From b1bbbafe00c65da63ce4eb66161134da4e15b92f Mon Sep 17 00:00:00 2001
From: nakabonne <ryo@nakao.dev>
Date: Sun, 11 Jul 2021 14:33:01 +0900
Subject: [PATCH] Add interface to clean partition resources

---
 disk_partition.go   | 5 +++++
 fake_partition.go   | 4 ++++
 memory_partition.go | 6 ++++++
 partition.go        | 2 ++
 partition_list.go   | 3 +++
 5 files changed, 20 insertions(+)

diff --git a/disk_partition.go b/disk_partition.go
index 415f656..407b380 100644
--- a/disk_partition.go
+++ b/disk_partition.go
@@ -142,3 +142,8 @@ func (d *diskPartition) size() int {
 func (d *diskPartition) active() bool {
 	return false
 }
+
+func (d *diskPartition) clean() error {
+	// FIXME: Remove the directory this partition holds.
+	return nil
+}
diff --git a/fake_partition.go b/fake_partition.go
index c14f961..43dd2db 100644
--- a/fake_partition.go
+++ b/fake_partition.go
@@ -32,3 +32,7 @@ func (f *fakePartition) size() int {
 func (f *fakePartition) active() bool {
 	return f.IsActive
 }
+
+func (f *fakePartition) clean() error {
+	return nil
+}
diff --git a/memory_partition.go b/memory_partition.go
index 2f13ee5..b5932bc 100644
--- a/memory_partition.go
+++ b/memory_partition.go
@@ -155,6 +155,12 @@ func (m *memoryPartition) active() bool {
 	return m.maxTimestamp()-m.minTimestamp()+1 < m.partitionDuration
 }
 
+func (m *memoryPartition) clean() error {
+	// What all data managed by memoryPartition is on heap that is automatically removed by GC.
+	// So do nothing.
+	return nil
+}
+
 // memoryMetric has a list of ordered data points that belong to the memoryMetric
 type memoryMetric struct {
 	name         string
diff --git a/partition.go b/partition.go
index 6adc5f2..fce0d6e 100644
--- a/partition.go
+++ b/partition.go
@@ -16,6 +16,8 @@ type partition interface {
 	// If data points older than its min timestamp were given, they won't be
 	// ingested, instead, gave back as a first returned value.
 	insertRows(rows []Row) (outdatedRows []Row, err error)
+	// clean removes everything managed by this partition.
+	clean() error
 
 	// Read operations
 	//
diff --git a/partition_list.go b/partition_list.go
index e553db1..247a2de 100644
--- a/partition_list.go
+++ b/partition_list.go
@@ -98,6 +98,9 @@ func (p *partitionListImpl) remove(target partition) error {
 		}
 
 		// remove the current node.
+		if err := current.value().clean(); err != nil {
+			return fmt.Errorf("failed to clean resources managed by partition to be removed: %w", err)
+		}
 
 		iterator.next()
 		next = iterator.currentNode()