org.modeshape.graph.request
Class ReadNextBlockOfChildrenRequest

java.lang.Object
  extended by org.modeshape.graph.request.Request
      extended by org.modeshape.graph.request.CacheableRequest
          extended by org.modeshape.graph.request.ReadNextBlockOfChildrenRequest
All Implemented Interfaces:
Serializable, Cacheable

public class ReadNextBlockOfChildrenRequest
extends CacheableRequest

Instruction to read a block of the children of a node, where the block is dictated by the location of the child preceding the block and the maximum number of children to include in the block. This command is useful when paging through a large number of children, when the previous block of children was already retrieved and the next block is to be read.

See Also:
ReadBlockOfChildrenRequest, Serialized Form

Field Summary
static int INDEX_NOT_USED
           
 
Constructor Summary
ReadNextBlockOfChildrenRequest(Location startingAfter, String workspaceName, int count)
          Create a request to read those children of a node that are immediately after a supplied sibling node.
 
Method Summary
 void addChild(Location child)
          Add to the list of children that has been read the child with the given path and identification properties.
 void addChild(Path pathToChild, Property idProperty)
          Add to the list of children that has been read the child with the given path and identification property.
 void addChild(Path pathToChild, Property firstIdProperty, Property... remainingIdProperties)
          Add to the list of children that has been read the child with the given path and identification properties.
 void addChildren(Iterable<Location> children)
          Add to the list of children that has been read the supplied children with the given path and identification properties.
 void cancel()
          Cancel this request.
 int count()
          Get the maximum number of children that may be returned in the block.
 boolean equals(Object obj)
          
 Location getActualLocationOfStartingAfterNode()
          Get the actual location of the starting after sibling.
 List<Location> getChildren()
          Get the children that were read from the RepositoryConnection after the request was processed.
 RequestType getType()
          Returns the type of the request
 int hashCode()
          
 String inWorkspace()
          Get the name of the workspace in which the parent and children exist.
 boolean isReadOnly()
          Return whether this request only reads information.
 void setActualLocationOfStartingAfterNode(Location actual)
          Sets the actual and complete location of the node whose children have been read.
 Location startingAfter()
          Get the location of the child after which the block begins.
 String toString()
          
 
Methods inherited from class org.modeshape.graph.request.CacheableRequest
getCachePolicy, getTimeLoaded, setCachePolicy, setTimeLoaded
 
Methods inherited from class org.modeshape.graph.request.Request
checkNotFrozen, freeze, getError, hasError, isCancelled, isFrozen, setError, setLatchForFreezing
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
 

Field Detail

INDEX_NOT_USED

public static final int INDEX_NOT_USED
See Also:
Constant Field Values
Constructor Detail

ReadNextBlockOfChildrenRequest

public ReadNextBlockOfChildrenRequest(Location startingAfter,
                                      String workspaceName,
                                      int count)
Create a request to read those children of a node that are immediately after a supplied sibling node.

Parameters:
startingAfter - the location of the previous sibling that was the last child of the previous block of children read
workspaceName - the name of the workspace containing the node
count - the maximum number of children that should be included in the block
Throws:
IllegalArgumentException - if the workspace name or startingAfter location is null, or if count is less than 1.
Method Detail

isReadOnly

public boolean isReadOnly()
Return whether this request only reads information.

Specified by:
isReadOnly in class Request
Returns:
true if this request reads information, or false if it requests that the repository content be changed in some way
See Also:
Request.isReadOnly()

count

public int count()
Get the maximum number of children that may be returned in the block.

Returns:
the block's maximum count
See Also:
startingAfter()

startingAfter

public Location startingAfter()
Get the location of the child after which the block begins. This form may be easier to use when paging through blocks, as the last children retrieved with the previous block can be supplied with the next read request.

Returns:
the location of the child that is immediately before the start of the block; index at which this block starts; never negative
See Also:
count()

inWorkspace

public String inWorkspace()
Get the name of the workspace in which the parent and children exist.

Returns:
the name of the workspace; never null

getChildren

public List<Location> getChildren()
Get the children that were read from the RepositoryConnection after the request was processed. Each child is represented by a location.

Returns:
the children that were read; never null

addChildren

public void addChildren(Iterable<Location> children)
Add to the list of children that has been read the supplied children with the given path and identification properties. The children are added in order.

Parameters:
children - the locations of the children that were read
Throws:
IllegalArgumentException - if the parameter is null
IllegalStateException - if the request is frozen
See Also:
addChild(Location), addChild(Path, Property), addChild(Path, Property, Property...)

addChild

public void addChild(Location child)
Add to the list of children that has been read the child with the given path and identification properties. The children should be added in order.

Parameters:
child - the location of the child that was read
Throws:
IllegalArgumentException - if the location is null
IllegalStateException - if the request is frozen
See Also:
addChild(Path, Property), addChild(Path, Property, Property...)

addChild

public void addChild(Path pathToChild,
                     Property firstIdProperty,
                     Property... remainingIdProperties)
Add to the list of children that has been read the child with the given path and identification properties. The children should be added in order.

Parameters:
pathToChild - the path of the child that was just read
firstIdProperty - the first identification property of the child that was just read
remainingIdProperties - the remaining identification properties of the child that was just read
Throws:
IllegalArgumentException - if the path or identification properties are null
IllegalStateException - if the request is frozen
See Also:
addChild(Location), addChild(Path, Property)

addChild

public void addChild(Path pathToChild,
                     Property idProperty)
Add to the list of children that has been read the child with the given path and identification property. The children should be added in order.

Parameters:
pathToChild - the path of the child that was just read
idProperty - the identification property of the child that was just read
Throws:
IllegalArgumentException - if the path or identification properties are null
IllegalStateException - if the request is frozen
See Also:
addChild(Location), addChild(Path, Property, Property...)

setActualLocationOfStartingAfterNode

public void setActualLocationOfStartingAfterNode(Location actual)
Sets the actual and complete location of the node whose children have been read. This method must be called when processing the request, and the actual location must have a path.

Parameters:
actual - the actual location of the node being read, or null if the starting after location should be used
Throws:
IllegalArgumentException - if the actual location is not equal to the starting after location, or if the actual location does not have a path.
IllegalStateException - if the request is frozen

getActualLocationOfStartingAfterNode

public Location getActualLocationOfStartingAfterNode()
Get the actual location of the starting after sibling.

Returns:
the actual location, or null if the actual location was not set

cancel

public void cancel()
Cancel this request. After this method is called, the cancellation flag is set, and any current or future processing of the request may be affected by the cancellation. (Note however, that processors may choose to not respect this request.)

This method is safe to be called by different threads.

Overrides:
cancel in class Request
See Also:
Request.cancel()

hashCode

public int hashCode()

Overrides:
hashCode in class Object
See Also:
Object.hashCode()

equals

public boolean equals(Object obj)

Overrides:
equals in class Object
See Also:
Object.equals(java.lang.Object)

toString

public String toString()

Overrides:
toString in class Object
See Also:
Object.toString()

getType

public RequestType getType()
Description copied from class: Request
Returns the type of the request

Specified by:
getType in class Request
Returns:
the type of the request


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