bundles/pycaml/chemoelectric-pycaml-8614105/examples/log.ml

   1 #use "topfind";;
   2 #require "pycaml";;
   3 #require "snippets";;
   4
   5 open Pycaml;;
   6
   7 (* See http://docs.python.org/lib/module-logging.html for Level values *)
   8 type logging_levels = Notset | Debug | Info | Warn | Error | Critical | Level of int;;
   9
  10 (* Set default logger *)
  11 let default_logger = (fun l m -> Printf.printf "ocaml-default log: %d %s%!\n%!" l m);;
  12
  13 let loggers = Hashtbl.create 10;;
  14 Hashtbl.add loggers "default-ocaml" default_logger;;
  15
  16 (* Translate level names into numerical values as used by Python
  17    See http://docs.python.org/lib/module-logging.html for Level values *)
  18 let int_of_level name =
  19   match name with
  20     | Notset   -> 0
  21     | Debug    -> 10
  22     | Info     -> 20
  23     | Warn     -> 30
  24     | Error    -> 40
  25     | Critical -> 50
  26     | Level (n)-> n
  27 ;;
  28
  29 let find_logger name =
  30   try
  31     Hashtbl.find loggers name
  32   with
  33     | Not_found ->
  34         try
  35           Hashtbl.find loggers "default-ocaml"
  36         with
  37           | Not_found -> failwith "Default logger missing -- internal problem";;
  38
  39
  40 (* Provide interface functions as in Python's logging module *)
  41 let debug name msg =
  42   let log = find_logger name in
  43     log (int_of_level Debug) msg;;
  44
  45 let info name msg =
  46   let log = find_logger name in
  47     log (int_of_level Info) msg;;
  48
  49 let warn name msg =
  50   let log = find_logger name in
  51     log (int_of_level Warn) msg;;
  52
  53 let warning = warn;;
  54
  55 let error name msg =
  56   let log = find_logger name in
  57     log (int_of_level Error) msg;;
  58
  59 let critical name msg =
  60   let log = find_logger name  in
  61     log (int_of_level Critical) msg;;
  62
  63 (* Function that takes a name, level integer (this is 'raw') and the message *)
  64 let lograw name level msg =
  65   let logf = find_logger name in
  66     logf level msg;;
  67
  68 (* Function that takes a name, level and the message.
  69    Presumably, this is what will be used most often. *)
  70 let log name level msg =
  71   let lograw = find_logger name in
  72     lograw (int_of_level level) msg;;
  73
  74
  75 (* Allowing to register loggers from Python *)
  76
  77 let add_logger_if_new name logger =
  78   let loggername =
  79     try
  80       let _ = Str.search_forward (Str.regexp "ocaml") name 0 in
  81         name
  82     with
  83       | Not_found -> Printf.sprintf "%s-ocaml" name
  84   in
  85   try
  86     let _ = Hashtbl.find loggers loggername
  87     in failwith (Printf.sprintf "Trying to register logger '%s' again. Why?" loggername)
  88   with
  89     | Not_found -> Printf.printf "Adding logger %s to hashtable\n%!" loggername;
  90         Hashtbl.add loggers loggername logger;;
  91
  92 let _py_register_logger =
  93   python_pre_interfaced_function
  94     ~doc:"Register a python-logger. \nArguments: Logger name (str) and callback function cb(). \nThe signature of cb() is cb( level: int, message:str). "
  95     [|StringType;CallableType|]
  96     (fun py_args ->
  97        let name = pystring_asstring py_args.(0) in
  98        let ocamllogger = (fun level msg ->
  99                             let callback_args =
 100                               pytuple_fromarray
 101                                 [|pyint_fromint level;
 102                                   pystring_fromstring msg|]
 103                             in
 104                             let _ = pyeval_callobject(py_args.(1),callback_args) in ()
 105                          )
 106        in let () = add_logger_if_new name ocamllogger
 107      in pynone() );;
 108
 109
 110
 111
 112
 113 (* Debugging tools: *)
 114
 115 (* getinfo returns an array of strings that contain the names of registered loggers. *)
 116 let getinfo loggers =
 117     let loggerarray = Array.make (Hashtbl.length loggers) "empty" in
 118     let () = Snippets.hashtbl_iteri (fun i key value -> (loggerarray.(i) <- key)) loggers in
 119     loggerarray;;
 120
 121 let print_loggers loggers =
 122   Array.iter (fun a -> Printf.printf "registered loggername=%s\n%!" a)  (getinfo loggers);;
 123
 124 let _py_ocaml_log  =
 125   python_pre_interfaced_function
 126     ~doc: "Function that calls the ocaml logger from Python (just for debugging useful) "
 127     [|StringType;IntType;StringType|] ( fun py_args ->
 128                                           let name = pystring_asstring py_args.(0) in
 129                                           let level = pyint_asint py_args.(1) in
 130                                           let msg = pystring_asstring py_args.(2) in
 131                                           let () =  lograw name level msg in
 132                                             pynone() );;
 133
 134 (* Register function for Python *)
 135
 136 let () = register_pre_functions_for_python
 137   [|  ("log", _py_ocaml_log);
 138       ("register_logger", _py_register_logger) |]
 139 ;;
 140
 141
 142
 143 (* This needs to go into the documentation *)
 144
 145 Printf.printf "About to start tests (Ocaml)\n";;
 146
 147 let () = add_logger_if_new "Ocaml" (fun l m -> Printf.printf "Ocamllog, Lev=%d: %s\n" l m);
 148
 149 python_load "log.py";;
 150
 151 log "default" (Level 30) "Purely called from Ocaml";;
 152
 153 info "ocaml" "This is information";;
 154
 155 print_loggers loggers;;
 156
 157 python_eval "logger.warn('Warning from Python')";;
 158
 159 let nmeshlog = log
 160 (* ipython();; *)
 161