Package org.pentaho.di.base

Interface IMetaFileCache

All Known Implementing Classes:

MetaFileCacheImpl

public interface IMetaFileCache

This cache lives for the runtime of the parent Job or Trans. It is used to cache the JobMeta or TransMeta of any kjb or ktr that it needs to load to the course of the main job/trans execution. The intent here is to minimize the overhead of loading and parsing the jobs/transformations into their associated metas. Loading a ktr/kjb will require a call to the server if attached. If that kjb/ktr is called multiple times during the run, then each execution will again make the call to get the meta. This cache eliminates the need to repetitively load the kjb/ktr.

Method Summary

Modifier and Type	Method	Description
void	cacheMeta(String key, JobMeta meta)
void	cacheMeta(String key, TransMeta meta)
JobMeta	getCachedJobMeta(String key)
TransMeta	getCachedTransMeta(String key)
default String	getKey(org.pentaho.di.core.ObjectLocationSpecificationMethod specificationMethod, String realFilenameOrId)	Keys to the cache should always be generated using a method provided by this interface.
static IMetaFileCache	initialize(Job parentJob, org.pentaho.di.core.logging.LogChannelInterface logger)	Each new job/transformation should call this method once to get the instance of the cache for the currently running job.
static IMetaFileCache	initialize(Trans parentTrans, org.pentaho.di.core.logging.LogChannelInterface logger)	Each new transformation should call this method once to get the instance of the cache for the currently running parent transformation/job.
void	logCacheSummary(org.pentaho.di.core.logging.LogChannelInterface logger)
static void	setCacheInstance(JobMeta jobMeta, IMetaFileCache cache)
static void	setCacheInstance(TransMeta transMeta, IMetaFileCache cache)

Method Detail

initialize

static IMetaFileCache initialize(Job parentJob,
                                 org.pentaho.di.core.logging.LogChannelInterface logger)

Each new job/transformation should call this method once to get the instance of the cache for the currently running job. This instance should then be passed to the new job's/transformation's meta by calling setCacheInstance(org.pentaho.di.job.JobMeta, org.pentaho.di.base.IMetaFileCache) after the Meta has been created. ThereAfter the cache can be referenced through AbstractMeta.getMetaFileCache()

Parameters:

parentJob - The parent job, or null if none.

Returns:

the IMetaFileCache in play

initialize

static IMetaFileCache initialize(Trans parentTrans,
                                 org.pentaho.di.core.logging.LogChannelInterface logger)

Each new transformation should call this method once to get the instance of the cache for the currently running parent transformation/job. This instance should then be passed to the new job's/transformation's meta by calling setCacheInstance(org.pentaho.di.job.JobMeta, org.pentaho.di.base.IMetaFileCache) after the Meta has been created. ThereAfter the cache can be referenced through AbstractMeta.getMetaFileCache()

Parameters:

parentTrans - The parent job, or null if none.

Returns:

the IMetaFileCache in play

setCacheInstance

static void setCacheInstance(JobMeta jobMeta,
                             IMetaFileCache cache)

setCacheInstance

static void setCacheInstance(TransMeta transMeta,
                             IMetaFileCache cache)

getCachedJobMeta

JobMeta getCachedJobMeta(String key)

getCachedTransMeta

TransMeta getCachedTransMeta(String key)

cacheMeta

void cacheMeta(String key,
               JobMeta meta)

cacheMeta

void cacheMeta(String key,
               TransMeta meta)

logCacheSummary

void logCacheSummary(org.pentaho.di.core.logging.LogChannelInterface logger)

getKey

default String getKey(org.pentaho.di.core.ObjectLocationSpecificationMethod specificationMethod,
                      String realFilenameOrId)

Keys to the cache should always be generated using a method provided by this interface. This ensures that keys will remain unique across different nameSpace catagories.

Parameters:

specificationMethod - Defines different sources for the Meta defined by the ObjectLocationSpecificationMethod enum.

realFilenameOrId - Contains the full file path or jackrabbit Id for the node

Returns:

The key to use to load or save an item to the cache.