optimize getting local position from global position

This change uses the newly optimized function from fasta vector to use binary search to find the local position. previously, this was done with a linear search, which could be slow for fastas with many sequences.

src/AwFmSearch.c

@@ -219,34 +219,19 @@ uint64_t *awFmFindDatabaseHitPositions(const struct AwFmIndex *_RESTRICT_ const
 
 enum AwFmReturnCode awFmGetLocalSequencePositionFromIndexPosition(const struct AwFmIndex *_RESTRICT_ const index,
 		size_t globalPosition, size_t *sequenceNumber, size_t *localSequencePosition) {
-	if(!index->fastaVector) {
+	if(__builtin_expect(!index->fastaVector, false)) {
 		return AwFmUnsupportedVersionError;
 	}
-	else {
-		if(globalPosition >= index->bwtLength) {
-			return AwFmIllegalPositionError;
-		}
 
-		const size_t numSequencesInIndex = index->fastaVector->metadata.count;
-		for(size_t sequenceIndex = 0; sequenceIndex < numSequencesInIndex; sequenceIndex++) {
-			size_t sequenceEndPosition = index->fastaVector->metadata.data[sequenceIndex].sequenceEndPosition;
-			if(sequenceEndPosition > globalPosition) {
-				// generate the sequenceNumber and localSequencePosition
-				size_t sequenceStartPosition;
-				if(sequenceIndex == 0) {
-					sequenceStartPosition = 0;
-				}
-				else {
-					sequenceStartPosition = index->fastaVector->metadata.data[sequenceIndex - 1].sequenceEndPosition;
-				}
-				*sequenceNumber				 = sequenceIndex;
-				*localSequencePosition = globalPosition - sequenceStartPosition;
-				return AwFmSuccess;
-			}
-		}
-
-		return AwFmIllegalPositionError;
+	struct FastaVectorLocalPosition fastaVectorLocalPosition;
+	bool findLocalPositionSuccessful = fastaVectorGetLocalSequencePositionFromGlobal(index->fastaVector, globalPosition,
+    &fastaVectorLocalPosition);
+	if(findLocalPositionSuccessful){
+		*localSequencePosition = fastaVectorLocalPosition.positionInSequence;
+		*sequenceNumber = fastaVectorLocalPosition.sequenceIndex;
+		return AwFmSuccess;
 	}
+	else return AwFmIllegalPositionError;
 }