org.lockss.repository

Interface RepositoryNode

All Superinterfaces:

RepositoryNodeVersion

public interface RepositoryNode
extends RepositoryNodeVersion

RepositoryNode is used to store the contents and meta-information of urls being cached.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	RepositoryNode.RepositoryNodeContents RepositoryNodeContents is used to obtain Properties and InputStream.

Method Summary

Modifier and Type	Method and Description
void	abandonNewVersion() Discards the currently open new version without writing.
void	deactivateContent() Deactivates the node.
int	getChildCount() Returns the number of children at this node.
long	getContentSize() Returns the size of the current version of stored cache.
int	getCurrentVersion() Returns the current version.
OutputStream	getNewOutputStream() Return an OutputStream object which writes to a new version in the cache.
RepositoryNode.RepositoryNodeContents	getNodeContents() Return a RepositoryNodeContents object which accesses the content in the cache and its properties.
String	getNodeUrl() Returns the url represented by this node.
RepositoryNodeVersion	getNodeVersion(int version) Return a RepositoryNodeVersion for the specified content version
RepositoryNodeVersion[]	getNodeVersions() Return an array of RepositoryNodeVersion for all versions of content/props at this node.
RepositoryNodeVersion[]	getNodeVersions(int maxVersions) Return an array of RepositoryNodeVersion for the most recent maxVersions versions of content/props at this node.
long	getTreeContentSize(org.lockss.daemon.CachedUrlSetSpec filter, boolean calcIfUnknown) Returns the size of the content tree under (and including) this cache, in bytes.
RepositoryNode.RepositoryNodeContents	getUnsealedRnc() Return a RepositoryNodeContents object which accesses the content written to the node but not yet sealed..
boolean	hasContent() Determines if the node has current stored content.
boolean	isContentInactive() Determines if the node is currently inactive.
boolean	isDeleted() Determines if the node is deleted.
boolean	isIdenticalVersion() Return true if the already-sealed node was identical to the previous version and was not stored.
boolean	isLeaf() Returns true if node has no children.
Iterator	listChildren(org.lockss.daemon.CachedUrlSetSpec filter, boolean includeInactive) Returns the immediate children of the entry, possibly filtered (null indicates no filtering).
void	makeNewVersion() Prepares the node to write to a new version.
void	markAsDeleted() Marks the node as deleted.
void	markAsNotDeleted() Marks the node as no longer deleted.
void	restoreLastVersion() Reverts to the last version.
void	sealNewVersion() Closes the new version to any further writing.
void	setNewProperties(Properties newProps) Stores the properties for a new version of the cache.

Methods inherited from interface org.lockss.repository.RepositoryNodeVersion

getVersion

Method Detail

getNodeUrl

String getNodeUrl()

Returns the url represented by this node.

Returns:

the node's url

hasContent

boolean hasContent()

Determines if the node has current stored content.

Specified by:

hasContent in interface RepositoryNodeVersion

Returns:

true if the node has content

isContentInactive

boolean isContentInactive()

Determines if the node is currently inactive. Inactive nodes often have old content but no current content, so hasContent() will return false. The node is still counted as part of the AU, and its children are present.

Returns:

true if the node is inactive

isDeleted

boolean isDeleted()

Determines if the node is deleted. Deleted nodes may have old content or children, but will not appear in lists of nodes. Their children will not be included in the AU.

Returns:

true if the node is deleted

getContentSize

long getContentSize()

Returns the size of the current version of stored cache. Throws an exception if called on a content-less node.

Specified by:

getContentSize in interface RepositoryNodeVersion

Returns:

size

Throws:

UnsupportedOperationException

getTreeContentSize

long getTreeContentSize(org.lockss.daemon.CachedUrlSetSpec filter,
                        boolean calcIfUnknown)

Returns the size of the content tree under (and including) this cache, in bytes.

Parameters:

filter - a spec to determine which urls to return

calcIfUnknown - if true, size will calculated if unknown (time consumeing)

Returns:

size, or -1 if currently unknown

isLeaf

boolean isLeaf()

Returns true if node has no children.

Returns:

true if no children

getChildCount

int getChildCount()

Returns the number of children at this node.

Returns:

the child count

listChildren

Iterator listChildren(org.lockss.daemon.CachedUrlSetSpec filter,
                      boolean includeInactive)

Returns the immediate children of the entry, possibly filtered (null indicates no filtering). Includes leaf and internal nodes, but not inactive nodes unless 'includeInactive' is true.

Parameters:

filter - a spec to determine which urls to return

includeInactive - true to include inactive nodes

Returns:

an Iterator of RepositoryNode objects

makeNewVersion

void makeNewVersion()

Prepares the node to write to a new version. Should be called before storing any data. Throws an exception if called while a new version is already open.

Throws:

UnsupportedOperationException

sealNewVersion

void sealNewVersion()

Closes the new version to any further writing. Should be called when done storing data. Throws an exception if called before makeNewVersion() or if either getNewOutputStream() or setNewProperties() has not been called.

Throws:

UnsupportedOperationException

abandonNewVersion

void abandonNewVersion()

Discards the currently open new version without writing. Throws an exception if called before makeNewVersion()

Throws:

UnsupportedOperationException

isIdenticalVersion

boolean isIdenticalVersion()

Return true if the already-sealed node was identical to the previous version and was not stored.

deactivateContent

void deactivateContent()

Deactivates the node. This marks its content as inactive, but still allows it to be present if it has children. Throws if called while a version is open. To reactivate, call restoreLastVersion() or make a new version.

Throws:

UnsupportedOperationException

markAsDeleted

void markAsDeleted()

Marks the node as deleted. This also calls deactivateContent(). To reactivate, call restoreLastVersion() or make a new version (which gives it content), or call markAsNotDeleted().

markAsNotDeleted

void markAsNotDeleted()

Marks the node as no longer deleted. This reactivates any content also.

getCurrentVersion

int getCurrentVersion()

Returns the current version. This is the open version when writing, and the one accessed by getNodeInfo(). If inactive, returns -1. Throws an exception if called on a content-less node.

Returns:

the current version

Throws:

UnsupportedOperationException

restoreLastVersion

void restoreLastVersion()

Reverts to the last version. Throws if called on a node without content or only one version (and active). Can be used to reactivate inactive nodes or deleted nodes.

Throws:

UnsupportedOperationException

getNodeVersions

RepositoryNodeVersion[] getNodeVersions()

Return an array of RepositoryNodeVersion for all versions of content/props at this node. The result is sorted from most to least recent; the RepositoryNodeVersion for current version is the first element in the array.

Returns:

array of RepositoryNodeVersion

Throws:

UnsupportedOperationException - if node has no versions

getNodeVersions

RepositoryNodeVersion[] getNodeVersions(int maxVersions)

Return an array of RepositoryNodeVersion for the most recent maxVersions versions of content/props at this node. The result is sorted from most to least recent; the RepositoryNodeVersion for current version is the first element in the array.

Returns:

array of RepositoryNodeVersion

Throws:

UnsupportedOperationException - if node has no versions

getNodeVersion

RepositoryNodeVersion getNodeVersion(int version)

Return a RepositoryNodeVersion for the specified content version

Returns:

a RepositoryNodeVersion bound to the specified version

Throws:

UnsupportedOperationException - if node has no versions

getNodeContents

RepositoryNode.RepositoryNodeContents getNodeContents()

Return a RepositoryNodeContents object which accesses the content in the cache and its properties. Throws if called on a content-less or inactive node.

Specified by:

getNodeContents in interface RepositoryNodeVersion

Returns:

an RepositoryNode.RepositoryNodeContents object from which the contents of the cache can be read.

Throws:

UnsupportedOperationException

getUnsealedRnc

RepositoryNode.RepositoryNodeContents getUnsealedRnc()

Return a RepositoryNodeContents object which accesses the content written to the node but not yet sealed.. Throws if called on a node that doesn't have a new version open.

Returns:

an RepositoryNode.RepositoryNodeContents object from which the contents of the unsealed node can be read.

Throws:

UnsupportedOperationException

getNewOutputStream

OutputStream getNewOutputStream()

Return an OutputStream object which writes to a new version in the cache. Throws an exception if called before makeNewVersion() or called twice.

Returns:

an OutputStream object to which the new contents can be written.

Throws:

UnsupportedOperationException

See Also:

makeNewVersion()

setNewProperties

void setNewProperties(Properties newProps)

Stores the properties for a new version of the cache. Throws an exception if called before makeNewVersion() or called twice.

Parameters:

newProps - a Properties object containing the headers of the new version being cached.

Throws:

UnsupportedOperationException

See Also:

makeNewVersion()