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module Gitlab
module Database
# The max value of INTEGER type is the same between MySQL and PostgreSQL:
# https://www.postgresql.org/docs/9.2/static/datatype-numeric.html
# http://dev.mysql.com/doc/refman/5.7/en/integer-types.html
MAX_INT_VALUE = 2147483647
def self.config
ActiveRecord::Base.configurations[Rails.env]
end
def self.username
config['username'] || ENV['USER']
end
def self.database_name
config['database']
end
def self.adapter_name
config['adapter']
end
def self.mysql?
adapter_name.casecmp('mysql2').zero?
end
def self.postgresql?
adapter_name.casecmp('postgresql').zero?
end
def self.version
database_version.match(/\A(?:PostgreSQL |)([^\s]+).*\z/)[1]
end
def self.join_lateral_supported?
postgresql? && version.to_f >= 9.3
end
def self.nulls_last_order(field, direction = 'ASC')
order = "#{field} #{direction}"
if postgresql?
order << ' NULLS LAST'
else
# `field IS NULL` will be `0` for non-NULL columns and `1` for NULL
# columns. In the (default) ascending order, `0` comes first.
order.prepend("#{field} IS NULL, ") if direction == 'ASC'
end
order
end
def self.nulls_first_order(field, direction = 'ASC')
order = "#{field} #{direction}"
if postgresql?
order << ' NULLS FIRST'
else
# `field IS NULL` will be `0` for non-NULL columns and `1` for NULL
# columns. In the (default) ascending order, `0` comes first.
order.prepend("#{field} IS NULL, ") if direction == 'DESC'
end
order
end
def self.random
postgresql? ? "RANDOM()" : "RAND()"
end
def self.true_value
if postgresql?
"'t'"
else
1
end
end
def self.false_value
if postgresql?
"'f'"
else
0
end
end
def self.with_connection_pool(pool_size)
pool = create_connection_pool(pool_size)
begin
yield(pool)
ensure
pool.disconnect!
end
end
def self.bulk_insert(table, rows)
return if rows.empty?
keys = rows.first.keys
columns = keys.map { |key| connection.quote_column_name(key) }
tuples = rows.map do |row|
row.values_at(*keys).map { |value| connection.quote(value) }
end
connection.execute <<-EOF
INSERT INTO #{table} (#{columns.join(', ')})
VALUES #{tuples.map { |tuple| "(#{tuple.join(', ')})" }.join(', ')}
EOF
end
# pool_size - The size of the DB pool.
# host - An optional host name to use instead of the default one.
def self.create_connection_pool(pool_size, host = nil)
# See activerecord-4.2.7.1/lib/active_record/connection_adapters/connection_specification.rb
env = Rails.env
original_config = ActiveRecord::Base.configurations
env_config = original_config[env].merge('pool' => pool_size)
env_config['host'] = host if host
config = original_config.merge(env => env_config)
spec =
ActiveRecord::
ConnectionAdapters::
ConnectionSpecification::Resolver.new(config).spec(env.to_sym)
ActiveRecord::ConnectionAdapters::ConnectionPool.new(spec)
end
def self.connection
ActiveRecord::Base.connection
end
private_class_method :connection
def self.database_version
row = connection.execute("SELECT VERSION()").first
if postgresql?
row['version']
else
row.first
end
end
private_class_method :database_version
end
end