diff --git a/rbf/cursor.go b/rbf/cursor.go index 68c165d94..eda6bec1d 100644 --- a/rbf/cursor.go +++ b/rbf/cursor.go @@ -774,6 +774,25 @@ func (c *Cursor) deleteBranchCell(stackIndex int, key uint64) (err error) { cells[len(cells)-1] = branchCell{} cells = cells[:len(cells)-1] + // Branches are not allowed to have zero element so we must remove the page + // or, in the case of the root page, convert to a leaf page. + if len(cells) == 0 { + // If this is the root page, convert to leaf page. + if stackIndex == 0 { + var buf [PageSize]byte + writePageNo(buf[:], elem.pgno) + writeFlags(buf[:], PageTypeLeaf) + writeCellN(buf[:], len(cells)) + return c.tx.writePage(buf[:]) + } + + // If this is a non-root page, free and remove from parent. + if err := c.tx.freePgno(elem.pgno); err != nil { + return err + } + return c.deleteBranchCell(stackIndex-1, oldPageKey) + } + // If the root only has one node, replace it with its child. if stackIndex == 0 && len(cells) == 1 { target, _, err := c.tx.readPage(cells[0].ChildPgno) @@ -802,6 +821,9 @@ func (c *Cursor) deleteBranchCell(stackIndex int, key uint64) (err error) { writeBranchCell(buf[:], j, offset, cell) offset += align8(branchCellSize) } + + assert(readCellN(buf[:]) > 0) // must have at least one cell + if err := c.tx.writePage(buf[:]); err != nil { return err } diff --git a/rbf/tx_test.go b/rbf/tx_test.go index 1004437a3..f05db6626 100644 --- a/rbf/tx_test.go +++ b/rbf/tx_test.go @@ -433,6 +433,52 @@ func TestTx_DeallocateToFreeList(t *testing.T) { } } +func TestTx_Remove(t *testing.T) { + t.Parallel() + + db := MustOpenDB(t) + defer MustCloseDB(t, db) + + tx := MustBegin(t, db, true) + defer tx.Rollback() + + if err := tx.CreateBitmap("x"); err != nil { + t.Fatal(err) + } + + // Insert large array values. + var values []uint64 + for i := 0; i < 1000; i++ { + for j := 0; j < rbf.ArrayMaxSize; j++ { + v := uint64((i << 16) + j) + values = append(values, v) + + if _, err := tx.Add("x", v); err != nil { + t.Fatalf("Add(%d) err=%q", v, err) + } + } + } + + if err := tx.Commit(); err != nil { + t.Fatal(err) + } + + tx = MustBegin(t, db, true) + defer tx.Rollback() + + // Remove all array values. + for _, i := range rand.Perm(len(values)) { + v := values[i] + if _, err := tx.Remove("x", v); err != nil { + t.Fatalf("Remove(%d) err=%q", v, err) + } + } + + if err := tx.Commit(); err != nil { + t.Fatal(err) + } +} + func TestTx_AddRemove_Quick(t *testing.T) { if testing.Short() { t.Skip("-short enabled, skipping")