AggMemberDataset Class Reference

#include <AggMemberDataset.h>

Inheritance diagram for AggMemberDataset:

Collaboration diagram for AggMemberDataset:

Public Member Functions
	AggMemberDataset (const AggMemberDataset &proto)
	AggMemberDataset (std::string location)
virtual void	fillDimensionCacheByUsingDDS ()=0
virtual void	flushDimensionCache ()=0
virtual unsigned int	getCachedDimensionSize (const std::string &dimName) const=0
virtual const libdap::DDS *	getDDS ()=0
const std::string &	getLocation () const
virtual bool	isDimensionCached (const std::string &dimName) const=0
virtual void	loadDimensionCache (std::istream &istr)=0
AggMemberDataset &	operator= (const AggMemberDataset &rhs)
virtual void	saveDimensionCache (std::ostream &ostr)=0
virtual void	setDimensionCacheFor (const Dimension &dim, bool throwIfFound)=0

Detailed Description

Abstract helper superclass for allowing lazy access to the DDS for an aggregation. This is used during a read() if the dataset is needed in an aggregation.

Note: This inherits from RCObject so is a ref-counted object to avoid making excessive copies of it and especially of any contained DDS.

Currently, there are two concrete subclasses:

o AggMemberDatasetUsingLocationRef: to load an external location into a DDS as needed (lazy eval so not loaded unless in the output of read() )

o AggMemberDatasetDDSWrapper: to hold a pre-loaded DDS for the case of virtual or pre-loaded datasets (data declared in NcML file, nested aggregations, e.g.) In this case, getLocation() is presumed empty().

Definition at line 63 of file AggMemberDataset.h.

Member Function Documentation

fillDimensionCacheByUsingDDS()

virtual void agg_util::AggMemberDataset::fillDimensionCacheByUsingDDS ( )

pure virtual

Uses the getDDS() call in order to find all named dimensions within it and to seed them into the dimension cache table for faster later lookups. Potentially slow!

flushDimensionCache()

virtual void agg_util::AggMemberDataset::flushDimensionCache ( )

pure virtual

Flush out any cache for the Dimensions so that it will have to be loaded.

getCachedDimensionSize()

virtual unsigned int agg_util::AggMemberDataset::getCachedDimensionSize ( const std::string & dimName ) const

pure virtual

Get the size of the given dimension named dimName cached within the dataset. If not found in cache, throws.

If a cached value exists from a prior load of the DDS using loadDimensionCacheFromDDS() or from a call to setDimensionCacheFor(), return that.

Otherwise, this must load the DDS to get the values.

Implementation is left up to subclasses for efficiency.

Returns

the size of the dimension if found

Exceptions

agg_util::DimensionNotFoundException

if not located via any means.

getDDS()

virtual const libdap::DDS * agg_util::AggMemberDataset::getDDS ( )

pure virtual

Return the DDS for the location, loading it in if it hasn't yet been loaded. Can return NULL if there's a problem. (Not const due to lazy eval)

Returns

the DDS ptr containing the loaded dataset or NULL.

getLocation()

const std::string & agg_util::AggMemberDataset::getLocation

(

)

const

The location to which the AggMemberDataset refers Note: this could be "" for some subclasses if they are virtual or nested

isDimensionCached()

virtual bool agg_util::AggMemberDataset::isDimensionCached ( const std::string & dimName ) const

pure virtual

Return whether the dimension is already cached, or would have to be loaded to be found.

loadDimensionCache()

virtual void agg_util::AggMemberDataset::loadDimensionCache ( std::istream & istr )

pure virtual

Load the values in the dimension cache from the input stream

saveDimensionCache()

virtual void agg_util::AggMemberDataset::saveDimensionCache ( std::ostream & ostr )

pure virtual

Append the values in the dimension cache to the output stream

setDimensionCacheFor()

virtual void agg_util::AggMemberDataset::setDimensionCacheFor ( const Dimension & dim, bool throwIfFound )

pure virtual

Seed the dimension cache using the given dimension, so that later calls to getDimensionSize for dim.name will return the dim.size immediately without checking or loading the actual DDS.

If it already exists and throwIfFound then will throw an AggregationException.

If it exists and !throwIfFound, will replace the old one.

Parameters

dim	the dimension to seed
if	true, throw if name take. Else replace original.

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

• AggMemberDataset.h