1 files changed, 140 insertions, 0 deletions
diff --git a/lib/pure/scgi.nim b/lib/pure/scgi.nim
new file mode 100644
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+++ b/lib/pure/scgi.nim
@@ -0,0 +1,140 @@
+#
+#
+#            Nimrod's Runtime Library
+#        (c) Copyright 2010 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+## This module implements helper procs for SCGI applictions. Example:
+## 
+## .. code-block:: Nimrod
+##
+##    import strtabs, sockets, scgi
+##
+##    var counter = 0
+##    proc handleRequest(client: TSocket, input: string, 
+##                       headers: PStringTable): bool {.procvar.} =
+##      inc(counter)
+##      client.writeStatusOkTextContent()
+##      client.send("Hello for the $#th time." % $counter & "\c\L")
+##      return false # do not stop processing
+##
+##    run(handleRequest)
+##
+
+import sockets, strutils, os, strtabs
+
+type
+  EScgi* = object of EIO ## the exception that is raised, if a SCGI error occurs
+
+proc scgiError*(msg: string) {.noreturn.} = 
+  ## raises an EScgi exception with message `msg`.
+  var e: ref EScgi
+  new(e)
+  e.msg = msg
+  raise e
+
+proc parseWord(inp: string, outp: var string, start: int): int = 
+  result = start
+  while inp[result] != '\0': inc(result)
+  outp = copy(inp, start, result-1)
+
+proc parseHeaders(s: string, L: int): PStringTable = 
+  result = newStringTable()
+  var i = 0
+  while i < L:
+    var key, val: string
+    i = parseWord(s, key, i)+1
+    i = parseWord(s, val, i)+1
+    result[key] = val
+  if s[i] == ',': inc(i)
+  else: scgiError("',' after netstring expected")
+  
+proc recvChar(s: TSocket): char = 
+  var c: char
+  if recv(s, addr(c), sizeof(c)) == sizeof(c): 
+    result = c
+  
+type
+  TScgiState* {.final.} = object ## SCGI state object
+    server: TSocket
+    bufLen: int
+    client*: TSocket ## the client socket to send data to
+    headers*: PStringTable ## the parsed headers
+    input*: string  ## the input buffer
+    
+proc recvBuffer(s: var TScgiState, L: int) =
+  if L > s.bufLen: 
+    s.bufLen = L
+    s.input = newString(L)
+  if L > 0 and recv(s.client, cstring(s.input), L) != L: 
+    scgiError("could not read all data")
+  setLen(s.input, L)
+  
+proc open*(s: var TScgiState, port = TPort(4000)) = 
+  ## opens a connection.
+  s.bufLen = 4000
+  s.input = newString(s.buflen) # will be reused
+  system.stackTraceNewLine = "<br />\n"
+  
+  s.server = socket()
+  if s.server == InvalidSocket: scgiError("could not open socket")
+  #s.server.connect(connectionName, port)
+  bindAddr(s.server, port)
+  listen(s.server)
+  
+proc close*(s: var TScgiState) = 
+  ## closes the connection.
+  s.server.close()
+
+proc next*(s: var TScgistate) = 
+  ## proceed to the first/next request.
+  s.client = accept(s.server)
+  var L = 0
+  while true:
+    var d = s.client.recvChar()
+    if d notin strutils.digits: 
+      if d != ':': scgiError("':' after length expected")
+      break
+    L = L * 10 + ord(d) - ord('0')  
+  recvBuffer(s, L+1)
+  s.headers = parseHeaders(s.input, L)
+  if s.headers["SCGI"] != "1": scgiError("SCGI Version 1 expected")
+  L = parseInt(s.headers["CONTENT_LENGTH"])
+  recvBuffer(s, L)
+  
+proc writeStatusOkTextContent*(c: TSocket) = 
+  ## sends the following string to the socket `c`::
+  ##
+  ##   Status: 200 OK\r\LContent-Type: text/plain\r\L\r\L
+  ##
+  ## You should send this before sending your HTML page, for example.
+  c.send("Status: 200 OK\r\L" &
+         "Content-Type: text/plain\r\L\r\L")
+
+proc run*(handleRequest: proc (client: TSocket, input: string, 
+                               headers: PStringTable): bool,
+          port = TPort(4000)) = 
+  ## encapsulates the SCGI object and main loop.
+  var s: TScgiState
+  s.open(port)
+  var stop = false
+  while not stop:
+    next(s)
+    stop = handleRequest(s.client, s.input, s.headers)
+    s.client.close()
+  s.close()
+
+when isMainModule:
+  var counter = 0
+  proc handleRequest(client: TSocket, input: string, 
+                     headers: PStringTable): bool {.procvar.} =
+    inc(counter)
+    client.writeStatusOkTextContent()
+    client.send("Hello for the $#th time." % $counter & "\c\L")
+    return false # do not stop processing
+
+  run(handleRequest)
+