Shortcuts on this page
r m x toggle line displays
j k next/prev highlighted chunk
0 (zero) top of page
1 (one) first highlighted chunk
1import os
2from threading import Lock
3import time
4import types
5from typing import (
6 Any, Callable, Dict, Iterable, List, Literal, Optional, Sequence, Tuple,
7 Type, TypeVar, Union,
8)
9import warnings
11from . import values # retain this import style for testability
12from .context_managers import ExceptionCounter, InprogressTracker, Timer
13from .metrics_core import (
14 Metric, METRIC_LABEL_NAME_RE, METRIC_NAME_RE,
15 RESERVED_METRIC_LABEL_NAME_RE,
16)
17from .registry import Collector, CollectorRegistry, REGISTRY
18from .samples import Exemplar, Sample
19from .utils import floatToGoString, INF
21T = TypeVar('T', bound='MetricWrapperBase')
22F = TypeVar("F", bound=Callable[..., Any])
25def _build_full_name(metric_type, name, namespace, subsystem, unit):
26 full_name = ''
27 if namespace:
28 full_name += namespace + '_'
29 if subsystem:
30 full_name += subsystem + '_'
31 full_name += name
32 if metric_type == 'counter' and full_name.endswith('_total'):
33 full_name = full_name[:-6] # Munge to OpenMetrics.
34 if unit and not full_name.endswith("_" + unit):
35 full_name += "_" + unit
36 if unit and metric_type in ('info', 'stateset'):
37 raise ValueError('Metric name is of a type that cannot have a unit: ' + full_name)
38 return full_name
41def _validate_labelname(l):
42 if not METRIC_LABEL_NAME_RE.match(l):
43 raise ValueError('Invalid label metric name: ' + l)
44 if RESERVED_METRIC_LABEL_NAME_RE.match(l):
45 raise ValueError('Reserved label metric name: ' + l)
48def _validate_labelnames(cls, labelnames):
49 labelnames = tuple(labelnames)
50 for l in labelnames:
51 _validate_labelname(l)
52 if l in cls._reserved_labelnames:
53 raise ValueError('Reserved label metric name: ' + l)
54 return labelnames
57def _validate_exemplar(exemplar):
58 runes = 0
59 for k, v in exemplar.items():
60 _validate_labelname(k)
61 runes += len(k)
62 runes += len(v)
63 if runes > 128:
64 raise ValueError('Exemplar labels have %d UTF-8 characters, exceeding the limit of 128')
67def _get_use_created() -> bool:
68 return os.environ.get("PROMETHEUS_DISABLE_CREATED_SERIES", 'False').lower() not in ('true', '1', 't')
71_use_created = _get_use_created()
74def disable_created_metrics():
75 """Disable exporting _created metrics on counters, histograms, and summaries."""
76 global _use_created
77 _use_created = False
80def enable_created_metrics():
81 """Enable exporting _created metrics on counters, histograms, and summaries."""
82 global _use_created
83 _use_created = True
86class MetricWrapperBase(Collector):
87 _type: Optional[str] = None
88 _reserved_labelnames: Sequence[str] = ()
90 def _is_observable(self):
91 # Whether this metric is observable, i.e.
92 # * a metric without label names and values, or
93 # * the child of a labelled metric.
94 return not self._labelnames or (self._labelnames and self._labelvalues)
96 def _raise_if_not_observable(self):
97 # Functions that mutate the state of the metric, for example incrementing
98 # a counter, will fail if the metric is not observable, because only if a
99 # metric is observable will the value be initialized.
100 if not self._is_observable():
101 raise ValueError('%s metric is missing label values' % str(self._type))
103 def _is_parent(self):
104 return self._labelnames and not self._labelvalues
106 def _get_metric(self):
107 return Metric(self._name, self._documentation, self._type, self._unit)
109 def describe(self) -> Iterable[Metric]:
110 return [self._get_metric()]
112 def collect(self) -> Iterable[Metric]:
113 metric = self._get_metric()
114 for suffix, labels, value, timestamp, exemplar in self._samples():
115 metric.add_sample(self._name + suffix, labels, value, timestamp, exemplar)
116 return [metric]
118 def __str__(self) -> str:
119 return f"{self._type}:{self._name}"
121 def __repr__(self) -> str:
122 metric_type = type(self)
123 return f"{metric_type.__module__}.{metric_type.__name__}({self._name})"
125 def __init__(self: T,
126 name: str,
127 documentation: str,
128 labelnames: Iterable[str] = (),
129 namespace: str = '',
130 subsystem: str = '',
131 unit: str = '',
132 registry: Optional[CollectorRegistry] = REGISTRY,
133 _labelvalues: Optional[Sequence[str]] = None,
134 ) -> None:
135 self._name = _build_full_name(self._type, name, namespace, subsystem, unit)
136 self._labelnames = _validate_labelnames(self, labelnames)
137 self._labelvalues = tuple(_labelvalues or ())
138 self._kwargs: Dict[str, Any] = {}
139 self._documentation = documentation
140 self._unit = unit
142 if not METRIC_NAME_RE.match(self._name):
143 raise ValueError('Invalid metric name: ' + self._name)
145 if self._is_parent():
146 # Prepare the fields needed for child metrics.
147 self._lock = Lock()
148 self._metrics: Dict[Sequence[str], T] = {}
150 if self._is_observable():
151 self._metric_init()
153 if not self._labelvalues:
154 # Register the multi-wrapper parent metric, or if a label-less metric, the whole shebang.
155 if registry:
156 registry.register(self)
158 def labels(self: T, *labelvalues: Any, **labelkwargs: Any) -> T:
159 """Return the child for the given labelset.
161 All metrics can have labels, allowing grouping of related time series.
162 Taking a counter as an example:
164 from prometheus_client import Counter
166 c = Counter('my_requests_total', 'HTTP Failures', ['method', 'endpoint'])
167 c.labels('get', '/').inc()
168 c.labels('post', '/submit').inc()
170 Labels can also be provided as keyword arguments:
172 from prometheus_client import Counter
174 c = Counter('my_requests_total', 'HTTP Failures', ['method', 'endpoint'])
175 c.labels(method='get', endpoint='/').inc()
176 c.labels(method='post', endpoint='/submit').inc()
178 See the best practices on [naming](http://prometheus.io/docs/practices/naming/)
179 and [labels](http://prometheus.io/docs/practices/instrumentation/#use-labels).
180 """
181 if not self._labelnames:
182 raise ValueError('No label names were set when constructing %s' % self)
184 if self._labelvalues:
185 raise ValueError('{} already has labels set ({}); can not chain calls to .labels()'.format(
186 self,
187 dict(zip(self._labelnames, self._labelvalues))
188 ))
190 if labelvalues and labelkwargs:
191 raise ValueError("Can't pass both *args and **kwargs")
193 if labelkwargs:
194 if sorted(labelkwargs) != sorted(self._labelnames):
195 raise ValueError('Incorrect label names')
196 labelvalues = tuple(str(labelkwargs[l]) for l in self._labelnames)
197 else:
198 if len(labelvalues) != len(self._labelnames):
199 raise ValueError('Incorrect label count')
200 labelvalues = tuple(str(l) for l in labelvalues)
201 with self._lock:
202 if labelvalues not in self._metrics:
203 self._metrics[labelvalues] = self.__class__(
204 self._name,
205 documentation=self._documentation,
206 labelnames=self._labelnames,
207 unit=self._unit,
208 _labelvalues=labelvalues,
209 **self._kwargs
210 )
211 return self._metrics[labelvalues]
213 def remove(self, *labelvalues: Any) -> None:
214 if 'prometheus_multiproc_dir' in os.environ or 'PROMETHEUS_MULTIPROC_DIR' in os.environ:
215 warnings.warn(
216 "Removal of labels has not been implemented in multi-process mode yet.",
217 UserWarning)
219 if not self._labelnames:
220 raise ValueError('No label names were set when constructing %s' % self)
222 """Remove the given labelset from the metric."""
223 if len(labelvalues) != len(self._labelnames):
224 raise ValueError('Incorrect label count (expected %d, got %s)' % (len(self._labelnames), labelvalues))
225 labelvalues = tuple(str(l) for l in labelvalues)
226 with self._lock:
227 del self._metrics[labelvalues]
229 def clear(self) -> None:
230 """Remove all labelsets from the metric"""
231 if 'prometheus_multiproc_dir' in os.environ or 'PROMETHEUS_MULTIPROC_DIR' in os.environ:
232 warnings.warn(
233 "Clearing labels has not been implemented in multi-process mode yet",
234 UserWarning)
235 with self._lock:
236 self._metrics = {}
238 def _samples(self) -> Iterable[Sample]:
239 if self._is_parent():
240 return self._multi_samples()
241 else:
242 return self._child_samples()
244 def _multi_samples(self) -> Iterable[Sample]:
245 with self._lock:
246 metrics = self._metrics.copy()
247 for labels, metric in metrics.items():
248 series_labels = list(zip(self._labelnames, labels))
249 for suffix, sample_labels, value, timestamp, exemplar in metric._samples():
250 yield Sample(suffix, dict(series_labels + list(sample_labels.items())), value, timestamp, exemplar)
252 def _child_samples(self) -> Iterable[Sample]: # pragma: no cover
253 raise NotImplementedError('_child_samples() must be implemented by %r' % self)
255 def _metric_init(self): # pragma: no cover
256 """
257 Initialize the metric object as a child, i.e. when it has labels (if any) set.
259 This is factored as a separate function to allow for deferred initialization.
260 """
261 raise NotImplementedError('_metric_init() must be implemented by %r' % self)
264class Counter(MetricWrapperBase):
265 """A Counter tracks counts of events or running totals.
267 Example use cases for Counters:
268 - Number of requests processed
269 - Number of items that were inserted into a queue
270 - Total amount of data that a system has processed
272 Counters can only go up (and be reset when the process restarts). If your use case can go down,
273 you should use a Gauge instead.
275 An example for a Counter:
277 from prometheus_client import Counter
279 c = Counter('my_failures_total', 'Description of counter')
280 c.inc() # Increment by 1
281 c.inc(1.6) # Increment by given value
283 There are utilities to count exceptions raised:
285 @c.count_exceptions()
286 def f():
287 pass
289 with c.count_exceptions():
290 pass
292 # Count only one type of exception
293 with c.count_exceptions(ValueError):
294 pass
296 You can also reset the counter to zero in case your logical "process" restarts
297 without restarting the actual python process.
299 c.reset()
301 """
302 _type = 'counter'
304 def _metric_init(self) -> None:
305 self._value = values.ValueClass(self._type, self._name, self._name + '_total', self._labelnames,
306 self._labelvalues, self._documentation)
307 self._created = time.time()
309 def inc(self, amount: float = 1, exemplar: Optional[Dict[str, str]] = None) -> None:
310 """Increment counter by the given amount."""
311 self._raise_if_not_observable()
312 if amount < 0:
313 raise ValueError('Counters can only be incremented by non-negative amounts.')
314 self._value.inc(amount)
315 if exemplar:
316 _validate_exemplar(exemplar)
317 self._value.set_exemplar(Exemplar(exemplar, amount, time.time()))
319 def reset(self) -> None:
320 """Reset the counter to zero. Use this when a logical process restarts without restarting the actual python process."""
321 self._value.set(0)
322 self._created = time.time()
324 def count_exceptions(self, exception: Union[Type[BaseException], Tuple[Type[BaseException], ...]] = Exception) -> ExceptionCounter:
325 """Count exceptions in a block of code or function.
327 Can be used as a function decorator or context manager.
328 Increments the counter when an exception of the given
329 type is raised up out of the code.
330 """
331 self._raise_if_not_observable()
332 return ExceptionCounter(self, exception)
334 def _child_samples(self) -> Iterable[Sample]:
335 sample = Sample('_total', {}, self._value.get(), None, self._value.get_exemplar())
336 if _use_created:
337 return (
338 sample,
339 Sample('_created', {}, self._created, None, None)
340 )
341 return (sample,)
344class Gauge(MetricWrapperBase):
345 """Gauge metric, to report instantaneous values.
347 Examples of Gauges include:
348 - Inprogress requests
349 - Number of items in a queue
350 - Free memory
351 - Total memory
352 - Temperature
354 Gauges can go both up and down.
356 from prometheus_client import Gauge
358 g = Gauge('my_inprogress_requests', 'Description of gauge')
359 g.inc() # Increment by 1
360 g.dec(10) # Decrement by given value
361 g.set(4.2) # Set to a given value
363 There are utilities for common use cases:
365 g.set_to_current_time() # Set to current unixtime
367 # Increment when entered, decrement when exited.
368 @g.track_inprogress()
369 def f():
370 pass
372 with g.track_inprogress():
373 pass
375 A Gauge can also take its value from a callback:
377 d = Gauge('data_objects', 'Number of objects')
378 my_dict = {}
379 d.set_function(lambda: len(my_dict))
380 """
381 _type = 'gauge'
382 _MULTIPROC_MODES = frozenset(('all', 'liveall', 'min', 'livemin', 'max', 'livemax', 'sum', 'livesum', 'mostrecent', 'livemostrecent'))
383 _MOST_RECENT_MODES = frozenset(('mostrecent', 'livemostrecent'))
385 def __init__(self,
386 name: str,
387 documentation: str,
388 labelnames: Iterable[str] = (),
389 namespace: str = '',
390 subsystem: str = '',
391 unit: str = '',
392 registry: Optional[CollectorRegistry] = REGISTRY,
393 _labelvalues: Optional[Sequence[str]] = None,
394 multiprocess_mode: Literal['all', 'liveall', 'min', 'livemin', 'max', 'livemax', 'sum', 'livesum', 'mostrecent', 'livemostrecent'] = 'all',
395 ):
396 self._multiprocess_mode = multiprocess_mode
397 if multiprocess_mode not in self._MULTIPROC_MODES:
398 raise ValueError('Invalid multiprocess mode: ' + multiprocess_mode)
399 super().__init__(
400 name=name,
401 documentation=documentation,
402 labelnames=labelnames,
403 namespace=namespace,
404 subsystem=subsystem,
405 unit=unit,
406 registry=registry,
407 _labelvalues=_labelvalues,
408 )
409 self._kwargs['multiprocess_mode'] = self._multiprocess_mode
410 self._is_most_recent = self._multiprocess_mode in self._MOST_RECENT_MODES
412 def _metric_init(self) -> None:
413 self._value = values.ValueClass(
414 self._type, self._name, self._name, self._labelnames, self._labelvalues,
415 self._documentation, multiprocess_mode=self._multiprocess_mode
416 )
418 def inc(self, amount: float = 1) -> None:
419 """Increment gauge by the given amount."""
420 if self._is_most_recent:
421 raise RuntimeError("inc must not be used with the mostrecent mode")
422 self._raise_if_not_observable()
423 self._value.inc(amount)
425 def dec(self, amount: float = 1) -> None:
426 """Decrement gauge by the given amount."""
427 if self._is_most_recent:
428 raise RuntimeError("dec must not be used with the mostrecent mode")
429 self._raise_if_not_observable()
430 self._value.inc(-amount)
432 def set(self, value: float) -> None:
433 """Set gauge to the given value."""
434 self._raise_if_not_observable()
435 if self._is_most_recent:
436 self._value.set(float(value), timestamp=time.time())
437 else:
438 self._value.set(float(value))
440 def set_to_current_time(self) -> None:
441 """Set gauge to the current unixtime."""
442 self.set(time.time())
444 def track_inprogress(self) -> InprogressTracker:
445 """Track inprogress blocks of code or functions.
447 Can be used as a function decorator or context manager.
448 Increments the gauge when the code is entered,
449 and decrements when it is exited.
450 """
451 self._raise_if_not_observable()
452 return InprogressTracker(self)
454 def time(self) -> Timer:
455 """Time a block of code or function, and set the duration in seconds.
457 Can be used as a function decorator or context manager.
458 """
459 return Timer(self, 'set')
461 def set_function(self, f: Callable[[], float]) -> None:
462 """Call the provided function to return the Gauge value.
464 The function must return a float, and may be called from
465 multiple threads. All other methods of the Gauge become NOOPs.
466 """
468 self._raise_if_not_observable()
470 def samples(_: Gauge) -> Iterable[Sample]:
471 return (Sample('', {}, float(f()), None, None),)
473 self._child_samples = types.MethodType(samples, self) # type: ignore
475 def _child_samples(self) -> Iterable[Sample]:
476 return (Sample('', {}, self._value.get(), None, None),)
479class Summary(MetricWrapperBase):
480 """A Summary tracks the size and number of events.
482 Example use cases for Summaries:
483 - Response latency
484 - Request size
486 Example for a Summary:
488 from prometheus_client import Summary
490 s = Summary('request_size_bytes', 'Request size (bytes)')
491 s.observe(512) # Observe 512 (bytes)
493 Example for a Summary using time:
495 from prometheus_client import Summary
497 REQUEST_TIME = Summary('response_latency_seconds', 'Response latency (seconds)')
499 @REQUEST_TIME.time()
500 def create_response(request):
501 '''A dummy function'''
502 time.sleep(1)
504 Example for using the same Summary object as a context manager:
506 with REQUEST_TIME.time():
507 pass # Logic to be timed
508 """
509 _type = 'summary'
510 _reserved_labelnames = ['quantile']
512 def _metric_init(self) -> None:
513 self._count = values.ValueClass(self._type, self._name, self._name + '_count', self._labelnames,
514 self._labelvalues, self._documentation)
515 self._sum = values.ValueClass(self._type, self._name, self._name + '_sum', self._labelnames, self._labelvalues, self._documentation)
516 self._created = time.time()
518 def observe(self, amount: float) -> None:
519 """Observe the given amount.
521 The amount is usually positive or zero. Negative values are
522 accepted but prevent current versions of Prometheus from
523 properly detecting counter resets in the sum of
524 observations. See
525 https://prometheus.io/docs/practices/histograms/#count-and-sum-of-observations
526 for details.
527 """
528 self._raise_if_not_observable()
529 self._count.inc(1)
530 self._sum.inc(amount)
532 def time(self) -> Timer:
533 """Time a block of code or function, and observe the duration in seconds.
535 Can be used as a function decorator or context manager.
536 """
537 return Timer(self, 'observe')
539 def _child_samples(self) -> Iterable[Sample]:
540 samples = [
541 Sample('_count', {}, self._count.get(), None, None),
542 Sample('_sum', {}, self._sum.get(), None, None),
543 ]
544 if _use_created:
545 samples.append(Sample('_created', {}, self._created, None, None))
546 return tuple(samples)
549class Histogram(MetricWrapperBase):
550 """A Histogram tracks the size and number of events in buckets.
552 You can use Histograms for aggregatable calculation of quantiles.
554 Example use cases:
555 - Response latency
556 - Request size
558 Example for a Histogram:
560 from prometheus_client import Histogram
562 h = Histogram('request_size_bytes', 'Request size (bytes)')
563 h.observe(512) # Observe 512 (bytes)
565 Example for a Histogram using time:
567 from prometheus_client import Histogram
569 REQUEST_TIME = Histogram('response_latency_seconds', 'Response latency (seconds)')
571 @REQUEST_TIME.time()
572 def create_response(request):
573 '''A dummy function'''
574 time.sleep(1)
576 Example of using the same Histogram object as a context manager:
578 with REQUEST_TIME.time():
579 pass # Logic to be timed
581 The default buckets are intended to cover a typical web/rpc request from milliseconds to seconds.
582 They can be overridden by passing `buckets` keyword argument to `Histogram`.
583 """
584 _type = 'histogram'
585 _reserved_labelnames = ['le']
586 DEFAULT_BUCKETS = (.005, .01, .025, .05, .075, .1, .25, .5, .75, 1.0, 2.5, 5.0, 7.5, 10.0, INF)
588 def __init__(self,
589 name: str,
590 documentation: str,
591 labelnames: Iterable[str] = (),
592 namespace: str = '',
593 subsystem: str = '',
594 unit: str = '',
595 registry: Optional[CollectorRegistry] = REGISTRY,
596 _labelvalues: Optional[Sequence[str]] = None,
597 buckets: Sequence[Union[float, str]] = DEFAULT_BUCKETS,
598 ):
599 self._prepare_buckets(buckets)
600 super().__init__(
601 name=name,
602 documentation=documentation,
603 labelnames=labelnames,
604 namespace=namespace,
605 subsystem=subsystem,
606 unit=unit,
607 registry=registry,
608 _labelvalues=_labelvalues,
609 )
610 self._kwargs['buckets'] = buckets
612 def _prepare_buckets(self, source_buckets: Sequence[Union[float, str]]) -> None:
613 buckets = [float(b) for b in source_buckets]
614 if buckets != sorted(buckets):
615 # This is probably an error on the part of the user,
616 # so raise rather than sorting for them.
617 raise ValueError('Buckets not in sorted order')
618 if buckets and buckets[-1] != INF:
619 buckets.append(INF)
620 if len(buckets) < 2:
621 raise ValueError('Must have at least two buckets')
622 self._upper_bounds = buckets
624 def _metric_init(self) -> None:
625 self._buckets: List[values.ValueClass] = []
626 self._created = time.time()
627 bucket_labelnames = self._labelnames + ('le',)
628 self._sum = values.ValueClass(self._type, self._name, self._name + '_sum', self._labelnames, self._labelvalues, self._documentation)
629 for b in self._upper_bounds:
630 self._buckets.append(values.ValueClass(
631 self._type,
632 self._name,
633 self._name + '_bucket',
634 bucket_labelnames,
635 self._labelvalues + (floatToGoString(b),),
636 self._documentation)
637 )
639 def observe(self, amount: float, exemplar: Optional[Dict[str, str]] = None) -> None:
640 """Observe the given amount.
642 The amount is usually positive or zero. Negative values are
643 accepted but prevent current versions of Prometheus from
644 properly detecting counter resets in the sum of
645 observations. See
646 https://prometheus.io/docs/practices/histograms/#count-and-sum-of-observations
647 for details.
648 """
649 self._raise_if_not_observable()
650 self._sum.inc(amount)
651 for i, bound in enumerate(self._upper_bounds):
652 if amount <= bound:
653 self._buckets[i].inc(1)
654 if exemplar:
655 _validate_exemplar(exemplar)
656 self._buckets[i].set_exemplar(Exemplar(exemplar, amount, time.time()))
657 break
659 def time(self) -> Timer:
660 """Time a block of code or function, and observe the duration in seconds.
662 Can be used as a function decorator or context manager.
663 """
664 return Timer(self, 'observe')
666 def _child_samples(self) -> Iterable[Sample]:
667 samples = []
668 acc = 0.0
669 for i, bound in enumerate(self._upper_bounds):
670 acc += self._buckets[i].get()
671 samples.append(Sample('_bucket', {'le': floatToGoString(bound)}, acc, None, self._buckets[i].get_exemplar()))
672 samples.append(Sample('_count', {}, acc, None, None))
673 if self._upper_bounds[0] >= 0:
674 samples.append(Sample('_sum', {}, self._sum.get(), None, None))
675 if _use_created:
676 samples.append(Sample('_created', {}, self._created, None, None))
677 return tuple(samples)
680class Info(MetricWrapperBase):
681 """Info metric, key-value pairs.
683 Examples of Info include:
684 - Build information
685 - Version information
686 - Potential target metadata
688 Example usage:
689 from prometheus_client import Info
691 i = Info('my_build', 'Description of info')
692 i.info({'version': '1.2.3', 'buildhost': 'foo@bar'})
694 Info metrics do not work in multiprocess mode.
695 """
696 _type = 'info'
698 def _metric_init(self):
699 self._labelname_set = set(self._labelnames)
700 self._lock = Lock()
701 self._value = {}
703 def info(self, val: Dict[str, str]) -> None:
704 """Set info metric."""
705 if self._labelname_set.intersection(val.keys()):
706 raise ValueError('Overlapping labels for Info metric, metric: {} child: {}'.format(
707 self._labelnames, val))
708 with self._lock:
709 self._value = dict(val)
711 def _child_samples(self) -> Iterable[Sample]:
712 with self._lock:
713 return (Sample('_info', self._value, 1.0, None, None),)
716class Enum(MetricWrapperBase):
717 """Enum metric, which of a set of states is true.
719 Example usage:
720 from prometheus_client import Enum
722 e = Enum('task_state', 'Description of enum',
723 states=['starting', 'running', 'stopped'])
724 e.state('running')
726 The first listed state will be the default.
727 Enum metrics do not work in multiprocess mode.
728 """
729 _type = 'stateset'
731 def __init__(self,
732 name: str,
733 documentation: str,
734 labelnames: Sequence[str] = (),
735 namespace: str = '',
736 subsystem: str = '',
737 unit: str = '',
738 registry: Optional[CollectorRegistry] = REGISTRY,
739 _labelvalues: Optional[Sequence[str]] = None,
740 states: Optional[Sequence[str]] = None,
741 ):
742 super().__init__(
743 name=name,
744 documentation=documentation,
745 labelnames=labelnames,
746 namespace=namespace,
747 subsystem=subsystem,
748 unit=unit,
749 registry=registry,
750 _labelvalues=_labelvalues,
751 )
752 if name in labelnames:
753 raise ValueError(f'Overlapping labels for Enum metric: {name}')
754 if not states:
755 raise ValueError(f'No states provided for Enum metric: {name}')
756 self._kwargs['states'] = self._states = states
758 def _metric_init(self) -> None:
759 self._value = 0
760 self._lock = Lock()
762 def state(self, state: str) -> None:
763 """Set enum metric state."""
764 self._raise_if_not_observable()
765 with self._lock:
766 self._value = self._states.index(state)
768 def _child_samples(self) -> Iterable[Sample]:
769 with self._lock:
770 return [
771 Sample('', {self._name: s}, 1 if i == self._value else 0, None, None)
772 for i, s
773 in enumerate(self._states)
774 ]