From 01ce9b5c44fa531fd6e81e7c93ada3daaea64552 Mon Sep 17 00:00:00 2001
From: vyzo <vyzo@hackzen.org>
Date: Thu, 11 Mar 2021 11:45:05 +0200
Subject: [PATCH 1/3] add Compact to badger blockstore

---
 blockstore/badger/blockstore.go | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/blockstore/badger/blockstore.go b/blockstore/badger/blockstore.go
index 2c00f424077..7c1615711f6 100644
--- a/blockstore/badger/blockstore.go
+++ b/blockstore/badger/blockstore.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"io"
+	"runtime"
 	"sync/atomic"
 
 	"github.com/dgraph-io/badger/v2"
@@ -150,6 +151,20 @@ func (b *Blockstore) CollectGarbage() error {
 	return err
 }
 
+// Compact runs a synchronous compaction
+func (b *Blockstore) Compact() error {
+	if atomic.LoadInt64(&b.state) != stateOpen {
+		return ErrBlockstoreClosed
+	}
+
+	nworkers := runtime.NumCPU() / 2
+	if nworkers < 2 {
+		nworkers = 2
+	}
+
+	return b.DB.Flatten(nworkers)
+}
+
 // View implements blockstore.Viewer, which leverages zero-copy read-only
 // access to values.
 func (b *Blockstore) View(cid cid.Cid, fn func([]byte) error) error {

From 353bb1881f7d23139167a803cdf8f28bf79050af Mon Sep 17 00:00:00 2001
From: vyzo <vyzo@hackzen.org>
Date: Thu, 11 Mar 2021 11:45:19 +0200
Subject: [PATCH 2/3] compact hotstore if it provides the method

---
 blockstore/splitstore/splitstore.go | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/blockstore/splitstore/splitstore.go b/blockstore/splitstore/splitstore.go
index fb3e2880315..bec19284ac2 100644
--- a/blockstore/splitstore/splitstore.go
+++ b/blockstore/splitstore/splitstore.go
@@ -798,6 +798,18 @@ func (s *SplitStore) purgeTracking(cids []cid.Cid) error {
 }
 
 func (s *SplitStore) gcHotstore() {
+	if compact, ok := s.hot.(interface{ Compact() error }); ok {
+		log.Infof("compacting hotstore")
+		startCompact := time.Now()
+		err := compact.Compact()
+		if err != nil {
+			log.Warnf("error compacting hotstore: %s", err)
+			return
+		} else {
+			log.Infow("hotstore compaction done", "took", time.Since(startCompact))
+		}
+	}
+
 	if gc, ok := s.hot.(interface{ CollectGarbage() error }); ok {
 		log.Infof("garbage collecting hotstore")
 		startGC := time.Now()

From 1b1d3606cd67480e5250ff56080a65107d4fee33 Mon Sep 17 00:00:00 2001
From: vyzo <vyzo@hackzen.org>
Date: Thu, 11 Mar 2021 13:10:44 +0200
Subject: [PATCH 3/3] make linter happy

---
 blockstore/splitstore/splitstore.go | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/blockstore/splitstore/splitstore.go b/blockstore/splitstore/splitstore.go
index bec19284ac2..23b2d342720 100644
--- a/blockstore/splitstore/splitstore.go
+++ b/blockstore/splitstore/splitstore.go
@@ -805,9 +805,8 @@ func (s *SplitStore) gcHotstore() {
 		if err != nil {
 			log.Warnf("error compacting hotstore: %s", err)
 			return
-		} else {
-			log.Infow("hotstore compaction done", "took", time.Since(startCompact))
 		}
+		log.Infow("hotstore compaction done", "took", time.Since(startCompact))
 	}
 
 	if gc, ok := s.hot.(interface{ CollectGarbage() error }); ok {
@@ -816,9 +815,9 @@ func (s *SplitStore) gcHotstore() {
 		err := gc.CollectGarbage()
 		if err != nil {
 			log.Warnf("error garbage collecting hotstore: %s", err)
-		} else {
-			log.Infow("garbage collection done", "took", time.Since(startGC))
+			return
 		}
+		log.Infow("hotstore garbage collection done", "took", time.Since(startGC))
 	}
 }