Add tests for WAL skipline

delete.go

@@ -105,23 +105,8 @@ func deleteBeforeTarget(target string, bk *Backup, pre *S3Prefix, findFull bool,
 		}
 	}
 
-	skip := true
-	skipLine := len(backups)
-	var walSkipFileName = ""
-	for i, b := range backups {
-		if skip {
-			log.Printf("%v skipped\n", b.Name)
-			if walSkipFileName == "" || walSkipFileName > b.WalFileName {
-				walSkipFileName = b.WalFileName
-			}
-		} else {
-			log.Printf("%v will be deleted\n", b.Name)
-		}
-		if b.Name == target {
-			skip = false
-			skipLine = i
-		}
-	}
+
+	skipLine, walSkipFileName := ComputeDeletionSkipline(backups, target)
 
 	if !dryRun {
 		if skipLine < len(backups)-1 {
@@ -133,6 +118,29 @@ func deleteBeforeTarget(target string, bk *Backup, pre *S3Prefix, findFull bool,
 	}
 }
 
+// ComputeDeletionSkipline selects last backup and name of last necessary WAL
+func ComputeDeletionSkipline(backups []BackupTime, target string) (skipLine int, walSkipFileName string) {
+	skip := true
+	skipLine = len(backups)
+	walSkipFileName = ""
+	for i, backupTime := range backups {
+		if skip {
+			log.Printf("%v skipped\n", backupTime.Name)
+			if walSkipFileName == "" || walSkipFileName > backupTime.WalFileName {
+				walSkipFileName = backupTime.WalFileName
+			}
+		} else {
+			log.Printf("%v will be deleted\n", backupTime.Name)
+		}
+		if backupTime.Name == target {
+			skip = false
+			skipLine = i
+		}
+	}
+	return skipLine, walSkipFileName
+}
+
+// TODO : unit tests
 func deleteBackupsBefore(backups []BackupTime, skipline int, pre *S3Prefix) {
 	for i, b := range backups {
 		if i > skipline {

walg_test/delete_test.go

@@ -0,0 +1,96 @@
+package walg_test
+
+import (
+	"github.com/wal-g/wal-g"
+	"sort"
+	"testing"
+	"time"
+)
+
+//NB: order will reverse after sorting
+var backup_times1 = []walg.BackupTime{
+	{
+		Name:        "base_00000001000000000000007C",
+		Time:        time.Date(2007, 2, 2, 30, 48, 39, 651387233, time.UTC),
+		WalFileName: "00000001000000000000007C",
+	},
+	{
+		Name:        "base_00000001000000000000008C",
+		Time:        time.Date(2008, 2, 27, 20, 8, 33, 651387235, time.UTC),
+		WalFileName: "00000001000000000000008C",
+	},
+	{
+		Name:        "base_00000001000000000000009C",
+		Time:        time.Date(2009, 11, 20, 16, 34, 58, 651387232, time.UTC),
+		WalFileName: "00000001000000000000009C",
+	},
+	{
+		Name:        "base_0000000100000000000000AC",
+		Time:        time.Date(2010, 11, 31, 20, 3, 58, 651387237, time.UTC),
+		WalFileName: "0000000100000000000000AC",
+	},
+	{
+		Name:        "base_0000000100000000000000BC",
+		Time:        time.Date(2011, 3, 13, 4, 2, 42, 651387234, time.UTC),
+		WalFileName: "0000000100000000000000BC",
+	},
+}
+
+func TestSkiplineComputation(t *testing.T) {
+
+	sort.Sort(walg.TimeSlice(backup_times1))
+
+	skipLine, walSkipFileName := walg.ComputeDeletionSkipline(backup_times1, "base_00000001000000000000008C")
+
+	if "00000001000000000000008C" != walSkipFileName {
+		t.Error("Incorrect walSkipFileName")
+	}
+
+	if 3 != skipLine { // we will skip 3 backups
+		t.Error("Incorrect skipLine")
+	}
+}
+
+//NB: order will reverse after sorting
+var backup_times2 = []walg.BackupTime{
+	{
+		Name:        "base_00000004000000000000007C",
+		Time:        time.Date(2007, 2, 2, 30, 48, 39, 651387233, time.UTC),
+		WalFileName: "00000004000000000000007C",
+	},
+	{
+		Name:        "base_00000004000000000000008C",
+		Time:        time.Date(2008, 2, 27, 20, 8, 33, 651387235, time.UTC),
+		WalFileName: "00000004000000000000008C",
+	},
+	{
+		Name:        "base_00000001000000000000009C",
+		Time:        time.Date(2009, 11, 20, 16, 34, 58, 651387232, time.UTC),
+		WalFileName: "00000001000000000000009C",
+	},
+	{
+		Name:        "base_0000000100000000000000AC",
+		Time:        time.Date(2010, 11, 31, 20, 3, 58, 651387237, time.UTC),
+		WalFileName: "0000000100000000000000AC",
+	},
+	{
+		Name:        "base_0000000100000000000000BC",
+		Time:        time.Date(2011, 3, 13, 4, 2, 42, 651387234, time.UTC),
+		WalFileName: "0000000100000000000000BC",
+	},
+}
+
+func TestSkiplineComputationAfterUpgrade(t *testing.T) {
+
+	sort.Sort(walg.TimeSlice(backup_times2))
+
+	skipLine, walSkipFileName := walg.ComputeDeletionSkipline(backup_times2, "base_00000004000000000000008C")
+
+	if "00000001000000000000009C" != walSkipFileName {
+		t.Error("Incorrect walSkipFileName")
+	}
+
+	if 3 != skipLine { // we will skip 3 backups
+		t.Error("Incorrect skipLine")
+	}
+}