verbose']     = ffi.C.S_VERBOSE,
+    ['debug']       = ffi.C.S_DEBUG,
+}
+
+local function log_level_list()
+    local keyset = {}
+    for k in pairs(log_level_keys) do
+        keyset[#keyset + 1] = k
+    end
+    return table.concat(keyset, ',')
+end
+
 local function say(level, fmt, ...)
     if ffi.C.log_level < level then
         -- don't waste cycles on debug.getinfo()
@@ -303,8 +323,20 @@ local function load_cfg(oldcfg, cfg)
     end
 
     if cfg.level ~= nil then
-        if type(cfg.level) ~= 'number' then
-            error("log: 'level' option must be a number")
+        if type(cfg.level) == 'number' then
+            if cfg.level < ffi.C.S_FATAL or
+                cfg.level > ffi.C.S_DEBUG then
+                local m = "log: 'level' must be in range [%d;%d]"
+                error(m:format(ffi.C.S_FATAL, ffi.C.S_DEBUG))
+            end
+        elseif type(cfg.level) == 'string' then
+            if log_level_keys[cfg.level] == nil then
+                local m = "log: 'level' must be one of [%s]"
+                error(m:format(log_level_list()))
+            end
+            cfg.level = log_level_keys[cfg.level]
+        else
+            error("log: 'level' must be a number or string")
         end
     end
 
diff --git a/test/app-tap/logger.test.lua b/test/app-tap/logger.test.lua
index bc301d720..48dc8af3e 100755
--- a/test/app-tap/logger.test.lua
+++ b/test/app-tap/logger.test.lua
@@ -1,7 +1,7 @@
 #!/usr/bin/env tarantool
 
 local test = require('tap').test('log')
-test:plan(34)
+test:plan(44)
 
 -- gh-3946: Assertion failure when using log_format() before box.cfg()
 local log = require('log')
@@ -60,6 +60,33 @@ log.cfg({format='plain', level=5})
 test:is(box.cfg.log_format, 'plain', 'box sees plain format')
 test:is(box.cfg.log_level, 5, 'box sees level change')
 
+-- Test symbolic names for loglevels
+log.cfg({level='fatal'})
+test:ok(log.cfg.level == 0 and box.cfg.log_level == 0, 'both got fatal')
+log.cfg({level='syserror'})
+test:ok(log.cfg.level == 1 and box.cfg.log_level == 1, 'both got syserror')
+log.cfg({level='error'})
+test:ok(log.cfg.level == 2 and box.cfg.log_level == 2, 'both got error')
+log.cfg({level='crit'})
+test:ok(log.cfg.level == 3 and box.cfg.log_level == 3, 'both got crit')
+log.cfg({level='warn'})
+test:ok(log.cfg.level == 4 and box.cfg.log_level == 4, 'both got warn')
+log.cfg({level='info'})
+test:ok(log.cfg.level == 5 and box.cfg.log_level == 5, 'both got info')
+log.cfg({level='verbose'})
+test:ok(log.cfg.level == 6 and box.cfg.log_level == 6, 'both got verbose')
+log.cfg({level='debug'})
+test:ok(log.cfg.level == 7 and box.cfg.log_level == 7, 'both got debug')
+
+_,err = pcall(log, {level = -1})
+test:ok(err ~= nil, 'level = -1 error')
+
+_,err = pcall(log, {level = 'unknown'})
+test:ok(err ~= nil, "level = 'unknown' error")
+
+-- restore to info for next tests
+log.cfg({level='info'})
+
 --
 -- Check that Tarantool creates ADMIN session for #! script
 --
-- 
2.26.2