1 #include <Python.h>
2 #include <structmember.h>
4 #include "collectd.h"
5 #include "common.h"
7 typedef struct cpy_callback_s {
8 char *name;
9 PyObject *callback;
10 PyObject *data;
11 struct cpy_callback_s *next;
12 } cpy_callback_t;
14 /* This is our global thread state. Python saves some stuff in thread-local
15 * storage. So if we allow the interpreter to run in the background
16 * (the scriptwriters might have created some threads from python), we have
17 * to save the state so we can resume it later from a different thread.
19 * Technically the Global Interpreter Lock (GIL) and thread states can be
20 * manipulated independently. But to keep stuff from getting too complex
21 * we'll just use PyEval_SaveTread and PyEval_RestoreThreas which takes
22 * care of the thread states as well as the GIL. */
24 static PyThreadState *state;
26 static cpy_callback_t *cpy_config_callbacks;
27 static cpy_callback_t *cpy_init_callbacks;
28 static cpy_callback_t *cpy_shutdown_callbacks;
30 typedef struct {
31 PyObject_HEAD /* No semicolon! */
32 PyObject *parent;
33 PyObject *key;
34 PyObject *values;
35 PyObject *children;
36 } Config;
38 static void Config_dealloc(PyObject *s) {
39 Config *self = (Config *) s;
41 Py_XDECREF(self->parent);
42 Py_XDECREF(self->key);
43 Py_XDECREF(self->values);
44 Py_XDECREF(self->children);
45 self->ob_type->tp_free(s);
46 }
48 static PyObject *Config_new(PyTypeObject *type, PyObject *args, PyObject *kwds) {
49 Config *self;
51 self = (Config *) type->tp_alloc(type, 0);
52 if (self == NULL)
53 return NULL;
55 self->parent = NULL;
56 self->key = NULL;
57 self->values = NULL;
58 self->children = NULL;
59 return (PyObject *) self;
60 }
62 static int Config_init(PyObject *s, PyObject *args, PyObject *kwds) {
63 PyObject *key = NULL, *parent = NULL, *values = NULL, *children = NULL, *tmp;
64 Config *self = (Config *) s;
65 static char *kwlist[] = {"key", "parent", "values", "children", NULL};
67 if (!PyArg_ParseTupleAndKeywords(args, kwds, "S|OOO", kwlist,
68 &key, &parent, &values, &children))
69 return -1;
71 if (values == NULL) {
72 values = PyTuple_New(0);
73 PyErr_Clear();
74 }
75 if (children == NULL) {
76 children = PyTuple_New(0);
77 PyErr_Clear();
78 }
79 tmp = self->key;
80 Py_INCREF(key);
81 self->key = key;
82 Py_XDECREF(tmp);
83 if (parent != NULL) {
84 tmp = self->parent;
85 Py_INCREF(parent);
86 self->parent = parent;
87 Py_XDECREF(tmp);
88 }
89 if (values != NULL) {
90 tmp = self->values;
91 Py_INCREF(values);
92 self->values = values;
93 Py_XDECREF(tmp);
94 }
95 if (children != NULL) {
96 tmp = self->children;
97 Py_INCREF(children);
98 self->children = children;
99 Py_XDECREF(tmp);
100 }
101 return 0;
102 }
104 static PyMemberDef Config_members[] = {
105 {"Parent", T_OBJECT, offsetof(Config, parent), 0, "Parent node"},
106 {"Key", T_OBJECT_EX, offsetof(Config, key), 0, "Keyword of this node"},
107 {"Values", T_OBJECT_EX, offsetof(Config, values), 0, "Values after the key"},
108 {"Children", T_OBJECT_EX, offsetof(Config, children), 0, "Childnodes of this node"},
109 {NULL}
110 };
112 static PyTypeObject ConfigType = {
113 PyObject_HEAD_INIT(NULL)
114 0, /* Always 0 */
115 "collectd.Config", /* tp_name */
116 sizeof(Config), /* tp_basicsize */
117 0, /* Will be filled in later */
118 Config_dealloc, /* tp_dealloc */
119 0, /* tp_print */
120 0, /* tp_getattr */
121 0, /* tp_setattr */
122 0, /* tp_compare */
123 0, /* tp_repr */
124 0, /* tp_as_number */
125 0, /* tp_as_sequence */
126 0, /* tp_as_mapping */
127 0, /* tp_hash */
128 0, /* tp_call */
129 0, /* tp_str */
130 0, /* tp_getattro */
131 0, /* tp_setattro */
132 0, /* tp_as_buffer */
133 Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /*tp_flags*/
134 "Cool help text later", /* tp_doc */
135 0, /* tp_traverse */
136 0, /* tp_clear */
137 0, /* tp_richcompare */
138 0, /* tp_weaklistoffset */
139 0, /* tp_iter */
140 0, /* tp_iternext */
141 0, /* tp_methods */
142 Config_members, /* tp_members */
143 0, /* tp_getset */
144 0, /* tp_base */
145 0, /* tp_dict */
146 0, /* tp_descr_get */
147 0, /* tp_descr_set */
148 0, /* tp_dictoffset */
149 Config_init, /* tp_init */
150 0, /* tp_alloc */
151 Config_new /* tp_new */
152 };
154 static PyObject *cpy_register_generic(cpy_callback_t **list_head, PyObject *args, PyObject *kwds) {
155 cpy_callback_t *c;
156 const char *name = NULL;
157 PyObject *callback = NULL, *data = NULL;
158 static char *kwlist[] = {"callback", "data", "name", NULL};
160 if (PyArg_ParseTupleAndKeywords(args, kwds, "O|Oz", kwlist, &callback, &data, &name) == 0) return NULL;
161 if (PyCallable_Check(callback) == 0) {
162 PyErr_SetString(PyExc_TypeError, "callback needs a be a callable object.");
163 return NULL;
164 }
165 if (name == NULL) {
166 PyObject *mod;
168 mod = PyObject_GetAttrString(callback, "__module__");
169 if (mod != NULL) name = PyString_AsString(mod);
170 if (name == NULL) {
171 PyErr_SetString(PyExc_ValueError, "No module name specified and "
172 "callback function does not have a \"__module__\" attribute.");
173 return NULL;
174 }
175 }
176 Py_INCREF(callback);
177 Py_XINCREF(data);
178 c = malloc(sizeof(*c));
179 c->name = strdup(name);
180 c->callback = callback;
181 c->data = data;
182 c->next = *list_head;
183 *list_head = c;
184 Py_RETURN_NONE;
185 }
187 static PyObject *cpy_register_config(PyObject *self, PyObject *args, PyObject *kwds) {
188 return cpy_register_generic(&cpy_config_callbacks, args, kwds);
189 }
191 static PyObject *cpy_register_init(PyObject *self, PyObject *args, PyObject *kwds) {
192 return cpy_register_generic(&cpy_init_callbacks, args, kwds);
193 }
195 static PyObject *cpy_register_shutdown(PyObject *self, PyObject *args, PyObject *kwds) {
196 return cpy_register_generic(&cpy_shutdown_callbacks, args, kwds);
197 }
199 static PyMethodDef cpy_methods[] = {
200 {"register_init", (PyCFunction) cpy_register_init, METH_VARARGS | METH_KEYWORDS, "This is an unhelpful text."},
201 {"register_config", (PyCFunction) cpy_register_config, METH_VARARGS | METH_KEYWORDS, "This is an unhelpful text."},
202 {"register_shutdown", (PyCFunction) cpy_register_shutdown, METH_VARARGS | METH_KEYWORDS, "This is an unhelpful text."},
203 {0, 0, 0, 0}
204 };
206 static int cpy_shutdown(void) {
207 cpy_callback_t *c;
208 PyObject *ret;
210 /* This can happen if the module was loaded but not configured. */
211 if (state != NULL)
212 PyEval_RestoreThread(state);
214 for (c = cpy_shutdown_callbacks; c; c = c->next) {
215 if (c->data == NULL)
216 ret = PyObject_CallObject(c->callback, NULL); /* New reference. */
217 else
218 ret = PyObject_CallFunctionObjArgs(c->callback, c->data, (void *) 0); /* New reference. */
219 if (ret == NULL)
220 PyErr_Print(); /* FIXME */
221 else
222 Py_DECREF(ret);
223 }
224 Py_Finalize();
225 return 0;
226 }
228 static int cpy_init(void) {
229 cpy_callback_t *c;
230 PyObject *ret;
232 PyEval_InitThreads();
233 /* Now it's finally OK to use python threads. */
234 for (c = cpy_init_callbacks; c; c = c->next) {
235 if (c->data == NULL)
236 ret = PyObject_CallObject(c->callback, NULL); /* New reference. */
237 else
238 ret = PyObject_CallFunctionObjArgs(c->callback, c->data, (void *) 0); /* New reference. */
239 if (ret == NULL)
240 PyErr_Print(); /* FIXME */
241 else
242 Py_DECREF(ret);
243 }
244 state = PyEval_SaveThread();
245 return 0;
246 }
248 static PyObject *cpy_oconfig_to_pyconfig(oconfig_item_t *ci, PyObject *parent) {
249 int i;
250 PyObject *item, *values, *children, *tmp;
252 if (parent == NULL)
253 parent = Py_None;
255 values = PyTuple_New(ci->values_num); /* New reference. */
256 for (i = 0; i < ci->values_num; ++i) {
257 if (ci->values[i].type == OCONFIG_TYPE_STRING) {
258 PyTuple_SET_ITEM(values, i, PyString_FromString(ci->values[i].value.string));
259 } else if (ci->values[i].type == OCONFIG_TYPE_NUMBER) {
260 PyTuple_SET_ITEM(values, i, PyFloat_FromDouble(ci->values[i].value.number));
261 } else if (ci->values[i].type == OCONFIG_TYPE_BOOLEAN) {
262 PyTuple_SET_ITEM(values, i, PyBool_FromLong(ci->values[i].value.boolean));
263 }
264 }
266 item = PyObject_CallFunction((PyObject *) &ConfigType, "sONO", ci->key, parent, values, Py_None);
267 if (item == NULL)
268 return NULL;
269 children = PyTuple_New(ci->children_num); /* New reference. */
270 for (i = 0; i < ci->children_num; ++i) {
271 PyTuple_SET_ITEM(children, i, cpy_oconfig_to_pyconfig(ci->children + i, item));
272 }
273 tmp = ((Config *) item)->children;
274 ((Config *) item)->children = children;
275 Py_XDECREF(tmp);
276 return item;
277 }
279 static int cpy_config(oconfig_item_t *ci) {
280 int i;
281 PyObject *sys;
282 PyObject *sys_path;
283 PyObject *module;
285 /* Ok in theory we shouldn't do initialization at this point
286 * but we have to. In order to give python scripts a chance
287 * to register a config callback we need to be able to execute
288 * python code during the config callback so we have to start
289 * the interpreter here. */
290 /* Do *not* use the python "thread" module at this point! */
291 Py_Initialize();
293 PyType_Ready(&ConfigType);
294 sys = PyImport_ImportModule("sys"); /* New reference. */
295 if (sys == NULL) {
296 ERROR("python module: Unable to import \"sys\" module.");
297 /* Just print the default python exception text to stderr. */
298 PyErr_Print();
299 return 1;
300 }
301 sys_path = PyObject_GetAttrString(sys, "path"); /* New reference. */
302 Py_DECREF(sys);
303 if (sys_path == NULL) {
304 ERROR("python module: Unable to read \"sys.path\".");
305 PyErr_Print();
306 return 1;
307 }
308 module = Py_InitModule("collectd", cpy_methods); /* Borrowed reference. */
309 PyModule_AddObject(module, "Config", (PyObject *) &ConfigType); /* Steals a reference. */
310 for (i = 0; i < ci->children_num; ++i) {
311 oconfig_item_t *item = ci->children + i;
313 if (strcasecmp(item->key, "ModulePath") == 0) {
314 char *dir = NULL;
315 PyObject *dir_object;
317 if (cf_util_get_string(item, &dir) != 0)
318 continue;
319 dir_object = PyString_FromString(dir); /* New reference. */
320 if (dir_object == NULL) {
321 ERROR("python plugin: Unable to convert \"%s\" to "
322 "a python object.", dir);
323 free(dir);
324 PyErr_Print();
325 continue;
326 }
327 if (PyList_Append(sys_path, dir_object) != 0) {
328 ERROR("python plugin: Unable to append \"%s\" to "
329 "python module path.", dir);
330 PyErr_Print();
331 }
332 Py_DECREF(dir_object);
333 free(dir);
334 } else if (strcasecmp(item->key, "Import") == 0) {
335 char *module_name = NULL;
336 PyObject *module;
338 if (cf_util_get_string(item, &module_name) != 0)
339 continue;
340 module = PyImport_ImportModule(module_name); /* New reference. */
341 if (module == NULL) {
342 ERROR("python plugin: Error importing module \"%s\".", module_name);
343 PyErr_Print();
344 }
345 free(module_name);
346 Py_XDECREF(module);
347 } else if (strcasecmp(item->key, "Module") == 0) {
348 char *name = NULL;
349 cpy_callback_t *c;
350 PyObject *ret;
352 if (cf_util_get_string(item, &name) != 0)
353 continue;
354 for (c = cpy_config_callbacks; c; c = c->next) {
355 if (strcasecmp(c->name, name) == 0)
356 break;
357 }
358 if (c == NULL) {
359 WARNING("python plugin: Found a configuration for the \"%s\" plugin, "
360 "but the plugin isn't loaded or didn't register "
361 "a configuration callback.", name);
362 free(name);
363 continue;
364 }
365 free(name);
366 if (c->data == NULL)
367 ret = PyObject_CallFunction(c->callback, "N",
368 cpy_oconfig_to_pyconfig(item, NULL)); /* New reference. */
369 else
370 ret = PyObject_CallFunction(c->callback, "NO",
371 cpy_oconfig_to_pyconfig(item, NULL), c->data); /* New reference. */
372 if (ret == NULL)
373 PyErr_Print();
374 else
375 Py_DECREF(ret);
376 } else {
377 WARNING("python plugin: Ignoring unknown config key \"%s\".", item->key);
378 }
379 }
380 Py_DECREF(sys_path);
381 return 0;
382 }
384 void module_register(void) {
385 plugin_register_complex_config("python", cpy_config);
386 plugin_register_init("python", cpy_init);
387 // plugin_register_read("python", cna_read);
388 plugin_register_shutdown("python", cpy_shutdown);
389 }