org.apache.hadoop.hive.metastore.properties

Class PropertyManager

java.lang.Object

org.apache.hadoop.hive.metastore.properties.PropertyManager

Direct Known Subclasses:

HMSPropertyManager

public abstract class PropertyManager
extends Object

A property manager.

This handles operations at the higher functional level; an instance is created per-session and drives queries and updates in a transactional manner.

The manager ties the property schemas into one namespace; all property maps it handles must and will use one of its known schema.

The manager class needs to be registered with its namespace as key

Since a collection of properties are stored in a map, to avoid hitting the persistence store for each update - which would mean rewriting the map multiple times - the manager keeps track of dirty maps whilst serving as transaction manager. This way, when importing multiple properties targeting different elements (think setting properties for different tables), each impacted map is only rewritten once by the persistence layer during commit. This also allows multiple calls to participate to one transactions.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	PropertyManager.MapWrapper JEXL adapter.

Field Summary

Fields

Modifier and Type	Field and Description
protected Map<String,PropertyMap>	dirtyMaps The set of dirty maps.
static org.slf4j.Logger	LOGGER The logger.
protected String	namespace This manager namespace.
protected PropertyStore	store The property map store.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	PropertyManager(String ns, PropertyStore store) Creates a manager instance.

Method Summary

Modifier and Type	Method and Description
void	commit() Saves all pending updates to store.
static PropertyManager	create(String namespace, PropertyStore store) Creates an instance of manager using its declared namespace.
static boolean	declare(String ns, Class<? extends PropertyManager> pmClazz) Declares a property manager class.
boolean	dropProperties(String mapName) Drops a property map.
String	exportPropertyValue(String key) Fetches and formats a property value.
protected int	getMapNameLength(String[] keys)
Object	getProperty(String key) Gets a property value.
Object	getProperty(String[] keys) Gets a property value.
Object	getPropertyValue(String key) Gets a property value.
Object	getPropertyValue(String[] keys) Gets a property value.
PropertySchema	getSchema(String name) Gets a schema by name.
void	importDefaultValues(Properties importsp) Imports a set of default values into this store"s schema.
protected String	mapKey(String name) Compose a property map key from a property map name.
protected String	mapKey(String[] keys) Compose a property map key from property key fragments.
protected String	mapKey(String[] keys, int maxkl) Compose a property map key from property key fragments.
protected String	mapName(String key) Extract a property map name from a property map key.
protected String	propertyName(String[] keys) Compose a property name from property key fragments.
protected String	propertyName(String[] keys, int maxkl) Compose a property name from property key fragments.
void	rollback() Forget all pending updates.
Object	runScript(String src) Runs a JEXL script using this manager as context.
protected PropertySchema	schemaOf(String[] keys) Determines the schema from the property key fragments.
Map<String,PropertyMap>	selectProperties(String namePrefix, Function<PropertyMap,PropertyMap> selector) Selects a set of properties.
Map<String,PropertyMap>	selectProperties(String namePrefix, org.apache.commons.jexl3.JexlExpression predicate, List<String> projectStr) Selects a set of properties.
Map<String,PropertyMap>	selectProperties(String namePrefix, org.apache.commons.jexl3.JexlExpression predicate, String... projectStr) Selects a set of properties.
Map<String,PropertyMap>	selectProperties(String namePrefix, String predicateStr, List<String> projectStr) Selects a set of properties.
Map<String,PropertyMap>	selectProperties(String namePrefix, String predicateStr, String... projectStr) Selects a set of properties.
void	setProperties(Map<String,?> map) Injects a set of properties.
void	setProperties(Properties map) Imports a set of property values.
protected void	setProperty(String[] keys, Object value) Sets a property value.
void	setProperty(String key, Object value) Sets a property value.
protected String[]	splitKey(String key) Splits a property key into its fragments.

Methods inherited from class java.lang.Object

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

Field Detail

LOGGER

public static final org.slf4j.Logger LOGGER

The logger.

dirtyMaps

protected final Map<String,PropertyMap> dirtyMaps

The set of dirty maps.

namespace

protected final String namespace

This manager namespace.

store

protected final PropertyStore store

The property map store.

Constructor Detail

PropertyManager

protected PropertyManager(String ns,
                          PropertyStore store)

Creates a manager instance.

Parameters:

store - the store instance which must use an appropriate property map factory (probably use createMap).

Method Detail

declare

public static boolean declare(String ns,
                              Class<? extends PropertyManager> pmClazz)

Declares a property manager class.

Parameters:

ns - the namespace

pmClazz - the property manager class

create

public static PropertyManager create(String namespace,
                                     PropertyStore store)
                              throws MetaException,
                                     NoSuchObjectException

Creates an instance of manager using its declared namespace.

Parameters:

namespace - the manager"s namespace

store - the property store

Returns:

a property manager instance

Throws:

MetaException - if the manager creation fails

NoSuchObjectException - if the store is null or no constructor was declared

commit

public void commit()

Saves all pending updates to store.

rollback

public void rollback()

Forget all pending updates.

importDefaultValues

public void importDefaultValues(Properties importsp)

Imports a set of default values into this store"s schema. The properties should be of the form schema_name.property_name=value. Note that this implies the manager has at least one known property map schema.

Parameters:

importsp - the properties

setProperties

public void setProperties(Properties map)

Imports a set of property values.

Transactional call that requires calling commit() or rollback().

Parameters:

map - the properties key=value

setProperties

public void setProperties(Map<String,?> map)

Injects a set of properties. If the value is null, the property is removed.

Transactional call that requires calling commit() or rollback().

Parameters:

map - the map of properties to inject.

setProperty

public void setProperty(String key,
                        Object value)

Sets a property value.

Transactional call that requires calling commit() or rollback().

Parameters:

key - the property key

value - the property value or null to unset

runScript

public Object runScript(String src)
                 throws PropertyException

Runs a JEXL script using this manager as context.

Parameters:

src - the script source

Returns:

the script result

Throws:

PropertyException - if any error occurs in JEXL

getProperty

public Object getProperty(String key)

Gets a property value.

Parameters:

key - the property key

Returns:

property value or null if not assigned

exportPropertyValue

public String exportPropertyValue(String key)

Fetches and formats a property value.

Parameters:

key - the property key

Returns:

the formatted property value (or the default value) or null if not assigned

getPropertyValue

public Object getPropertyValue(String key)

Gets a property value.

Parameters:

key - the property key

Returns:

property value or the schema default value if not assigned

splitKey

protected String[] splitKey(String key)

Splits a property key into its fragments.

Parameters:

key - the property key

Returns:

the key fragments

getSchema

public PropertySchema getSchema(String name)

Gets a schema by name.

Only used by importDefaultValues(Properties)

Parameters:

name - schema name

Returns:

the schema instance, null if no such schema is known

schemaOf

protected PropertySchema schemaOf(String[] keys)

Determines the schema from the property key fragments.

Parameters:

keys - the key fragments

Returns:

the schema, PropertySchema.NONE if no such schema is known

getMapNameLength

protected int getMapNameLength(String[] keys)

Parameters:

keys - property key fragments

Returns:

number of fragments composing the map name in the fragments array

mapKey

protected String mapKey(String name)

Compose a property map key from a property map name.

Parameters:

name - the property map name, may be null or empty

Returns:

the property map key used by the store

mapName

protected String mapName(String key)

Extract a property map name from a property map key.

Parameters:

key - property map key

Returns:

the property map name

mapKey

protected String mapKey(String[] keys)

Compose a property map key from property key fragments.

Parameters:

keys - the key fragments

Returns:

the property map key used by the store

mapKey

protected String mapKey(String[] keys,
                        int maxkl)

Compose a property map key from property key fragments.

Parameters:

keys - the property key fragments

maxkl - the maximum number of fragments in the map key

Returns:

the property key used by the store

propertyName

protected String propertyName(String[] keys)

Compose a property name from property key fragments.

Parameters:

keys - the key fragments

Returns:

the property name

propertyName

protected String propertyName(String[] keys,
                              int maxkl)

Compose a property name from property key fragments.

Parameters:

keys - the key fragments

maxkl - the maximum number of fragments in the map name

Returns:

the property name

getProperty

public Object getProperty(String[] keys)

Gets a property value.

Parameters:

keys - the key fragments

Returns:

the value or null if none was assigned

getPropertyValue

public Object getPropertyValue(String[] keys)

Gets a property value.

Parameters:

keys - the key fragments

Returns:

the value or the default schema value if not assigned

dropProperties

public boolean dropProperties(String mapName)

Drops a property map.

Transactional call that requires calling commit() or rollback().

Parameters:

mapName - the map name

Returns:

true if the properties may exist, false if they did nots

setProperty

protected void setProperty(String[] keys,
                           Object value)

Sets a property value.

Parameters:

keys - the key fragments

value - the new value or null if mapping should be removed

selectProperties

public Map<String,PropertyMap> selectProperties(String namePrefix,
                                                String predicateStr,
                                                String... projectStr)

Selects a set of properties.

Parameters:

namePrefix - the map name prefix

predicateStr - the condition selecting maps

projectStr - the projection property names or script

Returns:

the map of property maps keyed by their name

selectProperties

public Map<String,PropertyMap> selectProperties(String namePrefix,
                                                Function<PropertyMap,PropertyMap> selector)

Selects a set of properties.

Parameters:

namePrefix - the map name prefix

selector - the selector/transformer function

Returns:

the map of property maps keyed by their name

selectProperties

public Map<String,PropertyMap> selectProperties(String namePrefix,
                                                String predicateStr,
                                                List<String> projectStr)

Selects a set of properties.

Parameters:

namePrefix - the map name prefix

predicateStr - the condition selecting maps

projectStr - the projection property names or script

Returns:

the map of property maps keyed by their name

selectProperties

public Map<String,PropertyMap> selectProperties(String namePrefix,
                                                org.apache.commons.jexl3.JexlExpression predicate,
                                                String... projectStr)

Selects a set of properties.

Parameters:

namePrefix - the map name prefix

predicate - the condition selecting maps

projectStr - the projection property names or script

Returns:

the map of property maps keyed by their name

selectProperties

public Map<String,PropertyMap> selectProperties(String namePrefix,
                                                org.apache.commons.jexl3.JexlExpression predicate,
                                                List<String> projectStr)

Selects a set of properties.

Parameters:

namePrefix - the map name prefix

predicate - the condition selecting maps

projectStr - the projection property names or script

Returns:

the map of property maps keyed by their name