net.sf.farrago.namespace.util
Class FarragoDataWrapperCache

java.lang.Object
  org.eigenbase.util.CompoundClosableAllocation
      net.sf.farrago.util.FarragoCompoundAllocation
          net.sf.farrago.plugin.FarragoPluginCache
              net.sf.farrago.namespace.util.FarragoDataWrapperCache

All Implemented Interfaces:

FarragoAllocation, FarragoAllocationOwner, ClosableAllocation, ClosableAllocationOwner

public class FarragoDataWrapperCache
extends FarragoPluginCache

FarragoDataWrapperCache serves as a private cache of FarragoMedDataWrapper and FarragoMedDataServer instances. It requires an underlying shared FarragoObjectCache.

Version:

$Id: //open/dev/farrago/src/net/sf/farrago/namespace/util/FarragoDataWrapperCache.java#33 $

Author:

John V. Sichi

Nested Class Summary

private class	FarragoDataWrapperCache.ServerFactory
private class	FarragoDataWrapperCache.WrapperFactory

Field Summary

private FennelDbHandle	fennelDbHandle
private DataSource	loopbackDataSource

Fields inherited from class org.eigenbase.util.CompoundClosableAllocation

allocations

Constructor Summary

FarragoDataWrapperCache(FarragoAllocationOwner owner, FarragoObjectCache sharedCache, FarragoPluginClassLoader classLoader, FarragoRepos repos, FennelDbHandle fennelDbHandle, DataSource loopbackDataSource)
Creates an empty cache.

Method Summary

void	closeAllocation() Closes this object.
Properties	getStorageOptionsAsProperties(FemElementWithStorageOptions element) Extracts the storage options for an element into a Properties.
FarragoMedColumnSet	loadColumnSetFromCatalog(FemBaseColumnSet baseColumnSet, FarragoTypeFactory typeFactory) Loads a FarragoMedColumnSet from its catalog definition.
FarragoMedDataServer	loadServer(String mofId, FarragoMedDataWrapper dataWrapper, Properties options) Loads a data server, or uses a cached instance.
FarragoMedDataServer	loadServerFromCatalog(FemDataServer femServer) Loads a data server based on its catalog definition.
FarragoMedDataWrapper	loadWrapper(String mofId, String libraryName, Properties options) Loads a data wrapper, or uses a cached instance.
FarragoMedDataWrapper	loadWrapperFromCatalog(FemDataWrapper femWrapper) Loads a data wrapper based on its catalog definition.

Methods inherited from class net.sf.farrago.plugin.FarragoPluginCache

addToPrivateCache, getMapMofIdToPlugin, getRepos, getSharedCache, initializePlugin, searchPrivateCache

Methods inherited from class org.eigenbase.util.CompoundClosableAllocation

addAllocation, forgetAllocation, hasAllocations

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.eigenbase.util.ClosableAllocationOwner

addAllocation

Field Detail

fennelDbHandle

private FennelDbHandle fennelDbHandle

loopbackDataSource

private DataSource loopbackDataSource

Constructor Detail

FarragoDataWrapperCache

public FarragoDataWrapperCache(FarragoAllocationOwner owner,
                               FarragoObjectCache sharedCache,
                               FarragoPluginClassLoader classLoader,
                               FarragoRepos repos,
                               FennelDbHandle fennelDbHandle,
                               DataSource loopbackDataSource)

Creates an empty cache.

Parameters:

owner - FarragoAllocationOwner for this cache, to make sure everything gets discarded eventually

sharedCache - underlying shared cache

repos - FarragoRepos for wrapper initialization

fennelDbHandle - FennelDbHandle for wrapper initialization

loopbackDataSource - a DataSource for establishing a loopback connection into Farrago, or null if none is available

Method Detail

loadWrapper

public FarragoMedDataWrapper loadWrapper(String mofId,
                                         String libraryName,
                                         Properties options)

Loads a data wrapper, or uses a cached instance. If the requested wrapper is already available in this private or in the shared cache, it can be used directly. Otherwise, the wrapper is loaded, initialized, and cached at both levels.

Parameters:

mofId - key by which the wrapper can be uniquely identified (Farrago uses the MofId of the catalog object representing the wrapper)

libraryName - name of the library containing the wrapper implementation

options - wrapper-specific options

Returns:

loaded wrapper

loadServer

public FarragoMedDataServer loadServer(String mofId,
                                       FarragoMedDataWrapper dataWrapper,
                                       Properties options)

Loads a data server, or uses a cached instance.

Parameters:

mofId - key by which the server can be uniquely identified (Farrago uses the MofId of the catalog object representing the server)

dataWrapper - FarragoMedDataWrapper which provides access to the server

options - server-specific options

Returns:

loaded server

loadWrapperFromCatalog

public FarragoMedDataWrapper loadWrapperFromCatalog(FemDataWrapper femWrapper)

Loads a data wrapper based on its catalog definition.

Parameters:

femWrapper - catalog definition for data wrapper to load

Returns:

loaded data wrapper

loadServerFromCatalog

public FarragoMedDataServer loadServerFromCatalog(FemDataServer femServer)

Loads a data server based on its catalog definition.

Parameters:

femServer - catalog definition for data server to load

Returns:

loaded data server

loadColumnSetFromCatalog

public FarragoMedColumnSet loadColumnSetFromCatalog(FemBaseColumnSet baseColumnSet,
                                                    FarragoTypeFactory typeFactory)

Loads a FarragoMedColumnSet from its catalog definition.

Parameters:

baseColumnSet - column set definition

typeFactory - factory for column types

Returns:

loaded column set

getStorageOptionsAsProperties

public Properties getStorageOptionsAsProperties(FemElementWithStorageOptions element)

Extracts the storage options for an element into a Properties. No duplicate property names are allowed. Inline property references (such as ${varname} get expanded on read.

Parameters:

element - FemElement we want the options from

Returns:

Properties object populated with the storage options

closeAllocation

public void closeAllocation()

Description copied from interface: ClosableAllocation

Closes this object.

Specified by:

closeAllocation in interface ClosableAllocation

Overrides:

closeAllocation in class CompoundClosableAllocation