Package org.apache.nutch.scoring
Interface ScoringFilter
-
- All Superinterfaces:
Configurable
,Pluggable
- All Known Implementing Classes:
AbstractScoringFilter
,DepthScoringFilter
,LinkAnalysisScoringFilter
,MetadataScoringFilter
,OPICScoringFilter
,OrphanScoringFilter
,ScoringFilters
,SimilarityScoringFilter
,URLMetaScoringFilter
public interface ScoringFilter extends Configurable, Pluggable
A contract defining behavior of scoring plugins. A scoring filter will manipulate scoring variables in CrawlDatum and in resulting search indexes. Filters can be chained in a specific order, to provide multi-stage scoring adjustments.- Author:
- Andrzej Bialecki
-
-
Field Summary
Fields Modifier and Type Field Description static String
X_POINT_ID
The name of the extension point.
-
Method Summary
All Methods Instance Methods Abstract Methods Default Methods Modifier and Type Method Description CrawlDatum
distributeScoreToOutlinks(Text fromUrl, ParseData parseData, Collection<Map.Entry<Text,CrawlDatum>> targets, CrawlDatum adjust, int allCount)
Distribute score value from the current page to all its outlinked pages.float
generatorSortValue(Text url, CrawlDatum datum, float initSort)
This method prepares a sort value for the purpose of sorting and selecting top N scoring pages during fetchlist generation.float
indexerScore(Text url, NutchDocument doc, CrawlDatum dbDatum, CrawlDatum fetchDatum, Parse parse, Inlinks inlinks, float initScore)
This method calculates a indexed document score/boost.void
initialScore(Text url, CrawlDatum datum)
Set an initial score for newly discovered pages.void
injectedScore(Text url, CrawlDatum datum)
Set an initial score for newly injected pages.default void
orphanedScore(Text url, CrawlDatum datum)
This method may change the score or status of CrawlDatum during CrawlDb update, when the URL is neither fetched nor has any inlinks.void
passScoreAfterParsing(Text url, Content content, Parse parse)
Currently a part of score distribution is performed using only data coming from the parsing process.void
passScoreBeforeParsing(Text url, CrawlDatum datum, Content content)
This method takes all relevant score information from the current datum (coming from a generated fetchlist) and stores it intoContent
metadata.void
updateDbScore(Text url, CrawlDatum old, CrawlDatum datum, List<CrawlDatum> inlinked)
This method calculates a new score of CrawlDatum during CrawlDb update, based on the initial value of the original CrawlDatum, and also score values contributed by inlinked pages.-
Methods inherited from interface org.apache.hadoop.conf.Configurable
getConf, setConf
-
-
-
-
Field Detail
-
X_POINT_ID
static final String X_POINT_ID
The name of the extension point.
-
-
Method Detail
-
injectedScore
void injectedScore(Text url, CrawlDatum datum) throws ScoringFilterException
Set an initial score for newly injected pages. Note: newly injected pages may have no inlinks, so filter implementations may wish to set this score to a non-zero value, to give newly injected pages some initial credit.- Parameters:
url
- url of the pagedatum
- new datum. Filters will modify it in-place.- Throws:
ScoringFilterException
- if there is a fatal error setting an initial score for newly injected pages
-
initialScore
void initialScore(Text url, CrawlDatum datum) throws ScoringFilterException
Set an initial score for newly discovered pages. Note: newly discovered pages have at least one inlink with its score contribution, so filter implementations may choose to set initial score to zero (unknown value), and then the inlink score contribution will set the "real" value of the new page.- Parameters:
url
- url of the pagedatum
- new datum. Filters will modify it in-place.- Throws:
ScoringFilterException
- if there is a fatal error setting an initial score for newly discovered pages
-
generatorSortValue
float generatorSortValue(Text url, CrawlDatum datum, float initSort) throws ScoringFilterException
This method prepares a sort value for the purpose of sorting and selecting top N scoring pages during fetchlist generation.- Parameters:
url
- url of the pagedatum
- page's datum, should not be modifiedinitSort
- initial sort value, or a value from previous filters in chain- Returns:
- a sort value for use in sorting and selecting the top N scoring pages during fetchlist generation
- Throws:
ScoringFilterException
- if there is a fatal error preparing the sort value
-
passScoreBeforeParsing
void passScoreBeforeParsing(Text url, CrawlDatum datum, Content content) throws ScoringFilterException
This method takes all relevant score information from the current datum (coming from a generated fetchlist) and stores it intoContent
metadata. This is needed in order to pass this value(s) to the mechanism that distributes it to outlinked pages.- Parameters:
url
- url of the pagedatum
- source datum. NOTE: modifications to this value are not persisted.content
- instance of content. Implementations may modify this in-place, primarily by setting some metadata properties.- Throws:
ScoringFilterException
- if there is a fatal error injecting score information from the current datum intoContent
metadata
-
passScoreAfterParsing
void passScoreAfterParsing(Text url, Content content, Parse parse) throws ScoringFilterException
Currently a part of score distribution is performed using only data coming from the parsing process. We need this method in order to ensure the presence of score data in these steps.- Parameters:
url
- page urlcontent
- original content. NOTE: modifications to this value are not persisted.parse
- target instance to copy the score information to. Implementations may modify this in-place, primarily by setting some metadata properties.- Throws:
ScoringFilterException
- if there is a fatal error processing score data in subsequent steps after parsing
-
distributeScoreToOutlinks
CrawlDatum distributeScoreToOutlinks(Text fromUrl, ParseData parseData, Collection<Map.Entry<Text,CrawlDatum>> targets, CrawlDatum adjust, int allCount) throws ScoringFilterException
Distribute score value from the current page to all its outlinked pages.- Parameters:
fromUrl
- url of the source pageparseData
- ParseData instance, which stores relevant score value(s) in its metadata. NOTE: filters may modify this in-place, all changes will be persisted.targets
- <url, CrawlDatum> pairs. NOTE: filters can modify this in-place, all changes will be persisted.adjust
- a CrawlDatum instance, initially null, which implementations may use to pass adjustment values to the original CrawlDatum. When creating this instance, set its status toCrawlDatum.STATUS_LINKED
.allCount
- number of all collected outlinks from the source page- Returns:
- if needed, implementations may return an instance of CrawlDatum,
with status
CrawlDatum.STATUS_LINKED
, which contains adjustments to be applied to the original CrawlDatum score(s) and metadata. This can be null if not needed. - Throws:
ScoringFilterException
- there is a fatal error distributing score data from the current page to all of its outlinks
-
updateDbScore
void updateDbScore(Text url, CrawlDatum old, CrawlDatum datum, List<CrawlDatum> inlinked) throws ScoringFilterException
This method calculates a new score of CrawlDatum during CrawlDb update, based on the initial value of the original CrawlDatum, and also score values contributed by inlinked pages.- Parameters:
url
- url of the pageold
- original datum, with original score. May be null if this is a newly discovered page. If not null, filters should use score values from this parameter as the starting values - thedatum
parameter may contain values that are no longer valid, if other updates occurred between generation and this update.datum
- the new datum, with the original score saved at the time when fetchlist was generated. Filters should update this in-place, and it will be saved in the crawldb.inlinked
- (partial) list of CrawlDatum-s (with their scores) from links pointing to this page, found in the current update batch.- Throws:
ScoringFilterException
- there is a fatal error calculating a new score ofCrawlDatum
during CrawlDb update
-
orphanedScore
default void orphanedScore(Text url, CrawlDatum datum) throws ScoringFilterException
This method may change the score or status of CrawlDatum during CrawlDb update, when the URL is neither fetched nor has any inlinks.- Parameters:
url
- URL of the pagedatum
- CrawlDatum for page- Throws:
ScoringFilterException
- if there is a fatal error whilst changing the score or status ofCrawlDatum
duringCrawlDb
update, when the URL is neither fetched nor has any inlinks
-
indexerScore
float indexerScore(Text url, NutchDocument doc, CrawlDatum dbDatum, CrawlDatum fetchDatum, Parse parse, Inlinks inlinks, float initScore) throws ScoringFilterException
This method calculates a indexed document score/boost.- Parameters:
url
- url of the pagedoc
- indexed document. NOTE: this already contains all information collected by indexing filters. Implementations may modify this instance, in order to store/remove some information.dbDatum
- current page from CrawlDb. NOTE:- changes made to this instance are not persisted
- may be null if indexing is done without CrawlDb or if the segment is generated not from the CrawlDb (via FreeGenerator).
fetchDatum
- datum from FetcherOutput (containing among others the fetching status)parse
- parsing result. NOTE: changes made to this instance are not persisted.inlinks
- current inlinks from LinkDb. NOTE: changes made to this instance are not persisted.initScore
- initial boost value for the indexed document.- Returns:
- boost value for the indexed document. This value is passed as an argument to the next scoring filter in chain. NOTE: implementations may also express other scoring strategies by modifying the indexed document directly.
- Throws:
ScoringFilterException
- if there is a fatal error whilst calculating the indexed document score/boost
-
-