org.apache.xml.dtm
Class DTMManager

java.lang.Object
  |
  +--org.apache.xml.dtm.DTMManager
Direct Known Subclasses:
DTMManagerDefault, XPathContext

public abstract class DTMManager
extends java.lang.Object

A DTMManager instance can be used to create DTM and DTMIterator objects, and manage the DTM objects in the system.

The system property that determines which Factory implementation to create is named "org.apache.xml.utils.DTMFactory". This property names a concrete subclass of the DTMFactory abstract class. If the property is not defined, a platform default is be used.

An instance of this class must be safe to use across thread instances. It is expected that a client will create a single instance of a DTMManager to use across multiple threads. This will allow sharing of DTMs across multiple processes.

Note: this class is incomplete right now. It will be pretty much modeled after javax.xml.transform.TransformerFactory in terms of its factory support.

State: In progress!!


Field Summary
static int IDENT_DTM_DEFAULT
          When this bitmask is ANDed with a DTM node handle number, the result is the DTM's document identity number.
static int IDENT_DTM_NODE_BITS
          This value, set at compile time, controls how many bits of the DTM node identifier numbers are used to identify a node within a document, and thus sets the maximum number of nodes per document.
static int IDENT_MAX_DTMS
          This is the maximum number of DTMs available.
static int IDENT_NODE_DEFAULT
          When this bitmask is ANDed with a DTM node handle number, the result is the low bits of the node's index number within that DTM.
 boolean m_incremental
           
 boolean m_source_location
           
 
Method Summary
abstract  DTM createDocumentFragment()
          Creates a DTM representing an empty DocumentFragment object.
abstract  DTMIterator createDTMIterator(int node)
          Create a new DTMIterator that holds exactly one node.
abstract  DTMIterator createDTMIterator(int whatToShow, DTMFilter filter, boolean entityReferenceExpansion)
          Create a new DTMIterator based only on a whatToShow and a DTMFilter.
abstract  DTMIterator createDTMIterator(java.lang.Object xpathCompiler, int pos)
          Create a new DTMIterator based on an XPath UnionExpr.
abstract  DTMIterator createDTMIterator(java.lang.String xpathString, PrefixResolver presolver)
          Create a new DTMIterator based on an XPath UnionExpr.
abstract  DTM getDTM(int nodeHandle)
          Get the instance of DTM that "owns" a node handle.
abstract  DTM getDTM(Source source, boolean unique, DTMWSFilter whiteSpaceFilter, boolean incremental, boolean doIndexing)
          Get an instance of a DTM, loaded with the content from the specified source.
abstract  int getDTMHandleFromNode(Node node)
          Given a W3C DOM node, try and return a DTM handle.
abstract  int getDTMIdentity(DTM dtm)
          %TBD% Doc NEEDSDOC @param dtm NEEDSDOC ($objectName$) @return
 int getDTMIdentityMask()
          %TBD% Doc NEEDSDOC ($objectName$) @return
 boolean getIncremental()
          Get a flag indicating whether an incremental transform is desired
 int getNodeIdentityMask()
          %TBD% Doc NEEDSDOC ($objectName$) @return
 boolean getSource_location()
          Get a flag indicating whether the transformation phase should keep track of line and column numbers for the input source document.
 XMLStringFactory getXMLStringFactory()
          Get the XMLStringFactory used for the DTMs.
static DTMManager newInstance(XMLStringFactory xsf)
          Obtain a new instance of a DTMManager.
abstract  boolean release(DTM dtm, boolean shouldHardDelete)
          Release a DTM either to a lru pool, or completely remove reference.
 void setIncremental(boolean incremental)
          Set a flag indicating whether an incremental transform is desired This flag should have the same value as the FEATURE_INCREMENTAL feature which is set by the TransformerFactory.setAttribut() method before a DTMManager is created
 void setSource_location(boolean sourceLocation)
          Set a flag indicating whether the transformation phase should keep track of line and column numbers for the input source document.
 void setXMLStringFactory(XMLStringFactory xsf)
          Set the XMLStringFactory used for the DTMs.
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

m_incremental

public boolean m_incremental

m_source_location

public boolean m_source_location

IDENT_DTM_NODE_BITS

public static final int IDENT_DTM_NODE_BITS
This value, set at compile time, controls how many bits of the DTM node identifier numbers are used to identify a node within a document, and thus sets the maximum number of nodes per document. The remaining bits are used to identify the DTM document which contains this node. If you change IDENT_DTM_NODE_BITS, be sure to rebuild _ALL_ the files which use it... including the IDKey testcases. (FuncGenerateKey currently uses the node identifier directly and thus is affected when this changes. The IDKEY results will still be _correct_ (presuming no other breakage), but simple equality comparison against the previous "golden" files will probably complain.)

IDENT_NODE_DEFAULT

public static final int IDENT_NODE_DEFAULT
When this bitmask is ANDed with a DTM node handle number, the result is the low bits of the node's index number within that DTM. To obtain the high bits, add the DTM ID portion's offset as assigned in the DTM Manager.

IDENT_DTM_DEFAULT

public static final int IDENT_DTM_DEFAULT
When this bitmask is ANDed with a DTM node handle number, the result is the DTM's document identity number.

IDENT_MAX_DTMS

public static final int IDENT_MAX_DTMS
This is the maximum number of DTMs available. The highest DTM is one less than this.
Method Detail

getXMLStringFactory

public XMLStringFactory getXMLStringFactory()
Get the XMLStringFactory used for the DTMs.
Returns:
a valid XMLStringFactory object, or null if it hasn't been set yet.

setXMLStringFactory

public void setXMLStringFactory(XMLStringFactory xsf)
Set the XMLStringFactory used for the DTMs.
Parameters:
xsf - a valid XMLStringFactory object, should not be null.

newInstance

public static DTMManager newInstance(XMLStringFactory xsf)
                              throws DTMConfigurationException
Obtain a new instance of a DTMManager. This static method creates a new factory instance This method uses the following ordered lookup procedure to determine the DTMManager implementation class to load: Once an application has obtained a reference to a DTMManager it can use the factory to configure and obtain parser instances.
Returns:
new DTMManager instance, never null.
Throws:
DTMConfigurationException - if the implementation is not available or cannot be instantiated.

getDTM

public abstract DTM getDTM(Source source,
                           boolean unique,
                           DTMWSFilter whiteSpaceFilter,
                           boolean incremental,
                           boolean doIndexing)
Get an instance of a DTM, loaded with the content from the specified source. If the unique flag is true, a new instance will always be returned. Otherwise it is up to the DTMManager to return a new instance or an instance that it already created and may be being used by someone else. (More parameters may eventually need to be added for error handling and entity resolution, and to better control selection of implementations.)
Parameters:
source - the specification of the source object, which may be null, in which case it is assumed that node construction will take by some other means.
unique - true if the returned DTM must be unique, probably because it is going to be mutated.
whiteSpaceFilter - Enables filtering of whitespace nodes, and may be null.
incremental - true if the DTM should be built incrementally, if possible.
doIndexing - true if the caller considers it worth it to use indexing schemes.
Returns:
a non-null DTM reference.

getDTM

public abstract DTM getDTM(int nodeHandle)
Get the instance of DTM that "owns" a node handle.
Parameters:
nodeHandle - the nodeHandle.
Returns:
a non-null DTM reference.

getDTMHandleFromNode

public abstract int getDTMHandleFromNode(Node node)
Given a W3C DOM node, try and return a DTM handle. Note: calling this may be non-optimal.
Parameters:
node - Non-null reference to a DOM node.
Returns:
a valid DTM handle.

createDocumentFragment

public abstract DTM createDocumentFragment()
Creates a DTM representing an empty DocumentFragment object.
Returns:
a non-null DTM reference.

release

public abstract boolean release(DTM dtm,
                                boolean shouldHardDelete)
Release a DTM either to a lru pool, or completely remove reference. DTMs without system IDs are always hard deleted. State: experimental.
Parameters:
dtm - The DTM to be released.
shouldHardDelete - True if the DTM should be removed no matter what.
Returns:
true if the DTM was removed, false if it was put back in a lru pool.

createDTMIterator

public abstract DTMIterator createDTMIterator(java.lang.Object xpathCompiler,
                                              int pos)
Create a new DTMIterator based on an XPath UnionExpr.
Parameters:
xpathCompiler - ??? Somehow we need to pass in a subpart of the expression. I hate to do this with strings, since the larger expression has already been parsed.
pos - The position in the expression.
Returns:
The newly created DTMIterator.

createDTMIterator

public abstract DTMIterator createDTMIterator(java.lang.String xpathString,
                                              PrefixResolver presolver)
Create a new DTMIterator based on an XPath UnionExpr.
Parameters:
xpathString - Must be a valid string expressing a UnionExpr.
presolver - An object that can resolve prefixes to namespace URLs.
Returns:
The newly created DTMIterator.

createDTMIterator

public abstract DTMIterator createDTMIterator(int whatToShow,
                                              DTMFilter filter,
                                              boolean entityReferenceExpansion)
Create a new DTMIterator based only on a whatToShow and a DTMFilter. The traversal semantics are defined as the descendant access.

Note that DTMIterators may not be an exact match to DOM NodeIterators. They are initialized and used in much the same way as a NodeIterator, but their response to document mutation is not currently defined.

Parameters:
whatToShow - This flag specifies which node types may appear in the logical view of the tree presented by the iterator. See the description of NodeFilter for the set of possible SHOW_ values.These flags can be combined using OR.
filter - The NodeFilter to be used with this DTMFilter, or null to indicate no filter.
entityReferenceExpansion - The value of this flag determines whether entity reference nodes are expanded.
Returns:
The newly created DTMIterator.

createDTMIterator

public abstract DTMIterator createDTMIterator(int node)
Create a new DTMIterator that holds exactly one node.
Parameters:
node - The node handle that the DTMIterator will iterate to.
Returns:
The newly created DTMIterator.

getIncremental

public boolean getIncremental()
Get a flag indicating whether an incremental transform is desired
Returns:
incremental boolean.

setIncremental

public void setIncremental(boolean incremental)
Set a flag indicating whether an incremental transform is desired This flag should have the same value as the FEATURE_INCREMENTAL feature which is set by the TransformerFactory.setAttribut() method before a DTMManager is created
Parameters:
incremental - boolean to use to set m_incremental.

getSource_location

public boolean getSource_location()
Get a flag indicating whether the transformation phase should keep track of line and column numbers for the input source document.
Returns:
source location boolean

setSource_location

public void setSource_location(boolean sourceLocation)
Set a flag indicating whether the transformation phase should keep track of line and column numbers for the input source document. This flag should have the same value as the FEATURE_SOURCE_LOCATION feature which is set by the TransformerFactory.setAttribut() method before a DTMManager is created
Parameters:
sourceLocation - boolean to use to set m_source_location

getDTMIdentity

public abstract int getDTMIdentity(DTM dtm)
%TBD% Doc NEEDSDOC @param dtm NEEDSDOC ($objectName$) @return

getDTMIdentityMask

public int getDTMIdentityMask()
%TBD% Doc NEEDSDOC ($objectName$) @return

getNodeIdentityMask

public int getNodeIdentityMask()
%TBD% Doc NEEDSDOC ($objectName$) @return


Copyright 2006 Apache XML Project. All Rights Reserved.