make patterns runtime only

libp2p/helpers/debug.nim

@@ -7,64 +7,71 @@
 ## This file may not be copied, modified, or distributed except according to
 ## those terms.
 
-## Small debug module that's enabled through a ``-d:debugout``
-## flag. It's inspired by the Nodejs ``debug`` module that
-## allows printing colorized output based on patterns. This 
-## module is powered by the standard ``nre`` module and as such
-## it supports the same set of regexp expressions.
+## Small debug module that's only runs in non release builds.
+## It's inspired by the Nodejs ``debug`` module which allows printing 
+## colorized output based on matched patterns. This module is powered 
+## by the standard ``nre`` module and as such it supports the same set 
+## of regexp expressions.
 ##
-## To enable debug output, pass the ``debugout`` flag during build
-## time with ``-d`` flag. In addition, the debugout flag takes a comma
-## separated list of patters that will narow the debug output to
-## only those matched by the patterns. By default however, all
-## debug statements are outputed to the stderr.
+## The output is controled through two environment variables ``DEBUG``
+## and ``DEBUG_COLOR``. By default, it will print everything to stderr
+## but if only some output is of interested, ``DEBUG`` accepts a coma
+## separated list of regexp expressions to match the output against.
+## Each match gets assigned a different color to help differentiate 
+## the output lines.
+##
+## Colorization is done with 256 ANSI colors, and each run gets a random
+## color, if more than one match is specified, each one gets a random color
+## to disable this behavior use ``DEBUG_COLOR`` with a valid ANSI color code.
+## This will also disable individual colorization for each matched line.
+## 
 
-when defined(debugout) and not defined(release):
+when not defined(release):
   import random, 
          tables, 
          nre, 
          strutils, 
          times, 
          terminal, 
-         sequtils
-
-  const debugout {.strdefine.}: string = ".*"
+         sequtils,
+         os
 
   type
     Match = object
       pattern: Regex
       color: string
 
-  if isTrueColorSupported():
-    system.addQuitProc(resetAttributes)
-    enableTrueColors()
+  # if isTrueColorSupported():
+  #   system.addQuitProc(resetAttributes)
+  #   enableTrueColors()
 
   var context {.threadvar.} : OrderedTableRef[string, Match]
   proc initDebugCtx() = 
+    let debugout = getEnv("DEBUG", ".*")
+    let debugColor = getEnv("DEBUG_COLOR")
+    let isDebugColor = debugColor.len > 0
     context = newOrderedTable[string, Match]()
-    var patrns = @[".*"]
-    if debugout != "true":
-      patrns = debugout.split(re"[,\s]").filterIt(it.len > 0)
+    var patrns: seq[string] = @[]
+    patrns = debugout.split(re"[,\s]").filterIt(it.len > 0)
 
     randomize()
     for p in patrns:
-      context[p] = Match(pattern: re(p), color: $rand(0..272)) # 256 ansi colors
+      context[p] = Match(pattern: re(p), color: if isDebugColor: debugColor else: $rand(0..272)) # 256 ansi colors
 
-  proc doDebug(data: string): void {.gcsafe.} = 
+  proc doDebug(data: string, line: string): void {.gcsafe.} = 
     if isNil(context):
       initDebugCtx()
     for m in context.values:
-      if data.match(m.pattern).isSome:
-        stderr.writeLine("\u001b[38;5;" & m.color & "m " & alignLeft(data, 4) & "\e[0m")
+      if data.contains(m.pattern):
+        stderr.writeLine("\u001b[38;5;" & m.color & "m " & alignLeft(line & data, 4) & "\e[0m")
         return
 
   template debug*(data: string) = 
     let module = instantiationInfo()
-    let line = "$# $#:$# - $#" % 
+    let line = "$# $#:$# - " % 
                   [now().format("yyyy-MM-dd HH:mm:ss:fffffffff"), 
                   module.filename[0..^5], 
-                  $module.line,
-                  data]
-    doDebug(line)
+                  $module.line]
+    doDebug(data, line)
 else:
   template debug*(data: string) = discard