Oracle utilities for stmt_to_sqlid, stmt_to_hash and sqlid_to_hash.

oracle_stmt_utils.rb

require 'digest'

module OracleStmtUtils

    def stmt_to_sqlid(stmt)
        d1, d2, msb, lsb  = Digest::MD5.digest(stmt + "\x00").unpack('IIII')
        sqln = msb * (2 ** 32) + lsb
        stop = Math.log(sqln, Math::E) / Math.log(32, Math::E) + 1
        sqlid = String.new
        alphabet = '0123456789abcdfghjkmnpqrstuvwxyz'
        (0..stop-1).each {|i| sqlid = alphabet[(sqln / (32 ** i)) % 32] + sqlid}
        return sqlid
    end

    def stmt_to_hash(stmt)
        return Digest::MD5.digest(stmt + "\x00").unpack('IIII')[3]
    end

    def sqlid_to_hash(sqlid)
        sum = 0
        i = 1
        alphabet = '0123456789abcdfghjkmnpqrstuvwxyz'
        sqlid.each_char do |ch|
            sum += alphabet.index(ch) * (32**(sqlid.length - i))
            i += 1
        end
        return sum % (2 ** 32)
    end

end