20 lines
1 KiB
Text
20 lines
1 KiB
Text
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From README:
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This module implements a least recently used (LRU) cache in memory
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through a tie interface. Any time data is stored in the tied hash, that
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key/value pair has an entry time associated with it, and as the cache
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fills up, those members of the cache that are the oldest are removed to
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make room for new entries.
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So, the cache only "remembers" the last written entries, up to the size
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of the cache. This can be especially useful if you access great amounts
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of data, but only access a minority of the data a majority of the time.
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The implementation is a hash, for quick lookups, overlaying a doubly
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linked list for quick insertion and deletion. On a WinNT PII 300, writes
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to the hash were done at a rate 3100 per second, and reads from the hash
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at 6300 per second. Work has been done to optimize refreshing cache
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entries that are frequently read from, code like $cache{entry}, which
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moves the entry to the end of the linked list internally.
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-- Alex Kapranoff <kapr@crosswinds.net>
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