src/python.c

   1 /**
   2  * collectd - src/python.c
   3  * Copyright (C) 2009  Sven Trenkel
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a
   6  * copy of this software and associated documentation files (the "Software"),
   7  * to deal in the Software without restriction, including without limitation
   8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   9  * and/or sell copies of the Software, and to permit persons to whom the
  10  * Software is furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice shall be included in
  13  * all copies or substantial portions of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  18  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  21  * DEALINGS IN THE SOFTWARE.
  22  *
  23  * Authors:
  24  *   Sven Trenkel <collectd at semidefinite.de>
  25  **/
  26
  27 #include <Python.h>
  28 #include <structmember.h>
  29
  30 #include <signal.h>
  31 #if HAVE_PTHREAD_H
  32 # include <pthread.h>
  33 #endif
  34
  35 #include "collectd.h"
  36 #include "common.h"
  37
  38 #include "cpython.h"
  39
  40 typedef struct cpy_callback_s {
  41         char *name;
  42         PyObject *callback;
  43         PyObject *data;
  44         struct cpy_callback_s *next;
  45 } cpy_callback_t;
  46
  47 static char log_doc[] = "This function sends a string to all logging plugins.";
  48
  49 static char get_ds_doc[] = "get_dataset(name) -> definition\n"
  50                 "\n"
  51                 "Returns the definition of a dataset specified by name.\n"
  52                 "\n"
  53                 "'name' is a string specifying the dataset to query.\n"
  54                 "'definition' is a list of 4-tuples. Every tuple represents a \n"
  55                 "    data source within the data set and its 4 values are the \n"
  56                 "    name, type, min and max value.\n"
  57                 "    'name' is a string.\n"
  58                 "    'type' is a string that is equal to either DS_TYPE_COUNTER,\n"
  59                 "        DS_TYPE_GAUGE, DS_TYPE_DERIVE or DS_TYPE_ABSOLUTE.\n"
  60                 "    'min' and 'max' are either a float or None.";
  61
  62 static char flush_doc[] = "flush([plugin][, timeout][, identifier]) -> None\n"
  63                 "\n"
  64                 "Flushes the cache of another plugin.";
  65
  66 static char unregister_doc[] = "Unregisters a callback. This function needs exactly one parameter either\n"
  67                 "the function to unregister or the callback identifier to unregister.";
  68
  69 static char reg_log_doc[] = "register_log(callback[, data][, name]) -> identifier\n"
  70                 "\n"
  71                 "Register a callback function for log messages.\n"
  72                 "\n"
  73                 "'callback' is a callable object that will be called every time something\n"
  74                 "    is logged.\n"
  75                 "'data' is an optional object that will be passed back to the callback\n"
  76                 "    function every time it is called.\n"
  77                 "'name' is an optional identifier for this callback. The default name\n"
  78                 "    is 'python.<module>'.\n"
  79                 "    Every callback needs a unique identifier, so if you want to\n"
  80                 "    register this callback multiple time from the same module you need\n"
  81                 "    to specify a name here.\n"
  82                 "'identifier' is the full identifier assigned to this callback.\n"
  83                 "\n"
  84                 "The callback function will be called with two or three parameters:\n"
  85                 "severity: An integer that should be compared to the LOG_ constants.\n"
  86                 "message: The text to be logged.\n"
  87                 "data: The optional data parameter passed to the register function.\n"
  88                 "    If the parameter was omitted it will be omitted here, too.";
  89
  90 static char reg_init_doc[] = "register_init(callback[, data][, name]) -> identifier\n"
  91                 "\n"
  92                 "Register a callback function that will be executed once after the config.\n"
  93                 "file has been read, all plugins heve been loaded and the collectd has\n"
  94                 "forked into the background.\n"
  95                 "\n"
  96                 "'callback' is a callable object that will be executed.\n"
  97                 "'data' is an optional object that will be passed back to the callback\n"
  98                 "    function when it is called.\n"
  99                 "'name' is an optional identifier for this callback. The default name\n"
 100                 "    is 'python.<module>'.\n"
 101                 "    Every callback needs a unique identifier, so if you want to\n"
 102                 "    register this callback multiple time from the same module you need\n"
 103                 "    to specify a name here.\n"
 104                 "'identifier' is the full identifier assigned to this callback.\n"
 105                 "\n"
 106                 "The callback function will be called without parameters, except for\n"
 107                 "data if it was supplied.";
 108
 109 static char reg_config_doc[] = "register_config(callback[, data][, name]) -> identifier\n"
 110                 "\n"
 111                 "Register a callback function for config file entries.\n"
 112                 "'callback' is a callable object that will be called for every config block.\n"
 113                 "'data' is an optional object that will be passed back to the callback\n"
 114                 "    function every time it is called.\n"
 115                 "'name' is an optional identifier for this callback. The default name\n"
 116                 "    is 'python.<module>'.\n"
 117                 "    Every callback needs a unique identifier, so if you want to\n"
 118                 "    register this callback multiple time from the same module you need\n"
 119                 "    to specify a name here.\n"
 120                 "'identifier' is the full identifier assigned to this callback.\n"
 121                 "\n"
 122                 "The callback function will be called with one or two parameters:\n"
 123                 "config: A Config object.\n"
 124                 "data: The optional data parameter passed to the register function.\n"
 125                 "    If the parameter was omitted it will be omitted here, too.";
 126
 127 static char reg_read_doc[] = "register_read(callback[, interval][, data][, name]) -> identifier\n"
 128                 "\n"
 129                 "Register a callback function for reading data. It will just be called\n"
 130                 "in a fixed interval to signal that it's time to dispatch new values.\n"
 131                 "'callback' is a callable object that will be called every time something\n"
 132                 "    is logged.\n"
 133                 "'interval' is the number of seconds between between calls to the callback\n"
 134                 "    function. Full float precision is supported here.\n"
 135                 "'data' is an optional object that will be passed back to the callback\n"
 136                 "    function every time it is called.\n"
 137                 "'name' is an optional identifier for this callback. The default name\n"
 138                 "    is 'python.<module>'.\n"
 139                 "    Every callback needs a unique identifier, so if you want to\n"
 140                 "    register this callback multiple time from the same module you need\n"
 141                 "    to specify a name here.\n"
 142                 "'identifier' is the full identifier assigned to this callback.\n"
 143                 "\n"
 144                 "The callback function will be called without parameters, except for\n"
 145                 "data if it was supplied.";
 146
 147 static char reg_write_doc[] = "register_write(callback[, data][, name]) -> identifier\n"
 148                 "\n"
 149                 "Register a callback function to receive values dispatched by other plugins.\n"
 150                 "'callback' is a callable object that will be called every time a value\n"
 151                 "    is dispatched.\n"
 152                 "'data' is an optional object that will be passed back to the callback\n"
 153                 "    function every time it is called.\n"
 154                 "'name' is an optional identifier for this callback. The default name\n"
 155                 "    is 'python.<module>'.\n"
 156                 "    Every callback needs a unique identifier, so if you want to\n"
 157                 "    register this callback multiple time from the same module you need\n"
 158                 "    to specify a name here.\n"
 159                 "'identifier' is the full identifier assigned to this callback.\n"
 160                 "\n"
 161                 "The callback function will be called with one or two parameters:\n"
 162                 "values: A Values object which is a copy of the dispatched values.\n"
 163                 "data: The optional data parameter passed to the register function.\n"
 164                 "    If the parameter was omitted it will be omitted here, too.";
 165
 166 static char reg_notification_doc[] = "register_notification(callback[, data][, name]) -> identifier\n"
 167                 "\n"
 168                 "Register a callback function for notifications.\n"
 169                 "'callback' is a callable object that will be called every time a notification\n"
 170                 "    is dispatched.\n"
 171                 "'data' is an optional object that will be passed back to the callback\n"
 172                 "    function every time it is called.\n"
 173                 "'name' is an optional identifier for this callback. The default name\n"
 174                 "    is 'python.<module>'.\n"
 175                 "    Every callback needs a unique identifier, so if you want to\n"
 176                 "    register this callback multiple time from the same module you need\n"
 177                 "    to specify a name here.\n"
 178                 "'identifier' is the full identifier assigned to this callback.\n"
 179                 "\n"
 180                 "The callback function will be called with one or two parameters:\n"
 181                 "notification: A copy of the notification that was dispatched.\n"
 182                 "data: The optional data parameter passed to the register function.\n"
 183                 "    If the parameter was omitted it will be omitted here, too.";
 184
 185 static char reg_flush_doc[] = "register_flush(callback[, data][, name]) -> identifier\n"
 186                 "\n"
 187                 "Register a callback function for flush messages.\n"
 188                 "'callback' is a callable object that will be called every time a plugin\n"
 189                 "    requests a flush for either this or all plugins.\n"
 190                 "'data' is an optional object that will be passed back to the callback\n"
 191                 "    function every time it is called.\n"
 192                 "'name' is an optional identifier for this callback. The default name\n"
 193                 "    is 'python.<module>'.\n"
 194                 "    Every callback needs a unique identifier, so if you want to\n"
 195                 "    register this callback multiple time from the same module you need\n"
 196                 "    to specify a name here.\n"
 197                 "'identifier' is the full identifier assigned to this callback.\n"
 198                 "\n"
 199                 "The callback function will be called with two or three parameters:\n"
 200                 "timeout: Indicates that only data older than 'timeout' seconds is to\n"
 201                 "    be flushed.\n"
 202                 "id: Specifies which values are to be flushed.\n"
 203                 "data: The optional data parameter passed to the register function.\n"
 204                 "    If the parameter was omitted it will be omitted here, too.";
 205
 206 static char reg_shutdown_doc[] = "register_shutdown(callback[, data][, name]) -> identifier\n"
 207                 "\n"
 208                 "Register a callback function for collectd shutdown.\n"
 209                 "'callback' is a callable object that will be called once collectd is\n"
 210                 "    shutting down.\n"
 211                 "'data' is an optional object that will be passed back to the callback\n"
 212                 "    function if it is called.\n"
 213                 "'name' is an optional identifier for this callback. The default name\n"
 214                 "    is 'python.<module>'.\n"
 215                 "    Every callback needs a unique identifier, so if you want to\n"
 216                 "    register this callback multiple time from the same module you need\n"
 217                 "    to specify a name here.\n"
 218                 "'identifier' is the full identifier assigned to this callback.\n"
 219                 "\n"
 220                 "The callback function will be called with no parameters except for\n"
 221                 "    data if it was supplied.";
 222
 223
 224 static int do_interactive = 0;
 225
 226 /* This is our global thread state. Python saves some stuff in thread-local
 227  * storage. So if we allow the interpreter to run in the background
 228  * (the scriptwriters might have created some threads from python), we have
 229  * to save the state so we can resume it later after shutdown. */
 230
 231 static PyThreadState *state;
 232
 233 static PyObject *sys_path, *cpy_format_exception;
 234
 235 static cpy_callback_t *cpy_config_callbacks;
 236 static cpy_callback_t *cpy_init_callbacks;
 237 static cpy_callback_t *cpy_shutdown_callbacks;
 238
 239 static void cpy_destroy_user_data(void *data) {
 240         cpy_callback_t *c = data;
 241         free(c->name);
 242         Py_DECREF(c->callback);
 243         Py_XDECREF(c->data);
 244         free(c);
 245 }
 246
 247 /* You must hold the GIL to call this function!
 248  * But if you managed to extract the callback parameter then you probably already do. */
 249
 250 static void cpy_build_name(char *buf, size_t size, PyObject *callback, const char *name) {
 251         const char *module = NULL;
 252         PyObject *mod = NULL;
 253
 254         if (name != NULL) {
 255                 snprintf(buf, size, "python.%s", name);
 256                 return;
 257         }
 258
 259         mod = PyObject_GetAttrString(callback, "__module__"); /* New reference. */
 260         if (mod != NULL)
 261                 module = cpy_unicode_or_bytes_to_string(&mod);
 262
 263         if (module != NULL) {
 264                 snprintf(buf, size, "python.%s", module);
 265                 Py_XDECREF(mod);
 266                 PyErr_Clear();
 267                 return;
 268         }
 269         Py_XDECREF(mod);
 270
 271         snprintf(buf, size, "python.%p", callback);
 272         PyErr_Clear();
 273 }
 274
 275 void cpy_log_exception(const char *context) {
 276         int l = 0, i;
 277         const char *typename = NULL, *message = NULL;
 278         PyObject *type, *value, *traceback, *tn, *m, *list;
 279
 280         PyErr_Fetch(&type, &value, &traceback);
 281         PyErr_NormalizeException(&type, &value, &traceback);
 282         if (type == NULL) return;
 283         tn = PyObject_GetAttrString(type, "__name__"); /* New reference. */
 284         m = PyObject_Str(value); /* New reference. */
 285         if (tn != NULL)
 286                 typename = cpy_unicode_or_bytes_to_string(&tn);
 287         if (m != NULL)
 288                 message = cpy_unicode_or_bytes_to_string(&m);
 289         if (typename == NULL)
 290                 typename = "NamelessException";
 291         if (message == NULL)
 292                 message = "N/A";
 293         Py_BEGIN_ALLOW_THREADS
 294         ERROR("Unhandled python exception in %s: %s: %s", context, typename, message);
 295         Py_END_ALLOW_THREADS
 296         Py_XDECREF(tn);
 297         Py_XDECREF(m);
 298         if (!cpy_format_exception || !traceback) {
 299                 PyErr_Clear();
 300                 Py_DECREF(type);
 301                 Py_XDECREF(value);
 302                 Py_XDECREF(traceback);
 303                 return;
 304         }
 305         list = PyObject_CallFunction(cpy_format_exception, "NNN", type, value, traceback); /* New reference. */
 306         if (list)
 307                 l = PyObject_Length(list);
 308         for (i = 0; i < l; ++i) {
 309                 char *s;
 310                 PyObject *line;
 311
 312                 line = PyList_GET_ITEM(list, i); /* Borrowed reference. */
 313                 Py_INCREF(line);
 314                 s = strdup(cpy_unicode_or_bytes_to_string(&line));
 315                 Py_DECREF(line);
 316                 if (s[strlen(s) - 1] == '\n')
 317                         s[strlen(s) - 1] = 0;
 318                 Py_BEGIN_ALLOW_THREADS
 319                 ERROR("%s", s);
 320                 Py_END_ALLOW_THREADS
 321                 free(s);
 322         }
 323         Py_XDECREF(list);
 324         PyErr_Clear();
 325         Py_DECREF(type);
 326         Py_XDECREF(value);
 327         Py_XDECREF(traceback);
 328 }
 329
 330 static int cpy_read_callback(user_data_t *data) {
 331         cpy_callback_t *c = data->data;
 332         PyObject *ret;
 333
 334         CPY_LOCK_THREADS
 335                 ret = PyObject_CallFunctionObjArgs(c->callback, c->data, (void *) 0); /* New reference. */
 336                 if (ret == NULL) {
 337                         cpy_log_exception("read callback");
 338                 } else {
 339                         Py_DECREF(ret);
 340                 }
 341         CPY_RELEASE_THREADS
 342         if (ret == NULL)
 343                 return 1;
 344         return 0;
 345 }
 346
 347 static int cpy_write_callback(const data_set_t *ds, const value_list_t *value_list, user_data_t *data) {
 348         int i;
 349         cpy_callback_t *c = data->data;
 350         PyObject *ret, *list, *temp, *dict = NULL;
 351         Values *v;
 352
 353         CPY_LOCK_THREADS
 354                 list = PyList_New(value_list->values_len); /* New reference. */
 355                 if (list == NULL) {
 356                         cpy_log_exception("write callback");
 357                         CPY_RETURN_FROM_THREADS 0;
 358                 }
 359                 for (i = 0; i < value_list->values_len; ++i) {
 360                         if (ds->ds[i].type == DS_TYPE_COUNTER) {
 361                                 if ((long) value_list->values[i].counter == value_list->values[i].counter)
 362                                         PyList_SetItem(list, i, PyInt_FromLong(value_list->values[i].counter));
 363                                 else
 364                                         PyList_SetItem(list, i, PyLong_FromUnsignedLongLong(value_list->values[i].counter));
 365                         } else if (ds->ds[i].type == DS_TYPE_GAUGE) {
 366                                 PyList_SetItem(list, i, PyFloat_FromDouble(value_list->values[i].gauge));
 367                         } else if (ds->ds[i].type == DS_TYPE_DERIVE) {
 368                                 if ((long) value_list->values[i].derive == value_list->values[i].derive)
 369                                         PyList_SetItem(list, i, PyInt_FromLong(value_list->values[i].derive));
 370                                 else
 371                                         PyList_SetItem(list, i, PyLong_FromLongLong(value_list->values[i].derive));
 372                         } else if (ds->ds[i].type == DS_TYPE_ABSOLUTE) {
 373                                 if ((long) value_list->values[i].absolute == value_list->values[i].absolute)
 374                                         PyList_SetItem(list, i, PyInt_FromLong(value_list->values[i].absolute));
 375                                 else
 376                                         PyList_SetItem(list, i, PyLong_FromUnsignedLongLong(value_list->values[i].absolute));
 377                         } else {
 378                                 Py_BEGIN_ALLOW_THREADS
 379                                 ERROR("cpy_write_callback: Unknown value type %d.", ds->ds[i].type);
 380                                 Py_END_ALLOW_THREADS
 381                                 Py_DECREF(list);
 382                                 CPY_RETURN_FROM_THREADS 0;
 383                         }
 384                         if (PyErr_Occurred() != NULL) {
 385                                 cpy_log_exception("value building for write callback");
 386                                 Py_DECREF(list);
 387                                 CPY_RETURN_FROM_THREADS 0;
 388                         }
 389                 }
 390                 dict = PyDict_New();  /* New reference. */
 391                 if (value_list->meta) {
 392                         int i, num;
 393                         char **table;
 394                         meta_data_t *meta = value_list->meta;
 395
 396                         num = meta_data_toc(meta, &table);
 397                         for (i = 0; i < num; ++i) {
 398                                 int type;
 399                                 char *string;
 400                                 int64_t si;
 401                                 uint64_t ui;
 402                                 double d;
 403                                 _Bool b;
 404
 405                                 type = meta_data_type(meta, table[i]);
 406                                 if (type == MD_TYPE_STRING) {
 407                                         if (meta_data_get_string(meta, table[i], &string))
 408                                                 continue;
 409                                         temp = cpy_string_to_unicode_or_bytes(string);  /* New reference. */
 410                                         free(string);
 411                                         PyDict_SetItemString(dict, table[i], temp);
 412                                         Py_XDECREF(temp);
 413                                 } else if (type == MD_TYPE_SIGNED_INT) {
 414                                         if (meta_data_get_signed_int(meta, table[i], &si))
 415                                                 continue;
 416                                         temp = PyObject_CallFunctionObjArgs((void *) &SignedType, PyLong_FromLongLong(si), (void *) 0);  /* New reference. */
 417                                         PyDict_SetItemString(dict, table[i], temp);
 418                                         Py_XDECREF(temp);
 419                                 } else if (type == MD_TYPE_UNSIGNED_INT) {
 420                                         if (meta_data_get_unsigned_int(meta, table[i], &ui))
 421                                                 continue;
 422                                         temp = PyObject_CallFunctionObjArgs((void *) &UnsignedType, PyLong_FromUnsignedLongLong(ui), (void *) 0);  /* New reference. */
 423                                         PyDict_SetItemString(dict, table[i], temp);
 424                                         Py_XDECREF(temp);
 425                                 } else if (type == MD_TYPE_DOUBLE) {
 426                                         if (meta_data_get_double(meta, table[i], &d))
 427                                                 continue;
 428                                         temp = PyFloat_FromDouble(d);  /* New reference. */
 429                                         PyDict_SetItemString(dict, table[i], temp);
 430                                         Py_XDECREF(temp);
 431                                 } else if (type == MD_TYPE_BOOLEAN) {
 432                                         if (meta_data_get_boolean(meta, table[i], &b))
 433                                                 continue;
 434                                         if (b)
 435                                                 PyDict_SetItemString(dict, table[i], Py_True);
 436                                         else
 437                                                 PyDict_SetItemString(dict, table[i], Py_False);
 438                                 }
 439                                 free(table[i]);
 440                         }
 441                         free(table);
 442                 }
 443                 v = (Values *) Values_New(); /* New reference. */
 444                 sstrncpy(v->data.host, value_list->host, sizeof(v->data.host));
 445                 sstrncpy(v->data.type, value_list->type, sizeof(v->data.type));
 446                 sstrncpy(v->data.type_instance, value_list->type_instance, sizeof(v->data.type_instance));
 447                 sstrncpy(v->data.plugin, value_list->plugin, sizeof(v->data.plugin));
 448                 sstrncpy(v->data.plugin_instance, value_list->plugin_instance, sizeof(v->data.plugin_instance));
 449                 v->data.time = CDTIME_T_TO_DOUBLE(value_list->time);
 450                 v->interval = CDTIME_T_TO_DOUBLE(value_list->interval);
 451                 Py_CLEAR(v->values);
 452                 v->values = list;
 453                 Py_CLEAR(v->meta);
 454                 v->meta = dict;  /* Steals a reference. */
 455                 ret = PyObject_CallFunctionObjArgs(c->callback, v, c->data, (void *) 0); /* New reference. */
 456                 Py_XDECREF(v);
 457                 if (ret == NULL) {
 458                         cpy_log_exception("write callback");
 459                 } else {
 460                         Py_DECREF(ret);
 461                 }
 462         CPY_RELEASE_THREADS
 463         return 0;
 464 }
 465
 466 static int cpy_notification_callback(const notification_t *notification, user_data_t *data) {
 467         cpy_callback_t *c = data->data;
 468         PyObject *ret, *notify;
 469         Notification *n;
 470
 471         CPY_LOCK_THREADS
 472                 notify = Notification_New(); /* New reference. */
 473                 n = (Notification *) notify;
 474                 sstrncpy(n->data.host, notification->host, sizeof(n->data.host));
 475                 sstrncpy(n->data.type, notification->type, sizeof(n->data.type));
 476                 sstrncpy(n->data.type_instance, notification->type_instance, sizeof(n->data.type_instance));
 477                 sstrncpy(n->data.plugin, notification->plugin, sizeof(n->data.plugin));
 478                 sstrncpy(n->data.plugin_instance, notification->plugin_instance, sizeof(n->data.plugin_instance));
 479                 n->data.time = CDTIME_T_TO_DOUBLE(notification->time);
 480                 sstrncpy(n->message, notification->message, sizeof(n->message));
 481                 n->severity = notification->severity;
 482                 ret = PyObject_CallFunctionObjArgs(c->callback, n, c->data, (void *) 0); /* New reference. */
 483                 Py_XDECREF(notify);
 484                 if (ret == NULL) {
 485                         cpy_log_exception("notification callback");
 486                 } else {
 487                         Py_DECREF(ret);
 488                 }
 489         CPY_RELEASE_THREADS
 490         return 0;
 491 }
 492
 493 static void cpy_log_callback(int severity, const char *message, user_data_t *data) {
 494         cpy_callback_t * c = data->data;
 495         PyObject *ret, *text;
 496
 497         CPY_LOCK_THREADS
 498         text = cpy_string_to_unicode_or_bytes(message);  /* New reference. */
 499         if (c->data == NULL)
 500                 ret = PyObject_CallFunction(c->callback, "iN", severity, text); /* New reference. Steals a reference from "text". */
 501         else
 502                 ret = PyObject_CallFunction(c->callback, "iNO", severity, text, c->data); /* New reference. Steals a reference from "text". */
 503
 504         if (ret == NULL) {
 505                 /* FIXME */
 506                 /* Do we really want to trigger a log callback because a log callback failed?
 507                  * Probably not. */
 508                 PyErr_Print();
 509                 /* In case someone wanted to be clever, replaced stderr and failed at that. */
 510                 PyErr_Clear();
 511         } else {
 512                 Py_DECREF(ret);
 513         }
 514         CPY_RELEASE_THREADS
 515 }
 516
 517 static void cpy_flush_callback(int timeout, const char *id, user_data_t *data) {
 518         cpy_callback_t * c = data->data;
 519         PyObject *ret, *text;
 520
 521         CPY_LOCK_THREADS
 522         text = cpy_string_to_unicode_or_bytes(id);
 523         if (c->data == NULL)
 524                 ret = PyObject_CallFunction(c->callback, "iN", timeout, text); /* New reference. */
 525         else
 526                 ret = PyObject_CallFunction(c->callback, "iNO", timeout, text, c->data); /* New reference. */
 527
 528         if (ret == NULL) {
 529                 cpy_log_exception("flush callback");
 530         } else {
 531                 Py_DECREF(ret);
 532         }
 533         CPY_RELEASE_THREADS
 534 }
 535
 536 static PyObject *cpy_register_generic(cpy_callback_t **list_head, PyObject *args, PyObject *kwds) {
 537         char buf[512];
 538         cpy_callback_t *c;
 539         char *name = NULL;
 540         PyObject *callback = NULL, *data = NULL, *mod = NULL;
 541         static char *kwlist[] = {"callback", "data", "name", NULL};
 542
 543         if (PyArg_ParseTupleAndKeywords(args, kwds, "O|Oet", kwlist, &callback, &data, NULL, &name) == 0) return NULL;
 544         if (PyCallable_Check(callback) == 0) {
 545                 PyMem_Free(name);
 546                 PyErr_SetString(PyExc_TypeError, "callback needs a be a callable object.");
 547                 return NULL;
 548         }
 549         cpy_build_name(buf, sizeof(buf), callback, name);
 550
 551         Py_INCREF(callback);
 552         Py_XINCREF(data);
 553         c = malloc(sizeof(*c));
 554         c->name = strdup(buf);
 555         c->callback = callback;
 556         c->data = data;
 557         c->next = *list_head;
 558         *list_head = c;
 559         Py_XDECREF(mod);
 560         PyMem_Free(name);
 561         return cpy_string_to_unicode_or_bytes(buf);
 562 }
 563
 564 static PyObject *float_or_none(float number) {
 565         if (isnan(number)) {
 566                 Py_RETURN_NONE;
 567         }
 568         return PyFloat_FromDouble(number);
 569 }
 570
 571 static PyObject *cpy_get_dataset(PyObject *self, PyObject *args) {
 572         int i;
 573         char *name;
 574         const data_set_t *ds;
 575         PyObject *list, *tuple;
 576
 577         if (PyArg_ParseTuple(args, "et", NULL, &name) == 0) return NULL;
 578         ds = plugin_get_ds(name);
 579         PyMem_Free(name);
 580         if (ds == NULL) {
 581                 PyErr_Format(PyExc_TypeError, "Dataset %s not found", name);
 582                 return NULL;
 583         }
 584         list = PyList_New(ds->ds_num); /* New reference. */
 585         for (i = 0; i < ds->ds_num; ++i) {
 586                 tuple = PyTuple_New(4);
 587                 PyTuple_SET_ITEM(tuple, 0, cpy_string_to_unicode_or_bytes(ds->ds[i].name));
 588                 PyTuple_SET_ITEM(tuple, 1, cpy_string_to_unicode_or_bytes(DS_TYPE_TO_STRING(ds->ds[i].type)));
 589                 PyTuple_SET_ITEM(tuple, 2, float_or_none(ds->ds[i].min));
 590                 PyTuple_SET_ITEM(tuple, 3, float_or_none(ds->ds[i].max));
 591                 PyList_SET_ITEM(list, i, tuple);
 592         }
 593         return list;
 594 }
 595
 596 static PyObject *cpy_flush(PyObject *self, PyObject *args, PyObject *kwds) {
 597         int timeout = -1;
 598         char *plugin = NULL, *identifier = NULL;
 599         static char *kwlist[] = {"plugin", "timeout", "identifier", NULL};
 600
 601         if (PyArg_ParseTupleAndKeywords(args, kwds, "|etiet", kwlist, NULL, &plugin, &timeout, NULL, &identifier) == 0) return NULL;
 602         Py_BEGIN_ALLOW_THREADS
 603         plugin_flush(plugin, timeout, identifier);
 604         Py_END_ALLOW_THREADS
 605         PyMem_Free(plugin);
 606         PyMem_Free(identifier);
 607         Py_RETURN_NONE;
 608 }
 609
 610 static PyObject *cpy_register_config(PyObject *self, PyObject *args, PyObject *kwds) {
 611         return cpy_register_generic(&cpy_config_callbacks, args, kwds);
 612 }
 613
 614 static PyObject *cpy_register_init(PyObject *self, PyObject *args, PyObject *kwds) {
 615         return cpy_register_generic(&cpy_init_callbacks, args, kwds);
 616 }
 617
 618 typedef int reg_function_t(const char *name, void *callback, void *data);
 619
 620 static PyObject *cpy_register_generic_userdata(void *reg, void *handler, PyObject *args, PyObject *kwds) {
 621         char buf[512];
 622         reg_function_t *register_function = (reg_function_t *) reg;
 623         cpy_callback_t *c = NULL;
 624         user_data_t *user_data = NULL;
 625         char *name = NULL;
 626         PyObject *callback = NULL, *data = NULL;
 627         static char *kwlist[] = {"callback", "data", "name", NULL};
 628
 629         if (PyArg_ParseTupleAndKeywords(args, kwds, "O|Oet", kwlist, &callback, &data, NULL, &name) == 0) return NULL;
 630         if (PyCallable_Check(callback) == 0) {
 631                 PyMem_Free(name);
 632                 PyErr_SetString(PyExc_TypeError, "callback needs a be a callable object.");
 633                 return NULL;
 634         }
 635         cpy_build_name(buf, sizeof(buf), callback, name);
 636         PyMem_Free(name);
 637
 638         Py_INCREF(callback);
 639         Py_XINCREF(data);
 640         c = malloc(sizeof(*c));
 641         c->name = strdup(buf);
 642         c->callback = callback;
 643         c->data = data;
 644         c->next = NULL;
 645         user_data = malloc(sizeof(*user_data));
 646         user_data->free_func = cpy_destroy_user_data;
 647         user_data->data = c;
 648         register_function(buf, handler, user_data);
 649         return cpy_string_to_unicode_or_bytes(buf);
 650 }
 651
 652 static PyObject *cpy_register_read(PyObject *self, PyObject *args, PyObject *kwds) {
 653         char buf[512];
 654         cpy_callback_t *c = NULL;
 655         user_data_t *user_data = NULL;
 656         double interval = 0;
 657         char *name = NULL;
 658         PyObject *callback = NULL, *data = NULL;
 659         static char *kwlist[] = {"callback", "interval", "data", "name", NULL};
 660
 661         if (PyArg_ParseTupleAndKeywords(args, kwds, "O|dOet", kwlist, &callback, &interval, &data, NULL, &name) == 0) return NULL;
 662         if (PyCallable_Check(callback) == 0) {
 663                 PyMem_Free(name);
 664                 PyErr_SetString(PyExc_TypeError, "callback needs a be a callable object.");
 665                 return NULL;
 666         }
 667         cpy_build_name(buf, sizeof(buf), callback, name);
 668         PyMem_Free(name);
 669
 670         Py_INCREF(callback);
 671         Py_XINCREF(data);
 672         c = malloc(sizeof(*c));
 673         c->name = strdup(buf);
 674         c->callback = callback;
 675         c->data = data;
 676         c->next = NULL;
 677         user_data = malloc(sizeof(*user_data));
 678         user_data->free_func = cpy_destroy_user_data;
 679         user_data->data = c;
 680         plugin_register_complex_read(/* group = */ NULL, buf,
 681                         cpy_read_callback, DOUBLE_TO_CDTIME_T (interval), user_data);
 682         return cpy_string_to_unicode_or_bytes(buf);
 683 }
 684
 685 static PyObject *cpy_register_log(PyObject *self, PyObject *args, PyObject *kwds) {
 686         return cpy_register_generic_userdata((void *) plugin_register_log,
 687                         (void *) cpy_log_callback, args, kwds);
 688 }
 689
 690 static PyObject *cpy_register_write(PyObject *self, PyObject *args, PyObject *kwds) {
 691         return cpy_register_generic_userdata((void *) plugin_register_write,
 692                         (void *) cpy_write_callback, args, kwds);
 693 }
 694
 695 static PyObject *cpy_register_notification(PyObject *self, PyObject *args, PyObject *kwds) {
 696         return cpy_register_generic_userdata((void *) plugin_register_notification,
 697                         (void *) cpy_notification_callback, args, kwds);
 698 }
 699
 700 static PyObject *cpy_register_flush(PyObject *self, PyObject *args, PyObject *kwds) {
 701         return cpy_register_generic_userdata((void *) plugin_register_flush,
 702                         (void *) cpy_flush_callback, args, kwds);
 703 }
 704
 705 static PyObject *cpy_register_shutdown(PyObject *self, PyObject *args, PyObject *kwds) {
 706         return cpy_register_generic(&cpy_shutdown_callbacks, args, kwds);
 707 }
 708
 709 static PyObject *cpy_error(PyObject *self, PyObject *args) {
 710         char *text;
 711         if (PyArg_ParseTuple(args, "et", NULL, &text) == 0) return NULL;
 712         Py_BEGIN_ALLOW_THREADS
 713         plugin_log(LOG_ERR, "%s", text);
 714         Py_END_ALLOW_THREADS
 715         PyMem_Free(text);
 716         Py_RETURN_NONE;
 717 }
 718
 719 static PyObject *cpy_warning(PyObject *self, PyObject *args) {
 720         char *text;
 721         if (PyArg_ParseTuple(args, "et", NULL, &text) == 0) return NULL;
 722         Py_BEGIN_ALLOW_THREADS
 723         plugin_log(LOG_WARNING, "%s", text);
 724         Py_END_ALLOW_THREADS
 725         PyMem_Free(text);
 726         Py_RETURN_NONE;
 727 }
 728
 729 static PyObject *cpy_notice(PyObject *self, PyObject *args) {
 730         char *text;
 731         if (PyArg_ParseTuple(args, "et", NULL, &text) == 0) return NULL;
 732         Py_BEGIN_ALLOW_THREADS
 733         plugin_log(LOG_NOTICE, "%s", text);
 734         Py_END_ALLOW_THREADS
 735         PyMem_Free(text);
 736         Py_RETURN_NONE;
 737 }
 738
 739 static PyObject *cpy_info(PyObject *self, PyObject *args) {
 740         char *text;
 741         if (PyArg_ParseTuple(args, "et", NULL, &text) == 0) return NULL;
 742         Py_BEGIN_ALLOW_THREADS
 743         plugin_log(LOG_INFO, "%s", text);
 744         Py_END_ALLOW_THREADS
 745         PyMem_Free(text);
 746         Py_RETURN_NONE;
 747 }
 748
 749 static PyObject *cpy_debug(PyObject *self, PyObject *args) {
 750 #ifdef COLLECT_DEBUG
 751         char *text;
 752         if (PyArg_ParseTuple(args, "et", NULL, &text) == 0) return NULL;
 753         Py_BEGIN_ALLOW_THREADS
 754         plugin_log(LOG_DEBUG, "%s", text);
 755         Py_END_ALLOW_THREADS
 756         PyMem_Free(text);
 757 #endif
 758         Py_RETURN_NONE;
 759 }
 760
 761 static PyObject *cpy_unregister_generic(cpy_callback_t **list_head, PyObject *arg, const char *desc) {
 762         char buf[512];
 763         const char *name;
 764         cpy_callback_t *prev = NULL, *tmp;
 765
 766         Py_INCREF(arg);
 767         name = cpy_unicode_or_bytes_to_string(&arg);
 768         if (name == NULL) {
 769                 PyErr_Clear();
 770                 if (!PyCallable_Check(arg)) {
 771                         PyErr_SetString(PyExc_TypeError, "This function needs a string or a callable object as its only parameter.");
 772                         Py_DECREF(arg);
 773                         return NULL;
 774                 }
 775                 cpy_build_name(buf, sizeof(buf), arg, NULL);
 776                 name = buf;
 777         }
 778         for (tmp = *list_head; tmp; prev = tmp, tmp = tmp->next)
 779                 if (strcmp(name, tmp->name) == 0)
 780                         break;
 781
 782         Py_DECREF(arg);
 783         if (tmp == NULL) {
 784                 PyErr_Format(PyExc_RuntimeError, "Unable to unregister %s callback '%s'.", desc, name);
 785                 return NULL;
 786         }
 787         /* Yes, this is actually save. To call this function the caller has to
 788          * hold the GIL. Well, save as long as there is only one GIL anyway ... */
 789         if (prev == NULL)
 790                 *list_head = tmp->next;
 791         else
 792                 prev->next = tmp->next;
 793         cpy_destroy_user_data(tmp);
 794         Py_RETURN_NONE;
 795 }
 796
 797 typedef int cpy_unregister_function_t(const char *name);
 798
 799 static PyObject *cpy_unregister_generic_userdata(cpy_unregister_function_t *unreg, PyObject *arg, const char *desc) {
 800         char buf[512];
 801         const char *name;
 802
 803         Py_INCREF(arg);
 804         name = cpy_unicode_or_bytes_to_string(&arg);
 805         if (name == NULL) {
 806                 PyErr_Clear();
 807                 if (!PyCallable_Check(arg)) {
 808                         PyErr_SetString(PyExc_TypeError, "This function needs a string or a callable object as its only parameter.");
 809                         Py_DECREF(arg);
 810                         return NULL;
 811                 }
 812                 cpy_build_name(buf, sizeof(buf), arg, NULL);
 813                 name = buf;
 814         }
 815         if (unreg(name) == 0) {
 816                 Py_DECREF(arg);
 817                 Py_RETURN_NONE;
 818         }
 819         PyErr_Format(PyExc_RuntimeError, "Unable to unregister %s callback '%s'.", desc, name);
 820         Py_DECREF(arg);
 821         return NULL;
 822 }
 823
 824 static PyObject *cpy_unregister_log(PyObject *self, PyObject *arg) {
 825         return cpy_unregister_generic_userdata(plugin_unregister_log, arg, "log");
 826 }
 827
 828 static PyObject *cpy_unregister_init(PyObject *self, PyObject *arg) {
 829         return cpy_unregister_generic(&cpy_init_callbacks, arg, "init");
 830 }
 831
 832 static PyObject *cpy_unregister_config(PyObject *self, PyObject *arg) {
 833         return cpy_unregister_generic(&cpy_config_callbacks, arg, "config");
 834 }
 835
 836 static PyObject *cpy_unregister_read(PyObject *self, PyObject *arg) {
 837         return cpy_unregister_generic_userdata(plugin_unregister_read, arg, "read");
 838 }
 839
 840 static PyObject *cpy_unregister_write(PyObject *self, PyObject *arg) {
 841         return cpy_unregister_generic_userdata(plugin_unregister_write, arg, "write");
 842 }
 843
 844 static PyObject *cpy_unregister_notification(PyObject *self, PyObject *arg) {
 845         return cpy_unregister_generic_userdata(plugin_unregister_notification, arg, "notification");
 846 }
 847
 848 static PyObject *cpy_unregister_flush(PyObject *self, PyObject *arg) {
 849         return cpy_unregister_generic_userdata(plugin_unregister_flush, arg, "flush");
 850 }
 851
 852 static PyObject *cpy_unregister_shutdown(PyObject *self, PyObject *arg) {
 853         return cpy_unregister_generic(&cpy_shutdown_callbacks, arg, "shutdown");
 854 }
 855
 856 static PyMethodDef cpy_methods[] = {
 857         {"debug", cpy_debug, METH_VARARGS, log_doc},
 858         {"info", cpy_info, METH_VARARGS, log_doc},
 859         {"notice", cpy_notice, METH_VARARGS, log_doc},
 860         {"warning", cpy_warning, METH_VARARGS, log_doc},
 861         {"error", cpy_error, METH_VARARGS, log_doc},
 862         {"get_dataset", (PyCFunction) cpy_get_dataset, METH_VARARGS, get_ds_doc},
 863         {"flush", (PyCFunction) cpy_flush, METH_VARARGS | METH_KEYWORDS, flush_doc},
 864         {"register_log", (PyCFunction) cpy_register_log, METH_VARARGS | METH_KEYWORDS, reg_log_doc},
 865         {"register_init", (PyCFunction) cpy_register_init, METH_VARARGS | METH_KEYWORDS, reg_init_doc},
 866         {"register_config", (PyCFunction) cpy_register_config, METH_VARARGS | METH_KEYWORDS, reg_config_doc},
 867         {"register_read", (PyCFunction) cpy_register_read, METH_VARARGS | METH_KEYWORDS, reg_read_doc},
 868         {"register_write", (PyCFunction) cpy_register_write, METH_VARARGS | METH_KEYWORDS, reg_write_doc},
 869         {"register_notification", (PyCFunction) cpy_register_notification, METH_VARARGS | METH_KEYWORDS, reg_notification_doc},
 870         {"register_flush", (PyCFunction) cpy_register_flush, METH_VARARGS | METH_KEYWORDS, reg_flush_doc},
 871         {"register_shutdown", (PyCFunction) cpy_register_shutdown, METH_VARARGS | METH_KEYWORDS, reg_shutdown_doc},
 872         {"unregister_log", cpy_unregister_log, METH_O, unregister_doc},
 873         {"unregister_init", cpy_unregister_init, METH_O, unregister_doc},
 874         {"unregister_config", cpy_unregister_config, METH_O, unregister_doc},
 875         {"unregister_read", cpy_unregister_read, METH_O, unregister_doc},
 876         {"unregister_write", cpy_unregister_write, METH_O, unregister_doc},
 877         {"unregister_notification", cpy_unregister_notification, METH_O, unregister_doc},
 878         {"unregister_flush", cpy_unregister_flush, METH_O, unregister_doc},
 879         {"unregister_shutdown", cpy_unregister_shutdown, METH_O, unregister_doc},
 880         {0, 0, 0, 0}
 881 };
 882
 883 static int cpy_shutdown(void) {
 884         cpy_callback_t *c;
 885         PyObject *ret;
 886
 887         /* This can happen if the module was loaded but not configured. */
 888         if (state != NULL)
 889                 PyEval_RestoreThread(state);
 890
 891         for (c = cpy_shutdown_callbacks; c; c = c->next) {
 892                 ret = PyObject_CallFunctionObjArgs(c->callback, c->data, (void *) 0); /* New reference. */
 893                 if (ret == NULL)
 894                         cpy_log_exception("shutdown callback");
 895                 else
 896                         Py_DECREF(ret);
 897         }
 898         PyErr_Print();
 899         Py_Finalize();
 900         return 0;
 901 }
 902
 903 static void cpy_int_handler(int sig) {
 904         return;
 905 }
 906
 907 static void *cpy_interactive(void *data) {
 908         sigset_t sigset;
 909         struct sigaction sig_int_action, old;
 910
 911         /* Signal handler in a plugin? Bad stuff, but the best way to
 912          * handle it I guess. In an interactive session people will
 913          * press Ctrl+C at some time, which will generate a SIGINT.
 914          * This will cause collectd to shutdown, thus killing the
 915          * interactive interpreter, and leaving the terminal in a
 916          * mess. Chances are, this isn't what the user wanted to do.
 917          *
 918          * So this is the plan:
 919          * 1. Block SIGINT in the main thread.
 920          * 2. Install our own signal handler that does nothing.
 921          * 3. Unblock SIGINT in the interactive thread.
 922          *
 923          * This will make sure that SIGINT won't kill collectd but
 924          * still interrupt syscalls like sleep and pause.
 925          * It does not raise a KeyboardInterrupt exception because so
 926          * far nobody managed to figure out how to do that. */
 927         memset (&sig_int_action, '\0', sizeof (sig_int_action));
 928         sig_int_action.sa_handler = cpy_int_handler;
 929         sigaction (SIGINT, &sig_int_action, &old);
 930
 931         sigemptyset(&sigset);
 932         sigaddset(&sigset, SIGINT);
 933         pthread_sigmask(SIG_UNBLOCK, &sigset, NULL);
 934         PyEval_AcquireThread(state);
 935         if (PyImport_ImportModule("readline") == NULL) {
 936                 /* This interactive session will suck. */
 937                 cpy_log_exception("interactive session init");
 938         }
 939         PyRun_InteractiveLoop(stdin, "<stdin>");
 940         PyErr_Print();
 941         PyEval_ReleaseThread(state);
 942         NOTICE("python: Interactive interpreter exited, stopping collectd ...");
 943         /* Restore the original collectd SIGINT handler and raise SIGINT.
 944          * The main thread still has SIGINT blocked and there's nothing we
 945          * can do about that so this thread will handle it. But that's not
 946          * important, except that it won't interrupt the main loop and so
 947          * it might take a few seconds before collectd really shuts down. */
 948         sigaction (SIGINT, &old, NULL);
 949         raise(SIGINT);
 950         pause();
 951         return NULL;
 952 }
 953
 954 static int cpy_init(void) {
 955         cpy_callback_t *c;
 956         PyObject *ret;
 957         static pthread_t thread;
 958         sigset_t sigset;
 959
 960         if (!Py_IsInitialized()) {
 961                 WARNING("python: Plugin loaded but not configured.");
 962                 plugin_unregister_shutdown("python");
 963                 return 0;
 964         }
 965         PyEval_InitThreads();
 966         /* Now it's finally OK to use python threads. */
 967         for (c = cpy_init_callbacks; c; c = c->next) {
 968                 ret = PyObject_CallFunctionObjArgs(c->callback, c->data, (void *) 0); /* New reference. */
 969                 if (ret == NULL)
 970                         cpy_log_exception("init callback");
 971                 else
 972                         Py_DECREF(ret);
 973         }
 974         sigemptyset(&sigset);
 975         sigaddset(&sigset, SIGINT);
 976         pthread_sigmask(SIG_BLOCK, &sigset, NULL);
 977         state = PyEval_SaveThread();
 978         if (do_interactive) {
 979                 if (plugin_thread_create(&thread, NULL, cpy_interactive, NULL)) {
 980                         ERROR("python: Error creating thread for interactive interpreter.");
 981                 }
 982         }
 983
 984         return 0;
 985 }
 986
 987 static PyObject *cpy_oconfig_to_pyconfig(oconfig_item_t *ci, PyObject *parent) {
 988         int i;
 989         PyObject *item, *values, *children, *tmp;
 990
 991         if (parent == NULL)
 992                 parent = Py_None;
 993
 994         values = PyTuple_New(ci->values_num); /* New reference. */
 995         for (i = 0; i < ci->values_num; ++i) {
 996                 if (ci->values[i].type == OCONFIG_TYPE_STRING) {
 997                         PyTuple_SET_ITEM(values, i, cpy_string_to_unicode_or_bytes(ci->values[i].value.string));
 998                 } else if (ci->values[i].type == OCONFIG_TYPE_NUMBER) {
 999                         PyTuple_SET_ITEM(values, i, PyFloat_FromDouble(ci->values[i].value.number));
1000                 } else if (ci->values[i].type == OCONFIG_TYPE_BOOLEAN) {
1001                         PyTuple_SET_ITEM(values, i, PyBool_FromLong(ci->values[i].value.boolean));
1002                 }
1003         }
1004
1005         tmp = cpy_string_to_unicode_or_bytes(ci->key);
1006         item = PyObject_CallFunction((void *) &ConfigType, "NONO", tmp, parent, values, Py_None);
1007         if (item == NULL)
1008                 return NULL;
1009         children = PyTuple_New(ci->children_num); /* New reference. */
1010         for (i = 0; i < ci->children_num; ++i) {
1011                 PyTuple_SET_ITEM(children, i, cpy_oconfig_to_pyconfig(ci->children + i, item));
1012         }
1013         tmp = ((Config *) item)->children;
1014         ((Config *) item)->children = children;
1015         Py_XDECREF(tmp);
1016         return item;
1017 }
1018
1019 #ifdef IS_PY3K
1020 static struct PyModuleDef collectdmodule = {
1021         PyModuleDef_HEAD_INIT,
1022         "collectd",   /* name of module */
1023         "The python interface to collectd", /* module documentation, may be NULL */
1024         -1,
1025         cpy_methods
1026 };
1027
1028 PyMODINIT_FUNC PyInit_collectd(void) {
1029         return PyModule_Create(&collectdmodule);
1030 }
1031 #endif
1032
1033 static int cpy_init_python() {
1034         PyObject *sys;
1035         PyObject *module;
1036
1037 #ifdef IS_PY3K
1038         wchar_t *argv = L"";
1039         /* Add a builtin module, before Py_Initialize */
1040         PyImport_AppendInittab("collectd", PyInit_collectd);
1041 #else
1042         char *argv = "";
1043 #endif
1044
1045         Py_Initialize();
1046
1047         PyType_Ready(&ConfigType);
1048         PyType_Ready(&PluginDataType);
1049         ValuesType.tp_base = &PluginDataType;
1050         PyType_Ready(&ValuesType);
1051         NotificationType.tp_base = &PluginDataType;
1052         PyType_Ready(&NotificationType);
1053         SignedType.tp_base = &PyLong_Type;
1054         PyType_Ready(&SignedType);
1055         UnsignedType.tp_base = &PyLong_Type;
1056         PyType_Ready(&UnsignedType);
1057         sys = PyImport_ImportModule("sys"); /* New reference. */
1058         if (sys == NULL) {
1059                 cpy_log_exception("python initialization");
1060                 return 1;
1061         }
1062         sys_path = PyObject_GetAttrString(sys, "path"); /* New reference. */
1063         Py_DECREF(sys);
1064         if (sys_path == NULL) {
1065                 cpy_log_exception("python initialization");
1066                 return 1;
1067         }
1068         PySys_SetArgv(1, &argv);
1069         PyList_SetSlice(sys_path, 0, 1, NULL);
1070
1071 #ifdef IS_PY3K
1072         module = PyImport_ImportModule("collectd");
1073 #else
1074         module = Py_InitModule("collectd", cpy_methods); /* Borrowed reference. */
1075 #endif
1076         PyModule_AddObject(module, "Config", (void *) &ConfigType); /* Steals a reference. */
1077         PyModule_AddObject(module, "Values", (void *) &ValuesType); /* Steals a reference. */
1078         PyModule_AddObject(module, "Notification", (void *) &NotificationType); /* Steals a reference. */
1079         PyModule_AddObject(module, "Signed", (void *) &SignedType); /* Steals a reference. */
1080         PyModule_AddObject(module, "Unsigned", (void *) &UnsignedType); /* Steals a reference. */
1081         PyModule_AddIntConstant(module, "LOG_DEBUG", LOG_DEBUG);
1082         PyModule_AddIntConstant(module, "LOG_INFO", LOG_INFO);
1083         PyModule_AddIntConstant(module, "LOG_NOTICE", LOG_NOTICE);
1084         PyModule_AddIntConstant(module, "LOG_WARNING", LOG_WARNING);
1085         PyModule_AddIntConstant(module, "LOG_ERROR", LOG_ERR);
1086         PyModule_AddIntConstant(module, "NOTIF_FAILURE", NOTIF_FAILURE);
1087         PyModule_AddIntConstant(module, "NOTIF_WARNING", NOTIF_WARNING);
1088         PyModule_AddIntConstant(module, "NOTIF_OKAY", NOTIF_OKAY);
1089         PyModule_AddStringConstant(module, "DS_TYPE_COUNTER", DS_TYPE_TO_STRING(DS_TYPE_COUNTER));
1090         PyModule_AddStringConstant(module, "DS_TYPE_GAUGE", DS_TYPE_TO_STRING(DS_TYPE_GAUGE));
1091         PyModule_AddStringConstant(module, "DS_TYPE_DERIVE", DS_TYPE_TO_STRING(DS_TYPE_DERIVE));
1092         PyModule_AddStringConstant(module, "DS_TYPE_ABSOLUTE", DS_TYPE_TO_STRING(DS_TYPE_ABSOLUTE));
1093         return 0;
1094 }
1095
1096 static int cpy_config(oconfig_item_t *ci) {
1097         int i;
1098         PyObject *tb;
1099
1100         /* Ok in theory we shouldn't do initialization at this point
1101          * but we have to. In order to give python scripts a chance
1102          * to register a config callback we need to be able to execute
1103          * python code during the config callback so we have to start
1104          * the interpreter here. */
1105         /* Do *not* use the python "thread" module at this point! */
1106
1107         if (!Py_IsInitialized() && cpy_init_python()) return 1;
1108
1109         for (i = 0; i < ci->children_num; ++i) {
1110                 oconfig_item_t *item = ci->children + i;
1111
1112                 if (strcasecmp(item->key, "Interactive") == 0) {
1113                         if (item->values_num != 1 || item->values[0].type != OCONFIG_TYPE_BOOLEAN)
1114                                 continue;
1115                         do_interactive = item->values[0].value.boolean;
1116                 } else if (strcasecmp(item->key, "Encoding") == 0) {
1117                         if (item->values_num != 1 || item->values[0].type != OCONFIG_TYPE_STRING)
1118                                 continue;
1119 #ifdef IS_PY3K
1120                         NOTICE("python: \"Encoding\" was used in the config file but Python3 was used, which does not support changing encodings. Ignoring this.");
1121 #else
1122                         /* Why is this even necessary? And undocumented? */
1123                         if (PyUnicode_SetDefaultEncoding(item->values[0].value.string))
1124                                 cpy_log_exception("setting default encoding");
1125 #endif
1126                 } else if (strcasecmp(item->key, "LogTraces") == 0) {
1127                         if (item->values_num != 1 || item->values[0].type != OCONFIG_TYPE_BOOLEAN)
1128                                 continue;
1129                         if (!item->values[0].value.boolean) {
1130                                 Py_XDECREF(cpy_format_exception);
1131                                 cpy_format_exception = NULL;
1132                                 continue;
1133                         }
1134                         if (cpy_format_exception)
1135                                 continue;
1136                         tb = PyImport_ImportModule("traceback"); /* New reference. */
1137                         if (tb == NULL) {
1138                                 cpy_log_exception("python initialization");
1139                                 continue;
1140                         }
1141                         cpy_format_exception = PyObject_GetAttrString(tb, "format_exception"); /* New reference. */
1142                         Py_DECREF(tb);
1143                         if (cpy_format_exception == NULL)
1144                                 cpy_log_exception("python initialization");
1145                 } else if (strcasecmp(item->key, "ModulePath") == 0) {
1146                         char *dir = NULL;
1147                         PyObject *dir_object;
1148
1149                         if (cf_util_get_string(item, &dir) != 0)
1150                                 continue;
1151                         dir_object = cpy_string_to_unicode_or_bytes(dir); /* New reference. */
1152                         if (dir_object == NULL) {
1153                                 ERROR("python plugin: Unable to convert \"%s\" to "
1154                                       "a python object.", dir);
1155                                 free(dir);
1156                                 cpy_log_exception("python initialization");
1157                                 continue;
1158                         }
1159                         if (PyList_Insert(sys_path, 0, dir_object) != 0) {
1160                                 ERROR("python plugin: Unable to prepend \"%s\" to "
1161                                       "python module path.", dir);
1162                                 cpy_log_exception("python initialization");
1163                         }
1164                         Py_DECREF(dir_object);
1165                         free(dir);
1166                 } else if (strcasecmp(item->key, "Import") == 0) {
1167                         char *module_name = NULL;
1168                         PyObject *module;
1169
1170                         if (cf_util_get_string(item, &module_name) != 0)
1171                                 continue;
1172                         module = PyImport_ImportModule(module_name); /* New reference. */
1173                         if (module == NULL) {
1174                                 ERROR("python plugin: Error importing module \"%s\".", module_name);
1175                                 cpy_log_exception("importing module");
1176                         }
1177                         free(module_name);
1178                         Py_XDECREF(module);
1179                 } else if (strcasecmp(item->key, "Module") == 0) {
1180                         char *name = NULL;
1181                         cpy_callback_t *c;
1182                         PyObject *ret;
1183
1184                         if (cf_util_get_string(item, &name) != 0)
1185                                 continue;
1186                         for (c = cpy_config_callbacks; c; c = c->next) {
1187                                 if (strcasecmp(c->name + 7, name) == 0)
1188                                         break;
1189                         }
1190                         if (c == NULL) {
1191                                 WARNING("python plugin: Found a configuration for the \"%s\" plugin, "
1192                                         "but the plugin isn't loaded or didn't register "
1193                                         "a configuration callback.", name);
1194                                 free(name);
1195                                 continue;
1196                         }
1197                         free(name);
1198                         if (c->data == NULL)
1199                                 ret = PyObject_CallFunction(c->callback, "N",
1200                                         cpy_oconfig_to_pyconfig(item, NULL)); /* New reference. */
1201                         else
1202                                 ret = PyObject_CallFunction(c->callback, "NO",
1203                                         cpy_oconfig_to_pyconfig(item, NULL), c->data); /* New reference. */
1204                         if (ret == NULL)
1205                                 cpy_log_exception("loading module");
1206                         else
1207                                 Py_DECREF(ret);
1208                 } else {
1209                         WARNING("python plugin: Ignoring unknown config key \"%s\".", item->key);
1210                 }
1211         }
1212         return 0;
1213 }
1214
1215 void module_register(void) {
1216         plugin_register_complex_config("python", cpy_config);
1217         plugin_register_init("python", cpy_init);
1218         plugin_register_shutdown("python", cpy_shutdown);
1219 }