From 289dc398bd88ea1bd9c952772e2323b64c0ec2a5 Mon Sep 17 00:00:00 2001
From: Marty Schoch <marty.schoch@gmail.com>
Date: Wed, 13 Dec 2017 14:26:11 -0500
Subject: [PATCH] more refacotring of build/merge

---
 index/scorch/segment/zap/build.go | 39 -------------------------------
 index/scorch/segment/zap/merge.go |  3 +++
 index/scorch/segment/zap/write.go | 39 +++++++++++++++++++++++++++++++
 3 files changed, 42 insertions(+), 39 deletions(-)

diff --git a/index/scorch/segment/zap/build.go b/index/scorch/segment/zap/build.go
index 2cad61a5..56061a2e 100644
--- a/index/scorch/segment/zap/build.go
+++ b/index/scorch/segment/zap/build.go
@@ -572,42 +572,3 @@ func persistDictionary(memSegment *mem.Segment, w *CountHashWriter, postingsLocs
 
 	return rv, nil
 }
-
-// FooterSize is the size of the footer record in bytes
-// crc + ver + chunk + field offset + stored offset + num docs
-const FooterSize = 4 + 4 + 4 + 8 + 8 + 8
-
-func persistFooter(numDocs, storedIndexOffset, fieldIndexOffset uint64,
-	chunkFactor uint32, w *CountHashWriter) error {
-	// write out the number of docs
-	err := binary.Write(w, binary.BigEndian, numDocs)
-	if err != nil {
-		return err
-	}
-	// write out the stored field index location:
-	err = binary.Write(w, binary.BigEndian, storedIndexOffset)
-	if err != nil {
-		return err
-	}
-	// write out the field index location
-	err = binary.Write(w, binary.BigEndian, fieldIndexOffset)
-	if err != nil {
-		return err
-	}
-	// write out 32-bit chunk factor
-	err = binary.Write(w, binary.BigEndian, chunkFactor)
-	if err != nil {
-		return err
-	}
-	// write out 32-bit version
-	err = binary.Write(w, binary.BigEndian, version)
-	if err != nil {
-		return err
-	}
-	// write out CRC-32 of everything upto but not including this CRC
-	err = binary.Write(w, binary.BigEndian, w.Sum32())
-	if err != nil {
-		return err
-	}
-	return nil
-}
diff --git a/index/scorch/segment/zap/merge.go b/index/scorch/segment/zap/merge.go
index 972b1d16..670c8d79 100644
--- a/index/scorch/segment/zap/merge.go
+++ b/index/scorch/segment/zap/merge.go
@@ -84,6 +84,7 @@ func Merge(segments []*Segment, drops []*roaring.Bitmap, path string,
 	return newDocNums, nil
 }
 
+// mapFields takes the fieldsInv list and builds the map
 func mapFields(fields []string) map[string]uint16 {
 	rv := make(map[string]uint16)
 	for i, fieldName := range fields {
@@ -92,6 +93,8 @@ func mapFields(fields []string) map[string]uint16 {
 	return rv
 }
 
+// computeNewDocCount determines how many documents will be in the newly
+// merged segment when obsoleted docs are dropped
 func computeNewDocCount(segments []*Segment, drops []*roaring.Bitmap) uint64 {
 	var newSegDocCount uint64
 	for segI, segment := range segments {
diff --git a/index/scorch/segment/zap/write.go b/index/scorch/segment/zap/write.go
index 9772b3a6..bd63e147 100644
--- a/index/scorch/segment/zap/write.go
+++ b/index/scorch/segment/zap/write.go
@@ -93,3 +93,42 @@ func persistFields(fieldsInv []string, w *CountHashWriter, dictLocs []uint64) (u
 
 	return rv, nil
 }
+
+// FooterSize is the size of the footer record in bytes
+// crc + ver + chunk + field offset + stored offset + num docs
+const FooterSize = 4 + 4 + 4 + 8 + 8 + 8
+
+func persistFooter(numDocs, storedIndexOffset, fieldIndexOffset uint64,
+	chunkFactor uint32, w *CountHashWriter) error {
+	// write out the number of docs
+	err := binary.Write(w, binary.BigEndian, numDocs)
+	if err != nil {
+		return err
+	}
+	// write out the stored field index location:
+	err = binary.Write(w, binary.BigEndian, storedIndexOffset)
+	if err != nil {
+		return err
+	}
+	// write out the field index location
+	err = binary.Write(w, binary.BigEndian, fieldIndexOffset)
+	if err != nil {
+		return err
+	}
+	// write out 32-bit chunk factor
+	err = binary.Write(w, binary.BigEndian, chunkFactor)
+	if err != nil {
+		return err
+	}
+	// write out 32-bit version
+	err = binary.Write(w, binary.BigEndian, version)
+	if err != nil {
+		return err
+	}
+	// write out CRC-32 of everything upto but not including this CRC
+	err = binary.Write(w, binary.BigEndian, w.Sum32())
+	if err != nil {
+		return err
+	}
+	return nil
+}