Package org.apache.velocity.context

Class ProxyVMContext

java.lang.Object

org.apache.velocity.context.ChainedInternalContextAdapter

org.apache.velocity.context.ProxyVMContext

All Implemented Interfaces:

Context, InternalContextAdapter, InternalEventContext, InternalHousekeepingContext, InternalWrapperContext

public class ProxyVMContext
extends ChainedInternalContextAdapter

Context for Velocity macro arguments. This special context combines ideas of earlier VMContext and VMProxyArgs by implementing routing functionality internally. This significantly reduces memory allocation upon macro invocations. Since the macro AST is now shared and RuntimeMacro directive is used, the earlier implementation of precalculating VMProxyArgs would not work. See Issue 607 for more info on this class.

Since:

1.6

Version:

$Id$

Field Summary

Fields

Modifier and Type	Field	Description
(package private) Map	localcontext	container for any local or constant macro arguments.
private boolean	localContextScope	support for local context scope feature, where all references are local
private RuntimeServices	rsvc	needed for writing log entries.
(package private) Map	vmproxyhash	container for our macro AST node arguments.

Fields inherited from class org.apache.velocity.context.ChainedInternalContextAdapter

innerContext

Constructor Summary

Constructors

Constructor	Description
ProxyVMContext(InternalContextAdapter inner, RuntimeServices rsvc, boolean localContextScope)

Method Summary

Modifier and Type	Method	Description
void	addVMProxyArg(InternalContextAdapter context, String macroArgumentName, String literalMacroArgumentName, Node argumentValue)	Used to put Velocity macro arguments into this context.
void	addVMProxyArg(InternalContextAdapter context, String macroArgumentName, String literalMacroArgumentName, Renderable argumentValue)	Used to put Velocity macro bodyContext arguments into this context.
boolean	containsKey(Object key)	Indicates whether the specified key is in the context.
Object	get(String key)	Implementation of the Context.get() method.
Object[]	getKeys()	Get all the keys for the values in the context.
private boolean	isConstant(Node node)	AST nodes that are considered constants can be directly saved into the context.
Object	localPut(String key, Object value)	Allows callers to explicitly put objects in the local context, no matter what the velocimacro.context.local setting says.
Object	put(String key, Object value)	Impl of the Context.put() method.
protected Object	put(String key, Object value, boolean forceLocal)	Internal put method to select between local and global scope.
Object	remove(Object key)	Removes the value associated with the specified key from the context.

Methods inherited from class org.apache.velocity.context.ChainedInternalContextAdapter

attachEventCartridge, getBaseContext, getCurrentMacroCallDepth, getCurrentMacroName, getCurrentResource, getCurrentTemplateName, getEventCartridge, getInternalUserContext, getMacroLibraries, getMacroNameStack, getTemplateNameStack, icacheGet, icachePut, popCurrentMacroName, popCurrentTemplateName, pushCurrentMacroName, pushCurrentTemplateName, setCurrentResource, setMacroLibraries

Methods inherited from class java.lang.Object

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

Field Details

vmproxyhash

Map vmproxyhash

container for our macro AST node arguments. Size must be power of 2.

localcontext

Map localcontext

container for any local or constant macro arguments. Size must be power of 2.

localContextScope

private boolean localContextScope

support for local context scope feature, where all references are local

rsvc

private RuntimeServices rsvc

needed for writing log entries.

Constructor Details

ProxyVMContext

public ProxyVMContext(InternalContextAdapter inner,
 RuntimeServices rsvc,
 boolean localContextScope)

Parameters:

inner - Velocity context for processing

rsvc - RuntimeServices provides logging reference

localContextScope - if true, all references are set to be local

Method Details

addVMProxyArg

public void addVMProxyArg(InternalContextAdapter context,
 String macroArgumentName,
 String literalMacroArgumentName,
 Node argumentValue)
                   throws MethodInvocationException

Used to put Velocity macro arguments into this context.

Parameters:

context - rendering context

macroArgumentName - name of the macro argument that we received

literalMacroArgumentName - ".literal.$"+macroArgumentName

argumentValue - actual value of the macro argument

Throws:

MethodInvocationException

addVMProxyArg

public void addVMProxyArg(InternalContextAdapter context,
 String macroArgumentName,
 String literalMacroArgumentName,
 Renderable argumentValue)
                   throws MethodInvocationException

Used to put Velocity macro bodyContext arguments into this context.

Parameters:

context - rendering context

macroArgumentName - name of the macro argument that we received

literalMacroArgumentName - ".literal.$"+macroArgumentName

argumentValue - actual value of the macro body

Throws:

MethodInvocationException

isConstant

private boolean isConstant(Node node)

AST nodes that are considered constants can be directly saved into the context. Dynamic values are stored in another argument hashmap.

Parameters:

node - macro argument as AST node

Returns:

true if the node is a constant value

put

public Object put(String key,
 Object value)

Impl of the Context.put() method.

Specified by:

put in interface Context

Overrides:

put in class ChainedInternalContextAdapter

Parameters:

key - name of item to set

value - object to set to key

Returns:

old stored object

localPut

public Object localPut(String key,
 Object value)

Allows callers to explicitly put objects in the local context, no matter what the velocimacro.context.local setting says. Needed e.g. for loop variables in foreach.

Specified by:

localPut in interface InternalWrapperContext

Overrides:

localPut in class ChainedInternalContextAdapter

Parameters:

key - name of item to set.

value - object to set to key.

Returns:

old stored object

See Also:

• InternalWrapperContext.localPut(java.lang.String,java.lang.Object)

put

protected Object put(String key,
 Object value,
 boolean forceLocal)

Internal put method to select between local and global scope.

Parameters:

key - name of item to set

value - object to set to key

forceLocal - True forces the object into the local scope.

Returns:

old stored object

get

public Object get(String key)

Implementation of the Context.get() method. First checks localcontext, then arguments, then global context.

Specified by:

get in interface Context

Overrides:

get in class ChainedInternalContextAdapter

Parameters:

key - name of item to get

Returns:

stored object or null

containsKey

public boolean containsKey(Object key)

Description copied from interface: Context

Indicates whether the specified key is in the context.

Specified by:

containsKey in interface Context

Overrides:

containsKey in class ChainedInternalContextAdapter

Parameters:

key - The key to look for.

Returns:

Whether the key is in the context.

See Also:

• Context.containsKey(java.lang.Object)

getKeys

public Object[] getKeys()

Description copied from interface: Context

Get all the keys for the values in the context.

Specified by:

getKeys in interface Context

Overrides:

getKeys in class ChainedInternalContextAdapter

Returns:

All the keys for the values in the context.

See Also:

• Context.getKeys()

remove

public Object remove(Object key)

Description copied from interface: Context

Removes the value associated with the specified key from the context.

Specified by:

remove in interface Context

Overrides:

remove in class ChainedInternalContextAdapter

Parameters:

key - The name of the value to remove.

Returns:

The value that the key was mapped to, or null if unmapped.

See Also:

• Context.remove(java.lang.Object)