Add a registry for VIEWs to the catalog

Signed-off-by: Alejandro García Montoro <alejandro.garciamontoro@gmail.com>

Author: agarciamontoro

sql/catalog.go

@@ -17,6 +17,7 @@ var ErrDatabaseNotFound = errors.NewKind("database not found: %s")
 type Catalog struct {
 	FunctionRegistry
 	*IndexRegistry
+	*ViewRegistry
 	*ProcessList
 	*MemoryManager
 
@@ -37,6 +38,7 @@ func NewCatalog() *Catalog {
 	return &Catalog{
 		FunctionRegistry: NewFunctionRegistry(),
 		IndexRegistry:    NewIndexRegistry(),
+		ViewRegistry:     NewViewRegistry(),
 		MemoryManager:    NewMemoryManager(ProcessMemory),
 		ProcessList:      NewProcessList(),
 		locks:            make(sessionLocks),

sql/parse/views.go

@@ -3,7 +3,6 @@ package parse
 import (
 	"bufio"
 	"strings"
-	// "io"
 
 	"github.com/src-d/go-mysql-server/sql"
 	"github.com/src-d/go-mysql-server/sql/plan"

sql/plan/create_view.go

@@ -9,7 +9,7 @@ import (
 
 type CreateView struct {
 	UnaryNode
-	Database sql.Database
+	database sql.Database
 	Name     string
 	Columns  []string
 	Catalog *sql.Catalog
@@ -37,16 +37,15 @@ func (create *CreateView) Children() []sql.Node {
 
 // Resolved implements the Node interface.
 func (create *CreateView) Resolved() bool {
-	// TOOD: Check whether the database has been resolved
-	// _, ok := create.Database.(sql.UnresolvedDatabase)
-	return create.Child.Resolved()
+	_, ok := create.database.(sql.UnresolvedDatabase)
+	return !ok && create.Child.Resolved()
 }
 
 // RowIter implements the Node interface.
 func (create *CreateView) RowIter(ctx *sql.Context) (sql.RowIter, error) {
-	// TODO: add it to the register
+	view := sql.View{create.Name, create.Child}
 
-	return sql.RowsToRowIter(), nil
+	return sql.RowsToRowIter(), create.Catalog.ViewRegistry.Register(create.database.Name(), view)
 }
 
 // Schema implements the Node interface.
@@ -57,7 +56,7 @@ func (create *CreateView) String() string {
 	_ = pr.WriteNode("CreateView(%s)", create.Name)
 	_ = pr.WriteChildren(
 		fmt.Sprintf("Columns (%s)", strings.Join(create.Columns, ", ")),
-		fmt.Sprintf("As (%s)", create.Child.String()),
+		create.Child.String(),
 	)
 	return pr.String()
 }

sql/viewregistry.go

@@ -0,0 +1,81 @@
+package sql
+
+import (
+	"sync"
+
+	"gopkg.in/src-d/go-errors.v1"
+)
+
+var ErrExistingView = errors.NewKind("the view %s.%s already exists in the registry")
+var ErrNonExistingView = errors.NewKind("the view %s.%s does not exist in the registry")
+
+type View struct {
+	Name       string
+	Definition Node
+}
+
+type viewKey struct {
+	dbName, viewName string
+}
+
+type ViewRegistry struct {
+	mutex sync.RWMutex
+	views map[viewKey]View
+}
+
+func NewViewRegistry() *ViewRegistry {
+	return &ViewRegistry{
+		views: make(map[viewKey]View),
+	}
+}
+
+func (registry *ViewRegistry) Register(database string, view View) error {
+	registry.mutex.Lock()
+	defer registry.mutex.Unlock()
+
+	key := viewKey{database, view.Name}
+
+	if _, ok := registry.views[key]; ok {
+		return ErrExistingView.New(database, view.Name)
+	}
+
+	registry.views[key] = view
+	return nil
+}
+
+func (registry *ViewRegistry) Delete(databaseName, viewName string) error {
+	key := viewKey{databaseName, viewName}
+
+	if _, ok := registry.views[key]; !ok {
+		return ErrNonExistingView.New(databaseName, viewName)
+	}
+
+	delete(registry.views, key)
+	return nil
+}
+
+func (registry *ViewRegistry) View(databaseName, viewName string) (*View, error) {
+	registry.mutex.RLock()
+	defer registry.mutex.RUnlock()
+
+	key := viewKey{databaseName, viewName}
+
+	if view, ok := registry.views[key]; ok {
+		return &view, nil
+	}
+
+	return nil, ErrNonExistingView.New(databaseName, viewName)
+}
+
+func (registry *ViewRegistry) ViewsInDatabase(databaseName string) (views []View) {
+	registry.mutex.RLock()
+	defer registry.mutex.RUnlock()
+
+	for key, value := range registry.views {
+		if key.dbName == databaseName {
+			views = append(views, value)
+		}
+	}
+
+	return views
+}