OMQ::DbRemoteRawReceive Class Reference

A class for inbound/reading data from the remote instance from a raw SQL query, I/O is handled in a background thread and is made available in the getData() and getAllData() methods. More...

Inheritance diagram for OMQ::DbRemoteRawReceive:

Public Member Methods
	constructor (DbRemoteBase remote, string sql, *softlist< auto > args, *hash< auto > options)
	constructor taking an OMQ::DbRemoteBase object for the remote connection More...
	constructor (string remote, string datasource, string sql, *softlist< auto > args, *hash< auto > options)
	constructor taking a string giving the name of the remote connection for the remote server More...
	constructor (QorusSystemRestHelper remote, string datasource, string sql, *softlist< auto > args, *hash< auto > options)
	constructor taking an OMQ::QorusSystemRestHelper object for the remote connection and assuming the "select" stream More...
Public Member Methods inherited from OMQ::DbRemoteReceive
private	constructor (*hash< auto > options, DbRemoteBase remote, string sql, *list< auto > args)
	Private constructor.
private	constructor (*hash< auto > options, string remote, string datasource, string sql, *list< auto > args)
	Private constructor.
private	constructor (*hash< auto > options, QorusSystemRestHelper remote, string datasource, string sql, *list< auto > args)
	Private constructor.
	constructor (DbRemoteBase remote, string stream, string table_name, *hash< auto > options)
	constructor taking an OMQ::DbRemoteBase object for the remote connection More...
	constructor (DbRemoteBase remote, string table_name, *hash< auto > options)
	constructor taking an OMQ::DbRemoteBase object for the remote connection and assuming the "select" stream More...
	constructor (string remote, string datasource, string stream, string table_name, *hash< auto > options)
	constructor taking a string giving the name of the remote connection for the remote server More...
	constructor (string remote, string datasource, string table_name, *hash< auto > options)
	constructor taking a string giving the name of the remote connection for the remote server and assuming the "select" stream More...
	constructor (QorusSystemRestHelper remote, string datasource, string stream, string table_name, *hash< auto > options)
	constructor taking an OMQ::QorusSystemRestHelper object for the remote connection More...
	constructor (QorusSystemRestHelper remote, string datasource, string table_name, *hash< auto > options)
	constructor taking an OMQ::QorusSystemRestHelper object for the remote connection and assuming the "select" stream More...
	openStream (string stream, string table_name, *hash< auto > options)
	flushes the current stream and reopens a new stream with the same remote connection and in the same datasource More...
private	throwAbortedExceptionImpl (string meth)
	throw a user-friendly exception about why the I/O thread was aborted and the connection forcibly closed and how to avoid such situations in the future
private	startStreamImpl ()
	opens the remote transaction if necessary
private	socketThreadImpl ()
	receive reimplementation
	commit ()
	Commit remote transaction. More...
	rollback (bool action=DO_DISCONNECT)
	Rollback remote transaction. More...
	disconnect ()
	Disconnects the connection.
private nothing	recvDataImpl (auto rdata)
	An abstract method to handle incoming data. More...
private nothing	recvDataDoneImpl (*string err)
	called when all data has been received or the background I/O operation terminates due to an error
*hash< auto >	getData (*timeout timeout_ms)
	returns queued data as soon as it is available, if the timeout is omitted or equal or less than 0, no timeout is used and the call will block until data is available on the queue; once this method return NOTHING it signifies that the end of stream data condition has been reached; do not call this method again after it returns NOTHING More...
*hash< auto >	getAllData (*timeout timeout_ms)
	returns all data recevied by the object in a single call, if the timeout is omitted or equal or less than 0, no timeout is used and the call will block until data is available on the queue More...
*list< auto >	getDataRows (*timeout timeout_ms)
	returns queued data as a list<auto> of rows as soon as it is available, if the timeout is omitted or equal or less than 0, no timeout is used and the call will block until data is available on the queue; once this method return NOTHING it signifies that the end of stream data condition has been reached; do not call this method again after it returns NOTHING More...
*list< auto >	getAllDataRows (*timeout timeout_ms)
	returns all data recevied by the object in a single call as a list<auto> of rows, if the timeout is omitted or equal or less than 0, no timeout is used and the call will block until data is available on the queue More...
private	checkComplete (string meth)
	checks if data is requested after the transfer is complete
OMQ::StreamConfig	config ()
	returns the configuration object
Public Member Methods inherited from OMQ::AbstractParallelReceiveStream
	destructor ()
	disconnects and aborts the I/O thread if it's still running
nothing	cleanup ()
	called when the thread resource is still allocated and the thread exits or one of Qore::throw_thread_resource_exceptions() or Qore::throw_thread_resource_exceptions_to_mark() is called
private	abortInternMethod (string meth)
	if the I/O thread is running, then abort it, disconnect the connection, and throw a user-friendly exception what happened and how to avoid such situations in the future
private	abortIntern (string meth, string fmt)
	if the I/O thread is running, then abort it, disconnect the connection, and throw a user-friendly exception what happened and how to avoid such situations in the future

Additional Inherited Members
Private Attributes inherited from OMQ::DbRemoteReceive
DbSelectStreamConfig	m_config
	stream configuration
bool	complete
	flag indicating that all data has been taken from the Queue

Detailed Description

A class for inbound/reading data from the remote instance from a raw SQL query, I/O is handled in a background thread and is made available in the getData() and getAllData() methods.

See also

OMQ::DbRemoteReceive for information about usage

Example:

DbRemoteRawReceive recv(qrest, "omquser", sql, args, ("block": 2000));
while (*hash<auto> h = recv.getData()) {
    processData(h);
}

Note

a remote transaction is only started in this object's constructor if the transaction option is set, otherwise the remote transaction status is left unchanged

Member Function Documentation

constructor() [1/3]

OMQ::DbRemoteRawReceive::constructor	(	DbRemoteBase	remote,
		string	sql,
		*softlist< auto >	args,
		*hash< auto >	options
	)

constructor taking an OMQ::DbRemoteBase object for the remote connection

Example:

DbRemoteRawReceive recv(db, sql);
while (*hash<auto> h = recv.getData()) {
    processData(h);
}

Parameters

remote	an OMQ::DbRemoteBase object
sql	the SQL for the select statement in the remote DB
args	optional bind arguments for the SQL statement
options	optional Streaming API Constructor Options as follows: "block": data block size; the number of rows to retrieve from the remote database and send in each block "block_queue_size": the number of blocks to queue for receiving before the I/O thread will block (default: 2); the total number of rows that can be queued = block_queue_size * block "timeout": an HTTP socket timeout value in milliseconds; used locally and in the remote for socket I/O and queue operations; default value: 5m "loglevel": a default log level option for logging; see Log Levels for valid value "no_remote_timeout": if True the "timeout" option will not be sent to the remote "transaction": start a remote transaction; if this option is not given, the remote transaction status is left unchanged

Note

• this class always uses the system.sqlutil service stream: "select_raw"
• a remote transaction is only started in this object's constructor if the transaction option is set, otherwise the remote transaction status is left unchanged
• the explicit or default timeout value here overrides any socket I/O timeout set for the remote connection object

constructor() [2/3]

OMQ::DbRemoteRawReceive::constructor	(	string	remote,
		string	datasource,
		string	sql,
		*softlist< auto >	args,
		*hash< auto >	options
	)

constructor taking a string giving the name of the remote connection for the remote server

Example:

DbRemoteRawReceive recv(remote_name, datasource_name, sql);
while (*hash<auto> h = recv.getData()) {
    processData(h);
}

Parameters

remote	a string giving the name of the remote connection for the remote server
datasource	a string with name of the remote datasource to use
sql	the SQL for the select statement in the remote DB
args	optional bind arguments for the SQL statement
options	optional Streaming API Constructor Options as follows: "block": data block size; the number of rows to retrieve from the remote database and send in each block "block_queue_size": the number of blocks to queue for receiving before the I/O thread will block (default: 2); the total number of rows that can be queued = block_queue_size * block "timeout": an HTTP socket timeout value in milliseconds; used locally and in the remote for socket I/O and queue operations; default value: 5m "loglevel": a default log level option for logging; see Log Levels for valid value "no_remote_timeout": if True the "timeout" option will not be sent to the remote "transaction": start a remote transaction; if this option is not given, the remote transaction status is left unchanged

Note

• this class always uses the system.sqlutil service stream: "select_raw"
• a remote transaction is only started in this object's constructor if the transaction option is set, otherwise the remote transaction status is left unchanged
• the explicit or default timeout value here overrides any socket I/O timeout set for the remote connection object

constructor() [3/3]

OMQ::DbRemoteRawReceive::constructor	(	QorusSystemRestHelper	remote,
		string	datasource,
		string	sql,
		*softlist< auto >	args,
		*hash< auto >	options
	)

constructor taking an OMQ::QorusSystemRestHelper object for the remote connection and assuming the "select" stream

Example:

DbRemoteReceive recv(qrest, datasource_name, table_name);
while (*hash<auto> h = recv.getData()) {
    processData(h);
}

Parameters

remote	an OMQ::QorusSystemRestHelper object
datasource	a string with name of the remote datasource to use
sql	the SQL for the select statement in the remote DB
args	optional bind arguments for the SQL statement
options	optional Streaming API Constructor Options as follows: "block": data block size; the number of rows to retrieve from the remote database and send in each block "block_queue_size": the number of blocks to queue for receiving before the I/O thread will block (default: 2); the total number of rows that can be queued = block_queue_size * block "timeout": an HTTP socket timeout value in milliseconds; used locally and in the remote for socket I/O and queue operations; default value: 5m "loglevel": a default log level option for logging; see Log Levels for valid value "no_remote_timeout": if True the "timeout" option will not be sent to the remote "transaction": start a remote transaction; if this option is not given, the remote transaction status is left unchanged

Note

• this class always uses the system.sqlutil service stream: "select_raw"
• a remote transaction is only started in this object's constructor if the transaction option is set, otherwise the remote transaction status is left unchanged
• the explicit or default timeout value here overrides any socket I/O timeout set for the remote connection object

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The documentation for this class was generated from the following file:

• Streams.qc