add support for logging topics (#293)

* add support for logging topics

* add top level codex topic

codex.nim

@@ -24,6 +24,9 @@ when isMainModule:
 
   import ./codex/utils/fileutils
 
+  logScope:
+    topics = "codex"
+
   when defined(posix):
     import system/ansi_c
 

codex/conf.nim

@@ -18,6 +18,7 @@ import std/strutils
 import std/typetraits
 
 import pkg/chronicles
+import pkg/chronicles/helpers
 import pkg/chronicles/topics_registry
 import pkg/confutils/defs
 import pkg/confutils/std/net
@@ -46,9 +47,9 @@ type
 
   CodexConf* = object
     logLevel* {.
-      defaultValue: LogLevel.INFO
+      defaultValue: "INFO"
       desc: "Sets the log level",
-      name: "log-level" }: LogLevel
+      name: "log-level" }: string
 
     logFormat* {.
       hidden
@@ -251,6 +252,19 @@ proc stripAnsi(v: string): string =
 
   res
 
+proc updateLogLevel*(logLevel: string) {.raises: [Defect, ValueError].} =
+  # Updates log levels (without clearing old ones)
+  let directives = logLevel.split(";")
+  try:
+    setLogLevel(parseEnum[LogLevel](directives[0]))
+  except ValueError:
+    raise (ref ValueError)(msg: "Please specify one of TRACE, DEBUG, INFO, NOTICE, WARN, ERROR or FATAL")
+
+  if directives.len > 1:
+    for topicName, settings in parseTopicDirectives(directives[1..^1]):
+      if not setTopicState(topicName, settings.state, settings.logLevel):
+        warn "Unrecognized logging topic", topic = topicName
+
 proc setupLogging*(conf: CodexConf) =
   when defaultChroniclesStream.outputs.type.arity != 2:
     warn "Logging configuration options not enabled in the current build"
@@ -286,7 +300,14 @@ proc setupLogging*(conf: CodexConf) =
       of LogKind.None:
         noOutput
 
-    setLogLevel(conf.logLevel)
+  try:
+    updateLogLevel(conf.logLevel)
+  except ValueError as err:
+    try:
+      stderr.write "Invalid value for --log-level. " & err.msg & "\n"
+    except IOError:
+      echo "Invalid value for --log-level. " & err.msg
+    quit QuitFailure
 
 proc setupMetrics*(config: CodexConf) =
   if config.metricsEnabled: