Add startup callback to settings

.gitignore

@@ -1,3 +1,18 @@
-/tests/*
-!/tests/*.nim
-!/tests/*.cfg
+*
+!**/
+!*.*
+*.out
+.DS_Store
+!.gitattributes
+!.gitignore
+!readme.md
+!.gitkeep
+!*.nim
+!*.nims
+!*.nimble
+!*.h
+!*.css
+!*.html
+*.exe
+!*/
+nimbledeps

src/httpbeast.nim

@@ -51,6 +51,8 @@ type
 
   OnRequest* = proc (req: Request): Future[void] {.gcsafe.}
 
+  Startup = proc () {.closure, gcsafe.}
+
   Settings* = object
     port*: Port
     bindAddr*: string
@@ -68,15 +70,23 @@ type
       ## 4096 for Linux/AMD64 and 128 for others.
       ##  * listen(2) Linux manual page: https://www.man7.org/linux/man-pages/man2/listen.2.html
       ##  * SYN packet handling int the wild: https://blog.cloudflare.com/syn-packet-handling-in-the-wild/
+    startup: Startup
+      ## An optional callback can be provided to execute at the beginning of 
+      ## the `eventLoop` function for initializing thread variables or performing other related tasks.
 
   HttpBeastDefect* = ref object of Defect
 
 const
   serverInfo = "HttpBeast"
 
+proc doNothing(): Startup {.gcsafe.} =
+  result = proc () {.closure, gcsafe.} =
+    discard
+
 proc initSettings*(port: Port = Port(8080),
                    bindAddr: string = "",
                    numThreads: int = 0,
+                   startup: Startup = doNothing(),
                    domain = Domain.AF_INET,
                    reusePort = true,
                    listenBacklog = SOMAXCONN): Settings =
@@ -88,6 +98,7 @@ proc initSettings*(port: Port = Port(8080),
     loggers: getHandlers(),
     reusePort: reusePort,
     listenBacklog: listenBacklog,
+    startup: startup
   )
 
 proc initData(fdKind: FdKind, ip = ""): Data =
@@ -333,6 +344,9 @@ proc eventLoop(
 ) =
   let (onRequest, settings, isMainThread) = params
 
+  if settings.startup != nil:
+    settings.startup()
+
   if not isMainThread:
     # We are on a new thread. Re-add the loggers from the main thread.
     for logger in settings.loggers:

tests/startup.ini

@@ -0,0 +1,7 @@
+charset = "utf-8"
+[Package]
+name = "hello"
+--threads:on
+[Author]
+name = "nim-lang"
+website = "nim-lang.org"

tests/startup.nim

@@ -0,0 +1,41 @@
+import os, options, asyncdispatch, parsecfg, strutils, streams
+import httpbeast
+
+const CurDir = currentSourcePath.parentDir
+
+var threadsOn {.threadvar.}: bool
+var name {.threadvar.}: string
+
+proc onRequest(req: Request): Future[void] =
+  if req.httpMethod == some(HttpGet):
+    case req.path.get()
+    of "/":
+      req.send("name:$#,threads:$#." % [name, $threadsOn])
+    else:
+      req.send(Http404)
+
+var startup = proc () =
+  let configFile = CurDir / "startup.ini"
+  var f = newFileStream(configFile, fmRead)
+  assert f != nil, "cannot open " & configFile
+  var p: CfgParser
+  var section: string
+  open(p, f, configFile)
+  while true:
+    var e = next(p)
+    case e.kind
+    of cfgEof: break
+    of cfgSectionStart:   ## a `[section]` has been parsed
+        section = e.section
+    of cfgKeyValuePair:
+        if section == "Package" and e.key == "name":
+          name = e.value
+    of cfgOption:
+        if e.key == "threads":
+          if e.value == "on":
+            threadsOn = true
+    of cfgError:
+        echo e.msg
+  close(p)
+
+run(onRequest, initSettings(startup = startup))