Class NetCursor

java.lang.Object

org.apache.derby.client.am.Cursor

org.apache.derby.client.net.NetCursor

Direct Known Subclasses:

NetSqldta

class NetCursor
extends Cursor

Field Summary

Fields

Modifier and Type	Field	Description
(package private) boolean	blocking_
(package private) ArrayList<byte[]>	extdtaData_	Queue to hold EXTDTA data that hasn't been correlated to its column number.
(package private) HashMap<Integer,Integer>	extdtaPositions_
(package private) boolean[]	isGraphic_
(package private) int	maximumRowSize_
private NetAgent	netAgent_
(package private) NetResultSet	netResultSet_
private boolean	qryclsimpEnabled_	Flag indicating whether the result set on the server is implicitly closed when end-of-data is received.
(package private) Typdef	qrydscTypdef_
(package private) boolean	rtnextrow_
(package private) int[]	typeToUseForComputingDataLength_

Fields inherited from class Cursor

agent_, BYTES, ccsid_, charset_, columnDataComputedLength_, columnDataIsNullCache_, columnDataLengthCache_, columnDataPosition_, columnDataPositionCache_, columns_, currentRowPosition_, dataBuffer_, dataBufferStream_, fdocaLength_, hasLobs_, isNull_, jdbcTypes_, lastValidBytePosition_, NULL_TERMINATED_BYTES, NULL_TERMINATED_STRING, nullable_, position_, STRING, VARIABLE_SHORT_STRING, VARIABLE_STRING

Constructor Summary

Constructors

Constructor	Description
NetCursor(NetAgent netAgent)
NetCursor(NetAgent netAgent, int qryprctyp)

Method Summary

Modifier and Type	Method	Description
private void	adjustColumnOffsetsForColumnsPreviouslyCalculated(int index)	Adjust column offsets after fetching the next part of a split row.
private int[]	allocateColumnDataComputedLengthArray(int row)
private boolean[]	allocateColumnDataIsNullArray(int row)
private int[]	allocateColumnDataPositionArray(int row)
(package private) void	allocateColumnOffsetAndLengthArrays()
protected boolean	calculateColumnOffsetsForRow_(int rowIndex, boolean allowServerFetch)	Calculate the column offsets for a row.
(package private) void	calculateLobColumnPositionsForRow()
private void	checkAndThrowReceivedEndqryrm()
private void	checkAndThrowReceivedEndqryrm(int lastValidBytePositionBeforeFetch)
private void	checkForSplitRowAndComplete(int length)	Check if the data we want crosses a row split, and fetch more data if necessary.
private void	checkForSplitRowAndComplete(int length, int index)	Check if the data we want crosses a row split, and fetch more data if necessary.
protected void	clearLobData_()
private int	completeSplitRow(int index)	Fetch more data for a row that has been split up.
private byte[]	findExtdtaData(int column)
ClientBlob	getBlobColumn_(int column, Agent agent, boolean toBePublished)	Returns a Blob object.
ClientClob	getClobColumn_(int column, Agent agent, boolean toBePublished)	Returns a Clob object.
protected int	getDecimalLength(int index)
protected void	getMoreData_()
(package private) final boolean	getQryclsimpEnabled()	Check whether QRYCLSIMP is enabled on this cursor.
(package private) void	initializeColumnInfoArrays(Typdef typdef, int columnCount)
private boolean	isNonTrivialDataLob(int index)
protected int	locator(int column)	Get locator for LOB of the designated column
void	nullDataForGC()
private NetSqlca[]	parseSQLCAGRP(Typdef typdef)
private NetSqlca[]	parseSQLCARD(Typdef typdef)
private void	parseSQLCAXGRP(Typdef typdef, NetSqlca netSqlca)
private NetSqlca	parseSQLDCGRP()
private NetSqlca	parseSQLDCROW()
private void	parseSQLDCTOKS()
private void	parseSQLDCXGRP()
private NetSqlca[]	parseSQLDIAGCI()
private void	parseSQLDIAGCN()
private NetSqlca[]	parseSQLDIAGGRP()
private void	parseSQLDIAGSTT()
private String	parseVCS(Typdef typdefInEffect)
private byte[]	readFdocaBytes(int length)
private int	readFdocaInt()
private int	readFdocaOneByte()
private int	readFdocaOneByte(int index)
private String	readFdocaString(int length, Charset encoding)
private int	readFdocaTwoByteLength()
private int	readFdocaTwoByteLength(int index)
private void	resetCurrentRowPosition()
(package private) void	scanDataBufferForEndOfData()	Scan the data buffer to see if end of data (SQL state 02000) has been received.
final void	setAllRowsReceivedFromServer(boolean b)	Set the value of value of allRowsReceivedFromServer_.
(package private) final void	setQryclsimpEnabled(boolean flag)	Set a flag indicating whether QRYCLSIMP is enabled.
private void	shiftPartialRowToBeginning()
private int	skipFdocaBytes(int length)
private int	skipFdocaBytes(int length, int index)

Methods inherited from class Cursor

allocateCharBuffer, allRowsReceivedFromServer, get_INTEGER, getIsRowUpdated, getIsUpdateDeleteHole, incrementRowsReadEvent, makeNextRowPositionCurrent, markNextRowPosition, next, resetDataBuffer, setIsRowUpdated, setIsUpdataDeleteHole, setNumberOfColumns, stepNext

Methods inherited from class Object

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

Field Details

netResultSet_

NetResultSet netResultSet_

netAgent_

private NetAgent netAgent_

qrydscTypdef_

Typdef qrydscTypdef_

maximumRowSize_

int maximumRowSize_

blocking_

boolean blocking_

typeToUseForComputingDataLength_

int[] typeToUseForComputingDataLength_

isGraphic_

boolean[] isGraphic_

extdtaPositions_

HashMap<Integer,Integer> extdtaPositions_

extdtaData_

ArrayList<byte[]> extdtaData_

Queue to hold EXTDTA data that hasn't been correlated to its column number.

rtnextrow_

boolean rtnextrow_

qryclsimpEnabled_

private boolean qryclsimpEnabled_

Flag indicating whether the result set on the server is implicitly closed when end-of-data is received.

Constructor Details

NetCursor

NetCursor(NetAgent netAgent)

NetCursor

NetCursor(NetAgent netAgent,
 int qryprctyp)

Method Details

calculateColumnOffsetsForRow_

protected boolean calculateColumnOffsetsForRow_(int rowIndex,
 boolean allowServerFetch)
                                         throws SqlException,
DisconnectException

Calculate the column offsets for a row.

Pseudo-code:

1. parse thru the current row in dataBuffer computing column offsets
2. if (we hit the super.lastValidBytePosition, ie. encounter partial row)
   1. shift partial row bytes to beginning of dataBuffer (this.shiftPartialRowToBeginning())
   2. reset current row position (also done by this.shiftPartialRowToBeginning())
   3. send and recv continue-query into commBuffer (rs.flowContinueQuery())
   4. parse commBuffer up to QRYDTA (rs.flowContinueQuery())
   5. copy query data from reply's commBuffer to our dataBuffer (this.copyQrydta())

Specified by:

calculateColumnOffsetsForRow_ in class Cursor

Parameters:

rowIndex - row index

allowServerFetch - if true, allow fetching more data from server

Returns:

true if the current row position is a valid row position.

Throws:

SqlException

DisconnectException

scanDataBufferForEndOfData

void scanDataBufferForEndOfData()
                         throws SqlException

Scan the data buffer to see if end of data (SQL state 02000) has been received. This method should only be called when the cursor is being closed since the pointer to the current row can be modified.

Throws:

SqlException

readFdocaInt

private int readFdocaInt()
                  throws DisconnectException,
SqlException

Throws:

DisconnectException

SqlException

readFdocaOneByte

private int readFdocaOneByte()
                      throws DisconnectException,
SqlException

Throws:

DisconnectException

SqlException

readFdocaOneByte

private int readFdocaOneByte(int index)
                      throws DisconnectException,
SqlException

Throws:

DisconnectException

SqlException

readFdocaBytes

private byte[] readFdocaBytes(int length)
                       throws DisconnectException,
SqlException

Throws:

DisconnectException

SqlException

readFdocaTwoByteLength

private int readFdocaTwoByteLength()
                            throws DisconnectException,
SqlException

Throws:

DisconnectException

SqlException

readFdocaTwoByteLength

private int readFdocaTwoByteLength(int index)
                            throws DisconnectException,
SqlException

Throws:

DisconnectException

SqlException

skipFdocaBytes

private int skipFdocaBytes(int length)
                    throws DisconnectException,
SqlException

Throws:

DisconnectException

SqlException

skipFdocaBytes

private int skipFdocaBytes(int length,
 int index)
                    throws DisconnectException,
SqlException

Throws:

DisconnectException

SqlException

shiftPartialRowToBeginning

private void shiftPartialRowToBeginning()

adjustColumnOffsetsForColumnsPreviouslyCalculated

private void adjustColumnOffsetsForColumnsPreviouslyCalculated(int index)

Adjust column offsets after fetching the next part of a split row.

Parameters:

index - the index of the column that was split, or -1 when not fetching column data

resetCurrentRowPosition

private void resetCurrentRowPosition()

calculateLobColumnPositionsForRow

void calculateLobColumnPositionsForRow()

isNonTrivialDataLob

private boolean isNonTrivialDataLob(int index)

clearLobData_

protected void clearLobData_()

Specified by:

clearLobData_ in class Cursor

parseSQLCARD

private NetSqlca[] parseSQLCARD(Typdef typdef)
                         throws DisconnectException,
SqlException

Throws:

DisconnectException

SqlException

parseSQLCAGRP

private NetSqlca[] parseSQLCAGRP(Typdef typdef)
                          throws DisconnectException,
SqlException

Throws:

DisconnectException

SqlException

parseSQLCAXGRP

private void parseSQLCAXGRP(Typdef typdef,
 NetSqlca netSqlca)
                     throws DisconnectException,
SqlException

Throws:

DisconnectException

SqlException

parseSQLDIAGGRP

private NetSqlca[] parseSQLDIAGGRP()
                            throws DisconnectException,
SqlException

Throws:

DisconnectException

SqlException

parseSQLDIAGSTT

private void parseSQLDIAGSTT()
                      throws DisconnectException,
SqlException

Throws:

DisconnectException

SqlException

parseSQLDIAGCI

private NetSqlca[] parseSQLDIAGCI()
                           throws DisconnectException,
SqlException

Throws:

DisconnectException

SqlException

parseSQLDIAGCN

private void parseSQLDIAGCN()
                     throws DisconnectException,
SqlException

Throws:

DisconnectException

SqlException

parseSQLDCGRP

private NetSqlca parseSQLDCGRP()
                        throws DisconnectException,
SqlException

Throws:

DisconnectException

SqlException

parseSQLDCROW

private NetSqlca parseSQLDCROW()
                        throws DisconnectException,
SqlException

Throws:

DisconnectException

SqlException

parseSQLDCTOKS

private void parseSQLDCTOKS()
                     throws DisconnectException,
SqlException

Throws:

DisconnectException

SqlException

parseSQLDCXGRP

private void parseSQLDCXGRP()
                     throws DisconnectException,
SqlException

Throws:

DisconnectException

SqlException

parseVCS

private String parseVCS(Typdef typdefInEffect)
                 throws DisconnectException,
SqlException

Throws:

DisconnectException

SqlException

readFdocaString

private String readFdocaString(int length,
 Charset encoding)
                        throws SqlException

Throws:

SqlException

allocateColumnOffsetAndLengthArrays

void allocateColumnOffsetAndLengthArrays()

findExtdtaData

private byte[] findExtdtaData(int column)

locator

protected int locator(int column)

Get locator for LOB of the designated column

Note that this method cannot be invoked on a LOB column that is NULL.

Specified by:

locator in class Cursor

Parameters:

column - column number, starts at 1

Returns:

locator value, Lob.INVALID_LOCATOR if LOB value was sent instead of locator

getBlobColumn_

public ClientBlob getBlobColumn_(int column,
 Agent agent,
 boolean toBePublished)
                          throws SqlException

Description copied from class: Cursor

Returns a Blob object.

Specified by:

getBlobColumn_ in class Cursor

Parameters:

column - 1-based column index

agent - associated agent

toBePublished - whether the Blob will be published to the user

Returns:

A Blob object.

Throws:

SqlException - if getting the Blob fails

See Also:

• Cursor.getBlobColumn_(int, Agent, boolean)

getClobColumn_

public ClientClob getClobColumn_(int column,
 Agent agent,
 boolean toBePublished)
                          throws SqlException

Description copied from class: Cursor

Returns a Clob object.

Specified by:

getClobColumn_ in class Cursor

Parameters:

column - 1-based column index

agent - associated agent

toBePublished - whether the Clob will be published to the user

Returns:

A java.sql.Clob object.

Throws:

SqlException - if getting the Clob fails

See Also:

• Cursor.getClobColumn_(int, Agent, boolean)

initializeColumnInfoArrays

void initializeColumnInfoArrays(Typdef typdef,
 int columnCount)
                         throws DisconnectException

Throws:

DisconnectException

getMoreData_

protected void getMoreData_()
                     throws SqlException

Specified by:

getMoreData_ in class Cursor

Throws:

SqlException

nullDataForGC

public void nullDataForGC()

Overrides:

nullDataForGC in class Cursor

checkForSplitRowAndComplete

private void checkForSplitRowAndComplete(int length,
 int index)
                                  throws SqlException

Check if the data we want crosses a row split, and fetch more data if necessary.

Parameters:

length - the length in bytes of the data needed

index - the index of the column to be fetched, or -1 when not fetching column data

Throws:

SqlException

checkForSplitRowAndComplete

private void checkForSplitRowAndComplete(int length)
                                  throws SqlException

Check if the data we want crosses a row split, and fetch more data if necessary. This method is not for column data; use checkForSplitRowAndComplete(int, int) for that.

Parameters:

length - the length in bytes of the data needed

Throws:

SqlException

checkAndThrowReceivedEndqryrm

private void checkAndThrowReceivedEndqryrm()
                                    throws SqlException

Throws:

SqlException

checkAndThrowReceivedEndqryrm

private void checkAndThrowReceivedEndqryrm(int lastValidBytePositionBeforeFetch)
                                    throws SqlException

Throws:

SqlException

completeSplitRow

private int completeSplitRow(int index)
                      throws DisconnectException,
SqlException

Fetch more data for a row that has been split up.

Parameters:

index - the index of the column that was split, or -1 when not fetching column data

Returns:

the value of lastValidBytePosition_ before more data was fetched

Throws:

DisconnectException

SqlException

allocateColumnDataPositionArray

private int[] allocateColumnDataPositionArray(int row)

allocateColumnDataComputedLengthArray

private int[] allocateColumnDataComputedLengthArray(int row)

allocateColumnDataIsNullArray

private boolean[] allocateColumnDataIsNullArray(int row)

getDecimalLength

protected int getDecimalLength(int index)

setAllRowsReceivedFromServer

public final void setAllRowsReceivedFromServer(boolean b)

Set the value of value of allRowsReceivedFromServer_.

Overrides:

setAllRowsReceivedFromServer in class Cursor

Parameters:

b - a boolean value indicating whether all rows are received from the server

setQryclsimpEnabled

final void setQryclsimpEnabled(boolean flag)

Set a flag indicating whether QRYCLSIMP is enabled.

Parameters:

flag - true if QRYCLSIMP is enabled

getQryclsimpEnabled

final boolean getQryclsimpEnabled()

Check whether QRYCLSIMP is enabled on this cursor.

Returns:

true if QRYCLSIMP is enabled