Merge pull request #525 from mschoch/refactor-phrase

refactor phrase search into seprate methods

search/searcher/search_phrase.go

@@ -96,20 +96,73 @@ func (s *PhraseSearcher) Next(ctx *search.SearchContext) (*search.DocumentMatch,
 		}
 	}
 
-	var rv *search.DocumentMatch
 	for s.currMust != nil {
+		rv := s.checkCurrMustMatch(ctx)
+		if rv != nil {
+			// prepare for next iteration
+			err := s.advanceNextMust(ctx)
+			if err != nil {
+				return nil, err
+			}
+			return rv, nil
+		}
+
+		err := s.advanceNextMust(ctx)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return nil, nil
+}
+
+// checkCurrMustMatch is soley concerned with determining if the DocumentMatch
+// pointed to by s.currMust (which satisifies the pre-condition searcher)
+// also satisfies the phase constraints.  if so, it returns a DocumentMatch
+// for this document, otherwise nil
+func (s *PhraseSearcher) checkCurrMustMatch(ctx *search.SearchContext) *search.DocumentMatch {
 	rvftlm := make(search.FieldTermLocationMap, 0)
 	freq := 0
+	// typically we would expect there to only actually be results in
+	// one field, but we allow for this to not be the case
+	// but, we note that phrase constraints can only be satisfied within
+	// a single field, so we can check them each independently
+	for field := range s.currMust.Locations {
+
+		f, rvtlm := s.checkCurrMustMatchField(ctx, field)
+		if f > 0 {
+			freq += f
+			rvftlm[field] = rvtlm
+		}
+	}
+
+	if freq > 0 {
+		// return match
+		rv := s.currMust
+		rv.Locations = rvftlm
+		return rv
+	}
+
+	return nil
+}
+
+// checkCurrMustMatchField is soley concerned with determining if one particular
+// field within the currMust DocumentMatch Locations satisfies the phase
+// constraints (possibly more than once).  if so, the number of times it was
+// satisfied, and these locations are returned.  otherwise 0 and either
+// a nil or empty TermLocationMap
+func (s *PhraseSearcher) checkCurrMustMatchField(ctx *search.SearchContext, field string) (int, search.TermLocationMap) {
 	firstTerm := s.terms[0]
-		for field, termLocMap := range s.currMust.Locations {
+	freq := 0
+	termLocMap := s.currMust.Locations[field]
 	locations, ok := termLocMap[firstTerm]
 	if !ok {
-				continue
+		return 0, nil
 	}
 
 	rvtlm := make(search.TermLocationMap, 0)
 
-		OUTER:
+OUTER:
 	for _, location := range locations {
 		crvtlm := make(search.TermLocationMap, 0)
 		crvtlm.AddLocation(firstTerm, location)
@@ -138,28 +191,9 @@ func (s *PhraseSearcher) Next(ctx *search.SearchContext) (*search.DocumentMatch,
 		// if we got here all the terms matched
 		freq++
 		search.MergeTermLocationMaps(rvtlm, crvtlm)
-				rvftlm[field] = rvtlm
-			}
 	}
 
-		if freq > 0 {
-			// return match
-			rv = s.currMust
-			rv.Locations = rvftlm
-			err := s.advanceNextMust(ctx)
-			if err != nil {
-				return nil, err
-			}
-			return rv, nil
-		}
-
-		err := s.advanceNextMust(ctx)
-		if err != nil {
-			return nil, err
-		}
-	}
-
-	return nil, nil
+	return freq, rvtlm
 }
 
 func (s *PhraseSearcher) Advance(ctx *search.SearchContext, ID index.IndexInternalID) (*search.DocumentMatch, error) {