Module: ActiveRecord::ConnectionAdapters::Spanner::DatabaseStatements

Included in:
ActiveRecord::ConnectionAdapters::SpannerAdapter
Defined in:
lib/active_record/connection_adapters/spanner/database_statements.rb

Constant Summary collapse

RequestOptions = 
Google::Cloud::Spanner::V1::RequestOptions
TransactionMutationLimitExceededError = 
Google::Cloud::Spanner::Errors::TransactionMutationLimitExceededError
COMMENT_REGEX = 
ActiveRecord::ConnectionAdapters::AbstractAdapter::COMMENT_REGEX

Instance Method Summary collapse

Instance Method Details

#_has_pk_binding(pk, binds) ⇒ Object 



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# File 'lib/active_record/connection_adapters/spanner/database_statements.rb', line 154

def _has_pk_binding pk, binds
  if pk.respond_to? :each
    has_value = true
    pk.each { |col| has_value &&= binds.any? { |bind| bind.name == col } }
    has_value
  else
    binds.any? { |bind| bind.name == pk }
  end
end

#append_request_tag_from_query_logs(sql, binds) ⇒ Object 



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# File 'lib/active_record/connection_adapters/spanner/database_statements.rb', line 106

def append_request_tag_from_query_logs sql, binds
  REQUEST_TAG_PREFIXES.each do |prefix|
    if sql.start_with? prefix
      append_request_tag_from_query_logs_with_format sql, binds, prefix
      break
    end
  end
end

#append_request_tag_from_query_logs_with_format(sql, binds, prefix) ⇒ Object 



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# File 'lib/active_record/connection_adapters/spanner/database_statements.rb', line 115

def append_request_tag_from_query_logs_with_format sql, binds, prefix
  end_of_comment = sql.index "*/", prefix.length
  return unless end_of_comment

  request_tag = sql[prefix.length, end_of_comment - prefix.length]
  options = binds.find { |bind| bind.is_a? RequestOptions }
  if options
    options.request_tag = if options.request_tag.empty?
                            request_tag
                          else
                            "#{options.request_tag},#{request_tag}"
                          end
  else
    binds.append RequestOptions.new(request_tag: request_tag)
  end
end

#begin_db_transaction ⇒ Object 



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# File 'lib/active_record/connection_adapters/spanner/database_statements.rb', line 285

def begin_db_transaction
  log "BEGIN" do
    opts = @_spanner_begin_transaction_options || {}
    @connection.begin_transaction nil, **opts
  end
end

#begin_isolated_db_transaction(isolation) ⇒ Object

Begins a transaction on the database with the specified isolation level. Cloud Spanner only supports isolation level :serializable, but also defines three additional 'isolation levels' that can be used to start specific types of Spanner transactions:

  • :read_only: Starts a read-only snapshot transaction using a strong timestamp bound.
  • :buffered_mutations: Starts a read/write transaction that will use mutations instead of DML for single-row inserts/updates/deletes. Mutations are buffered locally until the transaction is committed, and any changes during a transaction cannot be read by the application.
  • :pdml: Starts a Partitioned DML transaction. Executing multiple DML statements in one PDML transaction block is NOT supported A PDML transaction is not guaranteed to be atomic. See https://cloud.google.com/spanner/docs/dml-partitioned for more information.

In addition to the above, a Hash containing read-only snapshot options may be used to start a specific read-only snapshot:

  • { timestamp: Time } Starts a read-only snapshot at the given timestamp.
  • { staleness: Integer } Starts a read-only snapshot with the given staleness in seconds.
  • { strong: } Starts a read-only snapshot with strong timestamp bound (this is the same as :read_only)


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# File 'lib/active_record/connection_adapters/spanner/database_statements.rb', line 310

def begin_isolated_db_transaction isolation
  opts = @_spanner_begin_transaction_options || {}
  # If isolation level is specified in the options, use that instead of the default isolation level.
  isolation_option = opts[:isolation] || isolation
  if isolation_option.is_a? Hash
    raise "Unsupported isolation level: #{isolation_option}" unless
      isolation_option[:timestamp] || isolation_option[:staleness] || isolation_option[:strong]
    raise "Only one option is supported. It must be one of `timestamp`, `staleness` or `strong`." \
      if isolation_option.count != 1
  else
    raise "Unsupported isolation level: #{isolation_option}" unless
      [:serializable, :repeatable_read, :read_only, :buffered_mutations, :pdml,
       :fallback_to_pdml].include? isolation_option
  end

  log "BEGIN #{isolation_option}" do
    @connection.begin_transaction isolation_option, **opts.except(:isolation)
  end
end

#commit_db_transaction ⇒ Object 



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# File 'lib/active_record/connection_adapters/spanner/database_statements.rb', line 330

def commit_db_transaction
  log "COMMIT" do
    @connection.commit_transaction
  end
end

#exec_mutation(mutation) ⇒ Object 



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# File 'lib/active_record/connection_adapters/spanner/database_statements.rb', line 164

def exec_mutation mutation
  @connection.current_transaction.buffer mutation
end

#exec_update(sql, name = "SQL", binds = []) ⇒ Object Also known as: exec_delete

Raises:

  • (ActiveRecord::StatementInvalid) 


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# File 'lib/active_record/connection_adapters/spanner/database_statements.rb', line 182

def exec_update sql, name = "SQL", binds = []
  # Check if a DML batch is active on the connection.
  if @connection.dml_batch?
    # This call buffers the SQL.
    execute sql, name, binds
    return
  end
  result = execute sql, name, binds
  # Make sure that we consume the entire result stream before trying to get the stats.
  # This is required because the ExecuteStreamingSql RPC is also used for (Partitioned) DML,
  # and this RPC can return multiple partial result sets for DML as well. Only the last partial
  # result set will contain the statistics. Although there will never be any rows, this makes
  # sure that the stream is fully consumed.
  result.rows.each { |_| } # rubocop:disable Lint/EmptyBlock
  return result.row_count if result.row_count

  raise ActiveRecord::StatementInvalid.new(
    "DML statement is invalid.", sql: sql
  )
end

#execute(sql, name = nil, binds = []) ⇒ Object

DDL, DML and DQL Statements



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# File 'lib/active_record/connection_adapters/spanner/database_statements.rb', line 29

def execute sql, name = nil, binds = []
  internal_execute sql, name, binds
end

#execute_ddl(statements) ⇒ Object 



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# File 'lib/active_record/connection_adapters/spanner/database_statements.rb', line 216

def execute_ddl statements
  log "MIGRATION", "SCHEMA" do
    ActiveSupport::Dependencies.interlock.permit_concurrent_loads do
      @connection.execute_ddl statements
    end
  end
rescue Google::Cloud::Error => error
  raise ActiveRecord::StatementInvalid, error
end

#execute_query_or_dml(statement_type, sql, name, binds) ⇒ Object 



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# File 'lib/active_record/connection_adapters/spanner/database_statements.rb', line 64

def execute_query_or_dml statement_type, sql, name, binds
  transaction_required = statement_type == :dml
  materialize_transactions

  # First process and remove any hints in the binds that indicate that
  # a different read staleness should be used than the default.
  staleness_hint = binds.find { |b| b.is_a? Arel::Visitors::StalenessHint }
  if staleness_hint
    selector = Google::Cloud::Spanner::Session.single_use_transaction staleness_hint.value
    binds.delete staleness_hint
  end
  request_options = binds.find { |b| b.is_a? RequestOptions }
  if request_options
    binds.delete request_options
  end

  log_args = [sql, name]
  log_args.push binds, type_casted_binds(binds) if log_statement_binds

  log(*log_args) do
    types, params = to_types_and_params binds
    ActiveSupport::Dependencies.interlock.permit_concurrent_loads do
      if transaction_required
        transaction do
          @connection.execute_query sql,
                                    params: params,
                                    types: types,
                                    request_options: request_options,
                                    statement_type: statement_type
        end
      else
        @connection.execute_query sql,
                                  params: params,
                                  types: types,
                                  single_use_selector: selector,
                                  request_options: request_options,
                                  statement_type: statement_type
      end
    end
  end
end

#internal_exec_query(sql, name = "SQL", binds = [], prepare: false, async: false, allow_retry: false) ⇒ Object 



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# File 'lib/active_record/connection_adapters/spanner/database_statements.rb', line 33

def internal_exec_query sql, name = "SQL", binds = [], prepare: false, async: false, allow_retry: false
  result = internal_execute sql, name, binds, prepare: prepare, async: async, allow_retry: allow_retry
  if result
    ActiveRecord::Result.new(
      result.fields.keys.map(&:to_s), result.rows.map(&:values)
    )
  else
    ActiveRecord::Result.new [], []
  end
end

#internal_execute(sql, name = "SQL", binds = [], prepare: false, async: false, allow_retry: false) ⇒ Object 



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# File 'lib/active_record/connection_adapters/spanner/database_statements.rb', line 44

def internal_execute sql, name = "SQL", binds = [],
                     prepare: false, async: false, allow_retry: false # rubocop:disable Lint/UnusedMethodArgument
  statement_type = sql_statement_type sql
  # Call `transform` to invoke any query transformers that might have been registered.
  sql = transform sql
  append_request_tag_from_query_logs sql, binds

  if preventing_writes? && [:dml, :ddl].include?(statement_type)
    raise ActiveRecord::ReadOnlyError(
      "Write query attempted while in readonly mode: #{sql}"
    )
  end

  if statement_type == :ddl
    execute_ddl sql
  else
    execute_query_or_dml statement_type, sql, name, binds
  end
end

#query(sql, name = nil) ⇒ Object 



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# File 'lib/active_record/connection_adapters/spanner/database_statements.rb', line 150

def query sql, name = nil
  exec_query sql, name
end

#rollback_db_transaction ⇒ Object 



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# File 'lib/active_record/connection_adapters/spanner/database_statements.rb', line 336

def rollback_db_transaction
  log "ROLLBACK" do
    @connection.rollback_transaction
  end
end

#sql_for_insert(sql, pk, binds, returning) ⇒ Object 



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# File 'lib/active_record/connection_adapters/spanner/database_statements.rb', line 132

def sql_for_insert sql, pk, binds, returning
  if pk && !_has_pk_binding(pk, binds)
    # Add the primary key to the columns that should be returned if there is no value specified for it.
    returning ||= []
    returning |= if pk.respond_to? :each
                   pk
                 else
                   [pk]
                 end
  end
  if returning&.any?
    returning_columns_statement = returning.map { |c| quote_column_name c }.join(", ")
    sql = "#{sql} THEN RETURN #{returning_columns_statement}"
  end

  [sql, binds]
end

#transaction(requires_new: nil, isolation: nil, joinable: true, **kwargs, &block) ⇒ Object

Transaction



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# File 'lib/active_record/connection_adapters/spanner/database_statements.rb', line 228

def transaction requires_new: nil, isolation: nil, joinable: true, **kwargs, &block # rubocop:disable Metrics/PerceivedComplexity,Metrics/CyclomaticComplexity
  commit_options = kwargs.delete :commit_options
  exclude_from_streams = kwargs.delete :exclude_txn_from_change_streams
  @_spanner_begin_transaction_options = {
    exclude_txn_from_change_streams: exclude_from_streams
  }
  if !requires_new && current_transaction.joinable?
    return super
  end

  backoff = 0.2
  begin
    super do
      # Once the transaction has been started by `super`, apply your custom options
      # to the Spanner transaction object.
      if commit_options && @connection.current_transaction
        @connection.current_transaction.set_commit_options commit_options
      end

      yield
    end
  rescue ActiveRecord::StatementInvalid => err
    if err.cause.is_a? Google::Cloud::AbortedError
      sleep(delay_from_aborted(err) || (backoff *= 1.3))
      retry
    elsif TransactionMutationLimitExceededError.is_mutation_limit_error? err.cause
      is_fallback_enabled = isolation == :fallback_to_pdml
      raise unless is_fallback_enabled
      @_spanner_begin_transaction_options[:isolation] = :pdml
      retry
    else
      raise
    end
  rescue Google::Cloud::AbortedError => err
    sleep(delay_from_aborted(err) || backoff *= 1.3)
    retry
  ensure
    # Clean up the instance variable to avoid leaking options.
    @_spanner_begin_transaction_options = nil
  end
end

#transaction_isolation_levels ⇒ Object 



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# File 'lib/active_record/connection_adapters/spanner/database_statements.rb', line 270

def transaction_isolation_levels
  {
    read_uncommitted:   "READ UNCOMMITTED",
    read_committed:     "READ COMMITTED",
    repeatable_read:    "REPEATABLE READ",
    serializable:       "SERIALIZABLE",

    # These are not really isolation levels, but it is the only (best) way to pass in additional
    # transaction options to the connection.
    read_only:          "READ_ONLY",
    buffered_mutations: "BUFFERED_MUTATIONS",
    fallback_to_pdml: "FALLBACK_TO_PDML"
  }
end

#truncate(table_name, name = nil) ⇒ Object 



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# File 'lib/active_record/connection_adapters/spanner/database_statements.rb', line 204

def truncate table_name, name = nil
  Array(table_name).each do |t|
    log "TRUNCATE #{t}", name do
      @connection.truncate t
    end
  end
end

#update(arel, name = nil, binds = []) ⇒ Object Also known as: delete 



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# File 'lib/active_record/connection_adapters/spanner/database_statements.rb', line 168

def update arel, name = nil, binds = []
  # Add a `WHERE TRUE` if it is an update_all or delete_all call that uses DML.
  if !should_use_mutation(arel) && arel.respond_to?(:ast) && arel.ast.wheres.empty?
    arel.ast.wheres << Arel::Nodes::SqlLiteral.new("TRUE")
  end
  return super unless should_use_mutation arel

  raise "Unsupported update for use with mutations: #{arel}" unless arel.is_a? Arel::DeleteManager

  exec_mutation create_delete_all_mutation arel if arel.is_a? Arel::DeleteManager
  0 # Affected rows (unknown)
end

#write_query?(sql) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/active_record/connection_adapters/spanner/database_statements.rb', line 212

def write_query? sql
  sql_statement_type(sql) == :dml
end