chore: Add error param to operation queue, 'nack' function

pkg/batch/cutter/cutter.go

@@ -26,7 +26,7 @@ type OperationQueue interface {
 	// - The operations that are to be removed.
 	// - The 'Ack' function that must be called to commit the remove.
 	// - The 'Nack' function that must be called to roll back the remove.
-	Remove(num uint) (ops operation.QueuedOperationsAtTime, ack func() uint, nack func(), err error)
+	Remove(num uint) (ops operation.QueuedOperationsAtTime, ack func() uint, nack func(error), err error)
 	// Peek returns (up to) the given number of operations from the head of the queue but does not remove them.
 	Peek(num uint) (operation.QueuedOperationsAtTime, error)
 	// Len returns the number of operation in the queue.
@@ -48,7 +48,7 @@ type Result struct {
 	// Ack commits the remove from the queue and returns the number of pending operations.
 	Ack func() uint
 	// Nack rolls back the remove so that a retry may occur.
-	Nack func()
+	Nack func(error)
 }
 
 // BatchCutter implements batch cutting.

pkg/batch/cutter/cutter_test.go

@@ -7,6 +7,7 @@ SPDX-License-Identifier: Apache-2.0
 package cutter
 
 import (
+	"errors"
 	"fmt"
 	"testing"
 
@@ -68,7 +69,7 @@ func TestBatchCutter(t *testing.T) {
 	require.Zero(t, result.Pending)
 	require.Equal(t, uint64(10), result.ProtocolVersion)
 
-	result.Nack()
+	result.Nack(errors.New("injected error"))
 
 	// After a rollback, the operations should still be in the queue
 	result, err = r.Cut(true)

pkg/batch/opqueue/memqueue.go

@@ -45,7 +45,7 @@ func (q *MemQueue) Peek(num uint) (operation.QueuedOperationsAtTime, error) {
 }
 
 // Remove removes (up to) the given number of items from the head of the queue.
-func (q *MemQueue) Remove(num uint) (ops operation.QueuedOperationsAtTime, ack func() uint, nack func(), err error) {
+func (q *MemQueue) Remove(num uint) (ops operation.QueuedOperationsAtTime, ack func() uint, nack func(error), err error) {
 	q.mutex.Lock()
 	defer q.mutex.Unlock()
 
@@ -64,7 +64,7 @@ func (q *MemQueue) Remove(num uint) (ops operation.QueuedOperationsAtTime, ack f
 
 			return uint(len(q.items))
 		},
-		func() {
+		func(error) {
 			q.mutex.Lock()
 			defer q.mutex.Unlock()
 

pkg/batch/opqueue/memqueue_test.go

@@ -7,6 +7,7 @@ SPDX-License-Identifier: Apache-2.0
 package opqueue
 
 import (
+	"errors"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -76,7 +77,7 @@ func TestMemQueue(t *testing.T) {
 	require.Equal(t, *op2, ops[0].QueuedOperation)
 	require.Equal(t, *op3, ops[1].QueuedOperation)
 
-	nack()
+	nack(errors.New("injected error"))
 
 	ops, ack, _, err = q.Remove(5)
 	require.NoError(t, err)

pkg/batch/writer.go

@@ -239,7 +239,7 @@ func (r *Writer) cutAndProcess(forceCut bool) (numProcessed int, pending uint, e
 	if err != nil {
 		r.logger.Error("Error processing batch operations", logfields.WithTotal(len(result.Operations)), log.WithError(err))
 
-		result.Nack()
+		result.Nack(err)
 
 		return 0, result.Pending + uint(len(result.Operations)), err
 	}

pkg/batch/writer_test.go

@@ -377,7 +377,7 @@ func TestProcessError(t *testing.T) {
 
 		q.LenReturns(1)
 		q.PeekReturns(invalidQueue, nil)
-		q.RemoveReturns(nil, func() uint { return 0 }, func() {}, nil)
+		q.RemoveReturns(nil, func() uint { return 0 }, func(error) {}, nil)
 
 		ctx := newMockContext()
 		ctx.ProtocolClient.Protocol.MaxOperationCount = 1