org.apache.ambari.server.stack

Class StackModule

java.lang.Object

org.apache.ambari.server.stack.BaseModule<StackModule,StackInfo>

org.apache.ambari.server.stack.StackModule

All Implemented Interfaces:

StackDefinitionModule<StackModule,StackInfo>, Validable

public class StackModule
extends BaseModule<StackModule,StackInfo>
implements Validable

Stack module which provides all functionality related to parsing and fully resolving stacks from the stack definition.

Each stack node is identified by name and version, contains service and configuration child nodes and may extend a single parent stack.

Resolution of a stack is a depth first traversal up the inheritance chain where each stack node calls resolve on its parent before resolving itself. After the parent resolve call returns, all ancestors in the inheritance tree are fully resolved. The act of resolving the stack includes resolution of the configuration and services children of the stack as well as merging of other stack state with the fully resolved parent.

Configuration child node resolution involves merging configuration types, properties and attributes with the fully resolved parent.

Because a service may explicitly extend another service in a stack outside of the inheritance tree, service child node resolution involves a depth first resolution of the stack associated with the services explicit parent, if any. This follows the same steps defined above fore stack node resolution. After the services explicit parent is fully resolved, the services state is merged with it's parent.

If a cycle in a stack definition is detected, an exception is thrown from the resolve call.

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	valid validity flag

Fields inherited from class org.apache.ambari.server.stack.BaseModule

moduleState

Constructor Summary

Constructors

Constructor and Description
StackModule(StackDirectory stackDirectory, StackContext stackContext) Constructor.

Method Summary

Modifier and Type	Method and Description
void	addError(String error)
void	addErrors(Collection<String> errors)
void	finalizeModule() Lifecycle even which is called when the associated stack has been fully resolved.
Collection<String>	getErrors()
Map<String,ExtensionModule>	getExtensionModules()
String	getId() Obtain the id of the module.
StackInfo	getModuleInfo() Obtain the associated module information.
Map<String,ServiceModule>	getServiceModules()
StackDirectory	getStackDirectory() Get the associated stack directory.
static URI	getURI(StackModule module, String uriString)
boolean	isDeleted() Determine whether the module has been marked for deletion.
boolean	isValid()
void	resolve(StackModule parentModule, Map<String,StackModule> allStacks, Map<String,ServiceModule> commonServices, Map<String,ExtensionModule> extensions) Fully resolve the stack.
void	setValid(boolean valid)

Methods inherited from class org.apache.ambari.server.stack.BaseModule

finalizeChildModules, getModuleState, mergeChildModules

Methods inherited from class java.lang.Object

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

Field Detail

valid

protected boolean valid

validity flag

Constructor Detail

StackModule

public StackModule(StackDirectory stackDirectory,
                   StackContext stackContext)

Constructor.

Parameters:

stackDirectory - represents stack directory

stackContext - general stack context

Method Detail

getServiceModules

public Map<String,ServiceModule> getServiceModules()

getExtensionModules

public Map<String,ExtensionModule> getExtensionModules()

resolve

public void resolve(StackModule parentModule,
                    Map<String,StackModule> allStacks,
                    Map<String,ServiceModule> commonServices,
                    Map<String,ExtensionModule> extensions)
             throws org.apache.ambari.server.AmbariException

Fully resolve the stack. See stack resolution description in the class documentation. If the stack has a parent, this stack will be merged against its fully resolved parent if one is specified.Merging applies to all stack state including child service and configuration modules. Services may extend a service in another version in the same stack hierarchy or may explicitly extend a service in a stack in a different hierarchy.

Specified by:

resolve in interface StackDefinitionModule<StackModule,StackInfo>

Parameters:

parentModule - not used. Each stack determines its own parent since stacks don't have containing modules

allStacks - all stacks modules contained in the stack definition

commonServices - all common services specified in the stack definition

extensions - all extension modules contained in the stack definition

Throws:

org.apache.ambari.server.AmbariException - if an exception occurs during stack resolution

getModuleInfo

public StackInfo getModuleInfo()

Description copied from interface: StackDefinitionModule

Obtain the associated module information.

Specified by:

getModuleInfo in interface StackDefinitionModule<StackModule,StackInfo>

Returns:

associated module information

isDeleted

public boolean isDeleted()

Description copied from interface: StackDefinitionModule

Determine whether the module has been marked for deletion.

Specified by:

isDeleted in interface StackDefinitionModule<StackModule,StackInfo>

Returns:

true if the module is marked for deletion; otherwise false

getId

public String getId()

Description copied from interface: StackDefinitionModule

Obtain the id of the module.

Specified by:

getId in interface StackDefinitionModule<StackModule,StackInfo>

Returns:

module id

finalizeModule

public void finalizeModule()

Description copied from interface: StackDefinitionModule

Lifecycle even which is called when the associated stack has been fully resolved.

Specified by:

finalizeModule in interface StackDefinitionModule<StackModule,StackInfo>

Overrides:

finalizeModule in class BaseModule<StackModule,StackInfo>

getStackDirectory

public StackDirectory getStackDirectory()

Get the associated stack directory.

Returns:

associated stack directory

getURI

public static URI getURI(StackModule module,
                         String uriString)

Parameters:

module - the stack module

uriString - the uri string

Returns:

a repo URI, even if it is relative-file based

isValid

public boolean isValid()

Specified by:

isValid in interface StackDefinitionModule<StackModule,StackInfo>

Specified by:

isValid in interface Validable

Returns:

valid xml flag

setValid

public void setValid(boolean valid)

Specified by:

setValid in interface StackDefinitionModule<StackModule,StackInfo>

Specified by:

setValid in interface Validable

Parameters:

valid - set validity flag

addError

public void addError(String error)

Specified by:

addError in interface Validable

getErrors

public Collection<String> getErrors()

Specified by:

getErrors in interface Validable

addErrors

public void addErrors(Collection<String> errors)

Specified by:

addErrors in interface Validable