From a299c7b6d61cbbfc898962acb3e88430bd7e048e Mon Sep 17 00:00:00 2001
From: Bryan Boreham <bjboreham@gmail.com>
Date: Mon, 15 Jul 2024 20:10:17 +0100
Subject: [PATCH] TSDB: Remove OOOHeadChunkReader

Use HeadAndOOOChunkReader instead.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
---
 tsdb/ooo_head_read.go      | 55 +-------------------------------------
 tsdb/ooo_head_read_test.go |  8 +++---
 2 files changed, 5 insertions(+), 58 deletions(-)

diff --git a/tsdb/ooo_head_read.go b/tsdb/ooo_head_read.go
index f844cfaca..01ba12986 100644
--- a/tsdb/ooo_head_read.go
+++ b/tsdb/ooo_head_read.go
@@ -248,59 +248,6 @@ func (oh *OOOHeadIndexReader) Postings(ctx context.Context, name string, values
 	}
 }
 
-type OOOHeadChunkReader struct {
-	head       *Head
-	mint, maxt int64
-	isoState   *oooIsolationState
-	maxMmapRef chunks.ChunkDiskMapperRef
-}
-
-func NewOOOHeadChunkReader(head *Head, mint, maxt int64, isoState *oooIsolationState, maxMmapRef chunks.ChunkDiskMapperRef) *OOOHeadChunkReader {
-	return &OOOHeadChunkReader{
-		head:       head,
-		mint:       mint,
-		maxt:       maxt,
-		isoState:   isoState,
-		maxMmapRef: maxMmapRef,
-	}
-}
-
-func (cr OOOHeadChunkReader) ChunkOrIterable(meta chunks.Meta) (chunkenc.Chunk, chunkenc.Iterable, error) {
-	sid, _ := chunks.HeadChunkRef(meta.Ref).Unpack()
-
-	s := cr.head.series.getByID(sid)
-	// This means that the series has been garbage collected.
-	if s == nil {
-		return nil, nil, storage.ErrNotFound
-	}
-
-	s.Lock()
-	if s.ooo == nil {
-		// There is no OOO data for this series.
-		s.Unlock()
-		return nil, nil, storage.ErrNotFound
-	}
-	mc, err := s.oooMergedChunks(meta, cr.head.chunkDiskMapper, nil, cr.mint, cr.maxt, cr.maxMmapRef)
-	s.Unlock()
-	if err != nil {
-		return nil, nil, err
-	}
-
-	// This means that the query range did not overlap with the requested chunk.
-	if len(mc.chunkIterables) == 0 {
-		return nil, nil, storage.ErrNotFound
-	}
-
-	return nil, mc, nil
-}
-
-func (cr OOOHeadChunkReader) Close() error {
-	if cr.isoState != nil {
-		cr.isoState.Close()
-	}
-	return nil
-}
-
 type OOOCompactionHead struct {
 	oooIR       *OOOHeadIndexReader
 	lastMmapRef chunks.ChunkDiskMapperRef
@@ -397,7 +344,7 @@ func (ch *OOOCompactionHead) Index() (IndexReader, error) {
 }
 
 func (ch *OOOCompactionHead) Chunks() (ChunkReader, error) {
-	return NewOOOHeadChunkReader(ch.oooIR.head, ch.oooIR.mint, ch.oooIR.maxt, nil, ch.lastMmapRef), nil
+	return NewHeadAndOOOChunkReader(ch.oooIR.head, ch.oooIR.mint, ch.oooIR.maxt, nil, nil, ch.lastMmapRef), nil
 }
 
 func (ch *OOOCompactionHead) Tombstones() (tombstones.Reader, error) {
diff --git a/tsdb/ooo_head_read_test.go b/tsdb/ooo_head_read_test.go
index b837b9e2f..c0b130ffb 100644
--- a/tsdb/ooo_head_read_test.go
+++ b/tsdb/ooo_head_read_test.go
@@ -481,10 +481,10 @@ func testOOOHeadChunkReader_Chunk(t *testing.T, scenario sampleTypeScenario) {
 	t.Run("Getting a non existing chunk fails with not found error", func(t *testing.T) {
 		db := newTestDBWithOpts(t, opts)
 
-		cr := NewOOOHeadChunkReader(db.head, 0, 1000, nil, 0)
+		cr := NewHeadAndOOOChunkReader(db.head, 0, 1000, nil, nil, 0)
 		defer cr.Close()
 		c, iterable, err := cr.ChunkOrIterable(chunks.Meta{
-			Ref: 0x1000000, Chunk: chunkenc.Chunk(nil), MinTime: 100, MaxTime: 300,
+			Ref: 0x1800000, Chunk: chunkenc.Chunk(nil), MinTime: 100, MaxTime: 300,
 		})
 		require.Nil(t, iterable)
 		require.Equal(t, err, fmt.Errorf("not found"))
@@ -839,7 +839,7 @@ func testOOOHeadChunkReader_Chunk(t *testing.T, scenario sampleTypeScenario) {
 			require.NoError(t, err)
 			require.Equal(t, len(tc.expChunksSamples), len(chks))
 
-			cr := NewOOOHeadChunkReader(db.head, tc.queryMinT, tc.queryMaxT, nil, 0)
+			cr := NewHeadAndOOOChunkReader(db.head, tc.queryMinT, tc.queryMaxT, nil, nil, 0)
 			defer cr.Close()
 			for i := 0; i < len(chks); i++ {
 				c, iterable, err := cr.ChunkOrIterable(chks[i])
@@ -1013,7 +1013,7 @@ func testOOOHeadChunkReader_Chunk_ConsistentQueryResponseDespiteOfHeadExpanding(
 			}
 			require.NoError(t, app.Commit())
 
-			cr := NewOOOHeadChunkReader(db.head, tc.queryMinT, tc.queryMaxT, nil, 0)
+			cr := NewHeadAndOOOChunkReader(db.head, tc.queryMinT, tc.queryMaxT, nil, nil, 0)
 			defer cr.Close()
 			for i := 0; i < len(chks); i++ {
 				c, iterable, err := cr.ChunkOrIterable(chks[i])