Sha256: a23cb7688070a458d4360a97672250a52836b3122990af0ff4bf53377575b4a5
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Size: 1.21 KB
Versions: 6
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Stored size: 1.21 KB
Contents
module ActiveRecord::Turntable::Algorithm
class RangeBsearchAlgorithm < Base
def choose(shard_maps, key)
shard_map = shard_maps.bsearch { |shard| key <= shard.range.max }
raise ActiveRecord::Turntable::CannotSpecifyShardError, "cannot specify shard for key:#{key.inspect}" unless shard_map
shard_map.shard
end
def choose_index(shard_maps, key)
(0...shard_maps.size).bsearch { |idx| key <= shard_maps[idx].range.max } or
raise ActiveRecord::Turntable::CannotSpecifyShardError, "cannot specify shard for key:#{key.inspect}"
end
def shard_weights(shard_maps, current_sequence_value)
current_shard_index = choose_index(shard_maps, current_sequence_value)
shard_maps = shard_maps[0..current_shard_index]
weights_hash = Hash.new { |h, k| h[k] = 0 }
shard_maps.each_with_index do |shard_map, idx|
weights_hash[shard_map.shard] += if idx < current_shard_index
shard_map.range.size
else
current_sequence_value - shard_map.range.min + 1
end
end
weights_hash
end
end
end
Version data entries
6 entries across 6 versions & 1 rubygems