diff --git a/lucene/CHANGES.txt b/lucene/CHANGES.txt index 1a4fbab168a..7f034e6ba1e 100644 --- a/lucene/CHANGES.txt +++ b/lucene/CHANGES.txt @@ -7,7 +7,10 @@ http://s.apache.org/luceneversions API Changes --------------------- -(No changes) + +* LUCENE-9093: Not an API change but a change in behavior of the UnifiedHighlighter's LengthGoalBreakIterator that will + yield Passages sized a little different due to the fact that the sizing pivot is now the center of the first match and + not its left edge. New Features --------------------- @@ -30,6 +33,10 @@ Improvements * LUCENE-9106: UniformSplit postings format allows extension of block/line serializers. (Bruno Roustant) +* LUCENE-9093: UnifiedHighlighter's LengthGoalBreakIterator has a new fragmentAlignment option to better center the + first match in the passage. Also the sizing point now pivots at the center of the first match term and not its left + edge. This yields Passages that won't be identical to the previous behavior. (Nándor Mátravölgyi, David Smiley) + Optimizations --------------------- (No changes) diff --git a/lucene/highlighter/src/java/org/apache/lucene/search/uhighlight/FieldHighlighter.java b/lucene/highlighter/src/java/org/apache/lucene/search/uhighlight/FieldHighlighter.java index f2a34dc9ea5..5e45e3f40a9 100644 --- a/lucene/highlighter/src/java/org/apache/lucene/search/uhighlight/FieldHighlighter.java +++ b/lucene/highlighter/src/java/org/apache/lucene/search/uhighlight/FieldHighlighter.java @@ -141,6 +141,7 @@ public class FieldHighlighter { } }); Passage passage = new Passage(); // the current passage in-progress. Will either get reset or added to queue. + int lastPassageEnd = 0; do { int start = off.startOffset(); @@ -158,9 +159,12 @@ public class FieldHighlighter { if (start >= contentLength) { break; } + // find fragment from the middle of the match, so the result's length may be closer to fragsize + final int center = start + (end - start) / 2; // advance breakIterator - passage.setStartOffset(Math.max(this.breakIterator.preceding(start + 1), 0)); - passage.setEndOffset(Math.min(this.breakIterator.following(start), contentLength)); + passage.setStartOffset(Math.min(start, Math.max(this.breakIterator.preceding(Math.max(start + 1, center)), lastPassageEnd))); + lastPassageEnd = Math.max(end, Math.min(this.breakIterator.following(Math.min(end - 1, center)), contentLength)); + passage.setEndOffset(lastPassageEnd); } // Add this term to the passage. BytesRef term = off.getTerm();// a reference; safe to refer to diff --git a/lucene/highlighter/src/java/org/apache/lucene/search/uhighlight/LengthGoalBreakIterator.java b/lucene/highlighter/src/java/org/apache/lucene/search/uhighlight/LengthGoalBreakIterator.java index 3134013ab35..a4b5a07f63b 100644 --- a/lucene/highlighter/src/java/org/apache/lucene/search/uhighlight/LengthGoalBreakIterator.java +++ b/lucene/highlighter/src/java/org/apache/lucene/search/uhighlight/LengthGoalBreakIterator.java @@ -33,22 +33,49 @@ public class LengthGoalBreakIterator extends BreakIterator { private final BreakIterator baseIter; private final int lengthGoal; + private final float fragmentAlignment; // how much text to align before match-fragment, valid in range [0, 1] private final boolean isMinimumLength; // if false then is "closest to" length + private int currentCache; - /** Breaks will be at least {@code minLength} apart (to the extent possible). */ + /** + * Breaks will be at least {@code minLength} apart (to the extent possible), + * while trying to position the match inside the fragment according to {@code fragmentAlignment}. + */ + public static LengthGoalBreakIterator createMinLength(BreakIterator baseIter, int minLength, + float fragmentAlignment) { + return new LengthGoalBreakIterator(baseIter, minLength, fragmentAlignment, true, baseIter.current()); + } + + /** For backwards compatibility you can initialise the break iterator without fragmentAlignment. */ + @Deprecated public static LengthGoalBreakIterator createMinLength(BreakIterator baseIter, int minLength) { - return new LengthGoalBreakIterator(baseIter, minLength, true); + return createMinLength(baseIter, minLength, 0.f); } - /** Breaks will be on average {@code targetLength} apart; the closest break to this target (before or after) - * is chosen. */ + /** + * Breaks will be on average {@code targetLength} apart; the closest break to this target (before or after) + * is chosen. The match will be positioned according to {@code fragmentAlignment} as much as possible. + */ + public static LengthGoalBreakIterator createClosestToLength(BreakIterator baseIter, int targetLength, + float fragmentAlignment) { + return new LengthGoalBreakIterator(baseIter, targetLength, fragmentAlignment, false, baseIter.current()); + } + + /** For backwards compatibility you can initialise the break iterator without fragmentAlignment. */ + @Deprecated public static LengthGoalBreakIterator createClosestToLength(BreakIterator baseIter, int targetLength) { - return new LengthGoalBreakIterator(baseIter, targetLength, false); + return createClosestToLength(baseIter, targetLength, 0.f); } - private LengthGoalBreakIterator(BreakIterator baseIter, int lengthGoal, boolean isMinimumLength) { + private LengthGoalBreakIterator(BreakIterator baseIter, int lengthGoal, float fragmentAlignment, + boolean isMinimumLength, int currentCache) { this.baseIter = baseIter; + this.currentCache = currentCache; this.lengthGoal = lengthGoal; + if (fragmentAlignment < 0.f || fragmentAlignment > 1.f || !Float.isFinite(fragmentAlignment)) { + throw new IllegalArgumentException("fragmentAlignment must be >= zero and <= one"); + } + this.fragmentAlignment = fragmentAlignment; this.isMinimumLength = isMinimumLength; } @@ -60,12 +87,15 @@ public class LengthGoalBreakIterator extends BreakIterator { @Override public String toString() { String goalDesc = isMinimumLength ? "minLen" : "targetLen"; - return getClass().getSimpleName() + "{" + goalDesc + "=" + lengthGoal + ", baseIter=" + baseIter + "}"; + return getClass().getSimpleName() + "{" + goalDesc + "=" + lengthGoal + ", fragAlign=" + fragmentAlignment + + ", baseIter=" + baseIter + "}"; } @Override public Object clone() { - return new LengthGoalBreakIterator((BreakIterator) baseIter.clone(), lengthGoal, isMinimumLength); + return new LengthGoalBreakIterator( + (BreakIterator) baseIter.clone(), lengthGoal, fragmentAlignment, isMinimumLength, currentCache + ); } @Override @@ -76,26 +106,28 @@ public class LengthGoalBreakIterator extends BreakIterator { @Override public void setText(String newText) { baseIter.setText(newText); + currentCache = baseIter.current(); } @Override public void setText(CharacterIterator newText) { baseIter.setText(newText); + currentCache = baseIter.current(); } @Override public int current() { - return baseIter.current(); + return currentCache; } @Override public int first() { - return baseIter.first(); + return currentCache = baseIter.first(); } @Override public int last() { - return baseIter.last(); + return currentCache = baseIter.last(); } @Override @@ -104,10 +136,10 @@ public class LengthGoalBreakIterator extends BreakIterator { return baseIter.next(n); // probably wrong } - // called by getSummaryPassagesNoHighlight to generate default summary. + // Called by getSummaryPassagesNoHighlight to generate default summary. @Override public int next() { - return following(current()); + return following(currentCache, currentCache + lengthGoal); } @Override @@ -116,65 +148,70 @@ public class LengthGoalBreakIterator extends BreakIterator { return baseIter.previous(); } - // called while the current position is the start of a new passage; find end of passage @Override - public int following(int followingIdx) { - final int startIdx = current(); - if (followingIdx < startIdx) { - assert false : "Not supported"; - return baseIter.following(followingIdx); - } - final int targetIdx = startIdx + lengthGoal; - // When followingIdx >= targetIdx, we can simply delegate since it will be >= the target - if (followingIdx >= targetIdx - 1) { - return baseIter.following(followingIdx); - } - // If target exceeds the text length, return the last index. - if (targetIdx >= getText().getEndIndex()) { - return baseIter.last(); - } - - // Find closest break >= the target - final int afterIdx = baseIter.following(targetIdx - 1); - if (afterIdx == DONE) { // we're at the end; can this happen? - return current(); - } - if (afterIdx == targetIdx) { // right on the money - return afterIdx; - } - if (isMinimumLength) { // thus never undershoot - return afterIdx; - } - - // note: it is a shame that we invoke preceding() *in addition to* following(); BI's are sometimes expensive. - - // Find closest break < target - final int beforeIdx = baseIter.preceding(targetIdx); // or could do baseIter.previous() but we hope the BI implements preceding() - if (beforeIdx <= followingIdx) { // too far back - return moveToBreak(afterIdx); - } - - if (targetIdx - beforeIdx <= afterIdx - targetIdx) { - return beforeIdx; - } - return moveToBreak(afterIdx); + public int following(int matchEndIndex) { + return following(matchEndIndex, (matchEndIndex + 1) + (int)(lengthGoal * (1.f - fragmentAlignment))); } - private int moveToBreak(int idx) { // precondition: idx is a known break - // bi.isBoundary(idx) has side-effect of moving the position. Not obvious! - //boolean moved = baseIter.isBoundary(idx); // probably not particularly expensive - //assert moved && current() == idx; + private int following(int matchEndIndex, int targetIdx) { + if (targetIdx >= getText().getEndIndex()) { + if (currentCache == baseIter.last()) { + return DONE; + } + return currentCache = baseIter.last(); + } + final int afterIdx = baseIter.following(targetIdx - 1); + if (afterIdx == DONE) { + currentCache = baseIter.last(); + return DONE; + } + if (afterIdx == targetIdx) { // right on the money + return currentCache = afterIdx; + } + if (isMinimumLength) { // thus never undershoot + return currentCache = afterIdx; + } - // TODO fix: Would prefer to do "- 1" instead of "- 2" but CustomSeparatorBreakIterator has a bug. - int current = baseIter.following(idx - 2); - assert current == idx : "following() didn't move us to the expected index."; - return idx; + // note: it is a shame that we invoke preceding() *one more time*; BI's are sometimes expensive. + + // Find closest break to target + final int beforeIdx = baseIter.preceding(targetIdx); + if (targetIdx - beforeIdx < afterIdx - targetIdx && beforeIdx > matchEndIndex) { + return currentCache = beforeIdx; + } + return currentCache = afterIdx; } // called at start of new Passage given first word start offset @Override - public int preceding(int offset) { - return baseIter.preceding(offset); // no change needed + public int preceding(int matchStartIndex) { + final int targetIdx = (matchStartIndex - 1) - (int)(lengthGoal * fragmentAlignment); + if (targetIdx <= 0) { + if (currentCache == baseIter.first()) { + return DONE; + } + return currentCache = baseIter.first(); + } + final int beforeIdx = baseIter.preceding(targetIdx + 1); + if (beforeIdx == DONE) { + currentCache = baseIter.first(); + return DONE; + } + if (beforeIdx == targetIdx) { // right on the money + return currentCache = beforeIdx; + } + if (isMinimumLength) { // thus never undershoot + return currentCache = beforeIdx; + } + + // note: it is a shame that we invoke following() *one more time*; BI's are sometimes expensive. + + // Find closest break to target + final int afterIdx = baseIter.following(targetIdx - 1); + if (afterIdx - targetIdx < targetIdx - beforeIdx && afterIdx < matchStartIndex) { + return currentCache = afterIdx; + } + return currentCache = beforeIdx; } @Override diff --git a/lucene/highlighter/src/test/org/apache/lucene/search/uhighlight/LengthGoalBreakIteratorTest.java b/lucene/highlighter/src/test/org/apache/lucene/search/uhighlight/LengthGoalBreakIteratorTest.java index 2434f5259e5..c2406637bd3 100644 --- a/lucene/highlighter/src/test/org/apache/lucene/search/uhighlight/LengthGoalBreakIteratorTest.java +++ b/lucene/highlighter/src/test/org/apache/lucene/search/uhighlight/LengthGoalBreakIteratorTest.java @@ -18,6 +18,7 @@ package org.apache.lucene.search.uhighlight; import java.io.IOException; +import java.text.BreakIterator; import org.apache.lucene.analysis.Analyzer; import org.apache.lucene.analysis.MockAnalyzer; @@ -28,6 +29,7 @@ import org.apache.lucene.util.QueryBuilder; public class LengthGoalBreakIteratorTest extends LuceneTestCase { private static final String FIELD = "body"; + private static final float[] ALIGNS = {0.f, 0.5f, 1.f}; // We test LengthGoalBreakIterator as it is used by the UnifiedHighlighter instead of directly, because it is // not a general purpose BreakIterator. A unit test of it directly wouldn't give as much confidence. @@ -39,65 +41,159 @@ public class LengthGoalBreakIteratorTest extends LuceneTestCase { // 0 1 // 01234567890123456789 static final String CONTENT = "Aa bb. Cc dd. Ee ff"; + static final String CONTENT2 = "Aa bb Cc dd X Ee ff Gg hh."; + static final String CONTENT3 = "Aa bbcc ddxyzee ffgg hh."; + + public void testFragmentAlignmentConstructor() throws IOException { + BreakIterator baseBI = new CustomSeparatorBreakIterator('.'); + // test fragmentAlignment validation + float[] valid_aligns = {0.f, 0.3333f, 0.5f, 0.99f, 1.f}; + for (float alignment : valid_aligns) { + LengthGoalBreakIterator.createClosestToLength(baseBI, 50, alignment); + } + float[] invalid_aligns = {-0.01f, -1.f, 1.5f, Float.NaN, Float.NEGATIVE_INFINITY, Float.POSITIVE_INFINITY}; + for (float alignment : invalid_aligns) { + expectThrows(IllegalArgumentException.class, () -> { + LengthGoalBreakIterator.createClosestToLength(baseBI, 50, alignment); + }); + } + // test backwards compatibility constructors + String backwardCompString = LengthGoalBreakIterator.createClosestToLength(baseBI, 50).toString(); + assertTrue(backwardCompString, backwardCompString.contains("fragAlign=0.0")); + backwardCompString = LengthGoalBreakIterator.createMinLength(baseBI, 50).toString(); + assertTrue(backwardCompString, backwardCompString.contains("fragAlign=0.0")); + } public void testTargetLen() throws IOException { // "goal" means target length goal to find closest break // at first word: Query query = query("aa"); - assertEquals("almost two sent", - "Aa bb.", highlightClosestToLen(CONTENT, query, 9)); - assertEquals( "barely two sent", - "Aa bb. Cc dd.", highlightClosestToLen(CONTENT, query, 10)); - assertEquals("long goal", - "Aa bb. Cc dd. Ee ff", highlightClosestToLen(CONTENT, query, 17 + random().nextInt(20))); - + assertEquals("almost two sent A", + "Aa bb.", highlightClosestToLen(CONTENT, query, 7, 0.f)); + assertEquals("almost two sent B", + "Aa bb.", highlightClosestToLen(CONTENT, query, 15, 0.5f)); + assertEquals("almost two sent C", + "Aa bb.", highlightClosestToLen(CONTENT, query, 64, 1.f)); + assertEquals("barely two sent A", + "Aa bb. Cc dd.", highlightClosestToLen(CONTENT, query, 8, 0.f)); + assertEquals("barely two sent B", + "Aa bb. Cc dd.", highlightClosestToLen(CONTENT, query, 16, 0.5f)); + assertEquals("long goal A", + "Aa bb. Cc dd. Ee ff", highlightClosestToLen(CONTENT, query, 14 + random().nextInt(20), 0.f)); + assertEquals("long goal B", + "Aa bb. Cc dd. Ee ff", highlightClosestToLen(CONTENT, query, 28 + random().nextInt(20), 0.5f)); // at some word not at start of passage query = query("dd"); - assertEquals("short goal", - " Cc dd.", highlightClosestToLen(CONTENT, query, random().nextInt(5))); - assertEquals("almost two sent", - " Cc dd.", highlightClosestToLen(CONTENT, query, 10)); - assertEquals("barely two sent", - " Cc dd. Ee ff", highlightClosestToLen(CONTENT, query, 11)); - assertEquals("long goal", - " Cc dd. Ee ff", highlightClosestToLen(CONTENT, query, 12 + random().nextInt(20))); + for (float align : ALIGNS) { + // alignment is not meaningful if fragsize is shorter than or closer to match-fragment boundaries + assertEquals("short goal " + align, + " Cc dd.", highlightClosestToLen(CONTENT, query, random().nextInt(4), align)); + } + // preceding/following inclusion by alignment parameter + assertEquals("barely two sent A", + " Cc dd. Ee ff", highlightClosestToLen(CONTENT, query, 11, 0.f)); + assertEquals("barely two sent B", + " Cc dd. Ee ff", highlightClosestToLen(CONTENT, query, 11, 0.5f)); + assertEquals("barely two sent C", + "Aa bb. Cc dd.", highlightClosestToLen(CONTENT, query, 11, 1.f)); + assertEquals("long goal A", + " Cc dd. Ee ff", highlightClosestToLen(CONTENT, query, 17 + random().nextInt(20), 0.f)); + assertEquals("long goal B", + "Aa bb. Cc dd. Ee ff", highlightClosestToLen(CONTENT, query, 17 + random().nextInt(20), 0.5f)); + assertEquals("long goal C", + "Aa bb. Cc dd.", highlightClosestToLen(CONTENT, query, 17 + random().nextInt(20), 1.f)); + + query = query("ddxyzee"); + assertEquals("test fragment search from the middle of the match; almost including", + "ddxyzee ", highlightClosestToLen(CONTENT3, query, 7, 0.5f, 1, ' ')); + assertEquals("test fragment search from the middle of the match; barely including", + "bbcc ddxyzee ffgg ", highlightClosestToLen(CONTENT3, query, 14, 0.5f, 1, ' ')); } public void testMinLen() throws IOException { // minLen mode is simpler than targetLen... just test a few cases Query query = query("dd"); - assertEquals("almost two sent", - " Cc dd.", highlightMinLen(CONTENT, query, 6)); - assertEquals("barely two sent", - " Cc dd. Ee ff", highlightMinLen(CONTENT, query, 7)); + assertEquals("almost two sent A", + " Cc dd.", highlightMinLen(CONTENT, query, 0, 0.f)); + assertEquals("almost two sent B", + " Cc dd.", highlightMinLen(CONTENT, query, 1, 0.5f)); + assertEquals("almost two sent C", + " Cc dd.", highlightMinLen(CONTENT, query, 5, 1.f)); + + assertEquals("barely two sent A", + " Cc dd. Ee ff", highlightMinLen(CONTENT, query, 1, 0.f)); + assertEquals("barely two sent B", + " Cc dd. Ee ff", highlightMinLen(CONTENT, query, 2, 0.5f)); + assertEquals("barely two sent C", + "Aa bb. Cc dd.", highlightMinLen(CONTENT, query, 7, 1.f)); + assertEquals("barely two sent D/a", + " Cc dd.", highlightMinLen(CONTENT, query, 2, 0.55f)); + assertEquals("barely two sent D/b", + " Cc dd. Ee ff", highlightMinLen(CONTENT, query, 3, 0.55f)); + assertEquals("barely two sent E/a", + " Cc dd. Ee ff", highlightMinLen(CONTENT, query, 10, 0.5f)); + assertEquals("barely two sent E/b", + "Aa bb. Cc dd. Ee ff", highlightMinLen(CONTENT, query, 10, 0.7f)); + assertEquals("barely two sent E/c", + "Aa bb. Cc dd.", highlightMinLen(CONTENT, query, 9, 0.9f)); + + query = query("ddxyzee"); + assertEquals("test fragment search from the middle of the match; almost including", + "ddxyzee ", highlightMinLen(CONTENT3, query, 7, 0.5f, ' ')); + assertEquals("test fragment search from the middle of the match; barely including", + "bbcc ddxyzee ffgg ", highlightMinLen(CONTENT3, query, 8, 0.5f, ' ')); + } + + public void testMinLenPrecision() throws IOException { + Query query = query("x"); + assertEquals("test absolute minimal length", + "X ", highlightMinLen(CONTENT2, query, 1, 0.5f, ' ')); + assertEquals("test slightly above minimal length", + "dd X Ee ", highlightMinLen(CONTENT2, query, 4, 0.5f, ' ')); } public void testDefaultSummaryTargetLen() throws IOException { Query query = query("zz"); - assertEquals("Aa bb.", - highlightClosestToLen(CONTENT, query, random().nextInt(10))); // < 10 + for (float align : ALIGNS) { // alignment is not used for creating default-summary + assertEquals("Aa bb.", + highlightClosestToLen(CONTENT, query, 6 + random().nextInt(4), align)); + assertEquals("Aa bb. Cc dd.", + highlightClosestToLen(CONTENT, query, 12 + random().nextInt(4), align)); + assertEquals("Aa bb. Cc dd. Ee ff", + highlightClosestToLen(CONTENT, query, 17 + random().nextInt(20), align)); + } assertEquals("Aa bb. Cc dd.", - highlightClosestToLen(CONTENT, query, 10 + 6)); // cusp of adding 3rd sentence - assertEquals("Aa bb. Cc dd. Ee ff", - highlightClosestToLen(CONTENT, query, 17 + random().nextInt(20))); // >= 14 + highlightClosestToLen(CONTENT, query, 6 + random().nextInt(4), 0.f, 2)); } private Query query(String qStr) { return new QueryBuilder(analyzer).createBooleanQuery(FIELD, qStr); } - private String highlightClosestToLen(String content, Query query, int lengthGoal) throws IOException { - UnifiedHighlighter highlighter = new UnifiedHighlighter(null, analyzer); - highlighter.setBreakIterator(() -> LengthGoalBreakIterator.createClosestToLength(new CustomSeparatorBreakIterator('.'), lengthGoal)); - return highlighter.highlightWithoutSearcher(FIELD, query, content, 1).toString(); + private String highlightClosestToLen(String content, Query query, int lengthGoal, float fragAlign) throws IOException { + return highlightClosestToLen(content, query, lengthGoal, fragAlign, 1); } - private String highlightMinLen(String content, Query query, int lengthGoal) throws IOException { + private String highlightClosestToLen(String content, Query query, int lengthGoal, float fragAlign, int maxPassages) throws IOException { + return highlightClosestToLen(content, query, lengthGoal, fragAlign, maxPassages, '.'); + } + + private String highlightClosestToLen(String content, Query query, int lengthGoal, float fragAlign, int maxPassages, char separator) throws IOException { + UnifiedHighlighter highlighter = new UnifiedHighlighter(null, analyzer); + highlighter.setBreakIterator(() -> LengthGoalBreakIterator.createClosestToLength(new CustomSeparatorBreakIterator(separator), lengthGoal, fragAlign)); + return highlighter.highlightWithoutSearcher(FIELD, query, content, maxPassages).toString(); + } + + private String highlightMinLen(String content, Query query, int lengthGoal, float fragAlign) throws IOException { + return highlightMinLen(content, query, lengthGoal, fragAlign, '.'); + } + + private String highlightMinLen(String content, Query query, int lengthGoal, float fragAlign, char separator) throws IOException { // differs from above only by "createMinLength" UnifiedHighlighter highlighter = new UnifiedHighlighter(null, analyzer); - highlighter.setBreakIterator(() -> LengthGoalBreakIterator.createMinLength(new CustomSeparatorBreakIterator('.'), lengthGoal)); + highlighter.setBreakIterator(() -> LengthGoalBreakIterator.createMinLength(new CustomSeparatorBreakIterator(separator), lengthGoal, fragAlign)); return highlighter.highlightWithoutSearcher(FIELD, query, content, 1).toString(); } } \ No newline at end of file diff --git a/solr/CHANGES.txt b/solr/CHANGES.txt index a809f2af5e2..82e43e1d60b 100644 --- a/solr/CHANGES.txt +++ b/solr/CHANGES.txt @@ -105,6 +105,10 @@ Improvements * SOLR-14129: Reuse Jackson ObjectMapper in AuditLoggerPlugin (janhoy) +* LUCENE-9093: The Unified highlighter has two new passage sizing parameters, hl.fragAlignRatio and + hl.fragsizeIsMinimum, with defaults that aim to better center matches in fragments than previously. See the ref guide. + Regardless of the settings, the passages may be sized differently than before. (Nándor Mátravölgyi, David Smiley) + Optimizations --------------------- (No changes) diff --git a/solr/core/src/java/org/apache/solr/highlight/UnifiedSolrHighlighter.java b/solr/core/src/java/org/apache/solr/highlight/UnifiedSolrHighlighter.java index fc43687eaf6..90632146ecf 100644 --- a/solr/core/src/java/org/apache/solr/highlight/UnifiedSolrHighlighter.java +++ b/solr/core/src/java/org/apache/solr/highlight/UnifiedSolrHighlighter.java @@ -326,8 +326,11 @@ public class UnifiedSolrHighlighter extends SolrHighlighter implements PluginInf if (fragsize <= 1) { // no real minimum size return baseBI; } - return LengthGoalBreakIterator.createMinLength(baseBI, fragsize); - // TODO option for using createClosestToLength() + float fragalign = params.getFieldFloat(field, HighlightParams.FRAGALIGNRATIO, 0.5f); + if (params.getFieldBool(field, HighlightParams.FRAGSIZEISMINIMUM, false)) { + return LengthGoalBreakIterator.createMinLength(baseBI, fragsize, fragalign); + } + return LengthGoalBreakIterator.createClosestToLength(baseBI, fragsize, fragalign); } /** diff --git a/solr/core/src/test/org/apache/solr/highlight/TestUnifiedSolrHighlighter.java b/solr/core/src/test/org/apache/solr/highlight/TestUnifiedSolrHighlighter.java index ac3b7eaddcd..f6418cb8595 100644 --- a/solr/core/src/test/org/apache/solr/highlight/TestUnifiedSolrHighlighter.java +++ b/solr/core/src/test/org/apache/solr/highlight/TestUnifiedSolrHighlighter.java @@ -244,15 +244,24 @@ public class TestUnifiedSolrHighlighter extends SolrTestCaseJ4 { assertU(adoc("text", "This document contains # special characters, while the other document contains the same # special character.", "id", "103")); assertU(adoc("text", "While the other document contains the same # special character.", "id", "104")); assertU(commit()); - assertQ("CUSTOM breakiterator", + assertQ("CUSTOM breakiterator", req("q", "text:document", "sort", "id asc", "hl", "true", "hl.bs.type", "SEPARATOR","hl.bs.separator","#","hl.fragsize", "-1"), "//lst[@name='highlighting']/lst[@name='103']/arr[@name='text']/str='This document contains #'"); - assertQ("different breakiterator", + assertQ("different breakiterator", req("q", "text:document", "sort", "id asc", "hl", "true", "hl.bs.type", "SEPARATOR","hl.bs.separator","#","hl.fragsize", "-1"), "//lst[@name='highlighting']/lst[@name='104']/arr[@name='text']/str='While the other document contains the same #'"); + assertQ("CUSTOM breakiterator with fragsize 70 minimum", + req("q", "text:document", "sort", "id asc", "hl", "true", "hl.bs.type", "SEPARATOR","hl.bs.separator","#","hl.fragsize", "70", "hl.fragsizeIsMinimum", "true"), + "//lst[@name='highlighting']/lst[@name='103']/arr[@name='text']/str='This document contains # special characters, while the other document contains the same #'"); assertQ("CUSTOM breakiterator with fragsize 70", req("q", "text:document", "sort", "id asc", "hl", "true", "hl.bs.type", "SEPARATOR","hl.bs.separator","#","hl.fragsize", "70"), + "//lst[@name='highlighting']/lst[@name='103']/arr[@name='text']/str='This document contains #'"); + assertQ("CUSTOM breakiterator with fragsize 90", + req("q", "text:document", "sort", "id asc", "hl", "true", "hl.bs.type", "SEPARATOR","hl.bs.separator","#","hl.fragsize", "90"), + "//lst[@name='highlighting']/lst[@name='103']/arr[@name='text']/str='This document contains #'"); + assertQ("CUSTOM breakiterator with fragsize 100", + req("q", "text:document", "sort", "id asc", "hl", "true", "hl.bs.type", "SEPARATOR","hl.bs.separator","#","hl.fragsize", "100"), "//lst[@name='highlighting']/lst[@name='103']/arr[@name='text']/str='This document contains # special characters, while the other document contains the same #'"); } @@ -262,11 +271,17 @@ public class TestUnifiedSolrHighlighter extends SolrTestCaseJ4 { assertU(adoc("id", "10", "text", "This is a sentence just under seventy chars in length blah blah. Next sentence is here.")); assertU(commit()); assertQ("default fragsize", - req("q", "text:seventy", "hl", "true"), + req("q", "text:seventy", "hl", "true", "hl.fragsizeIsMinimum", "true"), "//lst[@name='highlighting']/lst[@name='10']/arr[@name='text']/str='This is a sentence just under seventy chars in length blah blah. Next sentence is here.'"); - assertQ("smaller fragsize", - req("q", "text:seventy", "hl", "true", "hl.fragsize", "60"), // a bit smaller + assertQ("default fragsize", + req("q", "text:seventy", "hl", "true", "hl.fragsizeIsMinimum", "true", "hl.fragsize", "60"), "//lst[@name='highlighting']/lst[@name='10']/arr[@name='text']/str='This is a sentence just under seventy chars in length blah blah. '"); + assertQ("smaller fragsize", + req("q", "text:seventy", "hl", "true"), + "//lst[@name='highlighting']/lst[@name='10']/arr[@name='text']/str='This is a sentence just under seventy chars in length blah blah. '"); + assertQ("default fragsize", + req("q", "text:seventy", "hl", "true", "hl.fragsize", "90"), + "//lst[@name='highlighting']/lst[@name='10']/arr[@name='text']/str='This is a sentence just under seventy chars in length blah blah. Next sentence is here.'"); } public void testEncoder() { diff --git a/solr/solr-ref-guide/src/highlighting.adoc b/solr/solr-ref-guide/src/highlighting.adoc index 8055b79d7de..ab6b5a6da0c 100644 --- a/solr/solr-ref-guide/src/highlighting.adoc +++ b/solr/solr-ref-guide/src/highlighting.adoc @@ -225,6 +225,14 @@ By default, the Unified Highlighter will usually pick the right offset source (s + The offset source can be explicitly configured to one of: `ANALYSIS`, `POSTINGS`, `POSTINGS_WITH_TERM_VECTORS`, or `TERM_VECTORS`. +`hl.fragAlignRatio`:: +Fragment alignment can influence where the match in a passage is positioned. This floating point value is used to break the `hl.fragsize` around the match. The default value of `0.5` means to align the match to the middle. A value of `0.0` would mean to align the match to the left, while `1.0` to align it to the right. _Note: there are situations where the requested alignment is not plausible. This depends on the length of the match, the used breakiterator and the text content around the match._ + +`hl.fragsizeIsMinimum`:: +By default this parameter is `false`. In this case the highlighter will accept a shorter fragment than `hl.fragsize`, if that is closer to the target than what the next longer choice would be. ++ +When treating `hl.fragsize` as a strict minimum length is acceptable, turning this on has some performance benefits to consider. + `hl.tag.ellipsis`:: By default, each snippet is returned as a separate value (as is done with the other highlighters). Set this parameter to instead return one string with this text as the delimiter. _Note: this is likely to be removed in the future._ diff --git a/solr/solrj/src/java/org/apache/solr/common/params/HighlightParams.java b/solr/solrj/src/java/org/apache/solr/common/params/HighlightParams.java index c4825b70627..c5d59800fb4 100644 --- a/solr/solrj/src/java/org/apache/solr/common/params/HighlightParams.java +++ b/solr/solrj/src/java/org/apache/solr/common/params/HighlightParams.java @@ -47,6 +47,8 @@ public interface HighlightParams { // sizing public static final String FRAGSIZE = HIGHLIGHT+".fragsize"; // OH, FVH, UH + public static final String FRAGSIZEISMINIMUM = HIGHLIGHT+".fragsizeIsMinimum"; // UH + public static final String FRAGALIGNRATIO = HIGHLIGHT+".fragAlignRatio"; // UH public static final String FRAGMENTER = HIGHLIGHT+".fragmenter"; // OH public static final String INCREMENT = HIGHLIGHT+".increment"; // OH public static final String REGEX = "regex"; // OH