import functools
import logging
import time
LOG = logging.getLogger(__name__)
class Timed:
"""
A context manager which measures and optionally logs context run time.
:param msg: A message that describes the thing that is being measured
:param threshold: Threshold, in seconds. When the context exceeds this
threshold, a log will be made.
:param log_mode: Control whether to log. Defaults to "threshold". Possible
values include:
"always" - Always log 'msg', even when 'threshold' is not reached.
"threshold" - Log when context time exceeds 'threshold'.
"skip" - Do not log. Context time and message are stored in the
'output' and 'delta' attributes, respectively. Used to manually
coalesce with other logs at the call site.
usage:
this call:
```
with Timed("Configuring the network"):
run_configure()
```
might produce this log:
```
Configuring the network took 0.100 seconds
```
"""
def __init__(
self,
msg: str,
*,
threshold: float = 0.01,
log_mode: str = "threshold",
):
self.msg = msg
self.threshold = threshold
self.log_mode = log_mode
self.output = ""
self.start = 0.0
self.delta = 0.0
def __enter__(self):
self.start = time.monotonic()
return self
def __exit__(self, exc_type, exc_val, exc_tb):
self.delta = time.monotonic() - self.start
suffix = f"took {self.delta:.3f} seconds"
if "always" == self.log_mode:
LOG.debug("%s %s", self.msg, suffix)
elif "skip" == self.log_mode:
return
elif "threshold" == self.log_mode:
if self.delta > self.threshold:
LOG.debug("%s %s", self.msg, suffix)
self.output = f"{self.msg} {suffix}"
else:
raise ValueError(
f"Invalid Timed log_mode value: '{self.log_mode}'."
)
def timed(msg: str, *, threshold: float = 0.01, log_mode: str = "threshold"):
"""
A decorator which measures and optionally logs context run time.
:param msg: A message that describes the thing that is being measured
:param threshold: Threshold, in seconds. When the context exceeds this
threshold, a log will be made.
:param log_mode: Control whether to log. Defaults to "threshold". Possible
values include:
"always" - Always log 'msg', even when 'threshold' is not reached.
"threshold" - Log when context time exceeds 'threshold'.
usage:
this call:
```
@timed("Configuring the network")
def run_configure():
...
```
might produce this log:
```
Configuring the network took 0.100 seconds
```
"""
def wrapper(func):
@functools.wraps(func)
def decorator(*args, **kwargs):
with Timed(msg, threshold=threshold, log_mode=log_mode):
return func(*args, **kwargs)
return decorator
return wrapper
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