votorola.a

Class WikiCache

java.lang.Object

java.io.File

WikiCache

All Implemented Interfaces:

Serializable, Comparable<File>

@ThreadSafe
public final class WikiCache
extends File

A directory of "semantic" data cached from the pollwiki ~/votorola/in/wiki. Cache files are created with broad permissions and may be overwritten by any runtime owner (vote-server account, servlet container and others). The administrator may safely delete the contained files at runtime without causing unrecoverable errors, but should not delete the directory itself until after shutting down all runtime processes.

See Also:

../s/manual.xht#wiki, Serialized Form

Field Summary

Fields inherited from class java.io.File

pathSeparator, pathSeparatorChar, separator, separatorChar

Constructor Summary

Constructors

Constructor and Description
WikiCache(VoteServer _voteServer) Constructs a WikiCache.

Method Summary

Methods

Modifier and Type	Method and Description
WikiCache	churn() Replaces any stale pages in the cache with fresh copies from the wiki.
long	lastChurnTime() Returns the time of the last churn based on the timestamp of the churn's serial file.
FileInputStream	openRDF_JSON(String fullPageName) Opens an input stream for the RDF of the specified wiki page in JSON format, UTF-8 character encoding.
FileInputStream	openRDF_JSON(String fullPageName, boolean toChurn) Opens an input stream for the RDF of the specified wiki page in JSON format, UTF-8 character encoding.
String	readRDF_JSON(String fullPageName) Fetches the RDF of the specified wiki page in JSON format.
String	readRDF_JSON(String fullPageName, boolean toChurn) Fetches the RDF of the specified wiki page in JSON format.

Methods inherited from class java.io.File

canExecute, canRead, canWrite, compareTo, createNewFile, createTempFile, createTempFile, delete, deleteOnExit, equals, exists, getAbsoluteFile, getAbsolutePath, getCanonicalFile, getCanonicalPath, getFreeSpace, getName, getParent, getParentFile, getPath, getTotalSpace, getUsableSpace, hashCode, isAbsolute, isDirectory, isFile, isHidden, lastModified, length, list, list, listFiles, listFiles, listFiles, listRoots, mkdir, mkdirs, renameTo, setExecutable, setExecutable, setLastModified, setReadable, setReadable, setReadOnly, setWritable, setWritable, toPath, toString, toURI, toURL

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

WikiCache

WikiCache(VoteServer _voteServer)
    throws IOException

Constructs a WikiCache.

Throws:

IOException

Method Detail

churn

public WikiCache churn()
                throws IOException

Replaces any stale pages in the cache with fresh copies from the wiki. This should be called periodically, e.g. via one of the administrative commands (such as votrace) that has a --churn option. However it should not be called too often as it has the side effect of clearing the poll cache. You may instead want to query the pollwiki directly; Semantic MediaWiki 1.7 introduces a MediaWiki API extension that might be more convenient than the RDF interface.

Note: only changes to page content are detected. A property change owing to a change in the content of a template will not be detected. This is a BUG and the current workaround is to manually delete the page in the cache.

Returns:

this wiki cache.

Throws:

IOException

See Also:

lastChurnTime(), PollService.VoteServerScope.Run.ensurePoll(String)

lastChurnTime

public long lastChurnTime()

Returns the time of the last churn based on the timestamp of the churn's serial file.

Returns:

time in milliseconds since the Epoch, or 0L if unknown.

openRDF_JSON

public FileInputStream openRDF_JSON(String fullPageName)
                             throws IOException

Opens an input stream for the RDF of the specified wiki page in JSON format, UTF-8 character encoding. Attempts first to use the local cache, falling back to the wiki if necessary and caching the result for future calls.

Parameters:

fullPageName - the full name of the page, including any namespace.

Throws:

IOException

openRDF_JSON

public FileInputStream openRDF_JSON(String fullPageName,
                           boolean toChurn)
                             throws IOException

Opens an input stream for the RDF of the specified wiki page in JSON format, UTF-8 character encoding. Attempts first to use the local cache, falling back to the wiki if necessary and caching the result for future calls.

Parameters:

fullPageName - the full name of the page, including any namespace.

toChurn - whether or not to bypass the cache and fetch the RDF straight from the wiki. If true, any previously cached file will be ignored and (if the fetch succeeds) overrwritten.

Throws:

IOException

readRDF_JSON

public String readRDF_JSON(String fullPageName)
                    throws IOException

Fetches the RDF of the specified wiki page in JSON format. Attempts first to use the local cache, falling back to the wiki if necessary and caching the result for future calls.

Parameters:

fullPageName - the full name of the page, including any namespace.

Throws:

IOException

readRDF_JSON

public String readRDF_JSON(String fullPageName,
                  boolean toChurn)
                    throws IOException

Fetches the RDF of the specified wiki page in JSON format. Attempts first to use the local cache, falling back to the wiki if necessary and caching the result for future calls.

Parameters:

fullPageName - the full name of the page, including any namespace.

toChurn - whether or not to bypass the cache and fetch the RDF straight from the wiki. If true, any previously cached file will be ignored and (if the fetch succeeds) overrwritten.

Throws:

IOException