loopdb+sweepbatcher: add the DropBatch call

loopdb/sqlc/batch.sql.go

@@ -25,6 +25,15 @@ func (q *Queries) ConfirmBatch(ctx context.Context, id int32) error {
 	return err
 }
 
+const dropBatch = `-- name: DropBatch :exec
+DELETE FROM sweep_batches WHERE id = $1
+`
+
+func (q *Queries) DropBatch(ctx context.Context, id int32) error {
+	_, err := q.db.ExecContext(ctx, dropBatch, id)
+	return err
+}
+
 const getBatchSweeps = `-- name: GetBatchSweeps :many
 SELECT
         sweeps.id, sweeps.swap_hash, sweeps.batch_id, sweeps.outpoint_txid, sweeps.outpoint_index, sweeps.amt, sweeps.completed,

loopdb/sqlc/querier.go

@@ -11,6 +11,7 @@ import (
 type Querier interface {
 	ConfirmBatch(ctx context.Context, id int32) error
 	CreateReservation(ctx context.Context, arg CreateReservationParams) error
+	DropBatch(ctx context.Context, id int32) error
 	FetchLiquidityParams(ctx context.Context) ([]byte, error)
 	GetBatchSweeps(ctx context.Context, batchID int32) ([]GetBatchSweepsRow, error)
 	GetBatchSweptAmount(ctx context.Context, batchID int32) (int64, error)

loopdb/sqlc/queries/batch.sql

@@ -23,6 +23,9 @@ INSERT INTO sweep_batches (
         $6
 ) RETURNING id;
 
+-- name: DropBatch :exec
+DELETE FROM sweep_batches WHERE id = $1;
+
 -- name: UpdateBatch :exec
 UPDATE sweep_batches SET
         confirmed = $2,

sweepbatcher/store.go

@@ -3,6 +3,7 @@ package sweepbatcher
 import (
 	"context"
 	"database/sql"
+	"fmt"
 
 	"github.com/btcsuite/btcd/btcutil"
 	"github.com/btcsuite/btcd/chaincfg"
@@ -46,6 +47,9 @@ type BaseDB interface {
 	InsertBatch(ctx context.Context, arg sqlc.InsertBatchParams) (
 		int32, error)
 
+	// DropBatch drops a batch from the database.
+	DropBatch(ctx context.Context, id int32) error
+
 	// UpdateBatch updates a batch in the database.
 	UpdateBatch(ctx context.Context, arg sqlc.UpdateBatchParams) error
 
@@ -108,6 +112,24 @@ func (s *SQLStore) InsertSweepBatch(ctx context.Context, batch *dbBatch) (int32,
 	return s.baseDb.InsertBatch(ctx, batchToInsertArgs(*batch))
 }
 
+// DropBatch drops a batch from the database. Note that we only use this call
+// for batches that have no sweeps and so we'd not be able to resume.
+func (s *SQLStore) DropBatch(ctx context.Context, id int32) error {
+	readOpts := loopdb.NewSqlReadOpts()
+	return s.baseDb.ExecTx(ctx, readOpts, func(tx *sqlc.Queries) error {
+		dbSweeps, err := tx.GetBatchSweeps(ctx, id)
+		if err != nil {
+			return err
+		}
+
+		if len(dbSweeps) != 0 {
+			return fmt.Errorf("cannot drop a non-empty batch")
+		}
+
+		return tx.DropBatch(ctx, id)
+	})
+}
+
 // UpdateSweepBatch updates a batch in the database.
 func (s *SQLStore) UpdateSweepBatch(ctx context.Context, batch *dbBatch) error {
 	return s.baseDb.UpdateBatch(ctx, batchToUpdateArgs(*batch))

sweepbatcher/store_mock.go

@@ -56,6 +56,12 @@ func (s *StoreMock) InsertSweepBatch(ctx context.Context,
 	return id, nil
 }
 
+// DropBatch drops a batch from the database.
+func (s *StoreMock) DropBatch(ctx context.Context, id int32) error {
+	delete(s.batches, id)
+	return nil
+}
+
 // UpdateSweepBatch updates a batch in the database.
 func (s *StoreMock) UpdateSweepBatch(ctx context.Context,
 	batch *dbBatch) error {