Sha256: 3eadab3d5469b3d40997d35b09a04ba493c48dd39f710d4c5c1907d843a4dc49
Contents?: true
Size: 1.18 KB
Versions: 28
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Stored size: 1.18 KB
Contents
# -*- coding: utf-8 -*-
module ActiveRecord::Turntable::Algorithm
class RangeAlgorithm < Base
def initialize(config)
@config = config
end
def calculate(key)
idx = calculate_idx(key)
@config["shards"][idx]["connection"]
rescue
raise ActiveRecord::Turntable::CannotSpecifyShardError, "cannot specify shard for key:#{key}"
end
def calculate_idx(key)
@config["shards"].find_index {|h| h["less_than"] > key }
end
# { connection_name => weight, ... }
def calculate_used_shards_with_weight(sequence_value)
idx = calculate_idx(sequence_value)
last_connection = calculate(sequence_value)
shards = @config["shards"][0..idx]
weighted_hash = Hash.new {|h,k| h[k]=0}
prev_max = 0
shards.each_with_index do |h,idx|
weighted_hash[h["connection"]] += if idx < shards.size - 1
h["less_than"] - prev_max - 1
else
sequence_value - prev_max
end
prev_max = h["less_than"] - 1
end
return weighted_hash
end
end
end
Version data entries
28 entries across 28 versions & 1 rubygems