org.h2.engine
Class SessionRemote

java.lang.Object
  org.h2.engine.SessionWithState
      org.h2.engine.SessionRemote

All Implemented Interfaces:

SessionFactory, SessionInterface, DataHandler

public class SessionRemote
extends SessionWithState
implements SessionFactory, DataHandler

The client side part of a session when using the server mode. This object communicates with a Session on the server side.

Field Summary

static int	CHANGE_ID
static int	COMMAND_CLOSE
static int	COMMAND_COMMIT
static int	COMMAND_EXECUTE_QUERY
static int	COMMAND_EXECUTE_UPDATE
static int	COMMAND_GET_META_DATA
static int	RESULT_CLOSE
static int	RESULT_FETCH_ROWS
static int	RESULT_RESET
static int	SESSION_CANCEL_STATEMENT
static int	SESSION_CHECK_KEY
static int	SESSION_CLOSE
static int	SESSION_PREPARE
static int	SESSION_PREPARE_READ_PARAMS
static int	SESSION_SET_ID
static int	STATUS_CLOSED
static int	STATUS_ERROR
static int	STATUS_OK
static int	STATUS_OK_STATE_CHANGED

Fields inherited from class org.h2.engine.SessionWithState

sessionState, sessionStateChanged

Constructor Summary

SessionRemote()

Method Summary

int	allocateObjectId(boolean needFresh, boolean dataFile) Get the next object id.
void	autoCommitIfCluster() Calls COMMIT if the session is in cluster mode.
boolean	autoReconnect(int count) Automatically re-connect if necessary and if configured to do so.
void	cancel() Cancel the current or next command (called when closing a connection).
void	cancelStatement(int id) Cancel the statement with the given id.
void	checkClosed() Check if this session is closed and throws an exception if so.
void	checkPowerOff() Check if the simulated power failure occurred.
void	checkWritingAllowed() Check if writing is allowed.
void	close() Roll back pending transactions and close the session.
int	compareTypeSave(Value a, Value b) Compare two values.
SessionInterface	createSession(ConnectionInfo ci) Create a new session.
java.lang.String	createTempFile() Create a temporary file and return the file name.
void	done(Transfer transfer) Called to flush the output after data has been sent to the server and just before receiving data.
void	freeUpDiskSpace() Free up disk space if possible.
int	getChecksum(byte[] data, int start, int end) Calculate the checksum for the byte array.
int	getClientVersion()
int	getCurrentId()
java.lang.String	getDatabasePath() Get the database path.
DataHandler	getDataHandler() Get the data handler object.
int	getLastReconnect()
java.lang.String	getLobCompressionAlgorithm(int type) Get the compression algorithm used for large objects.
SmallLRUCache<java.lang.String,java.lang.String[]>	getLobFileListCache() Get the lob file list cache if it is used.
boolean	getLobFilesInDirectories() Checks if the lob files stored in directories.
java.lang.Object	getLobSyncObject() Get the synchronization object for lob operations.
int	getMaxLengthInplaceLob() Get the maximum length of a in-place large object
int	getNextId()
int	getPowerOffCount() Get the number of disk operations before power failure is simulated.
TempFileDeleter	getTempFileDeleter() Get the temp file deleter mechanism.
Trace	getTrace() Get the trace object
void	handleInvalidChecksum() Called when the checksum was invalid.
boolean	isClosed() Check if close was called.
boolean	isClustered() Returns true if the connection is in cluster mode.
boolean	isReconnectNeeded(boolean write) Check if the database changed and therefore reconnecting is required.
FileStore	openFile(java.lang.String name, java.lang.String mode, boolean mustExist) Open a file at the given location.
CommandInterface	prepareCommand(java.lang.String sql, int fetchSize) Parse a command and prepare it for execution.
SessionInterface	reconnect(boolean write) Close the connection and open a new connection.
void	removeServer(java.io.IOException e, int i, int count) Remove a server from the list of cluster nodes and disables the cluster mode.
void	setAutoCommit(boolean autoCommit)
void	setPowerOffCount(int count) Set the number of disk operations before power failure is simulated.
void	traceOperation(java.lang.String operation, int id) Write the operation to the trace system if debug trace is enabled.

Methods inherited from class org.h2.engine.SessionWithState

readSessionState, recreateSessionState

Methods inherited from class java.lang.Object

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

Field Detail

SESSION_PREPARE

public static final int SESSION_PREPARE

See Also:

Constant Field Values

SESSION_CLOSE

public static final int SESSION_CLOSE

See Also:

Constant Field Values

COMMAND_EXECUTE_QUERY

public static final int COMMAND_EXECUTE_QUERY

See Also:

Constant Field Values

COMMAND_EXECUTE_UPDATE

public static final int COMMAND_EXECUTE_UPDATE

See Also:

Constant Field Values

COMMAND_CLOSE

public static final int COMMAND_CLOSE

See Also:

Constant Field Values

RESULT_FETCH_ROWS

public static final int RESULT_FETCH_ROWS

See Also:

Constant Field Values

RESULT_RESET

public static final int RESULT_RESET

See Also:

Constant Field Values

RESULT_CLOSE

public static final int RESULT_CLOSE

See Also:

Constant Field Values

COMMAND_COMMIT

public static final int COMMAND_COMMIT

See Also:

Constant Field Values

CHANGE_ID

public static final int CHANGE_ID

See Also:

Constant Field Values

COMMAND_GET_META_DATA

public static final int COMMAND_GET_META_DATA

See Also:

Constant Field Values

SESSION_PREPARE_READ_PARAMS

public static final int SESSION_PREPARE_READ_PARAMS

See Also:

Constant Field Values

SESSION_SET_ID

public static final int SESSION_SET_ID

See Also:

Constant Field Values

SESSION_CANCEL_STATEMENT

public static final int SESSION_CANCEL_STATEMENT

See Also:

Constant Field Values

SESSION_CHECK_KEY

public static final int SESSION_CHECK_KEY

See Also:

Constant Field Values

STATUS_ERROR

public static final int STATUS_ERROR

See Also:

Constant Field Values

STATUS_OK

public static final int STATUS_OK

See Also:

Constant Field Values

STATUS_CLOSED

public static final int STATUS_CLOSED

See Also:

Constant Field Values

STATUS_OK_STATE_CHANGED

public static final int STATUS_OK_STATE_CHANGED

See Also:

Constant Field Values

Constructor Detail

SessionRemote

public SessionRemote()

Method Detail

cancel

public void cancel()

Description copied from interface: SessionInterface

Cancel the current or next command (called when closing a connection).

Specified by:

cancel in interface SessionInterface

cancelStatement

public void cancelStatement(int id)

Cancel the statement with the given id.

Parameters:

id - the statement id

setAutoCommit

public void setAutoCommit(boolean autoCommit)

autoCommitIfCluster

public void autoCommitIfCluster()
                         throws java.sql.SQLException

Calls COMMIT if the session is in cluster mode.

Throws:

java.sql.SQLException

getPowerOffCount

public int getPowerOffCount()

Description copied from interface: SessionInterface

Get the number of disk operations before power failure is simulated. This is used for testing. If not set, 0 is returned

Specified by:

getPowerOffCount in interface SessionInterface

Returns:

the number of operations, or 0

setPowerOffCount

public void setPowerOffCount(int count)
                      throws java.sql.SQLException

Description copied from interface: SessionInterface

Set the number of disk operations before power failure is simulated. To disable the countdown, use 0.

Specified by:

setPowerOffCount in interface SessionInterface

Parameters:

count - the number of operations

Throws:

java.sql.SQLException

createSession

public SessionInterface createSession(ConnectionInfo ci)
                               throws java.sql.SQLException

Description copied from interface: SessionFactory

Create a new session.

Specified by:

createSession in interface SessionFactory

Parameters:

ci - the connection parameters

Returns:

the new session

Throws:

java.sql.SQLException

removeServer

public void removeServer(java.io.IOException e,
                         int i,
                         int count)
                  throws java.sql.SQLException

Remove a server from the list of cluster nodes and disables the cluster mode.

Parameters:

e - the exception (used for debugging)

i - the index of the server to remove

count - the retry count index

Throws:

java.sql.SQLException

prepareCommand

public CommandInterface prepareCommand(java.lang.String sql,
                                       int fetchSize)
                                throws java.sql.SQLException

Description copied from interface: SessionInterface

Parse a command and prepare it for execution.

Specified by:

prepareCommand in interface SessionInterface

Parameters:

sql - the SQL statement

fetchSize - the number of rows to fetch in one step

Returns:

the prepared command

Throws:

java.sql.SQLException

autoReconnect

public boolean autoReconnect(int count)
                      throws java.sql.SQLException

Automatically re-connect if necessary and if configured to do so.

Parameters:

count - the retry count index

Returns:

true if reconnected

Throws:

java.sql.SQLException

checkClosed

public void checkClosed()
                 throws java.sql.SQLException

Check if this session is closed and throws an exception if so.

Throws:

java.sql.SQLException - if the session is closed

close

public void close()
           throws java.sql.SQLException

Description copied from interface: SessionInterface

Roll back pending transactions and close the session.

Specified by:

close in interface SessionInterface

Throws:

java.sql.SQLException

getTrace

public Trace getTrace()

Description copied from interface: SessionInterface

Get the trace object

Specified by:

getTrace in interface SessionInterface

Specified by:

getTrace in interface DataHandler

Returns:

the trace object

getNextId

public int getNextId()

getCurrentId

public int getCurrentId()

done

public void done(Transfer transfer)
          throws java.sql.SQLException,
                 java.io.IOException

Called to flush the output after data has been sent to the server and just before receiving data. This method also reads the status code from the server and throws any exception the server sent.

Parameters:

transfer - the transfer object

Throws:

java.sql.SQLException - if the server sent an exception

java.io.IOException - if there is a communication problem between client and server

isClustered

public boolean isClustered()

Returns true if the connection is in cluster mode.

Returns:

true if it is

isClosed

public boolean isClosed()

Description copied from interface: SessionInterface

Check if close was called.

Specified by:

isClosed in interface SessionInterface

Returns:

if the session has been closed

traceOperation

public void traceOperation(java.lang.String operation,
                           int id)

Write the operation to the trace system if debug trace is enabled.

Parameters:

operation - the operation performed

id - the id of the operation

allocateObjectId

public int allocateObjectId(boolean needFresh,
                            boolean dataFile)

Description copied from interface: DataHandler

Get the next object id. This method is not required if LOB_FILES_IN_DIRECTORIES is enabled.

Specified by:

allocateObjectId in interface DataHandler

Parameters:

needFresh - if a fresh id is required

dataFile - true if the id is for the data file

Returns:

the new id

checkPowerOff

public void checkPowerOff()

Description copied from interface: DataHandler

Check if the simulated power failure occurred. This call will decrement the countdown.

Specified by:

checkPowerOff in interface DataHandler

checkWritingAllowed

public void checkWritingAllowed()

Description copied from interface: DataHandler

Check if writing is allowed.

Specified by:

checkWritingAllowed in interface DataHandler

compareTypeSave

public int compareTypeSave(Value a,
                           Value b)

Description copied from interface: DataHandler

Compare two values.

Specified by:

compareTypeSave in interface DataHandler

Parameters:

a - the first value

b - the second value

Returns:

0 for equal, 1 if a is larger than b, and -1 otherwise

createTempFile

public java.lang.String createTempFile()
                                throws java.sql.SQLException

Description copied from interface: DataHandler

Create a temporary file and return the file name.

Specified by:

createTempFile in interface DataHandler

Returns:

the file name

Throws:

java.sql.SQLException

freeUpDiskSpace

public void freeUpDiskSpace()

Description copied from interface: DataHandler

Free up disk space if possible. This method is called if more space is needed.

Specified by:

freeUpDiskSpace in interface DataHandler

getChecksum

public int getChecksum(byte[] data,
                       int start,
                       int end)

Description copied from interface: DataHandler

Calculate the checksum for the byte array.

Specified by:

getChecksum in interface DataHandler

Parameters:

data - the byte array

start - the starting offset

end - the end offset

Returns:

the checksum

getDatabasePath

public java.lang.String getDatabasePath()

Description copied from interface: DataHandler

Get the database path.

Specified by:

getDatabasePath in interface DataHandler

Returns:

the database path

getLobCompressionAlgorithm

public java.lang.String getLobCompressionAlgorithm(int type)

Description copied from interface: DataHandler

Get the compression algorithm used for large objects.

Specified by:

getLobCompressionAlgorithm in interface DataHandler

Parameters:

type - the data type (CLOB or BLOB)

Returns:

the compression algorithm, or null

getMaxLengthInplaceLob

public int getMaxLengthInplaceLob()

Description copied from interface: DataHandler

Get the maximum length of a in-place large object

Specified by:

getMaxLengthInplaceLob in interface DataHandler

Returns:

the maximum size

handleInvalidChecksum

public void handleInvalidChecksum()
                           throws java.sql.SQLException

Description copied from interface: DataHandler

Called when the checksum was invalid.

Specified by:

handleInvalidChecksum in interface DataHandler

Throws:

java.sql.SQLException - if this should not be ignored

openFile

public FileStore openFile(java.lang.String name,
                          java.lang.String mode,
                          boolean mustExist)
                   throws java.sql.SQLException

Description copied from interface: DataHandler

Open a file at the given location.

Specified by:

openFile in interface DataHandler

Parameters:

name - the file name

mode - the mode

mustExist - whether the file must already exist

Returns:

the file

Throws:

java.sql.SQLException

getDataHandler

public DataHandler getDataHandler()

Description copied from interface: SessionInterface

Get the data handler object.

Specified by:

getDataHandler in interface SessionInterface

Returns:

the data handler

getLobSyncObject

public java.lang.Object getLobSyncObject()

Description copied from interface: DataHandler

Get the synchronization object for lob operations.

Specified by:

getLobSyncObject in interface DataHandler

Returns:

the synchronization object

getLobFilesInDirectories

public boolean getLobFilesInDirectories()

Description copied from interface: DataHandler

Checks if the lob files stored in directories.

Specified by:

getLobFilesInDirectories in interface DataHandler

Returns:

true if lob files are stored in directories.

getLobFileListCache

public SmallLRUCache<java.lang.String,java.lang.String[]> getLobFileListCache()

Description copied from interface: DataHandler

Get the lob file list cache if it is used.

Specified by:

getLobFileListCache in interface DataHandler

Returns:

the cache or null

getClientVersion

public int getClientVersion()

getLastReconnect

public int getLastReconnect()

getTempFileDeleter

public TempFileDeleter getTempFileDeleter()

Description copied from interface: DataHandler

Get the temp file deleter mechanism.

Specified by:

getTempFileDeleter in interface DataHandler

Returns:

the temp file deleter

isReconnectNeeded

public boolean isReconnectNeeded(boolean write)

Description copied from interface: SessionInterface

Check if the database changed and therefore reconnecting is required.

Specified by:

isReconnectNeeded in interface SessionInterface

Parameters:

write - if the next operation may be writing

Returns:

true if reconnecting is required

reconnect

public SessionInterface reconnect(boolean write)

Description copied from interface: SessionInterface

Close the connection and open a new connection.

Specified by:

reconnect in interface SessionInterface

Parameters:

write - if the next operation may be writing

Returns:

the new connection