public class

TimeLimitingCollector

extends Collector
java.lang.Object
   ↳ org.apache.lucene.search.Collector
     ↳ org.apache.lucene.search.TimeLimitingCollector

Class Overview

The TimeLimitingCollector is used to timeout search requests that take longer than the maximum allowed search time limit. After this time is exceeded, the search thread is stopped by throwing a TimeLimitingCollector.TimeExceededException.

Summary

Nested Classes
class TimeLimitingCollector.TimeExceededException Thrown when elapsed search time exceeds allowed search time. 
Constants
int DEFAULT_RESOLUTION Default timer resolution.
Fields
public boolean DEFAULT_GREEDY Default for isGreedy().
Public Constructors
TimeLimitingCollector(Collector collector, long timeAllowed)
Create a TimeLimitedCollector wrapper over another Collector with a specified timeout.
Public Methods
boolean acceptsDocsOutOfOrder()
Return true if this collector does not require the matching docIDs to be delivered in int sort order (smallest to largest) to collect(int).
void collect(int doc)
Calls collect(int) on the decorated Collector unless the allowed time has passed, in which case it throws an exception.
static long getResolution()
Return the timer resolution.
boolean isGreedy()
Checks if this time limited collector is greedy in collecting the last hit.
void setGreedy(boolean greedy)
Sets whether this time limited collector is greedy.
void setNextReader(IndexReader reader, int base)
Called before collecting from each IndexReader.
static void setResolution(long newResolution)
Set the timer resolution.
void setScorer(Scorer scorer)
Called before successive calls to collect(int).
[Expand]
Inherited Methods
From class org.apache.lucene.search.Collector
From class java.lang.Object

Constants

public static final int DEFAULT_RESOLUTION

Default timer resolution.

See Also
Constant Value: 20 (0x00000014)

Fields

public boolean DEFAULT_GREEDY

Default for isGreedy().

See Also

Public Constructors

public TimeLimitingCollector (Collector collector, long timeAllowed)

Create a TimeLimitedCollector wrapper over another Collector with a specified timeout.

Parameters
collector the wrapped Collector
timeAllowed max time allowed for collecting hits after which TimeLimitingCollector.TimeExceededException is thrown

Public Methods

public boolean acceptsDocsOutOfOrder ()

Return true if this collector does not require the matching docIDs to be delivered in int sort order (smallest to largest) to collect(int).

Most Lucene Query implementations will visit matching docIDs in order. However, some queries (currently limited to certain cases of BooleanQuery) can achieve faster searching if the Collector allows them to deliver the docIDs out of order.

Many collectors don't mind getting docIDs out of order, so it's important to return true here.

public void collect (int doc)

Calls collect(int) on the decorated Collector unless the allowed time has passed, in which case it throws an exception.

Throws
TimeLimitingCollector.TimeExceededException if the time allowed has exceeded.
IOException

public static long getResolution ()

Return the timer resolution.

See Also

public boolean isGreedy ()

Checks if this time limited collector is greedy in collecting the last hit. A non greedy collector, upon a timeout, would throw a TimeLimitingCollector.TimeExceededException without allowing the wrapped collector to collect current doc. A greedy one would first allow the wrapped hit collector to collect current doc and only then throw a TimeLimitingCollector.TimeExceededException.

See Also

public void setGreedy (boolean greedy)

Sets whether this time limited collector is greedy.

Parameters
greedy true to make this time limited greedy
See Also

public void setNextReader (IndexReader reader, int base)

Called before collecting from each IndexReader. All doc ids in collect(int) will correspond to reader. Add docBase to the current IndexReaders internal document id to re-base ids in collect(int).

Parameters
reader next IndexReader
Throws
IOException

public static void setResolution (long newResolution)

Set the timer resolution. The default timer resolution is 20 milliseconds. This means that a search required to take no longer than 800 milliseconds may be stopped after 780 to 820 milliseconds.
Note that:

  • Finer (smaller) resolution is more accurate but less efficient.
  • Setting resolution to less than 5 milliseconds will be silently modified to 5 milliseconds.
  • Setting resolution smaller than current resolution might take effect only after current resolution. (Assume current resolution of 20 milliseconds is modified to 5 milliseconds, then it can take up to 20 milliseconds for the change to have effect.

public void setScorer (Scorer scorer)

Called before successive calls to collect(int). Implementations that need the score of the current document (passed-in to collect(int)), should save the passed-in Scorer and call scorer.score() when needed.

Throws
IOException