sends::fetch_stage Class Reference
[Sends Pipeline Stage Classes]

Data fetch SEDA stage. More...

#include <fetch_stage.hh>

Inheritance diagram for sends::fetch_stage:

List of all members.

Public Types
typedef transaction::gps_type	gps_type
	GPS times.
typedef transaction::chan_index	chan_index
	CHannel index.
typedef transaction::seg_index	seg_index
	Channel index.
typedef std::vector< chan_index >	chan_vect
	Channel list.
Public Member Functions
	fetch_stage (int nThread, int nTrans)
	Stage template constructor.
virtual	~fetch_stage (void)
void	filter (transaction *trans)
	Transaction filter for this stage.
void	find_data (transaction *trans)
	Search for a data source and read in data.
void	read (const frame_loc &fl, const chan_vect &v, gps_type start, gps_type stop)
	Read channels from a specified frame tpye.
const char *	stage_name (void) const
	Stage name.

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Detailed Description

Data fetch SEDA stage.

The fetch_stage class provides a minimal template for a SEDA stage thread pool. It is based on the seda_stage class and provides a stage with no filter processing. The constructor, destructor and filter methods are implemented. The filter method immediately passes the transactions to its output queue (the input queue of the next stage in the pipeline.

Author:

John Zweizig

Version:

1.0; Last modified December 28, 2007

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Member Typedef Documentation

typedef transaction::gps_type sends::fetch_stage::gps_type

GPS times.

Data type sused to represent GPS times.

typedef transaction::chan_index sends::fetch_stage::chan_index

CHannel index.

Data type use to represent indices into master channel list.

typedef transaction::seg_index sends::fetch_stage::seg_index

Channel index.

Data type use to represent indices into segment database.

typedef std::vector<chan_index> sends::fetch_stage::chan_vect

Channel list.

Channel index vector.

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Constructor & Destructor Documentation

sends::fetch_stage::fetch_stage	(	int	nThread,
		int	nTrans
	)

Stage template constructor.

Construct a fetch_stage object. The arguments indicate the number of threads in the pool and the number of input transactions that may be queue simultaneously (note that the pipline gets indigestion only after more than (nTrans + nThread) trasactions need to execute in this stage.

Parameters:

	nThread	Number of threads to run simultaneously in the pool.
	nTrans	Number of transactions that may be queued.

virtual sends::fetch_stage::~fetch_stage

(

void

)

[virtual]

Stage template destructor is null by default. It is mostly useful to remove resources allocated by the stages.

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Member Function Documentation

void sends::fetch_stage::filter

(

transaction *

trans

)

[virtual]

Transaction filter for this stage.

The fetch_stage filter method detemines what actions must be taken for the transaction type. It then calls find_data or passes the transaction to the next stage as appropriate.

Parameters:

trans

Pointer to the current transaction

Implements sends::seda_stage.

void sends::fetch_stage::find_data

(

transaction *

trans

)

Search for a data source and read in data.

The find_data method loops over channels and reserves the data data needed by the specified request.

Parameters:

trans

Pointer to the current transaction

void sends::fetch_stage::read	(	const frame_loc &	fl,
		const chan_vect &	v,
		gps_type	start,
		gps_type	stop
	)

Read channels from a specified frame tpye.

Read a list of channels from a single specified frame source into free data segments.

Parameters:

	fl	Frame location descriptor.
	v	Vector of channels (indices) to be read.
	start	Start GPS of data to be read
	stop	End GPS of data to be read

const char* sends::fetch_stage::stage_name

(

void

)

const [virtual]

Stage name.

Return a constant pointer to a null-terminated character vector containing the name of the stage.

Returns:

Constant pointer to the stage name string.

Implements sends::seda_stage.

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

• src/stages/fetch_stage.hh