feature(tsdb): decode name back into IDs

Signed-off-by: Leonardo Di Donato <leodidonato@gmail.com>

tsdb/explode.go

@@ -18,10 +18,16 @@ var (
 	MeasurementTagKeyBytes = []byte(MeasurementTagKey)
 )
 
+// DecodeName converts tsdb internal serialization back to organization and bucket IDs.
+func DecodeName(name [16]byte) (org, bucket platform.ID) {
+	org = platform.ID(binary.BigEndian.Uint64(name[0:8]))
+	bucket = platform.ID(binary.BigEndian.Uint64(name[8:16]))
+	return
+}
+
 // EncodeName converts org/bucket pairs to the tsdb internal serialization
 func EncodeName(org, bucket platform.ID) [16]byte {
 	var nameBytes [16]byte
-
 	binary.BigEndian.PutUint64(nameBytes[0:8], uint64(org))
 	binary.BigEndian.PutUint64(nameBytes[8:16], uint64(bucket))
 	return nameBytes

tsdb/explode_test.go

@@ -0,0 +1,42 @@
+package tsdb_test
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/influxdata/platform"
+	"github.com/influxdata/platform/tsdb"
+)
+
+func TestNames(t *testing.T) {
+	goodExamples := []struct {
+		Org    uint64
+		Bucket uint64
+		Name   [16]byte
+	}{
+		{Org: 12345678, Bucket: 87654321, Name: [16]byte{0, 0, 0, 0, 0, 188, 97, 78, 0, 0, 0, 0, 5, 57, 127, 177}},
+		{Org: 1234567891011, Bucket: 87654321, Name: [16]byte{0, 0, 1, 31, 113, 251, 8, 67, 0, 0, 0, 0, 5, 57, 127, 177}},
+		{Org: 12345678, Bucket: 8765432100000, Name: [16]byte{0, 0, 0, 0, 0, 188, 97, 78, 0, 0, 7, 248, 220, 119, 116, 160}},
+		{Org: 123456789929, Bucket: 8765432100000, Name: [16]byte{0, 0, 0, 28, 190, 153, 29, 169, 0, 0, 7, 248, 220, 119, 116, 160}},
+	}
+
+	for _, example := range goodExamples {
+		t.Run(fmt.Sprintf("%d%d", example.Org, example.Bucket), func(t *testing.T) {
+
+			name := tsdb.EncodeName(platform.ID(example.Org), platform.ID(example.Bucket))
+
+			if got, exp := name, example.Name; got != exp {
+				t.Errorf("got name %q, expected %q", got, exp)
+			}
+
+			org, bucket := tsdb.DecodeName(name)
+
+			if gotOrg, expOrg := org, example.Org; gotOrg != platform.ID(expOrg) {
+				t.Errorf("got organization ID %q, expected %q", gotOrg, expOrg)
+			}
+			if gotBucket, expBucket := bucket, example.Bucket; gotBucket != platform.ID(expBucket) {
+				t.Errorf("got organization ID %q, expected %q", gotBucket, expBucket)
+			}
+		})
+	}
+}