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

Command parser SEDA stage. More...

#include <parse_stage.hh>

Inheritance diagram for sends::parse_stage:

List of all members.

Public Types
typedef thread::mt_queue < buffer * >	buffer_queue
	Buffer list.
Public Member Functions
	parse_stage (int nThread, int nTrans)
	Stage template constructor.
virtual	~parse_stage (void)
void	filter (transaction *trans)
	Transaction filter for this stage.
void	init_thread (void)
	Thread initialization.
buffer_pool &	ref_resource (void)
virtual void	shut (void)
	Shut down all threads in the pool.
const char *	stage_name (void) const
	Stage name.

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Detailed Description

Command parser SEDA stage.

The parse_stage class is the command parser stage of the SENDS server. For each transaction entered into the input queue, the parse stage reads a command line (terminated by a new-line or null) and parses the command. The command format is:

      <command> [<start> [<end>] <delta>] [<type>] [{<chan1> [... <chanN>]}];
         

The command may be one of the following:

• noop: The command is parsed but no data are transferred.
• get-channels: Get channel data for specified time and types.
• get-data: Get specified data.
• get-status: Get status of specified channels.
• get-server-status: Get list of server info.
• quit: Close the client connection.

The data times are specified by a start GPS time and either an end time, a data stride or both. If two time fields are specified and the second is less than the first the second field is taken to be a duration (delta) time and the end time is caculated from the start minus the end. If the second field is greater than the first, or three fields are specified, the second field specifies the end time and the optional third field specifies the data stride (segment length for a single transfer).

The channel list contains an arbitrary number (up to 1024) of space separated channel descriptors enclosed in braces. Each channel descriptor has a channel name and optional channel-type, sample-rate or both separated by commas or percent signs.

Author:

J. Zweizig

Version:

1.0; Last modified December 28, 2007

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Member Typedef Documentation

typedef thread::mt_queue<buffer*> sends::parse_stage::buffer_queue

Buffer list.

Data type for preallocated buffer free list.

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Constructor & Destructor Documentation

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

Stage template constructor.

Construct a parse_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::parse_stage::~parse_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::parse_stage::filter

(

transaction *

trans

)

[virtual]

Transaction filter for this stage.

The filter method performs the transaction processing for a single stage. By default this is a null filter that passes the transaction on to the next

Parameters:

trans

Pointer to the current transaction

Implements sends::seda_stage.

void sends::parse_stage::init_thread

(

void

)

[virtual]

Thread initialization.

Set up the signal handling for this thread.

Reimplemented from sends::seda_stage.

buffer_pool & sends::parse_stage::ref_resource

(

void

)

[inline]

Reference the resource (input buffer) queue.

virtual void sends::parse_stage::shut

(

void

)

[virtual]

Shut down all threads in the pool.

Shut down all threads in the parse pool.

Reimplemented from sends::seda_stage.

const char* sends::parse_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/parse_stage.hh