Feat(graphql): Add vector support to graphql (#9074)

Adds support for vector predicate in GraphQL. Introduced new queries
like similar_to() in graphql

dgraphtest/local_cluster.go

@@ -22,6 +22,7 @@ import (
 	"fmt"
 	"io"
 	"log"
+	"math/rand"
 	"net/http"
 	"os"
 	"os/exec"
@@ -346,7 +347,8 @@ func (c *LocalCluster) Start() error {
 		if err1 := c.Stop(); err1 != nil {
 			log.Printf("[WARNING] error while stopping :%v", err)
 		}
-		c.Cleanup(false)
+		c.Cleanup(true)
+		c.conf.prefix = fmt.Sprintf("dgraphtest-%d", rand.NewSource(time.Now().UnixNano()).Int63()%1000000)
 		if err := c.init(); err != nil {
 			c.Cleanup(true)
 			return err
@@ -449,11 +451,7 @@ func (c *LocalCluster) HealthCheck(zeroOnly bool) error {
 		if !zo.isRunning {
 			break
 		}
-		url, err := zo.healthURL(c)
-		if err != nil {
-			return errors.Wrap(err, "error getting health URL")
-		}
-		if err := c.containerHealthCheck(url); err != nil {
+		if err := c.containerHealthCheck(zo.healthURL); err != nil {
 			return err
 		}
 		log.Printf("[INFO] container [%v] passed health check", zo.containerName)
@@ -470,11 +468,7 @@ func (c *LocalCluster) HealthCheck(zeroOnly bool) error {
 		if !aa.isRunning {
 			break
 		}
-		url, err := aa.healthURL(c)
-		if err != nil {
-			return errors.Wrap(err, "error getting health URL")
-		}
-		if err := c.containerHealthCheck(url); err != nil {
+		if err := c.containerHealthCheck(aa.healthURL); err != nil {
 			return err
 		}
 		log.Printf("[INFO] container [%v] passed health check", aa.containerName)
@@ -486,18 +480,27 @@ func (c *LocalCluster) HealthCheck(zeroOnly bool) error {
 	return nil
 }
 
-func (c *LocalCluster) containerHealthCheck(url string) error {
+func (c *LocalCluster) containerHealthCheck(url func(c *LocalCluster) (string, error)) error {
+	endpoint, err := url(c)
+	if err != nil {
+		return errors.Wrap(err, "error getting health URL")
+	}
 	for i := 0; i < 60; i++ {
 		time.Sleep(waitDurBeforeRetry)
 
-		req, err := http.NewRequest(http.MethodGet, url, nil)
+		endpoint, err = url(c)
+		if err != nil {
+			return errors.Wrap(err, "error getting health URL")
+		}
+
+		req, err := http.NewRequest(http.MethodGet, endpoint, nil)
 		if err != nil {
-			log.Printf("[WARNING] error building req for endpoint [%v], err: [%v]", url, err)
+			log.Printf("[WARNING] error building req for endpoint [%v], err: [%v]", endpoint, err)
 			continue
 		}
 		body, err := doReq(req)
 		if err != nil {
-			log.Printf("[WARNING] error hitting health endpoint [%v], err: [%v]", url, err)
+			log.Printf("[WARNING] error hitting health endpoint [%v], err: [%v]", endpoint, err)
 			continue
 		}
 		resp := string(body)
@@ -523,7 +526,7 @@ func (c *LocalCluster) containerHealthCheck(url string) error {
 		return nil
 	}
 
-	return fmt.Errorf("health failed, cluster took too long to come up [%v]", url)
+	return fmt.Errorf("health failed, cluster took too long to come up [%v]", endpoint)
 }
 
 func (c *LocalCluster) waitUntilLogin() error {

graphql/bench/schema.graphql

@@ -69,4 +69,4 @@ type Owner {
     hasRestaurants: [Restaurant] @hasInverse(field: owner)
 }
 
-# Dgraph.Authorization {"VerificationKey":"secretkey","Header":"X-Test-Auth","Namespace":"https://xyz.io/jwt/claims","Algo":"HS256","Audience":["aud1","63do0q16n6ebjgkumu05kkeian","aud5"]}
+# Dgraph.Authorization {"VerificationKey":"secretkey","Header":"X-Test-Auth","Namespace":"https://xyz.io/jwt/claims","Algo":"HS256","Audience":["aud1","63do0q16n6ebjgkumu05kkeian","aud5"]}

graphql/bench/schema_auth.graphql

@@ -248,4 +248,4 @@ type Owner @auth(
     hasRestaurants: [Restaurant] @hasInverse(field: owner)
 }
 
-# Dgraph.Authorization {"VerificationKey":"secretkey","Header":"X-Test-Auth","Namespace":"https://xyz.io/jwt/claims","Algo":"HS256","Audience":["aud1","63do0q16n6ebjgkumu05kkeian","aud5"]}
+# Dgraph.Authorization {"VerificationKey":"secretkey","Header":"X-Test-Auth","Namespace":"https://xyz.io/jwt/claims","Algo":"HS256","Audience":["aud1","63do0q16n6ebjgkumu05kkeian","aud5"]}

graphql/dgraph/graphquery.go

@@ -28,12 +28,16 @@ import (
 // validate query, and so doesn't return an error if query is 'malformed' - it might
 // just write something that wouldn't parse as a Dgraph query.
 func AsString(queries []*dql.GraphQuery) string {
-	if queries == nil {
+	if len(queries) == 0 {
 		return ""
 	}
 
 	var b strings.Builder
-	x.Check2(b.WriteString("query {\n"))
+	queryName := queries[len(queries)-1].Attr
+	x.Check2(b.WriteString("query "))
+	addQueryVars(&b, queryName, queries[0].Args)
+	x.Check2(b.WriteString("{\n"))
+
 	numRewrittenQueries := 0
 	for _, q := range queries {
 		if q == nil {
@@ -54,6 +58,24 @@ func AsString(queries []*dql.GraphQuery) string {
 	return b.String()
 }
 
+func addQueryVars(b *strings.Builder, queryName string, args map[string]string) {
+	dollarFound := false
+	for name, val := range args {
+		if strings.HasPrefix(name, "$") {
+			if !dollarFound {
+				x.Check2(b.WriteString(queryName + "("))
+				x.Check2(b.WriteString(name + ": " + val))
+				dollarFound = true
+			} else {
+				x.Check2(b.WriteString(", " + name + ": " + val))
+			}
+		}
+	}
+	if dollarFound {
+		x.Check2(b.WriteString(") "))
+	}
+}
+
 func writeQuery(b *strings.Builder, query *dql.GraphQuery, prefix string) {
 	if query.Var != "" || query.Alias != "" || query.Attr != "" {
 		x.Check2(b.WriteString(prefix))
@@ -145,6 +167,9 @@ func writeRoot(b *strings.Builder, q *dql.GraphQuery) {
 	}
 
 	switch {
+	// TODO: Instead of the hard-coded strings "uid", "type", etc., use the
+	// pre-defined constants in dql/parser.go such as dql.uidFunc, dql.typFunc,
+	// etc. This of course will require that we make these constants public.
 	case q.Func.Name == "uid":
 		x.Check2(b.WriteString("(func: "))
 		writeUIDFunc(b, q.Func.UID, q.Func.Args)
@@ -154,6 +179,10 @@ func writeRoot(b *strings.Builder, q *dql.GraphQuery) {
 		x.Check2(b.WriteString("(func: eq("))
 		writeFilterArguments(b, q.Func.Args)
 		x.Check2(b.WriteRune(')'))
+	case q.Func.Name == "similar_to":
+		x.Check2(b.WriteString("(func: similar_to("))
+		writeFilterArguments(b, q.Func.Args)
+		x.Check2(b.WriteRune(')'))
 	}
 	writeOrderAndPage(b, q, true)
 	x.Check2(b.WriteRune(')'))

graphql/e2e/auth/schema.graphql

@@ -568,7 +568,7 @@ type Contact @auth(
     query: { rule: "{$ContactRole: { eq: \"ADMINISTRATOR\"}}" }
 ) {
     id: ID!
-    nickName: String @search(by: [exact, term, fulltext, regexp])
+    nickName: String @search(by: ["exact", "term", "fulltext", "regexp"])
     adminTasks: [AdminTask] @hasInverse(field: forContact)
     tasks: [Task] @hasInverse(field: forContact)
 }
@@ -577,14 +577,14 @@ type AdminTask @auth(
     query: { rule: "{$TaskRole: { eq: \"ADMINISTRATOR\"}}" }
 ) {
     id: ID!
-    name: String @search(by: [exact, term, fulltext, regexp])
+    name: String @search(by: ["exact", "term", "fulltext", "regexp"])
     occurrences: [TaskOccurrence] @hasInverse(field: adminTask)
     forContact: Contact @hasInverse(field: adminTasks)
 }
 
 type Task {
     id: ID!
-    name: String @search(by: [exact, term, fulltext, regexp])
+    name: String @search(by: ["exact", "term", "fulltext", "regexp"])
     occurrences: [TaskOccurrence] @hasInverse(field: task)
     forContact: Contact @hasInverse(field: tasks)
 }
@@ -608,7 +608,7 @@ type TaskOccurrence @auth(
     task: Task @hasInverse(field: occurrences)
     adminTask: AdminTask @hasInverse(field: occurrences)
     isPublic: Boolean @search
-    role: String @search(by: [exact, term, fulltext, regexp])
+    role: String @search(by: ["exact", "term", "fulltext", "regexp"])
 }
 
 type Author {

graphql/e2e/common/query.go

@@ -1285,7 +1285,7 @@ func stringExactFilters(t *testing.T) {
 
 func scalarListFilters(t *testing.T) {
 
-	// tags is a list of strings with @search(by: exact).  So all the filters
+	// tags is a list of strings with @search(by: "exact").  So all the filters
 	// lt, le, ... mean "is there something in the list that's lt 'Dgraph'", etc.
 
 	cases := map[string]struct {

graphql/e2e/custom_logic/custom_logic_test.go

@@ -1067,7 +1067,7 @@ func TestCustomFieldsShouldPassBody(t *testing.T) {
 
 	schema := `
     type User {
-		id: String! @id @search(by: [hash, regexp])
+		id: String! @id @search(by: ["hash", "regexp"])
         address:String
 		name: String
 			@custom(
@@ -2573,7 +2573,7 @@ func TestCustomDQL(t *testing.T) {
 	}
 	type Tweets implements Node {
 		id: ID!
-		text: String! @search(by: [fulltext, exact])
+		text: String! @search(by: ["fulltext", "exact"])
 		user: User
 		timestamp: DateTime! @search
 	}
@@ -2864,7 +2864,7 @@ func TestCustomFieldsWithRestError(t *testing.T) {
 	}
 
 	type User {
-		id: String! @id @search(by: [hash, regexp])
+		id: String! @id @search(by: ["hash", "regexp"])
 		name: String
 			@custom(
 				http: {

graphql/e2e/directives/schema.graphql

@@ -423,4 +423,4 @@ type CricketTeam implements Team {
 type LibraryManager  {
     name: String! @id
     manages: [LibraryMember]
-}
+}

graphql/e2e/normal/schema.graphql

@@ -422,4 +422,4 @@ type CricketTeam implements Team {
 type LibraryManager  {
     name: String! @id
     manages: [LibraryMember]
-}
+}

graphql/e2e/schema/apollo_service_response.graphql

@@ -83,6 +83,7 @@ enum DgraphIndex {
 	day
 	hour
 	geo
+	hnsw
 }
 
 input AuthRule {
@@ -196,7 +197,8 @@ input GenerateMutationParams {
 }
 
 directive @hasInverse(field: String!) on FIELD_DEFINITION
-directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
+directive @search(by: [String!]) on FIELD_DEFINITION
+directive @embedding on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION

graphql/e2e/schema/generatedSchema.graphql

@@ -64,6 +64,7 @@ enum DgraphIndex {
 	day
 	hour
 	geo
+	hnsw
 }
 
 input AuthRule {
@@ -177,7 +178,8 @@ input GenerateMutationParams {
 }
 
 directive @hasInverse(field: String!) on FIELD_DEFINITION
-directive @search(by: [DgraphIndex!]) on FIELD_DEFINITION
+directive @search(by: [String!]) on FIELD_DEFINITION
+directive @embedding on FIELD_DEFINITION
 directive @dgraph(type: String, pred: String) on OBJECT | INTERFACE | FIELD_DEFINITION
 directive @id(interface: Boolean) on FIELD_DEFINITION
 directive @withSubscription on OBJECT | INTERFACE | FIELD_DEFINITION

graphql/e2e/schema/schema_test.go

@@ -564,7 +564,7 @@ func TestLargeSchemaUpdate(t *testing.T) {
 
 	schema := "type LargeSchema {"
 	for i := 1; i <= numFields; i++ {
-		schema = schema + "\n" + fmt.Sprintf("field%d: String! @search(by: [regexp])", i)
+		schema = schema + "\n" + fmt.Sprintf("field%d: String! @search(by: [\"regexp\"])", i)
 	}
 	schema = schema + "\n}"
 

graphql/e2e/subscription/subscription_test.go

@@ -46,7 +46,7 @@ const (
 	}
 
 	type Customer  {
-		username: String! @id @search(by: [hash, regexp])
+		username: String! @id @search(by: ["hash", "regexp"])
 		reviews: [Review] @hasInverse(field: by)
 	}
 

graphql/resolve/mutation_rewriter.go

@@ -1675,6 +1675,12 @@ func rewriteObject(
 			fieldName = fieldName[1 : len(fieldName)-1]
 		}
 
+		if fieldDef.HasEmbeddingDirective() {
+			// embedding is a JSON array of numbers. Rewrite it as a string, for now
+			var valBytes []byte
+			valBytes, _ = json.Marshal(val)
+			val = string(valBytes)
+		}
 		// TODO: Write a function for aggregating data of fragment from child nodes.
 		switch val := val.(type) {
 		case map[string]interface{}: