ba87959e31
This build is broken due to the mismatch in expected and actual error condition for get_chunk. The C code still expects it to return None.
63 lines
1.9 KiB
Python
63 lines
1.9 KiB
Python
# This file is part of the Minecraft Overviewer.
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#
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# Minecraft Overviewer is free software: you can redistribute it and/or
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# modify it under the terms of the GNU General Public License as published
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# by the Free Software Foundation, either version 3 of the License, or (at
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# your option) any later version.
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#
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# Minecraft Overviewer is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
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# Public License for more details.
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#
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# You should have received a copy of the GNU General Public License along
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# with the Overviewer. If not, see <http://www.gnu.org/licenses/>.
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"""This module has supporting functions for the caching logic used in world.py.
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"""
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import functools
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def lru_cache(max_size=100):
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"""A quick-and-dirty LRU implementation.
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Uses a dict to store mappings, and a list to store orderings.
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Only supports positional arguments
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"""
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def lru_decorator(fun):
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cache = {}
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lru_ordering = []
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@functools.wraps(fun)
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def new_fun(*args):
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try:
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result = cache[args]
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except KeyError:
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# cache miss =(
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new_fun.miss += 1
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result = fun(*args)
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# Insert into cache
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cache[args] = result
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lru_ordering.append(args)
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if len(cache) > max_size:
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# Evict an item
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del cache[ lru_ordering.pop(0) ]
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else:
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# Move the result item to the end of the list
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new_fun.hits += 1
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position = lru_ordering.index(args)
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lru_ordering.append(lru_ordering.pop(position))
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return result
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new_fun.hits = 0
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new_fun.miss = 0
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return new_fun
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return lru_decorator
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