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Contents
module Flydata
module QueryBasedSync
class RecordSizeEstimator
# Data size for the static part of sent record
# {"row":{},"type":"update","respect_order":true,
# "src_pos":"10051:10051:\t10520:10052:\t{\"id\":\"1000000000\"}",
# "v":2,"seq":10000000,"table_name":"","table_rev":1}
BASE_DATA_SIZE = 162
def initialize(table_name, num_columns)
@base_record_size = calc_base_record_size(table_name, num_columns)
end
# Calculate a record size for emitting
def calc_record_size(record)
@base_record_size + record.values.inject(0){|r, v| r+=v.to_s.size}
end
private
def calc_base_record_size(table_name, num_columns)
col_cnt = num_columns
# static part of {"1":"16","2":"cc", ...}
col_size_for_static = 6 * col_cnt - 1 + 2
col_size_for_key = 0
col_cnt_length = col_cnt.to_s.size # get position of number, ex: 9->1, 12->2, 132->3
# calc size of each key per position, 1, 10x, 100x,... ex: 123 -> calc size 1-9 and 10-99
1.upto(col_cnt_length-1){|i| col_size_for_key += ( i * (10**i - (10**(i-1))) )}
# calc size of the key for the hight position
col_size_for_key += (col_cnt - 10**(col_cnt_length-1) + 1) * col_cnt_length
col_size = col_size_for_static + col_size_for_key
BASE_DATA_SIZE + table_name.size + col_size
end
end
end
end
Version data entries
34 entries across 34 versions & 1 rubygems