bigquery: support update of Dataset.DefaultTableExpiration

Allow users to change or delete the DefaultTableExpiration property
of a Dataset.

We have to distinguish "do not update" from "delete". To do so,
we make an optional type for Duration, interpret the default value (nil)
as "do not update", and treat a zero duration (otherwise illegal) as "delete".
Note that the bq command-line tool makes the same choice: you write

  bq update --default_table_expiration 0

to delete. We also do this in storage.ObjectHandle.Update, where we
have a Metadata field that is a map. If the map is nil, nothing
happens; if you set it to an empty map, the metadata is deleted.

Change-Id: I3ffdf580cd84c12ea2527d49ddd61dc0b04a53c7
Reviewed-on: https://code-review.googlesource.com/15570
Reviewed-by: kokoro <[email protected]>
Reviewed-by: Michael Darakananda <[email protected]>

bigquery/dataset.go

@@ -32,10 +32,10 @@ type Dataset struct {
 
 type DatasetMetadata struct {
 	CreationTime           time.Time
-	LastModifiedTime       time.Time // When the dataset or any of its tables were modified.
-	DefaultTableExpiration time.Duration
-	Description            string // The user-friendly description of this dataset.
-	Name                   string // The user-friendly name for this dataset.
+	LastModifiedTime       time.Time     // When the dataset or any of its tables were modified.
+	DefaultTableExpiration time.Duration // The default expiration time for new tables.
+	Description            string        // The user-friendly description of this dataset.
+	Name                   string        // The user-friendly name for this dataset.
 	ID                     string
 	Location               string            // The geo location of the dataset.
 	Labels                 map[string]string // User-provided labels.
@@ -49,6 +49,9 @@ type DatasetMetadata struct {
 type DatasetMetadataToUpdate struct {
 	Description optional.String // The user-friendly description of this table.
 	Name        optional.String // The user-friendly name for this dataset.
+	// DefaultTableExpiration is the the default expiration time for new tables.
+	// If set to time.Duration(0), new tables never expire.
+	DefaultTableExpiration optional.Duration
 }
 
 // Dataset creates a handle to a BigQuery dataset in the client's project.
@@ -84,7 +87,6 @@ func (d *Dataset) Metadata(ctx context.Context) (*DatasetMetadata, error) {
 // Update modifies specific Dataset metadata fields.
 // To perform a read-modify-write that protects against intervening reads,
 // set the etag argument to the DatasetMetadata.ETag field from the read.
-// TODO(jba): describe errora
 // Pass the empty string for etag for a "blind write" that will always succeed.
 func (d *Dataset) Update(ctx context.Context, dm DatasetMetadataToUpdate, etag string) (*DatasetMetadata, error) {
 	return d.c.service.patchDataset(ctx, d.ProjectID, d.DatasetID, &dm, etag)

bigquery/integration_test.go

@@ -221,7 +221,7 @@ func TestIntegration_DatasetDelete(t *testing.T) {
 	}
 }
 
-func TestIntegration_DatasetUpdate(t *testing.T) {
+func TestIntegration_DatasetUpdateETags(t *testing.T) {
 	if client == nil {
 		t.Skip("Integration tests skipped")
 	}
@@ -266,6 +266,43 @@ func TestIntegration_DatasetUpdate(t *testing.T) {
 	check(md3, "", "")
 }
 
+func TestIntegration_DatasetUpdateDefaultExpiration(t *testing.T) {
+	if client == nil {
+		t.Skip("Integration tests skipped")
+	}
+	ctx := context.Background()
+	md, err := dataset.Metadata(ctx)
+	if err != nil {
+		t.Fatal(err)
+	}
+	// Set the default expiration time.
+	md, err = dataset.Update(ctx,
+		DatasetMetadataToUpdate{DefaultTableExpiration: time.Hour}, "")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if md.DefaultTableExpiration != time.Hour {
+		t.Fatalf("got %s, want 1h", md.DefaultTableExpiration)
+	}
+	// Omitting DefaultTableExpiration doesn't change it.
+	md, err = dataset.Update(ctx, DatasetMetadataToUpdate{Name: "xyz"}, "")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if md.DefaultTableExpiration != time.Hour {
+		t.Fatalf("got %s, want 1h", md.DefaultTableExpiration)
+	}
+	// Setting it to 0 deletes it (which looks like a 0 duration).
+	md, err = dataset.Update(ctx,
+		DatasetMetadataToUpdate{DefaultTableExpiration: time.Duration(0)}, "")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if md.DefaultTableExpiration != 0 {
+		t.Fatalf("got %s, want 0", md.DefaultTableExpiration)
+	}
+}
+
 func TestIntegration_Tables(t *testing.T) {
 	if client == nil {
 		t.Skip("Integration tests skipped")

bigquery/service.go

@@ -702,6 +702,15 @@ func (s *bigqueryService) patchDataset(ctx context.Context, projectID, datasetID
 		ds.FriendlyName = optional.ToString(dm.Name)
 		forceSend("FriendlyName")
 	}
+	if dm.DefaultTableExpiration != nil {
+		dur := optional.ToDuration(dm.DefaultTableExpiration)
+		if dur == 0 {
+			// Send a null to delete the field.
+			ds.NullFields = append(ds.NullFields, "DefaultTableExpirationMs")
+		} else {
+			ds.DefaultTableExpirationMs = int64(dur.Seconds() * 1000)
+		}
+	}
 	call := s.s.Datasets.Patch(projectID, datasetID, ds).Context(ctx)
 	setClientHeader(call.Header())
 	if etag != "" {

internal/optional/optional.go

@@ -20,6 +20,7 @@ package optional
 import (
 	"fmt"
 	"strings"
+	"time"
 )
 
 type (
@@ -37,6 +38,9 @@ type (
 
 	// Float64 is either a float64 or nil.
 	Float64 interface{}
+
+	// Duration is either a time.Duration or nil.
+	Duration interface{}
 )
 
 // ToBool returns its argument as a bool.
@@ -89,6 +93,16 @@ func ToFloat64(v Float64) float64 {
 	return x
 }
 
+// ToDuration returns its argument as a time.Duration.
+// It panics if its argument is nil or not a time.Duration.
+func ToDuration(v Duration) time.Duration {
+	x, ok := v.(time.Duration)
+	if !ok {
+		doPanic("Duration", v)
+	}
+	return x
+}
+
 func doPanic(capType string, v interface{}) {
 	panic(fmt.Sprintf("optional.%s value should be %s, got %T", capType, strings.ToLower(capType), v))
 }