Update folder size and modified time in details (#1881)

## Description

Caches folder info added during details construction in the details builder and keeps the size/modified time
updated as newer items are added.

As part of this, this PR refactors the details package to separate out building `details.Details` from the in-memory representation and model.

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

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

## Type of change

<!--- Please check the type of change your PR introduces: --->
- [x] 🌻 Feature
- [ ] 🐛 Bugfix
- [ ] 🗺️ Documentation
- [ ] 🤖 Test
- [ ] 💻 CI/Deployment
- [ ] 🐹 Trivial/Minor

## Issue(s)

<!-- Can reference multiple issues. Use one of the following "magic words" - "closes, fixes" to auto-close the Github issue. -->
* #1850 

## Test Plan

<!-- How will this be tested prior to merging.-->
- [ ] 💪 Manual
- [x] ⚡ Unit test
- [ ] 💚 E2E

src/internal/connector/exchange/service_restore.go

@@ -288,7 +288,7 @@ func RestoreExchangeDataCollections(
 	gs graph.Servicer,
 	dest control.RestoreDestination,
 	dcs []data.Collection,
-	deets *details.Details,
+	deets *details.Builder,
 ) (*support.ConnectorOperationStatus, error) {
 	var (
 		// map of caches... but not yet...
@@ -349,7 +349,7 @@ func restoreCollection(
 	dc data.Collection,
 	folderID string,
 	policy control.CollisionPolicy,
-	deets *details.Details,
+	deets *details.Builder,
 	errUpdater func(string, error),
 ) (support.CollectionMetrics, bool) {
 	ctx, end := D.Span(ctx, "gc:exchange:restoreCollection", D.Label("path", dc.FullPath()))

src/internal/connector/graph_connector.go

@@ -262,7 +262,7 @@ func (gc *GraphConnector) RestoreDataCollections(
 	var (
 		status *support.ConnectorOperationStatus
 		err    error
-		deets  = &details.Details{}
+		deets  = &details.Builder{}
 	)
 
 	switch selector.Service {
@@ -279,7 +279,7 @@ func (gc *GraphConnector) RestoreDataCollections(
 	gc.incrementAwaitingMessages()
 	gc.UpdateStatus(status)
 
-	return deets, err
+	return deets.Details(), err
 }
 
 // AwaitStatus waits for all gc tasks to complete and then returns status

src/internal/connector/onedrive/restore.go

@@ -53,7 +53,7 @@ func RestoreCollections(
 	service graph.Servicer,
 	dest control.RestoreDestination,
 	dcs []data.Collection,
-	deets *details.Details,
+	deets *details.Builder,
 ) (*support.ConnectorOperationStatus, error) {
 	var (
 		restoreMetrics support.CollectionMetrics
@@ -95,7 +95,7 @@ func RestoreCollection(
 	dc data.Collection,
 	source driveSource,
 	restoreContainerName string,
-	deets *details.Details,
+	deets *details.Builder,
 	errUpdater func(string, error),
 ) (support.CollectionMetrics, bool) {
 	ctx, end := D.Span(ctx, "gc:oneDrive:restoreCollection", D.Label("path", dc.FullPath()))

src/internal/connector/sharepoint/restore.go

@@ -20,7 +20,7 @@ func RestoreCollections(
 	service graph.Servicer,
 	dest control.RestoreDestination,
 	dcs []data.Collection,
-	deets *details.Details,
+	deets *details.Builder,
 ) (*support.ConnectorOperationStatus, error) {
 	var (
 		restoreMetrics support.CollectionMetrics

src/internal/kopia/upload.go

@@ -125,7 +125,7 @@ type itemDetails struct {
 type corsoProgress struct {
 	snapshotfs.UploadProgress
 	pending    map[string]*itemDetails
-	deets      *details.Details
+	deets      *details.Builder
 	mu         sync.RWMutex
 	totalBytes int64
 }
@@ -182,7 +182,7 @@ func (cp *corsoProgress) FinishedFile(relativePath string, err error) {
 		parent = nextParent
 	}
 
-	cp.deets.AddFolders(folders)
+	cp.deets.AddFoldersForItem(folders, d.info)
 }
 
 // Kopia interface function used as a callback when kopia finishes hashing a file.

src/internal/kopia/upload_test.go

@@ -435,7 +435,7 @@ var finishedFileTable = []struct {
 func (suite *CorsoProgressUnitSuite) TestFinishedFile() {
 	for _, test := range finishedFileTable {
 		suite.T().Run(test.name, func(t *testing.T) {
-			bd := &details.Details{}
+			bd := &details.Builder{}
 			cp := corsoProgress{
 				UploadProgress: &snapshotfs.NullUploadProgress{},
 				deets:          bd,
@@ -455,7 +455,7 @@ func (suite *CorsoProgressUnitSuite) TestFinishedFile() {
 			}
 
 			assert.Empty(t, cp.pending)
-			assert.Len(t, bd.Entries, test.expectedNumEntries)
+			assert.Len(t, bd.Details().Entries, test.expectedNumEntries)
 		})
 	}
 }
@@ -466,7 +466,7 @@ func (suite *CorsoProgressUnitSuite) TestFinishedFileBuildsHierarchy() {
 	expectedFolderOrder := suite.targetFilePath.ToBuilder().Dir().Elements()
 
 	// Setup stuff.
-	bd := &details.Details{}
+	bd := &details.Builder{}
 	cp := corsoProgress{
 		UploadProgress: &snapshotfs.NullUploadProgress{},
 		deets:          bd,
@@ -485,8 +485,10 @@ func (suite *CorsoProgressUnitSuite) TestFinishedFileBuildsHierarchy() {
 		refToEntry = map[string]*details.DetailsEntry{}
 	)
 
-	for i := 0; i < len(bd.Entries); i++ {
-		e := &bd.Entries[i]
+	entries := bd.Details().Entries
+
+	for i := 0; i < len(entries); i++ {
+		e := &entries[i]
 		if e.Folder == nil {
 			continue
 		}
@@ -522,7 +524,7 @@ func (suite *CorsoProgressUnitSuite) TestFinishedFileBuildsHierarchy() {
 func (suite *CorsoProgressUnitSuite) TestFinishedHashingFile() {
 	for _, test := range finishedFileTable {
 		suite.T().Run(test.name, func(t *testing.T) {
-			bd := &details.Details{}
+			bd := &details.Builder{}
 			cp := corsoProgress{
 				UploadProgress: &snapshotfs.NullUploadProgress{},
 				deets:          bd,

src/internal/kopia/wrapper.go

@@ -131,12 +131,12 @@ func (w Wrapper) BackupCollections(
 	defer end()
 
 	if len(collections) == 0 {
-		return &BackupStats{}, &details.Details{}, nil
+		return &BackupStats{}, (&details.Builder{}).Details(), nil
 	}
 
 	progress := &corsoProgress{
 		pending: map[string]*itemDetails{},
-		deets:   &details.Details{},
+		deets:   &details.Builder{},
 	}
 
 	// TODO(ashmrtn): Pass previousSnapshots here to enable building the directory
@@ -158,7 +158,7 @@ func (w Wrapper) BackupCollections(
 		return nil, nil, err
 	}
 
-	return s, progress.deets, nil
+	return s, progress.deets.Details(), nil
 }
 
 func (w Wrapper) makeSnapshotWithRoot(

src/internal/streamstore/streamstore_test.go

@@ -46,15 +46,17 @@ func (suite *StreamStoreIntegrationSuite) TestDetails() {
 
 	defer kw.Close(ctx)
 
-	deets := &details.Details{}
+	deetsBuilder := &details.Builder{}
 
-	deets.Add("ref", "shortref", "parentref", true,
+	deetsBuilder.Add("ref", "shortref", "parentref", true,
 		details.ItemInfo{
 			Exchange: &details.ExchangeInfo{
 				Subject: "hello world",
 			},
 		})
 
+	deets := deetsBuilder.Details()
+
 	ss := New(kw, "tenant", path.ExchangeService)
 
 	id, err := ss.WriteBackupDetails(ctx, deets)

src/pkg/backup/details/details.go

@@ -100,6 +100,78 @@ func (dm DetailsModel) Items() []*DetailsEntry {
 	return res
 }
 
+// Builder should be used to create a details model.
+type Builder struct {
+	d            Details
+	mu           sync.Mutex             `json:"-"`
+	knownFolders map[string]FolderEntry `json:"-"`
+}
+
+func (b *Builder) Add(repoRef, shortRef, parentRef string, updated bool, info ItemInfo) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	b.d.add(repoRef, shortRef, parentRef, updated, info)
+}
+
+func (b *Builder) Details() *Details {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	// Write the cached folder entries to details
+	for _, folder := range b.knownFolders {
+		b.d.addFolder(folder)
+	}
+
+	return &b.d
+}
+
+// AddFoldersForItem adds entries for the given folders. It skips adding entries that
+// have been added by previous calls.
+func (b *Builder) AddFoldersForItem(folders []FolderEntry, itemInfo ItemInfo) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	if b.knownFolders == nil {
+		b.knownFolders = map[string]FolderEntry{}
+	}
+
+	for _, folder := range folders {
+		if existing, ok := b.knownFolders[folder.ShortRef]; ok {
+			// We've seen this folder before for a different item.
+			// Update the "cached" folder entry
+			folder = existing
+		}
+
+		// Update the folder's size and modified time
+		var (
+			itemSize     int64
+			itemModified time.Time
+		)
+
+		switch {
+		case itemInfo.Exchange != nil:
+			itemSize = itemInfo.Exchange.Size
+			itemModified = itemInfo.Exchange.Modified
+
+		case itemInfo.OneDrive != nil:
+			itemSize = itemInfo.OneDrive.Size
+			itemModified = itemInfo.OneDrive.Modified
+
+		case itemInfo.SharePoint != nil:
+			itemSize = itemInfo.SharePoint.Size
+			itemModified = itemInfo.SharePoint.Modified
+		}
+
+		folder.Info.Folder.Size += itemSize
+
+		if folder.Info.Folder.Modified.Before(itemModified) {
+			folder.Info.Folder.Modified = itemModified
+		}
+
+		b.knownFolders[folder.ShortRef] = folder
+	}
+}
+
 // --------------------------------------------------------------------------------
 // Details
 // --------------------------------------------------------------------------------
@@ -109,15 +181,9 @@ func (dm DetailsModel) Items() []*DetailsEntry {
 // printing.
 type Details struct {
 	DetailsModel
-
-	// internal
-	mu           sync.Mutex          `json:"-"`
-	knownFolders map[string]struct{} `json:"-"`
 }
 
-func (d *Details) Add(repoRef, shortRef, parentRef string, updated bool, info ItemInfo) {
-	d.mu.Lock()
-	defer d.mu.Unlock()
+func (d *Details) add(repoRef, shortRef, parentRef string, updated bool, info ItemInfo) {
 	d.Entries = append(d.Entries, DetailsEntry{
 		RepoRef:   repoRef,
 		ShortRef:  shortRef,
@@ -127,23 +193,8 @@ func (d *Details) Add(repoRef, shortRef, parentRef string, updated bool, info It
 	})
 }
 
-// AddFolders adds entries for the given folders. It skips adding entries that
-// have been added by previous calls.
-func (d *Details) AddFolders(folders []FolderEntry) {
-	d.mu.Lock()
-	defer d.mu.Unlock()
-
-	if d.knownFolders == nil {
-		d.knownFolders = map[string]struct{}{}
-	}
-
-	for _, folder := range folders {
-		if _, ok := d.knownFolders[folder.ShortRef]; ok {
-			// Entry already exists, nothing to do.
-			continue
-		}
-
-		d.knownFolders[folder.ShortRef] = struct{}{}
+// addFolder adds an entry for the given folder.
+func (d *Details) addFolder(folder FolderEntry) {
 	d.Entries = append(d.Entries, DetailsEntry{
 		RepoRef:   folder.RepoRef,
 		ShortRef:  folder.ShortRef,
@@ -151,7 +202,6 @@ func (d *Details) AddFolders(folders []FolderEntry) {
 		ItemInfo:  folder.Info,
 	})
 }
-}
 
 // --------------------------------------------------------------------------------
 // Entry

src/pkg/backup/details/details_test.go

@@ -222,10 +222,22 @@ func (suite *DetailsUnitSuite) TestDetailsModel_Items() {
 }
 
 func (suite *DetailsUnitSuite) TestDetails_AddFolders() {
+	itemTime := time.Date(2022, 10, 21, 10, 0, 0, 0, time.UTC)
+	folderTimeOlderThanItem := time.Date(2022, 9, 21, 10, 0, 0, 0, time.UTC)
+	folderTimeNewerThanItem := time.Date(2022, 11, 21, 10, 0, 0, 0, time.UTC)
+
+	itemInfo := details.ItemInfo{
+		Exchange: &details.ExchangeInfo{
+			Size:     20,
+			Modified: itemTime,
+		},
+	}
+
 	table := []struct {
 		name               string
 		folders            []details.FolderEntry
 		expectedShortRefs  []string
+		expectedFolderInfo map[string]details.FolderInfo
 	}{
 		{
 			name: "MultipleFolders",
@@ -234,14 +246,28 @@ func (suite *DetailsUnitSuite) TestDetails_AddFolders() {
 					RepoRef:   "rr1",
 					ShortRef:  "sr1",
 					ParentRef: "pr1",
+					Info: details.ItemInfo{
+						Folder: &details.FolderInfo{
+							Modified: folderTimeOlderThanItem,
+						},
+					},
 				},
 				{
 					RepoRef:   "rr2",
 					ShortRef:  "sr2",
 					ParentRef: "pr2",
+					Info: details.ItemInfo{
+						Folder: &details.FolderInfo{
+							Modified: folderTimeNewerThanItem,
+						},
+					},
 				},
 			},
 			expectedShortRefs: []string{"sr1", "sr2"},
+			expectedFolderInfo: map[string]details.FolderInfo{
+				"sr1": {Size: 20, Modified: itemTime},
+				"sr2": {Size: 20, Modified: folderTimeNewerThanItem},
+			},
 		},
 		{
 			name: "MultipleFoldersWithRepeats",
@@ -250,36 +276,138 @@ func (suite *DetailsUnitSuite) TestDetails_AddFolders() {
 					RepoRef:   "rr1",
 					ShortRef:  "sr1",
 					ParentRef: "pr1",
+					Info: details.ItemInfo{
+						Folder: &details.FolderInfo{
+							Modified: folderTimeOlderThanItem,
+						},
+					},
 				},
 				{
 					RepoRef:   "rr2",
 					ShortRef:  "sr2",
 					ParentRef: "pr2",
+					Info: details.ItemInfo{
+						Folder: &details.FolderInfo{
+							Modified: folderTimeOlderThanItem,
+						},
+					},
 				},
 				{
 					RepoRef:   "rr1",
 					ShortRef:  "sr1",
 					ParentRef: "pr1",
+					Info: details.ItemInfo{
+						Folder: &details.FolderInfo{
+							Modified: folderTimeOlderThanItem,
+						},
+					},
 				},
 				{
 					RepoRef:   "rr3",
 					ShortRef:  "sr3",
 					ParentRef: "pr3",
+					Info: details.ItemInfo{
+						Folder: &details.FolderInfo{
+							Modified: folderTimeNewerThanItem,
+						},
+					},
 				},
 			},
 			expectedShortRefs: []string{"sr1", "sr2", "sr3"},
+			expectedFolderInfo: map[string]details.FolderInfo{
+				// Two items were added
+				"sr1": {Size: 40, Modified: itemTime},
+				"sr2": {Size: 20, Modified: itemTime},
+				"sr3": {Size: 20, Modified: folderTimeNewerThanItem},
+			},
 		},
 	}
 	for _, test := range table {
 		suite.T().Run(test.name, func(t *testing.T) {
-			deets := details.Details{}
-			deets.AddFolders(test.folders)
-
+			builder := details.Builder{}
+			builder.AddFoldersForItem(test.folders, itemInfo)
+			deets := builder.Details()
 			assert.Len(t, deets.Entries, len(test.expectedShortRefs))
 
 			for _, e := range deets.Entries {
 				assert.Contains(t, test.expectedShortRefs, e.ShortRef)
+				assert.Equal(t, test.expectedFolderInfo[e.ShortRef].Size, e.Folder.Size)
+				assert.Equal(t, test.expectedFolderInfo[e.ShortRef].Modified, e.Folder.Modified)
 			}
 		})
 	}
 }
+
+func (suite *DetailsUnitSuite) TestDetails_AddFoldersDifferentServices() {
+	itemTime := time.Date(2022, 10, 21, 10, 0, 0, 0, time.UTC)
+	folderTimeOlderThanItem := time.Date(2022, 9, 21, 10, 0, 0, 0, time.UTC)
+
+	table := []struct {
+		name               string
+		item               details.ItemInfo
+		expectedFolderInfo details.FolderInfo
+	}{
+		{
+			name: "Exchange",
+			item: details.ItemInfo{
+				Exchange: &details.ExchangeInfo{
+					Size:     20,
+					Modified: itemTime,
+				},
+			},
+			expectedFolderInfo: details.FolderInfo{
+				Size:     20,
+				Modified: itemTime,
+			},
+		},
+		{
+			name: "OneDrive",
+			item: details.ItemInfo{
+				OneDrive: &details.OneDriveInfo{
+					Size:     20,
+					Modified: itemTime,
+				},
+			},
+			expectedFolderInfo: details.FolderInfo{
+				Size:     20,
+				Modified: itemTime,
+			},
+		},
+		{
+			name: "SharePoint",
+			item: details.ItemInfo{
+				SharePoint: &details.SharePointInfo{
+					Size:     20,
+					Modified: itemTime,
+				},
+			},
+			expectedFolderInfo: details.FolderInfo{
+				Size:     20,
+				Modified: itemTime,
+			},
+		},
+	}
+	for _, test := range table {
+		suite.T().Run(test.name, func(t *testing.T) {
+			folderEntry := details.FolderEntry{
+				RepoRef:   "rr1",
+				ShortRef:  "sr1",
+				ParentRef: "pr1",
+				Info: details.ItemInfo{
+					Folder: &details.FolderInfo{
+						Modified: folderTimeOlderThanItem,
+					},
+				},
+			}
+
+			builder := details.Builder{}
+			builder.AddFoldersForItem([]details.FolderEntry{folderEntry}, test.item)
+			deets := builder.Details()
+			require.Len(t, deets.Entries, 1)
+
+			got := deets.Entries[0].Folder
+
+			assert.Equal(t, test.expectedFolderInfo, *got)
+		})
+	}
+}