Add implementation for RunDQL for v25 (#9355)

Author: mangalaman93

dgraph/cmd/alpha/http.go

@@ -402,7 +402,7 @@ func mutationHandler(w http.ResponseWriter, r *http.Request) {
 
 	case "application/rdf":
 		// Parse N-Quads.
-		req, err = dql.ParseMutation(string(body))
+		req, err = dql.ParseDQL(string(body))
 		if err != nil {
 			x.SetStatus(w, x.ErrorInvalidRequest, err.Error())
 			return

dgraph/cmd/alpha/http_test.go

@@ -934,7 +934,7 @@ func TestContentTypeCharset(t *testing.T) {
 	require.True(t, err != nil && strings.Contains(err.Error(), "Unsupported charset"))
 
 	_, err = mutationWithTs(
-		mutationInp{body: `{}`, typ: "application/rdf; charset=utf-8", commitNow: true})
+		mutationInp{body: `{ set {_:a <name> "alice" .}}`, typ: "application/rdf; charset=utf-8", commitNow: true})
 	require.NoError(t, err)
 
 	_, err = mutationWithTs(

dql/dql.go

@@ -0,0 +1,50 @@
+/*
+ * SPDX-FileCopyrightText: Hypermode Inc. <[email protected]>
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package dql
+
+import (
+	"github.com/dgraph-io/dgo/v240/protos/api"
+
+	"github.com/hypermodeinc/dgraph/v24/lex"
+)
+
+func ParseDQL(dqlQuery string) (*api.Request, error) {
+	var lexer lex.Lexer
+	lexer.Reset(dqlQuery)
+	lexer.Run(lexTopLevel)
+	if err := lexer.ValidateResult(); err != nil {
+		return nil, err
+	}
+
+	it := lexer.NewIterator()
+	if !it.Next() {
+		return nil, it.Errorf("Invalid mutation")
+	}
+
+	item := it.Item()
+	switch item.Typ {
+	case itemUpsertBlock:
+		it.Prev()
+		return parseUpsertBlock(it)
+
+	default:
+		it.Next()
+		item = it.Item()
+		if item.Typ == itemMutationOp {
+			it.Prev()
+			it.Prev()
+			mu, err := parseMutationBlock(it)
+			if err != nil {
+				return nil, err
+			}
+			return &api.Request{Mutations: []*api.Mutation{mu}}, nil
+		}
+
+		it.Prev()
+		it.Prev()
+		return &api.Request{Query: dqlQuery}, nil
+	}
+}

dql/dql_test.go

@@ -0,0 +1,95 @@
+/*
+ * SPDX-FileCopyrightText: © Hypermode Inc. <[email protected]>
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package dql
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestParseDQL(t *testing.T) {
+	testCases := []string{
+		`{ set {_:a <name> "Alice" .}}`,
+		"schema{}",
+		`upsert {
+			query {
+				ns(func: eq(dgraph.namespace.name, "ns1")) {
+					q as var
+					dgraph.namespace.id
+				}
+			}
+
+			mutation {
+				delete {
+					uid(q) * * .
+				}
+			}
+		}`,
+		`{
+			q(func: eq(dgraph.namespace.name, "ns1")) {
+				uid
+				dgraph.type
+				dgraph.namespace.id
+			}
+		}`,
+		` query test($a: int) {
+			q(func: uid(0x1)) {
+				x as count(uid)
+				p : math(x + $a)
+			}
+		}`,
+		`{
+			me(func: uid(1)) {
+				Upvote {
+					u as Author
+				}
+				count(val(u))
+			}
+		}`,
+		`{
+			user(func: uid(0x0a)) {
+				...fragmenta,...fragmentb
+				friends {
+					name
+				}
+				...fragmentc
+				hobbies
+				...fragmentd
+			}
+			me(func: uid(0x01)) {
+				...fragmenta
+				...fragmentb
+			}
+		}
+		fragment fragmenta {
+			name
+		}
+		fragment fragmentb {
+			id
+		}
+		fragment fragmentc {
+			name
+		}
+		fragment fragmentd {
+			id
+		}`,
+		`{
+			set {
+				<name> <is> <something> .
+				<hometown> <is> <san/francisco> .
+			}
+			delete {
+				<name> <is> <something-else> .
+			}
+		}`,
+	}
+
+	for _, tc := range testCases {
+		_, err := ParseDQL(tc)
+		require.NoError(t, err)
+	}
+}

dql/parser_mutation.go

@@ -15,7 +15,7 @@ import (
 func ParseMutation(mutation string) (req *api.Request, err error) {
 	var lexer lex.Lexer
 	lexer.Reset(mutation)
-	lexer.Run(lexIdentifyBlock)
+	lexer.Run(lexTopLevel)
 	if err := lexer.ValidateResult(); err != nil {
 		return nil, err
 	}

dql/parser_test.go

@@ -1960,7 +1960,7 @@ func TestParseMutationError(t *testing.T) {
 	`
 	_, err := ParseMutation(query)
 	require.Error(t, err)
-	require.Contains(t, err.Error(), `Invalid block: [mutation]`)
+	require.Contains(t, err.Error(), `Unexpected token: [mutation]`)
 }
 
 func TestParseMutationError2(t *testing.T) {
@@ -1975,7 +1975,7 @@ func TestParseMutationError2(t *testing.T) {
 	`
 	_, err := ParseMutation(query)
 	require.Error(t, err)
-	require.Contains(t, err.Error(), `Invalid block: [set]`)
+	require.Contains(t, err.Error(), `Invalid operation type: set`)
 }
 
 func TestParseMutationAndQueryWithComments(t *testing.T) {
@@ -4809,7 +4809,7 @@ func TestParseMutationTooManyBlocks(t *testing.T) {
          }{
 		   set { _:b2 <reg> "b2 content" . }
 		 }`,
-			errStr: "Unrecognized character in lexText",
+			errStr: "Unexpected { after the end of the block",
 		},
 		{m: `{set { _:a1 <reg> "a1 content" . }} something`,
 			errStr: "Invalid operation type: something",

dql/state.go

@@ -55,43 +55,6 @@ const (
 	itemStar
 )
 
-// lexIdentifyBlock identifies whether it is an upsert block
-// If the block begins with "{" => mutation block
-// Else if the block begins with "upsert" => upsert block
-func lexIdentifyBlock(l *lex.Lexer) lex.StateFn {
-	l.Mode = lexIdentifyBlock
-	for {
-		switch r := l.Next(); {
-		case isSpace(r) || lex.IsEndOfLine(r):
-			l.Ignore()
-		case isNameBegin(r):
-			return lexNameBlock
-		case r == leftCurl:
-			l.Backup()
-			return lexInsideMutation
-		case r == '#':
-			return lexComment
-		case r == lex.EOF:
-			return l.Errorf("Invalid mutation block")
-		default:
-			return l.Errorf("Unexpected character while identifying mutation block: %#U", r)
-		}
-	}
-}
-
-// lexNameBlock lexes the blocks, for now, only upsert block
-func lexNameBlock(l *lex.Lexer) lex.StateFn {
-	// The caller already checked isNameBegin, and absorbed one rune.
-	l.AcceptRun(isNameSuffix)
-	switch word := l.Input[l.Start:l.Pos]; word {
-	case "upsert":
-		l.Emit(itemUpsertBlock)
-		return lexUpsertBlock
-	default:
-		return l.Errorf("Invalid block: [%s]", word)
-	}
-}
-
 // lexUpsertBlock lexes the upsert block
 func lexUpsertBlock(l *lex.Lexer) lex.StateFn {
 	l.Mode = lexUpsertBlock
@@ -368,7 +331,7 @@ Loop:
 		case r == leftCurl:
 			l.Depth++ // one level down.
 			l.Emit(itemLeftCurl)
-			return lexQuery
+			return lexIdentifyMutationOrQuery
 		case r == rightCurl:
 			return l.Errorf("Too many right curl")
 		case r == lex.EOF:
@@ -396,6 +359,33 @@ Loop:
 	return nil
 }
 
+func lexIdentifyMutationOrQuery(l *lex.Lexer) lex.StateFn {
+	l.Mode = lexIdentifyMutationOrQuery
+	for {
+		switch r := l.Next(); {
+		case isSpace(r) || lex.IsEndOfLine(r):
+			l.Ignore()
+		case isNameBegin(r):
+			l.AcceptRun(isNameSuffix)
+			op := l.Input[l.Start:l.Pos]
+			// If it is a mutation
+			if op == "set" || op == "delete" || op == "del" {
+				l.Emit(itemMutationOp)
+				return lexInsideMutation
+			}
+			// else it is a query
+			l.Emit(itemName)
+			return lexQuery
+		case r == '#':
+			return lexComment
+		case r == lex.EOF:
+			return l.Errorf("Invalid DQL")
+		default:
+			return l.Errorf("Unexpected character while lexing DQL: %#U", r)
+		}
+	}
+}
+
 // lexQuery lexes the input string and calls other lex functions.
 func lexQuery(l *lex.Lexer) lex.StateFn {
 	l.Mode = lexQuery
@@ -592,6 +582,9 @@ func lexOperationType(l *lex.Lexer) lex.StateFn {
 	case "schema":
 		l.Emit(itemOpType)
 		return lexInsideSchema
+	case "upsert":
+		l.Emit(itemUpsertBlock)
+		return lexUpsertBlock
 	default:
 		return l.Errorf("Invalid operation type: %s", word)
 	}