org.apache.jackrabbit.oak.plugins.memory

Class MemoryNodeBuilder

java.lang.Object

org.apache.jackrabbit.oak.plugins.memory.MemoryNodeBuilder

All Implemented Interfaces:

NodeBuilder

public class MemoryNodeBuilder
extends java.lang.Object
implements NodeBuilder

In-memory node state builder.

A MemoryNodeBuilder instance tracks uncommitted changes without relying on weak references or requiring hard references on the entire accessed subtree. It does this by relying on MutableNodeState instances for tracking uncommitted changes and on Head instances for tracking the connectedness of the builder. A builder keeps a reference to the parent builder and knows its own name, which is used to check for relevant changes in its parent builder and update its state accordingly.

A builder is in one of three possible states, which is tracked within its Head instance:

unconnected

A child builder with no content changes starts in this state. Before each access the unconnected builder checks its parent for relevant changes.

connected

Once a builder is first modified, it switches to the connected state and records all modification in a shared MutableNodeState instance. Before each access the connected builder checks whether its parents base state has been reset and if so, resets its own base state accordingly.

root

Same as the connected state but only the root of the builder hierarchy can have this state.

Constructor Summary

Constructors

Constructor and Description
MemoryNodeBuilder(@NotNull NodeState base) Creates a new in-memory node state builder rooted at and based on the passed base state.

Method Summary

Modifier and Type	Method and Description
@NotNull NodeBuilder	child(@NotNull java.lang.String name) Returns a builder for constructing changes to the named child node.
Blob	createBlob(java.io.InputStream stream)
boolean	exists() Checks whether this builder represents a node that exists.
@NotNull NodeState	getBaseState() Returns the original base state that this builder is modifying.
boolean	getBoolean(@NotNull java.lang.String name) Returns the boolean value of the named property.
@NotNull NodeBuilder	getChildNode(@NotNull java.lang.String name) Returns a builder for constructing changes to the named child node.
long	getChildNodeCount(long max) Returns the current number of child nodes.
@NotNull java.lang.Iterable<java.lang.String>	getChildNodeNames() Returns the names of current child nodes.
@Nullable java.lang.String	getName(@NotNull java.lang.String name) Returns the name value of the named property.
@NotNull java.lang.Iterable<java.lang.String>	getNames(@NotNull java.lang.String name) Returns the name values of the named property.
@NotNull NodeState	getNodeState() Returns an immutable node state that matches the current state of the builder.
java.lang.String	getPath()
@NotNull java.lang.Iterable<? extends PropertyState>	getProperties() Returns the current properties.
PropertyState	getProperty(java.lang.String name) Returns the current state of the named property, or null if the property is not set.
long	getPropertyCount() Returns the current number of properties.
@Nullable java.lang.String	getString(@NotNull java.lang.String name) Returns the name value of the named property.
boolean	hasChildNode(@NotNull java.lang.String name) Checks whether the named child node currently exists.
boolean	hasProperty(java.lang.String name) Checks whether the named property exists.
boolean	isModified() Check whether this builder represents a modified node, which has either modified properties or removed or added child nodes.
boolean	isNew() Check whether this builder represents a new node, which is not present in the base state.
boolean	isNew(java.lang.String name) Check whether the named property is new, i.e.
boolean	isReplaced() Check whether this builder represents a node that used to exist but was then replaced with other content, for example as a result of a NodeBuilder.setChildNode(String) call.
boolean	isReplaced(java.lang.String name) Check whether the named property exists in the base state but is replaced with other content, for example as a result of a NodeBuilder.setProperty(PropertyState) call.
boolean	isRoot()
boolean	moveTo(@NotNull NodeBuilder newParent, @NotNull java.lang.String newName) This implementation has the same semantics as adding this node with name newName as a new child of newParent followed by removing this node.
boolean	remove() Remove this child node from its parent.
@NotNull NodeBuilder	removeProperty(java.lang.String name) Remove the named property.
void	reset(@NotNull NodeState newBase) Throws away all changes in this builder and resets the base to the given node state.
@NotNull NodeBuilder	setChildNode(@NotNull java.lang.String name) Adds the named child node and returns a builder for modifying it.
@NotNull NodeBuilder	setChildNode(@NotNull java.lang.String name, @NotNull NodeState state) Adds or replaces a subtree.
@NotNull NodeBuilder	setProperty(@NotNull PropertyState property) Set a property state
<T> @NotNull NodeBuilder	setProperty(java.lang.String name, T value) Set a property state
<T> @NotNull NodeBuilder	setProperty(java.lang.String name, T value, Type<T> type) Set a property state
java.lang.String	toString()

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

MemoryNodeBuilder

public MemoryNodeBuilder(@NotNull
                         @NotNull NodeState base)

Creates a new in-memory node state builder rooted at and based on the passed base state.

Parameters:

base - base state of the new builder

Method Detail

isRoot

public final boolean isRoot()

Returns:

true iff this is the root builder

reset

public void reset(@NotNull
                  @NotNull NodeState newBase)

Throws away all changes in this builder and resets the base to the given node state.

Parameters:

newBase - new base state

getNodeState

@NotNull
public @NotNull NodeState getNodeState()

Description copied from interface: NodeBuilder

Returns an immutable node state that matches the current state of the builder.

Specified by:

getNodeState in interface NodeBuilder

Returns:

immutable node state

getBaseState

@NotNull
public @NotNull NodeState getBaseState()

Description copied from interface: NodeBuilder

Returns the original base state that this builder is modifying. The return value may be non-existent (i.e. its exists method returns false) if this builder represents a new node that didn't exist in the base content tree.

Specified by:

getBaseState in interface NodeBuilder

Returns:

base node state, possibly non-existent

exists

public boolean exists()

Description copied from interface: NodeBuilder

Checks whether this builder represents a node that exists.

Specified by:

exists in interface NodeBuilder

Returns:

true if the node exists, false otherwise

isNew

public boolean isNew()

Description copied from interface: NodeBuilder

Check whether this builder represents a new node, which is not present in the base state.

Specified by:

isNew in interface NodeBuilder

Returns:

true for a new node

isNew

public boolean isNew(java.lang.String name)

Description copied from interface: NodeBuilder

Check whether the named property is new, i.e. not present in the base state.

Specified by:

isNew in interface NodeBuilder

Parameters:

name - property name

Returns:

true for a new property

isModified

public boolean isModified()

Description copied from interface: NodeBuilder

Check whether this builder represents a modified node, which has either modified properties or removed or added child nodes.

Specified by:

isModified in interface NodeBuilder

Returns:

true for a modified node

isReplaced

public boolean isReplaced()

Description copied from interface: NodeBuilder

Check whether this builder represents a node that used to exist but was then replaced with other content, for example as a result of a NodeBuilder.setChildNode(String) call.

Specified by:

isReplaced in interface NodeBuilder

Returns:

true for a replaced node

isReplaced

public boolean isReplaced(java.lang.String name)

Description copied from interface: NodeBuilder

Check whether the named property exists in the base state but is replaced with other content, for example as a result of a NodeBuilder.setProperty(PropertyState) call.

Specified by:

isReplaced in interface NodeBuilder

Parameters:

name - property name

Returns:

true for a replaced property

getChildNodeCount

public long getChildNodeCount(long max)

Description copied from interface: NodeBuilder

Returns the current number of child nodes.

If an implementation does know the exact value, it returns it (even if the value is higher than max). If the implementation does not know the exact value, and the child node count is higher than max, it may return Long.MAX_VALUE. The cost of the operation is at most O(max).

Specified by:

getChildNodeCount in interface NodeBuilder

Parameters:

max - the maximum value

Returns:

number of child nodes

getChildNodeNames

@NotNull
public @NotNull java.lang.Iterable<java.lang.String> getChildNodeNames()

Description copied from interface: NodeBuilder

Returns the names of current child nodes.

Specified by:

getChildNodeNames in interface NodeBuilder

Returns:

child node names

hasChildNode

public boolean hasChildNode(@NotNull
                            @NotNull java.lang.String name)

Description copied from interface: NodeBuilder

Checks whether the named child node currently exists.

Specified by:

hasChildNode in interface NodeBuilder

Parameters:

name - child node name

Returns:

true if the named child node exists, false otherwise

child

@NotNull
public @NotNull NodeBuilder child(@NotNull
                                           @NotNull java.lang.String name)

Description copied from interface: NodeBuilder

Returns a builder for constructing changes to the named child node. If the named child node does not already exist, a new empty child node is automatically created as the base state of the returned child builder. Otherwise the existing child node state is used as the base state of the returned builder.

All updates to the returned child builder will implicitly affect also this builder, as if a setNode(name, childBuilder.getNodeState()) method call had been made after each update. Repeated calls to this method with the same name will return the same child builder instance until an explicit NodeBuilder.setChildNode(String, NodeState) or NodeBuilder.remove() call is made, at which point the link between this builder and a previously returned child builder for that child node name will get broken.

Specified by:

child in interface NodeBuilder

Parameters:

name - name of the child node

Returns:

child builder

getChildNode

@NotNull
public @NotNull NodeBuilder getChildNode(@NotNull
                                                  @NotNull java.lang.String name)

Description copied from interface: NodeBuilder

Returns a builder for constructing changes to the named child node. If the named child node does not already exist, the returned builder will refer to a non-existent node and trying to modify it will cause IllegalStateExceptions to be thrown.

Specified by:

getChildNode in interface NodeBuilder

Parameters:

name - name of the child node

Returns:

child builder, possibly non-existent

setChildNode

@NotNull
public @NotNull NodeBuilder setChildNode(@NotNull
                                                  @NotNull java.lang.String name)

Description copied from interface: NodeBuilder

Adds the named child node and returns a builder for modifying it. Possible previous content in the named subtree is removed.

Specified by:

setChildNode in interface NodeBuilder

Parameters:

name - name of the child node

Returns:

child builder

setChildNode

@NotNull
public @NotNull NodeBuilder setChildNode(@NotNull
                                                  @NotNull java.lang.String name,
                                                  @NotNull
                                                  @NotNull NodeState state)

Description copied from interface: NodeBuilder

Adds or replaces a subtree.

Specified by:

setChildNode in interface NodeBuilder

Parameters:

name - name of the child node containing the new subtree

state - subtree

Returns:

child builder

remove

public boolean remove()

Description copied from interface: NodeBuilder

Remove this child node from its parent.

Specified by:

remove in interface NodeBuilder

Returns:

true for existing nodes, false otherwise

moveTo

public boolean moveTo(@NotNull
                      @NotNull NodeBuilder newParent,
                      @NotNull
                      @NotNull java.lang.String newName)
               throws java.lang.IllegalArgumentException

This implementation has the same semantics as adding this node with name newName as a new child of newParent followed by removing this node. As a consequence this implementation allows moving this node into the subtree rooted here, the result of which is the same as removing this node.

See also the general contract for MoveTo.

Specified by:

moveTo in interface NodeBuilder

Parameters:

newParent - builder for the new parent.

newName - name of this child at the new parent

Returns:

true on success, false otherwise

Throws:

java.lang.IllegalArgumentException - if the given name string is empty or contains the forward slash character

getPropertyCount

public long getPropertyCount()

Description copied from interface: NodeBuilder

Returns the current number of properties.

Specified by:

getPropertyCount in interface NodeBuilder

Returns:

number of properties

getProperties

@NotNull
public @NotNull java.lang.Iterable<? extends PropertyState> getProperties()

Description copied from interface: NodeBuilder

Returns the current properties.

Specified by:

getProperties in interface NodeBuilder

Returns:

current properties

hasProperty

public boolean hasProperty(java.lang.String name)

Description copied from interface: NodeBuilder

Checks whether the named property exists. The implementation is equivalent to getProperty(name) != null, but may be optimized to avoid having to load the property value.

Specified by:

hasProperty in interface NodeBuilder

Parameters:

name - property name

Returns:

true if the named property exists, false otherwise

getProperty

public PropertyState getProperty(java.lang.String name)

Description copied from interface: NodeBuilder

Returns the current state of the named property, or null if the property is not set.

Specified by:

getProperty in interface NodeBuilder

Parameters:

name - property name

Returns:

property state

getBoolean

public boolean getBoolean(@NotNull
                          @NotNull java.lang.String name)

Description copied from interface: NodeBuilder

Returns the boolean value of the named property. The implementation is equivalent to the following code, but may be optimized.

 
 PropertyState property = builder.getProperty(name);
 return property != null
     && property.getType() == Type.BOOLEAN
     && property.getValue(Type.BOOLEAN);
 
 

Specified by:

getBoolean in interface NodeBuilder

Parameters:

name - property name

Returns:

boolean value of the named property, or false

getString

@Nullable
public @Nullable java.lang.String getString(@NotNull
                                                      @NotNull java.lang.String name)

Description copied from interface: NodeBuilder

Returns the name value of the named property. The implementation is equivalent to the following code, but may be optimized.

 
 PropertyState property = builder.getProperty(name);
 if (property != null && property.getType() == Type.STRING) {
     return property.getValue(Type.STRING);
 } else {
     return null;
 }
 
 

Specified by:

getString in interface NodeBuilder

Parameters:

name - property name

Returns:

string value of the named property, or null

getName

@Nullable
public @Nullable java.lang.String getName(@NotNull
                                                    @NotNull java.lang.String name)

Description copied from interface: NodeBuilder

Returns the name value of the named property. The implementation is equivalent to the following code, but may be optimized.

 
 PropertyState property = builder.getProperty(name);
 if (property != null && property.getType() == Type.NAME) {
     return property.getValue(Type.NAME);
 } else {
     return null;
 }
 
 

Specified by:

getName in interface NodeBuilder

Parameters:

name - property name

Returns:

name value of the named property, or null

getNames

@NotNull
public @NotNull java.lang.Iterable<java.lang.String> getNames(@NotNull
                                                                       @NotNull java.lang.String name)

Description copied from interface: NodeBuilder

Returns the name values of the named property. The implementation is equivalent to the following code, but may be optimized.

 
 PropertyState property = builder.getProperty(name);
 if (property != null && property.getType() == Type.NAMES) {
     return property.getValue(Type.NAMES);
 } else {
     return Collections.emptyList();
 }
 
 

Specified by:

getNames in interface NodeBuilder

Parameters:

name - property name

Returns:

name values of the named property, or an empty collection

setProperty

@NotNull
public @NotNull NodeBuilder setProperty(@NotNull
                                                 @NotNull PropertyState property)

Description copied from interface: NodeBuilder

Set a property state

Specified by:

setProperty in interface NodeBuilder

Parameters:

property - The property state to set

Returns:

this builder

setProperty

@NotNull
public <T> @NotNull NodeBuilder setProperty(java.lang.String name,
                                                     @NotNull
                                                     T value)

Description copied from interface: NodeBuilder

Set a property state

Specified by:

setProperty in interface NodeBuilder

Type Parameters:

T - The type of this property. Must be one of String, Blob, byte[], Long, Integer, Double, Boolean, BigDecimal

Parameters:

name - The name of this property

value - The value of this property

Returns:

this builder

setProperty

@NotNull
public <T> @NotNull NodeBuilder setProperty(java.lang.String name,
                                                     @NotNull
                                                     T value,
                                                     Type<T> type)

Description copied from interface: NodeBuilder

Set a property state

Specified by:

setProperty in interface NodeBuilder

Type Parameters:

T - The type of this property.

Parameters:

name - The name of this property

value - The value of this property

Returns:

this builder

removeProperty

@NotNull
public @NotNull NodeBuilder removeProperty(java.lang.String name)

Description copied from interface: NodeBuilder

Remove the named property. This method has no effect if a property of the given name does not exist.

Specified by:

removeProperty in interface NodeBuilder

Parameters:

name - name of the property

createBlob

public Blob createBlob(java.io.InputStream stream)
                throws java.io.IOException

Specified by:

createBlob in interface NodeBuilder

Throws:

java.io.IOException

getPath

public final java.lang.String getPath()

Returns:

path of this builder.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object