From d19fc71903548a1642880b1e134c8f34715ef04c Mon Sep 17 00:00:00 2001
From: johncming <johncming@yahoo.com>
Date: Thu, 13 Aug 2020 17:55:35 +0800
Subject: [PATCH] tsdb: use NewRangeHead instead. (#7793)

Signed-off-by: johncming <johncming@yahoo.com>
---
 tsdb/db.go | 24 ++++--------------------
 1 file changed, 4 insertions(+), 20 deletions(-)

diff --git a/tsdb/db.go b/tsdb/db.go
index 2c15b13ff..e6772b9f3 100644
--- a/tsdb/db.go
+++ b/tsdb/db.go
@@ -346,11 +346,7 @@ func (db *DBReadOnly) FlushWAL(dir string) (returnErr error) {
 	}
 	mint := head.MinTime()
 	maxt := head.MaxTime()
-	rh := &RangeHead{
-		head: head,
-		mint: mint,
-		maxt: maxt,
-	}
+	rh := NewRangeHead(head, mint, maxt)
 	compactor, err := NewLeveledCompactor(
 		context.Background(),
 		nil,
@@ -1367,11 +1363,7 @@ func (db *DB) Snapshot(dir string, withHead bool) error {
 
 	mint := db.head.MinTime()
 	maxt := db.head.MaxTime()
-	head := &RangeHead{
-		head: db.head,
-		mint: mint,
-		maxt: maxt,
-	}
+	head := NewRangeHead(db.head, mint, maxt)
 	// Add +1 millisecond to block maxt because block intervals are half-open: [b.MinTime, b.MaxTime).
 	// Because of this block intervals are always +1 than the total samples it includes.
 	if _, err := db.compactor.Write(dir, head, mint, maxt+1, nil); err != nil {
@@ -1393,11 +1385,7 @@ func (db *DB) Querier(_ context.Context, mint, maxt int64) (storage.Querier, err
 		}
 	}
 	if maxt >= db.head.MinTime() {
-		blocks = append(blocks, &RangeHead{
-			head: db.head,
-			mint: mint,
-			maxt: maxt,
-		})
+		blocks = append(blocks, NewRangeHead(db.head, mint, maxt))
 	}
 
 	blockQueriers := make([]storage.Querier, 0, len(blocks))
@@ -1430,11 +1418,7 @@ func (db *DB) ChunkQuerier(_ context.Context, mint, maxt int64) (storage.ChunkQu
 		}
 	}
 	if maxt >= db.head.MinTime() {
-		blocks = append(blocks, &RangeHead{
-			head: db.head,
-			mint: mint,
-			maxt: maxt,
-		})
+		blocks = append(blocks, NewRangeHead(db.head, mint, maxt))
 	}
 
 	blockQueriers := make([]storage.ChunkQuerier, 0, len(blocks))