aspCheckpoint.Table Class Reference

Interface to ASP Checkpointing Service functionality User would create a Table object on which he can do read and write. More...

Public Member Functions
def	__init__
	Constructor function for the Table class. More...
def	ErrorHandler
	Function to handle the common error codes returned by ASP functions. More...
def	SetAutoActivate
	Set the global value of autoActivate to given value. More...
def	Activate
	Set the active replica for the asynchronous checkpoints. More...
def	Synchronize
	Synchronize checkpoint replicas. More...
def	Delete
	Delete the section of the checkpointed denoted by given key. More...
def	Read
	Read the checkpoint for the given section ids. More...
def	Write
	Write data into the table. More...
def	GetActiveStatus
	Get the active status of the checkpoint. More...

Public Attributes
	ckptName
	flags
	retentionMs
	maxSections
	maxSectionSizeBytes
	maxSectionIdSizeBytes
	sectionExpiration
	autoActivate
	tryAgainDelayMs
	svcHdl
	ckptHdl

Detailed Description

Interface to ASP Checkpointing Service functionality User would create a Table object on which he can do read and write.

Constructor & Destructor Documentation

def aspCheckpoint.Table.__init__	(		self,
			name,
			maxRows,
			maxRowSizeBytes,
			maxRowKeySizeBytes,
			flagsp = asp.SA_CKPT_WR_ALL_REPLICAS,
			retentionMs = asp.SA_TIME_MAX
	)

Constructor function for the Table class.

It creats a new checkpoint with the given parameters.

Parameters

name	Name of the table/checkpoint to be created
flagsp	This parameter indicates the type of checkpoint to be created. The supported values are: SA_CKPT_WR_ALL_REPLICAS, SA_CKPT_WR_ACTIVE_REPLICA, SA_CKPT_WR_ACTIVE_REPLICA_WEAK, SA_CKPT_CHECKPOINT_COLLOCATED. The meaning of these flags are as below:

SA_CKPT_WR_ALL_REPLICAS - Creates a checkpoint with synchronous update option SA_CKPT_WR_ACTIVE_REPLICA - Creates a checkpoint with the asynchronous update option and providing atomicity when updating the replicas SA_CKPT_WR_ACTIVE_REPLICA_WEAK - Creates a checkpoint with the asynchronous update option but there is no guarantee of atomicity with updating the replicas. SA_CKPT_CHECKPOINT_COLLOCATED - If this flag is specified at the creation time, there is no active replica created until user explicitly sets an Active replica for the checkpoint.

For more details about these flags and their usage, refer to SAF Checkpoint Service specification.

Parameters

retentionMs	Retention time indicates that any checkpoint that is inactive for this duration will automatically deleted by the checkpoint service
maxSections	Maximum number of checkpoints for this checkpoint
maxSectionSizeBytes	Maximum size of each section
maxSectionIdSizeBytes	Maximum length of the section identifier.

Member Function Documentation

def aspCheckpoint.Table.Activate

(

self

)

Set the active replica for the asynchronous checkpoints.

def aspCheckpoint.Table.Delete	(		self,
			key
	)

Delete the section of the checkpointed denoted by given key.

Parameters

key	String identifier for the checkpoint section

def aspCheckpoint.Table.ErrorHandler	(		self,
			s,
			e
	)

Function to handle the common error codes returned by ASP functions.

Parameters

s	String description for the exception
e	Exception caught from invoking the ASP APIs

def aspCheckpoint.Table.GetActiveStatus

(

self

)

Get the active status of the checkpoint.

Returns

Returns the boolean value indicating the status of the checkpoint

def aspCheckpoint.Table.Read	(		self,
			keys
	)

Read the checkpoint for the given section ids.

Parameters

keys	A list of section ids or keys

Returns

data Returns the data stored in the given sections

def aspCheckpoint.Table.SetAutoActivate	(		self,
			val = True
	)

Set the global value of autoActivate to given value.

Default being True When autoActivate is set to True, the library will take care of setting the Active repliaca for the asynchronous checkpoints. Otherwise, user will have to explicitly activate the replica using Activate() function.

Parameters

val	Boolean value indicate whether to enable auto activate or not

def aspCheckpoint.Table.Synchronize	(		self,
			timeout = asp.SA_TIME_END
	)

Synchronize checkpoint replicas.

Parameters

timeout

Timeout to wait for the completion of the update from the checkpoint service

def aspCheckpoint.Table.Write	(		self,
			keyOrContainer,
			data = None
	)

Write data into the table.

There are several ways to call this functions: Write("rowname","data"): Writes the value "data" into the row named "rowname" (will TRUNCATE the existing record if new record is shorter) Write([("rowname","data"),("rowname2","data2")]): List of tuples format (will NOT truncate the existing record) Write({"rowname":"data","rowname2":"data2"}): Dictionary format (will NOT truncate)

Parameters

keyOrContainer	Either a string, in which case this is interpreted as the row (section) identifier, and "data" will be the data to write OR a container of key/data pairs (see the function discription for formats)
data	This is the data to write into the row if key is a string, otherwise this is NOT USED.

Member Data Documentation

aspCheckpoint.Table.autoActivate

aspCheckpoint.Table.ckptHdl

aspCheckpoint.Table.ckptName

aspCheckpoint.Table.flags

aspCheckpoint.Table.maxSectionIdSizeBytes

aspCheckpoint.Table.maxSections

aspCheckpoint.Table.maxSectionSizeBytes

aspCheckpoint.Table.retentionMs

aspCheckpoint.Table.sectionExpiration

aspCheckpoint.Table.svcHdl

aspCheckpoint.Table.tryAgainDelayMs