Wire up config for pager result limit (#4657)

Allow callers of GetAddedRemovedItems to set the number of added items
they'd like returned from the call. Will eventually be leveraged for
Exchange preview backups

Doesn't change existing limits for pagers since everything uses the
default of zero for "get everything"

---

#### Does this PR need a docs update or release note?

- [ ] ✅ Yes, it's included
- [ ] 🕐 Yes, but in a later PR
- [x] ⛔ No

#### Type of change

- [x] 🌻 Feature
- [ ] 🐛 Bugfix
- [ ] 🗺️ Documentation
- [ ] 🤖 Supportability/Tests
- [ ] 💻 CI/Deployment
- [ ] 🧹 Tech Debt/Cleanup

#### Test Plan

- [x] 💪 Manual
- [ ] ⚡ Unit test
- [ ] 💚 E2E

src/internal/m365/collection/exchange/backup.go

@@ -122,10 +122,13 @@ func populateCollections(
 			return nil, el.Failure()
 		}
 
-		cID := ptr.Val(c.GetId())
-
 		var (
-			err         error
+			err        error
+			itemConfig = api.CallConfig{
+				CanMakeDeltaQueries: !ctrlOpts.ToggleFeatures.DisableDelta,
+				UseImmutableIDs:     ctrlOpts.ToggleFeatures.ExchangeImmutableIDs,
+			}
+			cID         = ptr.Val(c.GetId())
 			dp          = dps[cID]
 			prevDelta   = dp.Delta
 			prevPathStr = dp.Path // do not log: pii; log prevPath instead
@@ -146,6 +149,11 @@ func populateCollections(
 			continue
 		}
 
+		ictx = clues.Add(
+			ictx,
+			"current_path", currPath,
+			"current_location", locPath)
+
 		delete(tombstones, cID)
 
 		if len(prevPathStr) > 0 {
@@ -158,18 +166,13 @@ func populateCollections(
 
 		ictx = clues.Add(ictx, "previous_path", prevPath)
 
-		cc := api.CallConfig{
-			CanMakeDeltaQueries: !ctrlOpts.ToggleFeatures.DisableDelta,
-			UseImmutableIDs:     ctrlOpts.ToggleFeatures.ExchangeImmutableIDs,
-		}
-
 		addAndRem, err := bh.itemEnumerator().
 			GetAddedAndRemovedItemIDs(
 				ictx,
 				qp.ProtectedResource.ID(),
 				cID,
 				prevDelta,
-				cc)
+				itemConfig)
 		if err != nil {
 			if !graph.IsErrDeletedInFlight(err) {
 				el.AddRecoverable(ctx, clues.Stack(err).Label(fault.LabelForceNoBackupCreation))

src/internal/m365/collection/exchange/handlers.go

@@ -29,7 +29,7 @@ type addedAndRemovedItemGetter interface {
 	GetAddedAndRemovedItemIDs(
 		ctx context.Context,
 		user, containerID, oldDeltaToken string,
-		cc api.CallConfig,
+		config api.CallConfig,
 	) (pagers.AddedAndRemoved, error)
 }
 

src/pkg/services/m365/api/client.go

@@ -161,11 +161,19 @@ func (c Client) Post(
 // per-call config
 // ---------------------------------------------------------------------------
 
+// CallConfig defines additional parameters to add to the query like field
+// selection and limiting results.
+//
+// Not all calls may support all options. Check individual implementations to
+// see what's supported and what's not.
 type CallConfig struct {
 	Expand              []string
 	Select              []string
 	CanMakeDeltaQueries bool
 	UseImmutableIDs     bool
+	// LimitResults limits the returned results to the given number. If 0, returns
+	// all results.
+	LimitResults int
 }
 
 // ---------------------------------------------------------------------------

src/pkg/services/m365/api/contacts_pager.go

@@ -249,7 +249,7 @@ func (p *contactDeltaPager) ValidModTimes() bool {
 func (c Contacts) GetAddedAndRemovedItemIDs(
 	ctx context.Context,
 	userID, containerID, prevDeltaLink string,
-	cc CallConfig,
+	config CallConfig,
 ) (pagers.AddedAndRemoved, error) {
 	ctx = clues.Add(
 		ctx,
@@ -261,12 +261,12 @@ func (c Contacts) GetAddedAndRemovedItemIDs(
 		userID,
 		containerID,
 		prevDeltaLink,
-		cc.UseImmutableIDs,
+		config.UseImmutableIDs,
 		idAnd(lastModifiedDateTime)...)
 	pager := c.NewContactsPager(
 		userID,
 		containerID,
-		cc.UseImmutableIDs,
+		config.UseImmutableIDs,
 		idAnd(lastModifiedDateTime)...)
 
 	return pagers.GetAddedAndRemovedItemIDs[models.Contactable](
@@ -274,7 +274,7 @@ func (c Contacts) GetAddedAndRemovedItemIDs(
 		pager,
 		deltaPager,
 		prevDeltaLink,
-		cc.CanMakeDeltaQueries,
-		0,
+		config.CanMakeDeltaQueries,
+		config.LimitResults,
 		pagers.AddedAndRemovedByAddtlData[models.Contactable])
 }

src/pkg/services/m365/api/events_pager.go

@@ -244,7 +244,7 @@ func (p *eventDeltaPager) ValidModTimes() bool {
 func (c Events) GetAddedAndRemovedItemIDs(
 	ctx context.Context,
 	userID, containerID, prevDeltaLink string,
-	cc CallConfig,
+	config CallConfig,
 ) (pagers.AddedAndRemoved, error) {
 	ctx = clues.Add(
 		ctx,
@@ -256,12 +256,12 @@ func (c Events) GetAddedAndRemovedItemIDs(
 		userID,
 		containerID,
 		prevDeltaLink,
-		cc.UseImmutableIDs,
+		config.UseImmutableIDs,
 		idAnd()...)
 	pager := c.NewEventsPager(
 		userID,
 		containerID,
-		cc.UseImmutableIDs,
+		config.UseImmutableIDs,
 		idAnd(lastModifiedDateTime)...)
 
 	return pagers.GetAddedAndRemovedItemIDs[models.Eventable](
@@ -269,7 +269,7 @@ func (c Events) GetAddedAndRemovedItemIDs(
 		pager,
 		deltaPager,
 		prevDeltaLink,
-		cc.CanMakeDeltaQueries,
-		0,
+		config.CanMakeDeltaQueries,
+		config.LimitResults,
 		pagers.AddedAndRemovedByAddtlData[models.Eventable])
 }

src/pkg/services/m365/api/mail_pager.go

@@ -246,7 +246,7 @@ func (p *mailDeltaPager) ValidModTimes() bool {
 func (c Mail) GetAddedAndRemovedItemIDs(
 	ctx context.Context,
 	userID, containerID, prevDeltaLink string,
-	cc CallConfig,
+	config CallConfig,
 ) (pagers.AddedAndRemoved, error) {
 	ctx = clues.Add(
 		ctx,
@@ -258,12 +258,12 @@ func (c Mail) GetAddedAndRemovedItemIDs(
 		userID,
 		containerID,
 		prevDeltaLink,
-		cc.UseImmutableIDs,
+		config.UseImmutableIDs,
 		idAnd(lastModifiedDateTime)...)
 	pager := c.NewMailPager(
 		userID,
 		containerID,
-		cc.UseImmutableIDs,
+		config.UseImmutableIDs,
 		idAnd(lastModifiedDateTime)...)
 
 	return pagers.GetAddedAndRemovedItemIDs[models.Messageable](
@@ -271,7 +271,7 @@ func (c Mail) GetAddedAndRemovedItemIDs(
 		pager,
 		deltaPager,
 		prevDeltaLink,
-		cc.CanMakeDeltaQueries,
-		0,
+		config.CanMakeDeltaQueries,
+		config.LimitResults,
 		pagers.AddedAndRemovedByAddtlData[models.Messageable])
 }