Function TestTx_TruncateBeforeWrite

tx_test.go:1017–1056

TestTx_TruncateBeforeWrite ensures the file is truncated ahead whether we sync freelist or not.

(t *testing.T)

// TestTx_TruncateBeforeWrite ensures the file is truncated ahead whether we sync freelist or not.
func TestTx_TruncateBeforeWrite(t *testing.T) {
	if runtime.GOOS == "windows" {
		return
	}
	for _, isSyncFreelist := range []bool{false, true} {
		t.Run(fmt.Sprintf("isSyncFreelist:%v", isSyncFreelist), func(t *testing.T) {
			// Open the database.
			db := btesting.MustCreateDBWithOption(t, &bolt.Options{
				NoFreelistSync: isSyncFreelist,
			})

			bigvalue := make([]byte, db.AllocSize/100)
			count := 0
			for {
				count++
				tx, err := db.Begin(true)
				require.NoError(t, err)
				b, err := tx.CreateBucketIfNotExists([]byte("bucket"))
				require.NoError(t, err)
				err = b.Put([]byte{byte(count)}, bigvalue)
				require.NoError(t, err)
				err = tx.Commit()
				require.NoError(t, err)

				size := fileSize(db.Path())

				if size > int64(db.AllocSize) && size < int64(db.AllocSize)*2 {
					// db.grow expands the file aggresively, that double the size while smaller than db.AllocSize,
					// or increase with a step of db.AllocSize if larger, by which we can test if db.grow has run.
					t.Fatalf("db.grow doesn't run when file size changes. file size: %d", size)
				}
				if size > int64(db.AllocSize) {
					break
				}
			}
			db.MustClose()
			db.MustDeleteFile()
		})
	}
}