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Editing: bayes_cache_learn.lua
-- Lua script to perform cache learning for bayes classification (multi-class) -- This script accepts the following parameters: -- key1 - cache id -- argv1 - class name string (e.g. "spam", "ham", "transactional") -- argv2 - configuration table in message pack -- -- The cache value stored in Redis is the class name string. A numeric class_id -- hash was used previously, but uint64_t values > 2^53 lose precision when -- round-tripped through Lua doubles, so the equality check on retrieval was -- unreliable for arbitrary multiclass names. local cache_id = KEYS[1] local class_name = ARGV[1] local conf = cmsgpack.unpack(ARGV[2]) -- Store the class name directly as the cache value local cache_value = class_name cache_id = string.sub(cache_id, 1, conf.cache_elt_len) -- Try each prefix that is in Redis (as some other instance might have set it) for i = 0, conf.cache_max_keys do local prefix = conf.cache_prefix .. string.rep("X", i) local have = redis.call('HGET', prefix, cache_id) if have then -- Already in cache, but cache_value changes when relearning redis.call('HSET', prefix, cache_id, cache_value) return false end end local added = false local lim = conf.cache_max_elt for i = 0, conf.cache_max_keys do if not added then local prefix = conf.cache_prefix .. string.rep("X", i) local count = redis.call('HLEN', prefix) if count < lim then -- We can add it to this prefix redis.call('HSET', prefix, cache_id, cache_value) added = true end end end if not added then -- Need to expire some keys local expired = false for i = 0, conf.cache_max_keys do local prefix = conf.cache_prefix .. string.rep("X", i) local exists = redis.call('EXISTS', prefix) if exists then if not expired then redis.call('DEL', prefix) redis.call('HSET', prefix, cache_id, cache_value) -- Do not expire anything else expired = true elseif i > 0 then -- Move key to a shorter prefix, so we will rotate them eventually from lower to upper local new_prefix = conf.cache_prefix .. string.rep("X", i - 1) redis.call('RENAME', prefix, new_prefix) end end end end return true
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