add counter for skip-collision counting (#3722)

Introduces a counting bus, and threads it into restore operations so that we can count the number of
collision skips that occur.

---

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

- [x] ⛔ No

#### Type of change

- [x] 🌻 Feature

#### Issue(s)

* #3562

#### Test Plan

- [x] ⚡ Unit test
- [x] 💚 E2E

src/cli/restore/exchange.go

@@ -1,18 +1,11 @@
 package restore
 
 import (
-	"github.com/alcionai/clues"
-	"github.com/pkg/errors"
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
 
 	"github.com/alcionai/corso/src/cli/flags"
-	. "github.com/alcionai/corso/src/cli/print"
-	"github.com/alcionai/corso/src/cli/repo"
 	"github.com/alcionai/corso/src/cli/utils"
-	"github.com/alcionai/corso/src/internal/common/dttm"
-	"github.com/alcionai/corso/src/internal/data"
-	"github.com/alcionai/corso/src/pkg/path"
 )
 
 // called by restore.go to map subcommands to provider-specific handling.
@@ -94,33 +87,14 @@ func restoreExchangeCmd(cmd *cobra.Command, args []string) error {
 		return err
 	}
 
-	r, _, _, err := utils.GetAccountAndConnect(ctx, path.ExchangeService, repo.S3Overrides(cmd))
-	if err != nil {
-		return Only(ctx, err)
-	}
-
-	defer utils.CloseRepo(ctx, r)
-
-	restoreCfg := utils.MakeRestoreConfig(ctx, opts.RestoreCfg, dttm.HumanReadable)
-
 	sel := utils.IncludeExchangeRestoreDataSelectors(opts)
 	utils.FilterExchangeRestoreInfoSelectors(sel, opts)
 
-	ro, err := r.NewRestore(ctx, flags.BackupIDFV, sel.Selector, restoreCfg)
+	return runRestore(
-	if err != nil {
+		ctx,
-		return Only(ctx, clues.Wrap(err, "Failed to initialize Exchange restore"))
+		cmd,
-	}
+		opts.RestoreCfg,
-
+		sel.Selector,
-	ds, err := ro.Run(ctx)
+		flags.BackupIDFV,
-	if err != nil {
+		"Exchange")
-		if errors.Is(err, data.ErrNotFound) {
-			return Only(ctx, clues.New("Backup or backup details missing for id "+flags.BackupIDFV))
-		}
-
-		return Only(ctx, clues.Wrap(err, "Failed to run Exchange restore"))
-	}
-
-	ds.Items().MaybePrintEntries(ctx)
-
-	return nil
 }

src/cli/restore/onedrive.go

@@ -1,18 +1,12 @@
 package restore
 
 import (
-	"github.com/alcionai/clues"
-	"github.com/pkg/errors"
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
 
 	"github.com/alcionai/corso/src/cli/flags"
-	. "github.com/alcionai/corso/src/cli/print"
-	"github.com/alcionai/corso/src/cli/repo"
 	"github.com/alcionai/corso/src/cli/utils"
 	"github.com/alcionai/corso/src/internal/common/dttm"
-	"github.com/alcionai/corso/src/internal/data"
-	"github.com/alcionai/corso/src/pkg/path"
 )
 
 // called by restore.go to map subcommands to provider-specific handling.
@@ -84,6 +78,7 @@ func restoreOneDriveCmd(cmd *cobra.Command, args []string) error {
 	}
 
 	opts := utils.MakeOneDriveOpts(cmd)
+	opts.RestoreCfg.DTTMFormat = dttm.HumanReadableDriveItem
 
 	if flags.RunModeFV == flags.RunModeFlagTest {
 		return nil
@@ -93,33 +88,14 @@ func restoreOneDriveCmd(cmd *cobra.Command, args []string) error {
 		return err
 	}
 
-	r, _, _, err := utils.GetAccountAndConnect(ctx, path.OneDriveService, repo.S3Overrides(cmd))
-	if err != nil {
-		return Only(ctx, err)
-	}
-
-	defer utils.CloseRepo(ctx, r)
-
 	sel := utils.IncludeOneDriveRestoreDataSelectors(opts)
 	utils.FilterOneDriveRestoreInfoSelectors(sel, opts)
 
-	restoreCfg := utils.MakeRestoreConfig(ctx, opts.RestoreCfg, dttm.HumanReadableDriveItem)
+	return runRestore(
-
+		ctx,
-	ro, err := r.NewRestore(ctx, flags.BackupIDFV, sel.Selector, restoreCfg)
+		cmd,
-	if err != nil {
+		opts.RestoreCfg,
-		return Only(ctx, clues.Wrap(err, "Failed to initialize OneDrive restore"))
+		sel.Selector,
-	}
+		flags.BackupIDFV,
-
+		"OneDrive")
-	ds, err := ro.Run(ctx)
-	if err != nil {
-		if errors.Is(err, data.ErrNotFound) {
-			return Only(ctx, clues.New("Backup or backup details missing for id "+flags.BackupIDFV))
-		}
-
-		return Only(ctx, clues.Wrap(err, "Failed to run OneDrive restore"))
-	}
-
-	ds.Items().MaybePrintEntries(ctx)
-
-	return nil
 }

src/cli/restore/restore.go

@@ -1,7 +1,19 @@
 package restore
 
 import (
+	"context"
+
+	"github.com/alcionai/clues"
+	"github.com/pkg/errors"
 	"github.com/spf13/cobra"
+
+	"github.com/alcionai/corso/src/cli/flags"
+	. "github.com/alcionai/corso/src/cli/print"
+	"github.com/alcionai/corso/src/cli/repo"
+	"github.com/alcionai/corso/src/cli/utils"
+	"github.com/alcionai/corso/src/internal/data"
+	"github.com/alcionai/corso/src/pkg/count"
+	"github.com/alcionai/corso/src/pkg/selectors"
 )
 
 var restoreCommands = []func(cmd *cobra.Command) *cobra.Command{
@@ -39,3 +51,47 @@ func restoreCmd() *cobra.Command {
 func handleRestoreCmd(cmd *cobra.Command, args []string) error {
 	return cmd.Help()
 }
+
+// ---------------------------------------------------------------------------
+// common handlers
+// ---------------------------------------------------------------------------
+
+func runRestore(
+	ctx context.Context,
+	cmd *cobra.Command,
+	urco utils.RestoreCfgOpts,
+	sel selectors.Selector,
+	backupID, serviceName string,
+) error {
+	r, _, _, err := utils.GetAccountAndConnect(ctx, sel.PathService(), repo.S3Overrides(cmd))
+	if err != nil {
+		return Only(ctx, err)
+	}
+
+	defer utils.CloseRepo(ctx, r)
+
+	ro, err := r.NewRestore(ctx, backupID, sel, utils.MakeRestoreConfig(ctx, urco))
+	if err != nil {
+		return Only(ctx, clues.Wrap(err, "Failed to initialize "+serviceName+" restore"))
+	}
+
+	ds, err := ro.Run(ctx)
+	if err != nil {
+		if errors.Is(err, data.ErrNotFound) {
+			return Only(ctx, clues.New("Backup or backup details missing for id "+flags.BackupIDFV))
+		}
+
+		return Only(ctx, clues.Wrap(err, "Failed to run "+serviceName+" restore"))
+	}
+
+	Info(ctx, "Completed Restore:")
+
+	skipped := ro.Counter.Get(count.CollisionSkip)
+	if skipped > 0 {
+		Infof(ctx, "Skipped %d items due to collision", skipped)
+	}
+
+	ds.Items().MaybePrintEntries(ctx)
+
+	return nil
+}

src/cli/restore/sharepoint.go

@@ -1,18 +1,12 @@
 package restore
 
 import (
-	"github.com/alcionai/clues"
-	"github.com/pkg/errors"
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
 
 	"github.com/alcionai/corso/src/cli/flags"
-	. "github.com/alcionai/corso/src/cli/print"
-	"github.com/alcionai/corso/src/cli/repo"
 	"github.com/alcionai/corso/src/cli/utils"
 	"github.com/alcionai/corso/src/internal/common/dttm"
-	"github.com/alcionai/corso/src/internal/data"
-	"github.com/alcionai/corso/src/pkg/path"
 )
 
 // called by restore.go to map subcommands to provider-specific handling.
@@ -90,6 +84,7 @@ func restoreSharePointCmd(cmd *cobra.Command, args []string) error {
 	}
 
 	opts := utils.MakeSharePointOpts(cmd)
+	opts.RestoreCfg.DTTMFormat = dttm.HumanReadableDriveItem
 
 	if flags.RunModeFV == flags.RunModeFlagTest {
 		return nil
@@ -99,33 +94,14 @@ func restoreSharePointCmd(cmd *cobra.Command, args []string) error {
 		return err
 	}
 
-	r, _, _, err := utils.GetAccountAndConnect(ctx, path.SharePointService, repo.S3Overrides(cmd))
-	if err != nil {
-		return Only(ctx, err)
-	}
-
-	defer utils.CloseRepo(ctx, r)
-
 	sel := utils.IncludeSharePointRestoreDataSelectors(ctx, opts)
 	utils.FilterSharePointRestoreInfoSelectors(sel, opts)
 
-	restoreCfg := utils.MakeRestoreConfig(ctx, opts.RestoreCfg, dttm.HumanReadableDriveItem)
+	return runRestore(
-
+		ctx,
-	ro, err := r.NewRestore(ctx, flags.BackupIDFV, sel.Selector, restoreCfg)
+		cmd,
-	if err != nil {
+		opts.RestoreCfg,
-		return Only(ctx, clues.Wrap(err, "Failed to initialize SharePoint restore"))
+		sel.Selector,
-	}
+		flags.BackupIDFV,
-
+		"SharePoint")
-	ds, err := ro.Run(ctx)
-	if err != nil {
-		if errors.Is(err, data.ErrNotFound) {
-			return Only(ctx, clues.New("Backup or backup details missing for id "+flags.BackupIDFV))
-		}
-
-		return Only(ctx, clues.Wrap(err, "Failed to run SharePoint restore"))
-	}
-
-	ds.Items().MaybePrintEntries(ctx)
-
-	return nil
 }

src/cli/utils/restore_config.go

@@ -15,6 +15,10 @@ import (
 type RestoreCfgOpts struct {
 	Collisions  string
 	Destination string
+	// DTTMFormat is the timestamp format appended
+	// to the default folder name.  Defaults to
+	// dttm.HumanReadable.
+	DTTMFormat dttm.TimeFormat
 
 	Populated flags.PopulatedFlags
 }
@@ -23,6 +27,7 @@ func makeRestoreCfgOpts(cmd *cobra.Command) RestoreCfgOpts {
 	return RestoreCfgOpts{
 		Collisions:  flags.CollisionsFV,
 		Destination: flags.DestinationFV,
+		DTTMFormat:  dttm.HumanReadable,
 
 		// populated contains the list of flags that appear in the
 		// command, according to pflags.  Use this to differentiate
@@ -47,9 +52,12 @@ func validateRestoreConfigFlags(fv string, opts RestoreCfgOpts) error {
 func MakeRestoreConfig(
 	ctx context.Context,
 	opts RestoreCfgOpts,
-	locationTimeFormat dttm.TimeFormat,
 ) control.RestoreConfig {
-	restoreCfg := control.DefaultRestoreConfig(locationTimeFormat)
+	if len(opts.DTTMFormat) == 0 {
+		opts.DTTMFormat = dttm.HumanReadable
+	}
+
+	restoreCfg := control.DefaultRestoreConfig(opts.DTTMFormat)
 
 	if _, ok := opts.Populated[flags.CollisionsFN]; ok {
 		restoreCfg.OnCollision = control.CollisionPolicy(opts.Collisions)

src/cli/utils/restore_config_test.go

@@ -8,7 +8,6 @@ import (
 	"github.com/stretchr/testify/suite"
 
 	"github.com/alcionai/corso/src/cli/flags"
-	"github.com/alcionai/corso/src/internal/common/dttm"
 	"github.com/alcionai/corso/src/internal/tester"
 	"github.com/alcionai/corso/src/pkg/control"
 )
@@ -129,7 +128,7 @@ func (suite *RestoreCfgUnitSuite) TestMakeRestoreConfig() {
 			opts := *rco
 			opts.Populated = test.populated
 
-			result := MakeRestoreConfig(ctx, opts, dttm.HumanReadable)
+			result := MakeRestoreConfig(ctx, opts)
 			assert.Equal(t, test.expect.OnCollision, result.OnCollision)
 			assert.Contains(t, result.Location, test.expect.Location)
 		})

src/cli/utils/utils.go

@@ -71,8 +71,8 @@ func AccountConnectAndWriteRepoConfig(
 		return nil, nil, err
 	}
 
-	// repo config is already set while repo connect and init. This is just to confirm correct values.
+	// repo config gets set during repo connect and init.
-	// So won't fail is the write fails
+	// This call confirms we have the correct values.
 	err = config.WriteRepoConfig(ctx, s3Config, m365Config, r.GetID())
 	if err != nil {
 		logger.CtxErr(ctx, err).Info("writing to repository configuration")

src/cmd/factory/impl/common.go

@@ -27,6 +27,7 @@ import (
 	"github.com/alcionai/corso/src/pkg/backup/details"
 	"github.com/alcionai/corso/src/pkg/control"
 	"github.com/alcionai/corso/src/pkg/control/testdata"
+	"github.com/alcionai/corso/src/pkg/count"
 	"github.com/alcionai/corso/src/pkg/credentials"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/path"
@@ -63,6 +64,7 @@ func generateAndRestoreItems(
 	dbf dataBuilderFunc,
 	opts control.Options,
 	errs *fault.Bus,
+	ctr *count.Bus,
 ) (*details.Details, error) {
 	items := make([]item, 0, howMany)
 
@@ -102,7 +104,7 @@ func generateAndRestoreItems(
 
 	print.Infof(ctx, "Generating %d %s items in %s\n", howMany, cat, Destination)
 
-	return ctrl.ConsumeRestoreCollections(ctx, version.Backup, sel, restoreCfg, opts, dataColls, errs)
+	return ctrl.ConsumeRestoreCollections(ctx, version.Backup, sel, restoreCfg, opts, dataColls, errs, ctr)
 }
 
 // ------------------------------------------------------------------------------------------
@@ -220,8 +222,9 @@ func generateAndRestoreDriveItems(
 	cat path.CategoryType,
 	sel selectors.Selector,
 	tenantID, destFldr string,
-	count int,
+	intCount int,
 	errs *fault.Bus,
+	ctr *count.Bus,
 ) (
 	*details.Details,
 	error,
@@ -266,7 +269,7 @@ func generateAndRestoreDriveItems(
 		currentTime      = fmt.Sprintf("%d-%v-%d-%d-%d-%d", year, mnth, date, hour, min, sec)
 	)
 
-	for i := 0; i < count; i++ {
+	for i := 0; i < intCount; i++ {
 		col := []odStub.ColInfo{
 			// basic folder and file creation
 			{
@@ -426,5 +429,5 @@ func generateAndRestoreDriveItems(
 		return nil, err
 	}
 
-	return ctrl.ConsumeRestoreCollections(ctx, version.Backup, sel, restoreCfg, opts, collections, errs)
+	return ctrl.ConsumeRestoreCollections(ctx, version.Backup, sel, restoreCfg, opts, collections, errs, ctr)
 }

src/cmd/factory/impl/exchange.go

@@ -8,6 +8,7 @@ import (
 	exchMock "github.com/alcionai/corso/src/internal/m365/exchange/mock"
 	"github.com/alcionai/corso/src/internal/m365/resource"
 	"github.com/alcionai/corso/src/pkg/control"
+	"github.com/alcionai/corso/src/pkg/count"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/logger"
 	"github.com/alcionai/corso/src/pkg/path"
@@ -72,7 +73,8 @@ func handleExchangeEmailFactory(cmd *cobra.Command, args []string) error {
 				now, now, now, now)
 		},
 		control.Defaults(),
-		errs)
+		errs,
+		count.New())
 	if err != nil {
 		return Only(ctx, err)
 	}
@@ -120,7 +122,8 @@ func handleExchangeCalendarEventFactory(cmd *cobra.Command, args []string) error
 				exchMock.NoExceptionOccurrences)
 		},
 		control.Defaults(),
-		errs)
+		errs,
+		count.New())
 	if err != nil {
 		return Only(ctx, err)
 	}
@@ -170,7 +173,8 @@ func handleExchangeContactFactory(cmd *cobra.Command, args []string) error {
 			)
 		},
 		control.Defaults(),
-		errs)
+		errs,
+		count.New())
 	if err != nil {
 		return Only(ctx, err)
 	}

src/cmd/factory/impl/onedrive.go

@@ -8,6 +8,7 @@ import (
 	. "github.com/alcionai/corso/src/cli/print"
 	"github.com/alcionai/corso/src/cli/utils"
 	"github.com/alcionai/corso/src/internal/m365/resource"
+	"github.com/alcionai/corso/src/pkg/count"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/logger"
 	"github.com/alcionai/corso/src/pkg/path"
@@ -56,7 +57,8 @@ func handleOneDriveFileFactory(cmd *cobra.Command, args []string) error {
 		Tenant,
 		Destination,
 		Count,
-		errs)
+		errs,
+		count.New())
 	if err != nil {
 		return Only(ctx, err)
 	}

src/cmd/factory/impl/sharepoint.go

@@ -8,6 +8,7 @@ import (
 	. "github.com/alcionai/corso/src/cli/print"
 	"github.com/alcionai/corso/src/cli/utils"
 	"github.com/alcionai/corso/src/internal/m365/resource"
+	"github.com/alcionai/corso/src/pkg/count"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/logger"
 	"github.com/alcionai/corso/src/pkg/path"
@@ -56,7 +57,8 @@ func handleSharePointLibraryFileFactory(cmd *cobra.Command, args []string) error
 		Tenant,
 		Destination,
 		Count,
-		errs)
+		errs,
+		count.New())
 	if err != nil {
 		return Only(ctx, err)
 	}

src/go.mod

@@ -22,6 +22,7 @@ require (
 	github.com/microsoftgraph/msgraph-sdk-go v1.4.0
 	github.com/microsoftgraph/msgraph-sdk-go-core v1.0.0
 	github.com/pkg/errors v0.9.1
+	github.com/puzpuzpuz/xsync/v2 v2.4.1
 	github.com/rudderlabs/analytics-go v3.3.3+incompatible
 	github.com/spatialcurrent/go-lazy v0.0.0-20211115014721-47315cc003d1
 	github.com/spf13/cobra v1.7.0

src/go.sum

@@ -345,6 +345,8 @@ github.com/prometheus/procfs v0.0.2/go.mod h1:TjEm7ze935MbeOT/UhFTIMYKhuLP4wbCsT
 github.com/prometheus/procfs v0.0.8/go.mod h1:7Qr8sr6344vo1JqZ6HhLceV9o3AJ1Ff+GxbHq6oeK9A=
 github.com/prometheus/procfs v0.9.0 h1:wzCHvIvM5SxWqYvwgVL7yJY8Lz3PKn49KQtpgMYJfhI=
 github.com/prometheus/procfs v0.9.0/go.mod h1:+pB4zwohETzFnmlpe6yd2lSc+0/46IYZRB/chUwxUZY=
+github.com/puzpuzpuz/xsync/v2 v2.4.1 h1:aGdE1C/HaR/QC6YAFdtZXi60Df8/qBIrs8PKrzkItcM=
+github.com/puzpuzpuz/xsync/v2 v2.4.1/go.mod h1:gD2H2krq/w52MfPLE+Uy64TzJDVY7lP2znR9qmR35kU=
 github.com/rivo/uniseg v0.2.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
 github.com/rivo/uniseg v0.4.3 h1:utMvzDsuh3suAEnhH0RdHmoPbU648o6CvXxTx4SBMOw=
 github.com/rivo/uniseg v0.4.3/go.mod h1:FN3SvrM+Zdj16jyLfmOkMNblXMcoc8DfTHruCPUcx88=

src/internal/kopia/conn.go

@@ -385,7 +385,7 @@ func (w *conn) writePolicy(
 	ctx = clues.Add(ctx, "source_info", si)
 
 	writeOpts := repo.WriteSessionOptions{Purpose: purpose}
-	cb := func(innerCtx context.Context, rw repo.RepositoryWriter) error {
+	ctr := func(innerCtx context.Context, rw repo.RepositoryWriter) error {
 		if err := policy.SetPolicy(ctx, rw, si, p); err != nil {
 			return clues.Stack(err).WithClues(innerCtx)
 		}
@@ -393,7 +393,7 @@ func (w *conn) writePolicy(
 		return nil
 	}
 
-	if err := repo.WriteSession(ctx, w.Repository, writeOpts, cb); err != nil {
+	if err := repo.WriteSession(ctx, w.Repository, writeOpts, ctr); err != nil {
 		return clues.Wrap(err, "updating policy").WithClues(ctx)
 	}
 

src/internal/kopia/model_store.go

@@ -506,11 +506,11 @@ func (ms *ModelStore) DeleteWithModelStoreID(ctx context.Context, id manifest.ID
 	}
 
 	opts := repo.WriteSessionOptions{Purpose: "ModelStoreDelete"}
-	cb := func(innerCtx context.Context, w repo.RepositoryWriter) error {
+	ctr := func(innerCtx context.Context, w repo.RepositoryWriter) error {
 		return w.DeleteManifest(innerCtx, id)
 	}
 
-	if err := repo.WriteSession(ctx, ms.c, opts, cb); err != nil {
+	if err := repo.WriteSession(ctx, ms.c, opts, ctr); err != nil {
 		return clues.Wrap(err, "deleting model").WithClues(ctx)
 	}
 

src/internal/kopia/upload.go

@@ -302,7 +302,7 @@ func (cp *corsoProgress) get(k string) *itemDetails {
 
 func collectionEntries(
 	ctx context.Context,
-	cb func(context.Context, fs.Entry) error,
+	ctr func(context.Context, fs.Entry) error,
 	streamedEnts data.BackupCollection,
 	progress *corsoProgress,
 ) (map[string]struct{}, error) {
@@ -399,7 +399,7 @@ func collectionEntries(
 				modTime,
 				newBackupStreamReader(serializationVersion, e.ToReader()))
 
-			err = cb(ctx, entry)
+			err = ctr(ctx, entry)
 			if err != nil {
 				// Kopia's uploader swallows errors in most cases, so if we see
 				// something here it's probably a big issue and we should return.
@@ -411,7 +411,7 @@ func collectionEntries(
 
 func streamBaseEntries(
 	ctx context.Context,
-	cb func(context.Context, fs.Entry) error,
+	ctr func(context.Context, fs.Entry) error,
 	curPath path.Path,
 	prevPath path.Path,
 	locationPath *path.Builder,
@@ -501,7 +501,7 @@ func streamBaseEntries(
 			progress.put(encodeAsPath(itemPath.PopFront().Elements()...), d)
 		}
 
-		if err := cb(ctx, entry); err != nil {
+		if err := ctr(ctx, entry); err != nil {
 			return clues.Wrap(err, "executing callback on item").With("item_path", itemPath)
 		}
 
@@ -527,13 +527,13 @@ func getStreamItemFunc(
 	globalExcludeSet prefixmatcher.StringSetReader,
 	progress *corsoProgress,
 ) func(context.Context, func(context.Context, fs.Entry) error) error {
-	return func(ctx context.Context, cb func(context.Context, fs.Entry) error) error {
+	return func(ctx context.Context, ctr func(context.Context, fs.Entry) error) error {
 		ctx, end := diagnostics.Span(ctx, "kopia:getStreamItemFunc")
 		defer end()
 
 		// Return static entries in this directory first.
 		for _, d := range staticEnts {
-			if err := cb(ctx, d); err != nil {
+			if err := ctr(ctx, d); err != nil {
 				return clues.Wrap(err, "executing callback on static directory").WithClues(ctx)
 			}
 		}
@@ -544,14 +544,14 @@ func getStreamItemFunc(
 			locationPath = lp.LocationPath()
 		}
 
-		seen, err := collectionEntries(ctx, cb, streamedEnts, progress)
+		seen, err := collectionEntries(ctx, ctr, streamedEnts, progress)
 		if err != nil {
 			return clues.Wrap(err, "streaming collection entries")
 		}
 
 		if err := streamBaseEntries(
 			ctx,
-			cb,
+			ctr,
 			curPath,
 			prevPath,
 			locationPath,

src/internal/m365/controller_test.go

@@ -24,6 +24,7 @@ import (
 	"github.com/alcionai/corso/src/internal/version"
 	"github.com/alcionai/corso/src/pkg/control"
 	"github.com/alcionai/corso/src/pkg/control/testdata"
+	"github.com/alcionai/corso/src/pkg/count"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/path"
 	"github.com/alcionai/corso/src/pkg/selectors"
@@ -314,7 +315,8 @@ func (suite *ControllerIntegrationSuite) TestRestoreFailsBadService() {
 			ToggleFeatures:     control.Toggles{},
 		},
 		nil,
-		fault.New(true))
+		fault.New(true),
+		count.New())
 	assert.Error(t, err, clues.ToCore(err))
 	assert.NotNil(t, deets)
 
@@ -392,7 +394,8 @@ func (suite *ControllerIntegrationSuite) TestEmptyCollections() {
 					ToggleFeatures:     control.Toggles{},
 				},
 				test.col,
-				fault.New(true))
+				fault.New(true),
+				count.New())
 			require.NoError(t, err, clues.ToCore(err))
 			assert.NotNil(t, deets)
 
@@ -432,7 +435,8 @@ func runRestore(
 		sci.RestoreCfg,
 		sci.Opts,
 		collections,
-		fault.New(true))
+		fault.New(true),
+		count.New())
 	require.NoError(t, err, clues.ToCore(err))
 	assert.NotNil(t, deets)
 
@@ -1042,7 +1046,8 @@ func (suite *ControllerIntegrationSuite) TestMultiFolderBackupDifferentNames() {
 						ToggleFeatures:     control.Toggles{},
 					},
 					collections,
-					fault.New(true))
+					fault.New(true),
+					count.New())
 				require.NoError(t, err, clues.ToCore(err))
 				require.NotNil(t, deets)
 

src/internal/m365/exchange/contacts_restore.go

@@ -10,6 +10,7 @@ import (
 	"github.com/alcionai/corso/src/internal/m365/graph"
 	"github.com/alcionai/corso/src/pkg/backup/details"
 	"github.com/alcionai/corso/src/pkg/control"
+	"github.com/alcionai/corso/src/pkg/count"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/logger"
 	"github.com/alcionai/corso/src/pkg/path"
@@ -71,6 +72,7 @@ func (h contactRestoreHandler) restore(
 	collisionKeyToItemID map[string]string,
 	collisionPolicy control.CollisionPolicy,
 	errs *fault.Bus,
+	ctr *count.Bus,
 ) (*details.ExchangeInfo, error) {
 	return restoreContact(
 		ctx,
@@ -79,7 +81,8 @@ func (h contactRestoreHandler) restore(
 		userID, destinationID,
 		collisionKeyToItemID,
 		collisionPolicy,
-		errs)
+		errs,
+		ctr)
 }
 
 type contactRestorer interface {
@@ -95,6 +98,7 @@ func restoreContact(
 	collisionKeyToItemID map[string]string,
 	collisionPolicy control.CollisionPolicy,
 	errs *fault.Bus,
+	ctr *count.Bus,
 ) (*details.ExchangeInfo, error) {
 	contact, err := api.BytesToContactable(body)
 	if err != nil {
@@ -114,7 +118,9 @@ func restoreContact(
 		log.Debug("item collision")
 
 		if collisionPolicy == control.Skip {
+			ctr.Inc(count.CollisionSkip)
 			log.Debug("skipping item with collision")
+
 			return nil, graph.ErrItemAlreadyExistsConflict
 		}
 

src/internal/m365/exchange/contacts_restore_test.go

@@ -16,6 +16,7 @@ import (
 	"github.com/alcionai/corso/src/internal/tester/tconfig"
 	"github.com/alcionai/corso/src/pkg/control"
 	"github.com/alcionai/corso/src/pkg/control/testdata"
+	"github.com/alcionai/corso/src/pkg/count"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/path"
 	"github.com/alcionai/corso/src/pkg/services/m365/api"
@@ -191,7 +192,8 @@ func (suite *ContactsRestoreIntgSuite) TestRestoreContact() {
 				"destination",
 				test.collisionMap,
 				test.onCollision,
-				fault.New(true))
+				fault.New(true),
+				count.New())
 
 			test.expectErr(t, err)
 			test.expectMock(t, test.apiMock)

src/internal/m365/exchange/events_restore.go

@@ -11,6 +11,7 @@ import (
 	"github.com/alcionai/corso/src/internal/m365/graph"
 	"github.com/alcionai/corso/src/pkg/backup/details"
 	"github.com/alcionai/corso/src/pkg/control"
+	"github.com/alcionai/corso/src/pkg/count"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/logger"
 	"github.com/alcionai/corso/src/pkg/path"
@@ -72,6 +73,7 @@ func (h eventRestoreHandler) restore(
 	collisionKeyToItemID map[string]string,
 	collisionPolicy control.CollisionPolicy,
 	errs *fault.Bus,
+	ctr *count.Bus,
 ) (*details.ExchangeInfo, error) {
 	return restoreEvent(
 		ctx,
@@ -80,7 +82,8 @@ func (h eventRestoreHandler) restore(
 		userID, destinationID,
 		collisionKeyToItemID,
 		collisionPolicy,
-		errs)
+		errs,
+		ctr)
 }
 
 type eventRestorer interface {
@@ -96,6 +99,7 @@ func restoreEvent(
 	collisionKeyToItemID map[string]string,
 	collisionPolicy control.CollisionPolicy,
 	errs *fault.Bus,
+	ctr *count.Bus,
 ) (*details.ExchangeInfo, error) {
 	event, err := api.BytesToEventable(body)
 	if err != nil {
@@ -115,7 +119,9 @@ func restoreEvent(
 		log.Debug("item collision")
 
 		if collisionPolicy == control.Skip {
+			ctr.Inc(count.CollisionSkip)
 			log.Debug("skipping item with collision")
+
 			return nil, graph.ErrItemAlreadyExistsConflict
 		}
 

src/internal/m365/exchange/events_restore_test.go

@@ -17,6 +17,7 @@ import (
 	"github.com/alcionai/corso/src/internal/tester/tconfig"
 	"github.com/alcionai/corso/src/pkg/control"
 	"github.com/alcionai/corso/src/pkg/control/testdata"
+	"github.com/alcionai/corso/src/pkg/count"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/path"
 	"github.com/alcionai/corso/src/pkg/services/m365/api"
@@ -239,7 +240,8 @@ func (suite *EventsRestoreIntgSuite) TestRestoreEvent() {
 				"destination",
 				test.collisionMap,
 				test.onCollision,
-				fault.New(true))
+				fault.New(true),
+				count.New())
 
 			test.expectErr(t, err)
 			test.expectMock(t, test.apiMock)

src/internal/m365/exchange/handlers.go

@@ -8,6 +8,7 @@ import (
 	"github.com/alcionai/corso/src/internal/m365/graph"
 	"github.com/alcionai/corso/src/pkg/backup/details"
 	"github.com/alcionai/corso/src/pkg/control"
+	"github.com/alcionai/corso/src/pkg/count"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/path"
 	"github.com/alcionai/corso/src/pkg/services/m365/api"
@@ -80,6 +81,7 @@ type itemRestorer interface {
 		collisionKeyToItemID map[string]string,
 		collisionPolicy control.CollisionPolicy,
 		errs *fault.Bus,
+		ctr *count.Bus,
 	) (*details.ExchangeInfo, error)
 }
 

src/internal/m365/exchange/mail_restore.go

@@ -11,6 +11,7 @@ import (
 	"github.com/alcionai/corso/src/internal/m365/graph"
 	"github.com/alcionai/corso/src/pkg/backup/details"
 	"github.com/alcionai/corso/src/pkg/control"
+	"github.com/alcionai/corso/src/pkg/count"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/logger"
 	"github.com/alcionai/corso/src/pkg/path"
@@ -76,6 +77,7 @@ func (h mailRestoreHandler) restore(
 	collisionKeyToItemID map[string]string,
 	collisionPolicy control.CollisionPolicy,
 	errs *fault.Bus,
+	ctr *count.Bus,
 ) (*details.ExchangeInfo, error) {
 	return restoreMail(
 		ctx,
@@ -84,7 +86,8 @@ func (h mailRestoreHandler) restore(
 		userID, destinationID,
 		collisionKeyToItemID,
 		collisionPolicy,
-		errs)
+		errs,
+		ctr)
 }
 
 type mailRestorer interface {
@@ -101,6 +104,7 @@ func restoreMail(
 	collisionKeyToItemID map[string]string,
 	collisionPolicy control.CollisionPolicy,
 	errs *fault.Bus,
+	ctr *count.Bus,
 ) (*details.ExchangeInfo, error) {
 	msg, err := api.BytesToMessageable(body)
 	if err != nil {
@@ -120,7 +124,9 @@ func restoreMail(
 		log.Debug("item collision")
 
 		if collisionPolicy == control.Skip {
+			ctr.Inc(count.CollisionSkip)
 			log.Debug("skipping item with collision")
+
 			return nil, graph.ErrItemAlreadyExistsConflict
 		}
 

src/internal/m365/exchange/mail_restore_test.go

@@ -17,6 +17,7 @@ import (
 	"github.com/alcionai/corso/src/internal/tester/tconfig"
 	"github.com/alcionai/corso/src/pkg/control"
 	"github.com/alcionai/corso/src/pkg/control/testdata"
+	"github.com/alcionai/corso/src/pkg/count"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/path"
 	"github.com/alcionai/corso/src/pkg/services/m365/api"
@@ -208,7 +209,8 @@ func (suite *MailRestoreIntgSuite) TestRestoreMail() {
 				"destination",
 				test.collisionMap,
 				test.onCollision,
-				fault.New(true))
+				fault.New(true),
+				count.New())
 
 			test.expectErr(t, err)
 			test.expectMock(t, test.apiMock)

src/internal/m365/exchange/restore.go

@@ -16,6 +16,7 @@ import (
 	"github.com/alcionai/corso/src/internal/observe"
 	"github.com/alcionai/corso/src/pkg/backup/details"
 	"github.com/alcionai/corso/src/pkg/control"
+	"github.com/alcionai/corso/src/pkg/count"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/logger"
 	"github.com/alcionai/corso/src/pkg/path"
@@ -31,6 +32,7 @@ func ConsumeRestoreCollections(
 	dcs []data.RestoreCollection,
 	deets *details.Builder,
 	errs *fault.Bus,
+	ctr *count.Bus,
 ) (*support.ControllerOperationStatus, error) {
 	if len(dcs) == 0 {
 		return support.CreateStatus(ctx, support.Restore, 0, support.CollectionMetrics{}, ""), nil
@@ -103,7 +105,8 @@ func ConsumeRestoreCollections(
 			collisionKeyToItemID,
 			restoreCfg.OnCollision,
 			deets,
-			errs)
+			errs,
+			ctr.Local())
 
 		metrics = support.CombineMetrics(metrics, temp)
 
@@ -136,6 +139,7 @@ func restoreCollection(
 	collisionPolicy control.CollisionPolicy,
 	deets *details.Builder,
 	errs *fault.Bus,
+	ctr *count.Bus,
 ) (support.CollectionMetrics, error) {
 	ctx, end := diagnostics.Span(ctx, "m365:exchange:restoreCollection", diagnostics.Label("path", dc.FullPath()))
 	defer end()
@@ -185,7 +189,8 @@ func restoreCollection(
 				destinationID,
 				collisionKeyToItemID,
 				collisionPolicy,
-				errs)
+				errs,
+				ctr)
 			if err != nil {
 				if !graph.IsErrItemAlreadyExistsConflict(err) {
 					el.AddRecoverable(ictx, err)

src/internal/m365/exchange/restore_test.go

@@ -16,6 +16,7 @@ import (
 	"github.com/alcionai/corso/src/pkg/account"
 	"github.com/alcionai/corso/src/pkg/control"
 	"github.com/alcionai/corso/src/pkg/control/testdata"
+	"github.com/alcionai/corso/src/pkg/count"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/path"
 	"github.com/alcionai/corso/src/pkg/services/m365/api"
@@ -78,7 +79,8 @@ func (suite *RestoreIntgSuite) TestRestoreContact() {
 		userID, folderID,
 		nil,
 		control.Copy,
-		fault.New(true))
+		fault.New(true),
+		count.New())
 	assert.NoError(t, err, clues.ToCore(err))
 	assert.NotNil(t, info, "contact item info")
 }
@@ -152,7 +154,8 @@ func (suite *RestoreIntgSuite) TestRestoreEvent() {
 				userID, calendarID,
 				nil,
 				control.Copy,
-				fault.New(true))
+				fault.New(true),
+				count.New())
 			assert.NoError(t, err, clues.ToCore(err))
 			assert.NotNil(t, info, "event item info")
 		})
@@ -380,7 +383,8 @@ func (suite *RestoreIntgSuite) TestRestoreExchangeObject() {
 				userID, destination,
 				nil,
 				control.Copy,
-				fault.New(true))
+				fault.New(true),
+				count.New())
 			assert.NoError(t, err, clues.ToCore(err))
 			assert.NotNil(t, info, "item info was not populated")
 		})
@@ -413,7 +417,8 @@ func (suite *RestoreIntgSuite) TestRestoreAndBackupEvent_recurringInstancesWithA
 		userID, calendarID,
 		nil,
 		control.Copy,
-		fault.New(true))
+		fault.New(true),
+		count.New())
 	require.NoError(t, err, clues.ToCore(err))
 	assert.NotNil(t, info, "event item info")
 

src/internal/m365/graph/errors_test.go

@@ -384,22 +384,22 @@ func (suite *GraphErrorsUnitSuite) TestIsErrUnauthorized() {
 
 func (suite *GraphErrorsUnitSuite) TestMalwareInfo() {
 	var (
-		i        = models.NewDriveItem()
+		i         = models.NewDriveItem()
-		cb       = models.NewUser()
+		createdBy = models.NewUser()
-		cbID     = "created-by"
+		cbID      = "created-by"
-		lm       = models.NewUser()
+		lm        = models.NewUser()
-		lmID     = "last-mod-by"
+		lmID      = "last-mod-by"
-		ref      = models.NewItemReference()
+		ref       = models.NewItemReference()
-		refCID   = "container-id"
+		refCID    = "container-id"
-		refCN    = "container-name"
+		refCN     = "container-name"
-		refCP    = "/drives/b!vF-sdsdsds-sdsdsa-sdsd/root:/Folder/container-name"
+		refCP     = "/drives/b!vF-sdsdsds-sdsdsa-sdsd/root:/Folder/container-name"
-		refCPexp = "/Folder/container-name"
+		refCPexp  = "/Folder/container-name"
-		mal      = models.NewMalware()
+		mal       = models.NewMalware()
-		malDesc  = "malware-description"
+		malDesc   = "malware-description"
 	)
 
-	cb.SetId(&cbID)
+	createdBy.SetId(&cbID)
-	i.SetCreatedByUser(cb)
+	i.SetCreatedByUser(createdBy)
 
 	lm.SetId(&lmID)
 	i.SetLastModifiedByUser(lm)

src/internal/m365/mock/connector.go

@@ -9,6 +9,7 @@ import (
 	"github.com/alcionai/corso/src/internal/operations/inject"
 	"github.com/alcionai/corso/src/pkg/backup/details"
 	"github.com/alcionai/corso/src/pkg/control"
+	"github.com/alcionai/corso/src/pkg/count"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/path"
 	"github.com/alcionai/corso/src/pkg/selectors"
@@ -64,6 +65,7 @@ func (ctrl Controller) ConsumeRestoreCollections(
 	_ control.Options,
 	_ []data.RestoreCollection,
 	_ *fault.Bus,
+	_ *count.Bus,
 ) (*details.Details, error) {
 	return ctrl.Deets, ctrl.Err
 }

src/internal/m365/onedrive/restore.go

@@ -25,6 +25,7 @@ import (
 	"github.com/alcionai/corso/src/internal/version"
 	"github.com/alcionai/corso/src/pkg/backup/details"
 	"github.com/alcionai/corso/src/pkg/control"
+	"github.com/alcionai/corso/src/pkg/count"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/logger"
 	"github.com/alcionai/corso/src/pkg/path"
@@ -75,6 +76,7 @@ func ConsumeRestoreCollections(
 	dcs []data.RestoreCollection,
 	deets *details.Builder,
 	errs *fault.Bus,
+	ctr *count.Bus,
 ) (*support.ControllerOperationStatus, error) {
 	var (
 		restoreMetrics support.CollectionMetrics
@@ -113,7 +115,8 @@ func ConsumeRestoreCollections(
 			caches,
 			deets,
 			opts.RestorePermissions,
-			errs)
+			errs,
+			ctr.Local())
 		if err != nil {
 			el.AddRecoverable(ctx, err)
 		}
@@ -150,6 +153,7 @@ func RestoreCollection(
 	deets *details.Builder,
 	restorePerms bool, // TODD: move into restoreConfig
 	errs *fault.Bus,
+	ctr *count.Bus,
 ) (support.CollectionMetrics, error) {
 	var (
 		metrics        = support.CollectionMetrics{}
@@ -303,7 +307,8 @@ func RestoreCollection(
 					caches,
 					restorePerms,
 					itemData,
-					itemPath)
+					itemPath,
+					ctr)
 
 				// skipped items don't get counted, but they can error
 				if !skipped {
@@ -353,6 +358,7 @@ func restoreItem(
 	restorePerms bool,
 	itemData data.Stream,
 	itemPath path.Path,
+	ctr *count.Bus,
 ) (details.ItemInfo, bool, error) {
 	itemUUID := itemData.UUID()
 	ctx = clues.Add(ctx, "item_id", itemUUID)
@@ -367,7 +373,8 @@ func restoreItem(
 			restoreFolderID,
 			copyBuffer,
 			caches.collisionKeyToItemID,
-			itemData)
+			itemData,
+			ctr)
 		if err != nil {
 			if errors.Is(err, graph.ErrItemAlreadyExistsConflict) && restoreCfg.OnCollision == control.Skip {
 				return details.ItemInfo{}, true, nil
@@ -424,7 +431,8 @@ func restoreItem(
 			restorePerms,
 			caches,
 			itemPath,
-			itemData)
+			itemData,
+			ctr)
 		if err != nil {
 			if errors.Is(err, graph.ErrItemAlreadyExistsConflict) && restoreCfg.OnCollision == control.Skip {
 				return details.ItemInfo{}, true, nil
@@ -449,7 +457,8 @@ func restoreItem(
 		restorePerms,
 		caches,
 		itemPath,
-		itemData)
+		itemData,
+		ctr)
 	if err != nil {
 		if errors.Is(err, graph.ErrItemAlreadyExistsConflict) && restoreCfg.OnCollision == control.Skip {
 			return details.ItemInfo{}, true, nil
@@ -471,6 +480,7 @@ func restoreV0File(
 	copyBuffer []byte,
 	collisionKeyToItemID map[string]api.DriveCollisionItem,
 	itemData data.Stream,
+	ctr *count.Bus,
 ) (details.ItemInfo, error) {
 	_, itemInfo, err := restoreFile(
 		ctx,
@@ -482,7 +492,8 @@ func restoreV0File(
 		drivePath.DriveID,
 		restoreFolderID,
 		collisionKeyToItemID,
-		copyBuffer)
+		copyBuffer,
+		ctr)
 	if err != nil {
 		return itemInfo, clues.Wrap(err, "restoring file")
 	}
@@ -502,6 +513,7 @@ func restoreV1File(
 	caches *restoreCaches,
 	itemPath path.Path,
 	itemData data.Stream,
+	ctr *count.Bus,
 ) (details.ItemInfo, error) {
 	trimmedName := strings.TrimSuffix(itemData.UUID(), metadata.DataFileSuffix)
 
@@ -515,7 +527,8 @@ func restoreV1File(
 		drivePath.DriveID,
 		restoreFolderID,
 		caches.collisionKeyToItemID,
-		copyBuffer)
+		copyBuffer,
+		ctr)
 	if err != nil {
 		return details.ItemInfo{}, err
 	}
@@ -561,6 +574,7 @@ func restoreV6File(
 	caches *restoreCaches,
 	itemPath path.Path,
 	itemData data.Stream,
+	ctr *count.Bus,
 ) (details.ItemInfo, error) {
 	trimmedName := strings.TrimSuffix(itemData.UUID(), metadata.DataFileSuffix)
 
@@ -598,7 +612,8 @@ func restoreV6File(
 		drivePath.DriveID,
 		restoreFolderID,
 		caches.collisionKeyToItemID,
-		copyBuffer)
+		copyBuffer,
+		ctr)
 	if err != nil {
 		return details.ItemInfo{}, err
 	}
@@ -795,6 +810,7 @@ func restoreFile(
 	driveID, parentFolderID string,
 	collisionKeyToItemID map[string]api.DriveCollisionItem,
 	copyBuffer []byte,
+	ctr *count.Bus,
 ) (string, details.ItemInfo, error) {
 	ctx, end := diagnostics.Span(ctx, "gc:oneDrive:restoreItem", diagnostics.Label("item_uuid", itemData.UUID()))
 	defer end()
@@ -819,7 +835,9 @@ func restoreFile(
 		log.Debug("item collision")
 
 		if restoreCfg.OnCollision == control.Skip {
+			ctr.Inc(count.CollisionSkip)
 			log.Debug("skipping item with collision")
+
 			return "", details.ItemInfo{}, graph.ErrItemAlreadyExistsConflict
 		}
 

src/internal/m365/onedrive/restore_test.go

@@ -18,6 +18,7 @@ import (
 	"github.com/alcionai/corso/src/internal/tester"
 	"github.com/alcionai/corso/src/internal/version"
 	"github.com/alcionai/corso/src/pkg/control"
+	"github.com/alcionai/corso/src/pkg/count"
 	"github.com/alcionai/corso/src/pkg/path"
 	"github.com/alcionai/corso/src/pkg/services/m365/api"
 )
@@ -492,7 +493,8 @@ func (suite *RestoreUnitSuite) TestRestoreItem_collisionHandling() {
 					ID:     uuid.NewString(),
 					Reader: mock.FileRespReadCloser(mock.DriveFilePayloadData),
 				},
-				nil)
+				nil,
+				count.New())
 			require.NoError(t, err, clues.ToCore(err))
 			test.expectSkipped(t, skip)
 			test.expectMock(t, rh)

src/internal/m365/restore.go

@@ -14,6 +14,7 @@ import (
 	"github.com/alcionai/corso/src/internal/m365/support"
 	"github.com/alcionai/corso/src/pkg/backup/details"
 	"github.com/alcionai/corso/src/pkg/control"
+	"github.com/alcionai/corso/src/pkg/count"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/selectors"
 )
@@ -29,6 +30,7 @@ func (ctrl *Controller) ConsumeRestoreCollections(
 	opts control.Options,
 	dcs []data.RestoreCollection,
 	errs *fault.Bus,
+	ctr *count.Bus,
 ) (*details.Details, error) {
 	ctx, end := diagnostics.Span(ctx, "m365:restore")
 	defer end()
@@ -44,7 +46,7 @@ func (ctrl *Controller) ConsumeRestoreCollections(
 
 	switch sels.Service {
 	case selectors.ServiceExchange:
-		status, err = exchange.ConsumeRestoreCollections(ctx, ctrl.AC, restoreCfg, dcs, deets, errs)
+		status, err = exchange.ConsumeRestoreCollections(ctx, ctrl.AC, restoreCfg, dcs, deets, errs, ctr)
 	case selectors.ServiceOneDrive:
 		status, err = onedrive.ConsumeRestoreCollections(
 			ctx,
@@ -54,7 +56,8 @@ func (ctrl *Controller) ConsumeRestoreCollections(
 			opts,
 			dcs,
 			deets,
-			errs)
+			errs,
+			ctr)
 	case selectors.ServiceSharePoint:
 		status, err = sharepoint.ConsumeRestoreCollections(
 			ctx,
@@ -64,7 +67,8 @@ func (ctrl *Controller) ConsumeRestoreCollections(
 			opts,
 			dcs,
 			deets,
-			errs)
+			errs,
+			ctr)
 	default:
 		err = clues.Wrap(clues.New(sels.Service.String()), "service not supported")
 	}

src/internal/m365/sharepoint/restore.go

@@ -19,6 +19,7 @@ import (
 	"github.com/alcionai/corso/src/internal/m365/support"
 	"github.com/alcionai/corso/src/pkg/backup/details"
 	"github.com/alcionai/corso/src/pkg/control"
+	"github.com/alcionai/corso/src/pkg/count"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/logger"
 	"github.com/alcionai/corso/src/pkg/path"
@@ -35,6 +36,7 @@ func ConsumeRestoreCollections(
 	dcs []data.RestoreCollection,
 	deets *details.Builder,
 	errs *fault.Bus,
+	ctr *count.Bus,
 ) (*support.ControllerOperationStatus, error) {
 	var (
 		restoreMetrics support.CollectionMetrics
@@ -74,7 +76,8 @@ func ConsumeRestoreCollections(
 				caches,
 				deets,
 				opts.RestorePermissions,
-				errs)
+				errs,
+				ctr)
 
 		case path.ListsCategory:
 			metrics, err = RestoreListCollection(

src/internal/operations/inject/inject.go

@@ -11,6 +11,7 @@ import (
 	"github.com/alcionai/corso/src/pkg/backup/details"
 	"github.com/alcionai/corso/src/pkg/control"
 	"github.com/alcionai/corso/src/pkg/control/repository"
+	"github.com/alcionai/corso/src/pkg/count"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/path"
 	"github.com/alcionai/corso/src/pkg/selectors"
@@ -41,6 +42,7 @@ type (
 			opts control.Options,
 			dcs []data.RestoreCollection,
 			errs *fault.Bus,
+			ctr *count.Bus,
 		) (*details.Details, error)
 
 		Wait() *data.CollectionStats

src/internal/operations/operation.go

@@ -8,6 +8,7 @@ import (
 	"github.com/alcionai/corso/src/internal/events"
 	"github.com/alcionai/corso/src/internal/kopia"
 	"github.com/alcionai/corso/src/pkg/control"
+	"github.com/alcionai/corso/src/pkg/count"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/store"
 )
@@ -49,7 +50,8 @@ const (
 type operation struct {
 	CreatedAt time.Time `json:"createdAt"`
 
-	Errors  *fault.Bus      `json:"errors"`
+	Errors  *fault.Bus `json:"errors"`
+	Counter *count.Bus
 	Options control.Options `json:"options"`
 	Status  OpStatus        `json:"status"`
 
@@ -67,6 +69,7 @@ func newOperation(
 	return operation{
 		CreatedAt: time.Now(),
 		Errors:    fault.New(opts.FailureHandling == control.FailFast),
+		Counter:   count.New(),
 		Options:   opts,
 
 		bus:   bus,

src/internal/operations/restore.go

@@ -25,6 +25,7 @@ import (
 	"github.com/alcionai/corso/src/pkg/account"
 	"github.com/alcionai/corso/src/pkg/backup/details"
 	"github.com/alcionai/corso/src/pkg/control"
+	"github.com/alcionai/corso/src/pkg/count"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/logger"
 	"github.com/alcionai/corso/src/pkg/path"
@@ -178,6 +179,7 @@ func (op *RestoreOperation) Run(ctx context.Context) (restoreDetails *details.De
 
 	finalizeErrorHandling(ctx, op.Options, op.Errors, "running restore")
 	LogFaultErrors(ctx, op.Errors.Errors(), "running restore")
+	logger.Ctx(ctx).With("total_counts", op.Counter.Values()).Info("restore stats")
 
 	// -----
 	// Persistence
@@ -266,7 +268,8 @@ func (op *RestoreOperation) do(
 		op.RestoreCfg,
 		op.Options,
 		dcs,
-		op.Errors)
+		op.Errors,
+		op.Counter)
 	if err != nil {
 		return nil, clues.Wrap(err, "restoring collections")
 	}
@@ -324,6 +327,7 @@ func consumeRestoreCollections(
 	opts control.Options,
 	dcs []data.RestoreCollection,
 	errs *fault.Bus,
+	ctr *count.Bus,
 ) (*details.Details, error) {
 	complete := observe.MessageWithCompletion(ctx, "Restoring data")
 	defer func() {
@@ -338,7 +342,8 @@ func consumeRestoreCollections(
 		restoreCfg,
 		opts,
 		dcs,
-		errs)
+		errs,
+		ctr)
 	if err != nil {
 		return nil, clues.Wrap(err, "restoring collections")
 	}

src/internal/operations/test/helper_test.go

@@ -33,6 +33,7 @@ import (
 	"github.com/alcionai/corso/src/pkg/backup/details"
 	"github.com/alcionai/corso/src/pkg/control"
 	"github.com/alcionai/corso/src/pkg/control/repository"
+	"github.com/alcionai/corso/src/pkg/count"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/path"
 	"github.com/alcionai/corso/src/pkg/selectors"
@@ -425,7 +426,8 @@ func generateContainerOfItems(
 		restoreCfg,
 		opts,
 		dataColls,
-		fault.New(true))
+		fault.New(true),
+		count.New())
 	require.NoError(t, err, clues.ToCore(err))
 
 	// have to wait here, both to ensure the process

src/pkg/count/count.go

@@ -0,0 +1,108 @@
+package count
+
+import (
+	"github.com/puzpuzpuz/xsync/v2"
+)
+
+// Bus handles threadsafe counting of arbitrarily keyed metrics.
+type Bus struct {
+	parent *Bus
+	stats  *xsync.MapOf[string, *xsync.Counter]
+}
+
+func New() *Bus {
+	return &Bus{
+		stats: xsync.NewMapOf[*xsync.Counter](),
+	}
+}
+
+// Local generates a bus with a parent link.  Any value added to
+// the local instance also updates the parent by the same increment.
+// This allows you to maintain an isolated set of counts for a
+// bounded context while automatically tallying the global total.
+func (b *Bus) Local() *Bus {
+	bus := New()
+	bus.parent = b
+
+	return bus
+}
+
+func (b *Bus) getCounter(k key) *xsync.Counter {
+	xc, _ := b.stats.LoadOrStore(string(k), xsync.NewCounter())
+	return xc
+}
+
+// Inc increases the count by 1.
+func (b *Bus) Inc(k key) {
+	if b == nil {
+		return
+	}
+
+	b.Add(k, 1)
+}
+
+// Inc increases the count by n.
+func (b *Bus) Add(k key, n int64) {
+	if b == nil {
+		return
+	}
+
+	b.getCounter(k).Add(n)
+
+	if b.parent != nil {
+		b.parent.Add(k, n)
+	}
+}
+
+// Get returns the local count.
+func (b *Bus) Get(k key) int64 {
+	if b == nil {
+		return -1
+	}
+
+	return b.getCounter(k).Value()
+}
+
+// Total returns the global count.
+func (b *Bus) Total(k key) int64 {
+	if b == nil {
+		return -1
+	}
+
+	if b.parent != nil {
+		return b.parent.Total(k)
+	}
+
+	return b.Get(k)
+}
+
+// Values returns a map of all local values.
+// Not a snapshot, and therefore not threadsafe.
+func (b *Bus) Values() map[string]int64 {
+	if b == nil {
+		return map[string]int64{}
+	}
+
+	m := make(map[string]int64, b.stats.Size())
+
+	b.stats.Range(func(k string, v *xsync.Counter) bool {
+		m[k] = v.Value()
+		return true
+	})
+
+	return m
+}
+
+// TotalValues returns a map of all global values.
+// Not a snapshot, and therefore not threadsafe.
+func (b *Bus) TotalValues() map[string]int64 {
+	if b == nil {
+		return map[string]int64{}
+	}
+
+	if b.parent != nil {
+		return b.parent.TotalValues()
+	}
+
+	return b.Values()
+}

src/pkg/count/count_test.go

@@ -0,0 +1,180 @@
+package count
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/suite"
+
+	"github.com/alcionai/corso/src/internal/tester"
+)
+
+type CountUnitSuite struct {
+	tester.Suite
+}
+
+func TestCountUnitSuite(t *testing.T) {
+	suite.Run(t, &CountUnitSuite{Suite: tester.NewUnitSuite(t)})
+}
+
+const testKey = key("just-for-testing")
+
+func (suite *CountUnitSuite) TestBus_Inc() {
+	newParent := func() *Bus {
+		parent := New()
+		parent.Inc(testKey)
+
+		return parent
+	}
+
+	table := []struct {
+		name        string
+		skip        bool
+		bus         *Bus
+		expect      int64
+		expectTotal int64
+	}{
+		{
+			name:        "nil",
+			bus:         nil,
+			expect:      -1,
+			expectTotal: -1,
+		},
+		{
+			name:        "none",
+			skip:        true,
+			bus:         newParent().Local(),
+			expect:      0,
+			expectTotal: 1,
+		},
+		{
+			name:        "one",
+			bus:         newParent().Local(),
+			expect:      1,
+			expectTotal: 2,
+		},
+	}
+	for _, test := range table {
+		suite.Run(test.name, func() {
+			t := suite.T()
+
+			if !test.skip {
+				test.bus.Inc(testKey)
+			}
+
+			result := test.bus.Get(testKey)
+			assert.Equal(t, test.expect, result)
+
+			resultTotal := test.bus.Total(testKey)
+			assert.Equal(t, test.expectTotal, resultTotal)
+		})
+	}
+}
+
+func (suite *CountUnitSuite) TestBus_Add() {
+	newParent := func() *Bus {
+		parent := New()
+		parent.Add(testKey, 2)
+
+		return parent
+	}
+
+	table := []struct {
+		name        string
+		skip        bool
+		bus         *Bus
+		expect      int64
+		expectTotal int64
+	}{
+		{
+			name:        "nil",
+			bus:         nil,
+			expect:      -1,
+			expectTotal: -1,
+		},
+		{
+			name:        "none",
+			skip:        true,
+			bus:         newParent().Local(),
+			expect:      0,
+			expectTotal: 2,
+		},
+		{
+			name:        "some",
+			bus:         newParent().Local(),
+			expect:      4,
+			expectTotal: 6,
+		},
+	}
+	for _, test := range table {
+		suite.Run(test.name, func() {
+			t := suite.T()
+
+			if !test.skip {
+				test.bus.Add(testKey, 4)
+			}
+
+			result := test.bus.Get(testKey)
+			assert.Equal(t, test.expect, result)
+
+			resultTotal := test.bus.Total(testKey)
+			assert.Equal(t, test.expectTotal, resultTotal)
+		})
+	}
+}
+
+func (suite *CountUnitSuite) TestBus_Values() {
+	table := []struct {
+		name        string
+		bus         func() *Bus
+		expect      map[string]int64
+		expectTotal map[string]int64
+	}{
+		{
+			name:        "nil",
+			bus:         func() *Bus { return nil },
+			expect:      map[string]int64{},
+			expectTotal: map[string]int64{},
+		},
+		{
+			name: "none",
+			bus: func() *Bus {
+				parent := New()
+				parent.Add(testKey, 2)
+
+				l := parent.Local()
+
+				return l
+			},
+			expect:      map[string]int64{},
+			expectTotal: map[string]int64{string(testKey): 2},
+		},
+		{
+			name: "some",
+			bus: func() *Bus {
+				parent := New()
+				parent.Add(testKey, 2)
+
+				l := parent.Local()
+				l.Inc(testKey)
+
+				return l
+			},
+			expect:      map[string]int64{string(testKey): 1},
+			expectTotal: map[string]int64{string(testKey): 3},
+		},
+	}
+	for _, test := range table {
+		suite.Run(test.name, func() {
+			t := suite.T()
+
+			b := test.bus()
+
+			result := b.Values()
+			assert.Equal(t, test.expect, result)
+
+			resultTotal := b.TotalValues()
+			assert.Equal(t, test.expectTotal, resultTotal)
+		})
+	}
+}

src/pkg/count/keys.go

@@ -0,0 +1,7 @@
+package count
+
+type key string
+
+const (
+	CollisionSkip key = "collision-skip"
+)

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

@@ -22,8 +22,12 @@ const (
 	ccRecipients      = "ccRecipients"
 	createdDateTime   = "createdDateTime"
 	displayName       = "displayName"
+	emailAddresses    = "emailAddresses"
 	givenName         = "givenName"
+	mobilePhone       = "mobilePhone"
 	parentFolderID    = "parentFolderId"
+	receivedDateTime  = "receivedDateTime"
+	sentDateTime      = "sentDateTime"
 	surname           = "surname"
 	toRecipients      = "toRecipients"
 	userPrincipalName = "userPrincipalName"

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

@@ -317,7 +317,7 @@ func ContactInfo(contact models.Contactable) *details.ExchangeInfo {
 }
 
 func contactCollisionKeyProps() []string {
-	return idAnd(givenName)
+	return idAnd(givenName, surname, emailAddresses, mobilePhone)
 }
 
 // ContactCollisionKey constructs a key from the contactable's creation time and either displayName or given+surname.
@@ -327,5 +327,17 @@ func ContactCollisionKey(item models.Contactable) string {
 		return ""
 	}
 
-	return ptr.Val(item.GetId())
+	var (
+		given  = ptr.Val(item.GetGivenName())
+		sur    = ptr.Val(item.GetSurname())
+		emails = item.GetEmailAddresses()
+		email  string
+		phone  = ptr.Val(item.GetMobilePhone())
+	)
+
+	for _, em := range emails {
+		email += ptr.Val(em.GetAddress())
+	}
+
+	return given + sur + email + phone
 }

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

@@ -7,6 +7,7 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"github.com/stretchr/testify/suite"
+	"golang.org/x/exp/maps"
 
 	"github.com/alcionai/corso/src/internal/common/ptr"
 	"github.com/alcionai/corso/src/internal/tester"
@@ -52,16 +53,26 @@ func (suite *ContactsPagerIntgSuite) TestContacts_GetItemsInContainerByCollision
 	require.NoError(t, err, clues.ToCore(err))
 
 	cs := conts.GetValue()
-	expect := make([]string, 0, len(cs))
+	expectM := map[string]struct{}{}
 
 	for _, c := range cs {
-		expect = append(expect, api.ContactCollisionKey(c))
+		expectM[api.ContactCollisionKey(c)] = struct{}{}
 	}
 
+	expect := maps.Keys(expectM)
+
 	results, err := suite.its.ac.Contacts().GetItemsInContainerByCollisionKey(ctx, suite.its.userID, "contacts")
 	require.NoError(t, err, clues.ToCore(err))
 	require.Less(t, 0, len(results), "requires at least one result")
 
+	for _, k := range expect {
+		t.Log("expects key", k)
+	}
+
+	for k := range results {
+		t.Log("results key", k)
+	}
+
 	for k, v := range results {
 		assert.NotEmpty(t, k, "all keys should be populated")
 		assert.NotEmpty(t, v, "all values should be populated")

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

@@ -54,6 +54,9 @@ func (suite *DrivePagerIntgSuite) TestDrives_GetItemsInContainerByCollisionKey()
 			ctx, flush := tester.NewContext(t)
 			defer flush()
 
+			t.Log("drive", test.driveID)
+			t.Log("rootFolder", test.rootFolderID)
+
 			items, err := suite.its.ac.Stable.
 				Client().
 				Drives().
@@ -73,10 +76,20 @@ func (suite *DrivePagerIntgSuite) TestDrives_GetItemsInContainerByCollisionKey()
 				"need at least one item to compare in user %s drive %s folder %s",
 				suite.its.userID, test.driveID, test.rootFolderID)
 
-			results, err := suite.its.ac.Drives().GetItemsInContainerByCollisionKey(ctx, test.driveID, test.rootFolderID)
+			results, err := suite.its.ac.
+				Drives().
+				GetItemsInContainerByCollisionKey(ctx, test.driveID, test.rootFolderID)
 			require.NoError(t, err, clues.ToCore(err))
 			require.NotEmpty(t, results)
 
+			for _, k := range expect {
+				t.Log("expects key", k)
+			}
+
+			for k := range results {
+				t.Log("results key", k)
+			}
+
 			for k, v := range results {
 				assert.NotEmpty(t, k, "all keys should be populated")
 				assert.NotEmpty(t, v, "all values should be populated")

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

@@ -701,7 +701,7 @@ func EventFromMap(ev map[string]any) (models.Eventable, error) {
 }
 
 func eventCollisionKeyProps() []string {
-	return idAnd("subject")
+	return idAnd("subject", "type", "start", "end", "attendees", "recurrence")
 }
 
 // EventCollisionKey constructs a key from the eventable's creation time, subject, and organizer.
@@ -711,5 +711,39 @@ func EventCollisionKey(item models.Eventable) string {
 		return ""
 	}
 
-	return ptr.Val(item.GetSubject())
+	var (
+		subject   = ptr.Val(item.GetSubject())
+		attendees = item.GetAttendees()
+		a         string
+		oftype    = ptr.Val(item.GetType())
+		t         = oftype.String()
+		start     = item.GetStart()
+		s         string
+		end       = item.GetEnd()
+		e         string
+		recurs    = item.GetRecurrence()
+		r         string
+	)
+
+	for _, att := range attendees {
+		if att.GetEmailAddress() != nil {
+			a += ptr.Val(att.GetEmailAddress().GetAddress())
+		}
+	}
+
+	if start != nil {
+		s = ptr.Val(start.GetDateTime())
+	}
+
+	if end != nil {
+		e = ptr.Val(end.GetDateTime())
+	}
+
+	if recurs != nil && recurs.GetPattern() != nil {
+		r = ptr.Val(recurs.GetPattern().GetOdataType())
+	}
+
+	// this result gets hashed to ensure that an enormous list of attendees
+	// doesn't generate a multi-kb collision key.
+	return clues.ConcealWith(clues.SHA256, subject+a+t+s+e+r)
 }

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

@@ -7,6 +7,7 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"github.com/stretchr/testify/suite"
+	"golang.org/x/exp/maps"
 
 	"github.com/alcionai/corso/src/internal/common/ptr"
 	"github.com/alcionai/corso/src/internal/tester"
@@ -52,13 +53,17 @@ func (suite *EventsPagerIntgSuite) TestEvents_GetItemsInContainerByCollisionKey(
 	require.NoError(t, err, clues.ToCore(err))
 
 	es := evts.GetValue()
-	expect := make([]string, 0, len(es))
+	expectM := map[string]struct{}{}
 
 	for _, e := range es {
-		expect = append(expect, api.EventCollisionKey(e))
+		expectM[api.EventCollisionKey(e)] = struct{}{}
 	}
 
-	results, err := suite.its.ac.Events().GetItemsInContainerByCollisionKey(ctx, suite.its.userID, "calendar")
+	expect := maps.Keys(expectM)
+
+	results, err := suite.its.ac.
+		Events().
+		GetItemsInContainerByCollisionKey(ctx, suite.its.userID, "calendar")
 	require.NoError(t, err, clues.ToCore(err))
 	require.Less(t, 0, len(results), "requires at least one result")
 
@@ -67,6 +72,14 @@ func (suite *EventsPagerIntgSuite) TestEvents_GetItemsInContainerByCollisionKey(
 		assert.NotEmpty(t, v, "all values should be populated")
 	}
 
+	for _, k := range expect {
+		t.Log("expects key", k)
+	}
+
+	for k := range results {
+		t.Log("results key", k)
+	}
+
 	for _, e := range expect {
 		_, ok := results[e]
 		assert.Truef(t, ok, "expected results to contain collision key: %s", e)

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

@@ -12,6 +12,7 @@ import (
 	"github.com/microsoftgraph/msgraph-sdk-go/models"
 	"github.com/microsoftgraph/msgraph-sdk-go/users"
 
+	"github.com/alcionai/corso/src/internal/common/dttm"
 	"github.com/alcionai/corso/src/internal/common/ptr"
 	"github.com/alcionai/corso/src/internal/m365/graph"
 	"github.com/alcionai/corso/src/pkg/backup/details"
@@ -611,7 +612,7 @@ func UnwrapEmailAddress(contact models.Recipientable) string {
 }
 
 func mailCollisionKeyProps() []string {
-	return idAnd("subject")
+	return idAnd("subject", sentDateTime, receivedDateTime)
 }
 
 // MailCollisionKey constructs a key from the messageable's subject, sender, and recipients (to, cc, bcc).
@@ -621,5 +622,11 @@ func MailCollisionKey(item models.Messageable) string {
 		return ""
 	}
 
-	return ptr.Val(item.GetSubject())
+	var (
+		subject  = ptr.Val(item.GetSubject())
+		sent     = ptr.Val(item.GetSentDateTime())
+		received = ptr.Val(item.GetReceivedDateTime())
+	)
+
+	return subject + dttm.Format(sent) + dttm.Format(received)
 }

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

@@ -7,6 +7,7 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"github.com/stretchr/testify/suite"
+	"golang.org/x/exp/maps"
 
 	"github.com/alcionai/corso/src/internal/common/ptr"
 	"github.com/alcionai/corso/src/internal/tester"
@@ -52,16 +53,26 @@ func (suite *MailPagerIntgSuite) TestMail_GetItemsInContainerByCollisionKey() {
 	require.NoError(t, err, clues.ToCore(err))
 
 	ms := msgs.GetValue()
-	expect := make([]string, 0, len(ms))
+	expectM := map[string]struct{}{}
 
 	for _, m := range ms {
-		expect = append(expect, api.MailCollisionKey(m))
+		expectM[api.MailCollisionKey(m)] = struct{}{}
 	}
 
+	expect := maps.Keys(expectM)
+
 	results, err := suite.its.ac.Mail().GetItemsInContainerByCollisionKey(ctx, suite.its.userID, "inbox")
 	require.NoError(t, err, clues.ToCore(err))
 	require.Less(t, 0, len(results), "requires at least one result")
 
+	for _, k := range expect {
+		t.Log("expects key", k)
+	}
+
+	for k := range results {
+		t.Log("results key", k)
+	}
+
 	for k, v := range results {
 		assert.NotEmpty(t, k, "all keys should be populated")
 		assert.NotEmpty(t, v, "all values should be populated")