69 lines
1.6 KiB
Python
69 lines
1.6 KiB
Python
from __future__ import absolute_import, print_function, division
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import datetime
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import json
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import time
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import netlib.utils
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def timestamp():
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"""
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Returns a serializable UTC timestamp.
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"""
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return time.time()
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def format_timestamp(s):
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s = time.localtime(s)
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d = datetime.datetime.fromtimestamp(time.mktime(s))
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return d.strftime("%Y-%m-%d %H:%M:%S")
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def format_timestamp_with_milli(s):
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d = datetime.datetime.fromtimestamp(s)
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return d.strftime("%Y-%m-%d %H:%M:%S.%f")[:-3]
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def pretty_json(s):
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try:
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p = json.loads(s)
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except ValueError:
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return None
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return json.dumps(p, sort_keys=True, indent=4)
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pkg_data = netlib.utils.Data(__name__)
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class LRUCache:
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"""
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A simple LRU cache for generated values.
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"""
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def __init__(self, size=100):
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self.size = size
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self.cache = {}
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self.cacheList = []
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def get(self, gen, *args):
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"""
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gen: A (presumably expensive) generator function. The identity of
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gen is NOT taken into account by the cache.
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*args: A list of immutable arguments, used to establish identiy by
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*the cache, and passed to gen to generate values.
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"""
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if args in self.cache:
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self.cacheList.remove(args)
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self.cacheList.insert(0, args)
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return self.cache[args]
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else:
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ret = gen(*args)
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self.cacheList.insert(0, args)
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self.cache[args] = ret
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if len(self.cacheList) > self.size:
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d = self.cacheList.pop()
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self.cache.pop(d)
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return ret
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