schema/index: add storage-key option for indexes

Summary: Pull Request resolved: https://github.com/facebookincubator/ent/pull/172

Reviewed By: alexsn

Differential Revision: D18571700

fbshipit-source-id: 2b8dbcc7c36be01ba383c48f982f59361a68c621

entc/gen/type.go

@@ -340,7 +340,7 @@ func (t Type) TagTypes() []string {
 // AddIndex adds a new index for the type.
 // It fails if the schema index is invalid.
 func (t *Type) AddIndex(idx *load.Index) error {
-	index := &Index{Unique: idx.Unique}
+	index := &Index{Name: idx.StorageKey, Unique: idx.Unique}
 	if len(idx.Fields) == 0 && len(idx.Edges) == 0 {
 		return fmt.Errorf("missing fields or edges")
 	}
@@ -373,7 +373,10 @@ func (t *Type) AddIndex(idx *load.Index) error {
 			index.Columns = append(index.Columns, edge.Rel.Column())
 		}
 	}
-	index.Name += strings.Join(index.Columns, "_")
+	// If no storage-key was defined for this index, generate one.
+	if idx.StorageKey == "" {
+		index.Name += strings.Join(index.Columns, "_")
+	}
 	t.Indexes = append(t.Indexes, index)
 	return nil
 }

entc/integration/ent/migrate/schema.go

@@ -124,7 +124,7 @@ var (
 		},
 		Indexes: []*schema.Index{
 			{
-				Name:    "name_fsize",
+				Name:    "file_name_size",
 				Unique:  false,
 				Columns: []*schema.Column{FilesColumns[2], FilesColumns[1]},
 			},

entc/integration/ent/schema/file.go

@@ -50,7 +50,8 @@ func (File) Edges() []ent.Edge {
 func (File) Indexes() []ent.Index {
 	return []ent.Index{
 		// non-unique index should not prevent duplicates.
-		index.Fields("name", "size"),
+		index.Fields("name", "size").
+			StorageKey("file_name_size"),
 		// unique index prevents duplicates records.
 		index.Fields("name", "user").
 			Unique(),

entc/load/schema.go

@@ -64,9 +64,10 @@ type Edge struct {
 
 // Index represents an ent.Index that was loaded from a complied user package.
 type Index struct {
-	Unique bool     `json:"unique,omitempty"`
-	Edges  []string `json:"edges,omitempty"`
-	Fields []string `json:"fields,omitempty"`
+	Unique     bool     `json:"unique,omitempty"`
+	Edges      []string `json:"edges,omitempty"`
+	Fields     []string `json:"fields,omitempty"`
+	StorageKey string   `json:"storage_key,omitempty"`
 }
 
 // NewEdge creates an loaded edge from edge descriptor.
@@ -141,9 +142,10 @@ func MarshalSchema(schema ent.Interface) (b []byte, err error) {
 	for _, idx := range indexes {
 		idx := idx.Descriptor()
 		s.Indexes = append(s.Indexes, &Index{
-			Edges:  idx.Edges,
-			Fields: idx.Fields,
-			Unique: idx.Unique,
+			Edges:      idx.Edges,
+			Fields:     idx.Fields,
+			Unique:     idx.Unique,
+			StorageKey: idx.StorageKey,
 		})
 	}
 	return json.Marshal(s)

entc/load/schema_test.go

@@ -56,6 +56,7 @@ func (User) Indexes() []ent.Index {
 			Unique(),
 		index.Fields("name").
 			Edges("parent").
+			StorageKey("user_parent_name").
 			Unique(),
 	}
 }
@@ -123,6 +124,7 @@ func TestMarshalSchema(t *testing.T) {
 		require.True(t, schema.Indexes[0].Unique)
 		require.Equal(t, []string{"name"}, schema.Indexes[1].Fields)
 		require.Equal(t, []string{"parent"}, schema.Indexes[1].Edges)
+		require.Equal(t, "user_parent_name", schema.Indexes[1].StorageKey)
 		require.True(t, schema.Indexes[1].Unique)
 	}
 }

schema/index/index.go

@@ -6,9 +6,10 @@ package index
 
 // A Descriptor for index configuration.
 type Descriptor struct {
-	Unique bool     // unique index.
-	Edges  []string // edge columns.
-	Fields []string // field columns.
+	Unique     bool     // unique index.
+	Edges      []string // edge columns.
+	Fields     []string // field columns.
+	StorageKey string   // custom index name.
 }
 
 // Builder for indexes on vertex columns and edges in the graph.
@@ -90,6 +91,12 @@ func (b *Builder) Unique() *Builder {
 	return b
 }
 
+// StorageKey sets the storage key of the index. In SQL dialects, it's the index name.
+func (b *Builder) StorageKey(key string) *Builder {
+	b.desc.StorageKey = key
+	return b
+}
+
 // Descriptor implements the ent.Descriptor interface.
 func (b *Builder) Descriptor() *Descriptor {
 	return b.desc

schema/index/index_test.go

@@ -14,9 +14,11 @@ import (
 
 func TestIndex(t *testing.T) {
 	idx := index.Fields("name", "address").
+		StorageKey("user_index").
 		Descriptor()
 	require.Empty(t, idx.Edges)
 	require.False(t, idx.Unique)
+	require.Equal(t, "user_index", idx.StorageKey)
 	require.Equal(t, []string{"name", "address"}, idx.Fields)
 
 	idx = index.Fields("name", "address").
@@ -24,6 +26,7 @@ func TestIndex(t *testing.T) {
 		Descriptor()
 	require.Empty(t, idx.Edges)
 	require.True(t, idx.Unique)
+	require.Empty(t, idx.StorageKey)
 	require.Equal(t, []string{"name", "address"}, idx.Fields)
 
 	idx = index.Fields("name", "address").