org.apache.samza.sql.client.impl

Class SamzaExecutor

java.lang.Object

org.apache.samza.sql.client.impl.SamzaExecutor

All Implemented Interfaces:

SqlExecutor

public class SamzaExecutor
extends java.lang.Object
implements SqlExecutor

Samza implementation of Executor for Samza SQL Shell.

Constructor Summary

Constructors

Constructor and Description
SamzaExecutor()

Method Summary

Modifier and Type	Method and Description
java.util.List<java.lang.String[]>	consumeQueryResult(ExecutionContext context, int startRow, int endRow) Consumes rows from query result.
NonQueryResult	executeNonQuery(ExecutionContext context, java.io.File sqlFile) Executes all the NON-QUERY statements in the sqlFile.
NonQueryResult	executeNonQuery(ExecutionContext context, java.util.List<java.lang.String> statement)
QueryResult	executeQuery(ExecutionContext context, java.lang.String statement)
EnvironmentVariableHandler	getEnvironmentVariableHandler()
int	getRowCount()
org.apache.samza.sql.schema.SqlSchema	getTableSchema(ExecutionContext context, java.lang.String tableName)
java.lang.String	getVersion() Gets the version of this executor.
java.util.List<SqlFunction>	listFunctions(ExecutionContext context)
java.util.List<java.lang.String>	listTables(ExecutionContext context)
ExecutionStatus	queryExecutionStatus(int execId)
void	removeExecution(ExecutionContext context, int exeId) Removing an ongoing execution shall result in an error.
java.util.List<java.lang.String[]>	retrieveQueryResult(ExecutionContext context, int startRow, int endRow) Row starts at 0.
void	start(ExecutionContext context) SqlExecutor shall be ready to accept all other calls after start() is called.
void	stop(ExecutionContext context) Indicates no further calls will be made thus it's safe for the executor to clean up.
void	stopExecution(ExecutionContext context, int exeId)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

SamzaExecutor

public SamzaExecutor()

Method Detail

start

public void start(ExecutionContext context)

Description copied from interface: SqlExecutor

SqlExecutor shall be ready to accept all other calls after start() is called. However, it shall NOT store the ExecutionContext for future use, as each call will be given an ExecutionContext which may differ from this one.

Specified by:

start in interface SqlExecutor

Parameters:

context - The ExecutionContext at the time of the call.

stop

public void stop(ExecutionContext context)
          throws ExecutorException

Description copied from interface: SqlExecutor

Indicates no further calls will be made thus it's safe for the executor to clean up.

Specified by:

stop in interface SqlExecutor

Parameters:

context - The ExecutionContext at the time of the call.

Throws:

ExecutorException - if the Executor encounters an error.

getEnvironmentVariableHandler

public EnvironmentVariableHandler getEnvironmentVariableHandler()

Specified by:

getEnvironmentVariableHandler in interface SqlExecutor

Returns:

An EnvironmentVariableHandler that handles executor specific environment variables

listTables

public java.util.List<java.lang.String> listTables(ExecutionContext context)
                                            throws ExecutorException

Specified by:

listTables in interface SqlExecutor

Parameters:

context - The ExecutionContext at the time of the call.

Returns:

A list of table names. Could be empty.

Throws:

ExecutorException - if the Executor encounters an error.

getTableSchema

public org.apache.samza.sql.schema.SqlSchema getTableSchema(ExecutionContext context,
                                                            java.lang.String tableName)
                                                     throws ExecutorException

Specified by:

getTableSchema in interface SqlExecutor

Parameters:

context - The ExecutionContext at the time of the call.

tableName - Name of the table to get the schema for.

Returns:

Schema of the table.

Throws:

ExecutorException - if the Executor encounters an error.

executeQuery

public QueryResult executeQuery(ExecutionContext context,
                                java.lang.String statement)
                         throws ExecutorException

Specified by:

executeQuery in interface SqlExecutor

Parameters:

context - The ExecutionContext at the time of the call.

statement - statement to execute

Returns:

The query result.

Throws:

ExecutorException - if the Executor encounters an error.

getRowCount

public int getRowCount()

Specified by:

getRowCount in interface SqlExecutor

Returns:

how many rows available for reading.

retrieveQueryResult

public java.util.List<java.lang.String[]> retrieveQueryResult(ExecutionContext context,
                                                              int startRow,
                                                              int endRow)

Description copied from interface: SqlExecutor

Row starts at 0. Executor shall keep the data retrieved. For now we get strings for display but we might want strong typed values.

Specified by:

retrieveQueryResult in interface SqlExecutor

Parameters:

context - The ExecutionContext at the time of the call.

startRow - Start row index (inclusive)

endRow - End row index (inclusive)

Returns:

A list of row data represented by a String array.

consumeQueryResult

public java.util.List<java.lang.String[]> consumeQueryResult(ExecutionContext context,
                                                             int startRow,
                                                             int endRow)

Description copied from interface: SqlExecutor

Consumes rows from query result. Executor shall drop them, as "consume" indicates. ALL data before endRow (inclusive, including data before startRow) shall be deleted.

Specified by:

consumeQueryResult in interface SqlExecutor

Parameters:

context - The ExecutionContext at the time of the call.

startRow - Start row index (inclusive)

endRow - End row index (inclusive)

Returns:

available data between startRow and endRow (both are inclusive)

executeNonQuery

public NonQueryResult executeNonQuery(ExecutionContext context,
                                      java.io.File sqlFile)
                               throws ExecutorException

Description copied from interface: SqlExecutor

Executes all the NON-QUERY statements in the sqlFile. Query statements are ignored as it won't make sense.

Specified by:

executeNonQuery in interface SqlExecutor

Parameters:

context - The ExecutionContext at the time of the call.

sqlFile - A File object to read statements from.

Returns:

Execution result.

Throws:

ExecutorException - if the Executor encounters an error.

executeNonQuery

public NonQueryResult executeNonQuery(ExecutionContext context,
                                      java.util.List<java.lang.String> statement)
                               throws ExecutorException

Specified by:

executeNonQuery in interface SqlExecutor

Parameters:

context - The ExecutionContext at the time of the call.

statement - A list of non-query sql statements.

Returns:

Execution result.

Throws:

ExecutorException - if the Executor encounters an error.

stopExecution

public void stopExecution(ExecutionContext context,
                          int exeId)
                   throws ExecutorException

Specified by:

stopExecution in interface SqlExecutor

Parameters:

context - The ExecutionContext at the time of the call.

exeId - Execution ID.

Throws:

ExecutorException - if the Executor encounters an error.

removeExecution

public void removeExecution(ExecutionContext context,
                            int exeId)
                     throws ExecutorException

Description copied from interface: SqlExecutor

Removing an ongoing execution shall result in an error. Stop it first.

Specified by:

removeExecution in interface SqlExecutor

Parameters:

context - The ExecutionContext at the time of the call

exeId - Execution ID.

Throws:

ExecutorException - if the Executor encounters an error.

queryExecutionStatus

public ExecutionStatus queryExecutionStatus(int execId)
                                     throws ExecutorException

Specified by:

queryExecutionStatus in interface SqlExecutor

Parameters:

execId - Execution ID.

Returns:

ExecutionStatus.

Throws:

ExecutorException - if the Executor encounters an error.

listFunctions

public java.util.List<SqlFunction> listFunctions(ExecutionContext context)

Specified by:

listFunctions in interface SqlExecutor

Parameters:

context - The ExecutionContext at the time of the call.

Returns:

A list of SqlFunction.

getVersion

public java.lang.String getVersion()

Description copied from interface: SqlExecutor

Gets the version of this executor.

Specified by:

getVersion in interface SqlExecutor

Returns:

A String representing the version of the executor. This function does NOT throw an ExecutorException as the caller has nothing to do to "recover" if the function fails.