From d1e2b55c72f543300a1848f6c68fa4096846ed86 Mon Sep 17 00:00:00 2001
From: Steve Yen <steve.yen@gmail.com>
Date: Wed, 21 Mar 2018 17:47:56 -0700
Subject: [PATCH 1/2] scorch zap postingsItr.nextDocNum() maintains allNChunk
 correctly

When PostingsIterator.nextDocNum() moves the 'all' roaring bitmap
iterator forwards, it was incorrectly not keeping the allNChunk value
aligned.
---
 index/scorch/segment/zap/posting.go | 1 +
 1 file changed, 1 insertion(+)

diff --git a/index/scorch/segment/zap/posting.go b/index/scorch/segment/zap/posting.go
index 081ec5f6..4b4b4933 100644
--- a/index/scorch/segment/zap/posting.go
+++ b/index/scorch/segment/zap/posting.go
@@ -620,6 +620,7 @@ func (i *PostingsIterator) nextDocNum() (uint64, bool, error) {
 		}
 
 		allN = i.all.Next()
+		allNChunk = allN / i.postings.sb.chunkFactor
 	}
 
 	if i.currChunk != nChunk || i.currChunkFreqNorm == nil {

From b506fae4f73dcb73674b6d2f8f88df8f5726a78e Mon Sep 17 00:00:00 2001
From: Steve Yen <steve.yen@gmail.com>
Date: Wed, 21 Mar 2018 17:54:22 -0700
Subject: [PATCH 2/2] scorch zap postingsItr remove unused offset/locoffset
 fields

---
 index/scorch/segment/zap/posting.go | 25 ++++++++-----------------
 1 file changed, 8 insertions(+), 17 deletions(-)

diff --git a/index/scorch/segment/zap/posting.go b/index/scorch/segment/zap/posting.go
index 4b4b4933..f5ccad1a 100644
--- a/index/scorch/segment/zap/posting.go
+++ b/index/scorch/segment/zap/posting.go
@@ -316,11 +316,9 @@ func (rv *PostingsList) init1Hit(fstVal uint64) error {
 
 // PostingsIterator provides a way to iterate through the postings list
 type PostingsIterator struct {
-	postings  *PostingsList
-	all       roaring.IntIterable
-	offset    int
-	locoffset int
-	actual    roaring.IntIterable
+	postings *PostingsList
+	all      roaring.IntIterable
+	actual   roaring.IntIterable
 
 	currChunk         uint32
 	currChunkFreqNorm []byte
@@ -584,16 +582,12 @@ func (i *PostingsIterator) nextDocNum() (uint64, bool, error) {
 	nChunk := n / i.postings.sb.chunkFactor
 	allNChunk := allN / i.postings.sb.chunkFactor
 
-	// n is the next actual hit (excluding some postings)
-	// allN is the next hit in the full postings
-	// if they don't match, adjust offsets to factor in item we're skipping over
-	// incr the all iterator, and check again
+	// n is the next actual hit (excluding some postings), and
+	// allN is the next hit in the full postings, and
+	// if they don't match, move 'all' forwards until they do
 	for allN != n {
-		// in different chunks, reset offsets
-		if allNChunk != nChunk {
-			i.locoffset = 0
-			i.offset = 0
-		} else {
+		// in the same chunk, so move the freq/norm/loc decoders forward
+		if allNChunk == nChunk {
 			if i.currChunk != nChunk || i.currChunkFreqNorm == nil {
 				err := i.loadChunk(int(nChunk))
 				if err != nil {
@@ -614,9 +608,6 @@ func (i *PostingsIterator) nextDocNum() (uint64, bool, error) {
 					}
 				}
 			}
-
-			// in same chunk, need to account for offsets
-			i.offset++
 		}
 
 		allN = i.all.Next()