compute: don't hydrate file contents for "type:path" (#34681)

enterprise/internal/compute/output_command.go

@@ -19,6 +19,7 @@ type Output struct {
 	OutputPattern string
 	Separator     string
 	Selector      string
+	TypeValue     string
 }
 
 func (c *Output) ToSearchPattern() string {
@@ -61,11 +62,14 @@ func output(ctx context.Context, fragment string, matchPattern MatchPattern, rep
 	return &Text{Value: newContent, Kind: "output"}, nil
 }
 
-func resultContent(ctx context.Context, db database.DB, r result.Match) (string, bool, error) {
+func resultContent(ctx context.Context, db database.DB, r result.Match, onlyPath bool) (string, bool, error) {
 	switch m := r.(type) {
 	case *result.RepoMatch:
 		return string(m.Name), true, nil
 	case *result.FileMatch:
+		if onlyPath {
+			return m.Path, true, nil
+		}
 		contentBytes, err := git.ReadFile(ctx, db, m.Repo.Name, m.CommitID, m.Path, authz.DefaultSubRepoPermsChecker)
 		if err != nil {
 			return "", false, err
@@ -85,7 +89,8 @@ func resultContent(ctx context.Context, db database.DB, r result.Match) (string,
 }
 
 func (c *Output) Run(ctx context.Context, db database.DB, r result.Match) (Result, error) {
-	content, ok, err := resultContent(ctx, db, r)
+	onlyPath := c.TypeValue == "path" // don't read file contents for file matches when we only want type:path
+	content, ok, err := resultContent(ctx, db, r, onlyPath)
 	if err != nil {
 		return nil, err
 	}

enterprise/internal/compute/output_command_test.go

@@ -93,6 +93,11 @@ func TestRun(t *testing.T) {
 		"my/awesome/repo").
 		Equal(t, test(`lang:ocaml content:output((\d) -> $repo) select:repo`, fileMatch("a 1 b 2 c 3")))
 
+	autogold.Want(
+		"honor type:path efficiently (don't hydrate file content when type:path is set)",
+		"my/awesome/path.ml content is my/awesome/path.ml with extension: ml\n").
+		Equal(t, test(`content:output(awesome/.+\.(\w+) -> $path content is $content with extension: $1) type:path`, fileMatch("a 1 b 2 c 3")))
+
 	autogold.Want(
 		"template substitution regexp with commit author",
 		"bob: (1)\nbob: (2)\nbob: (3)\n").

enterprise/internal/compute/query.go

@@ -194,13 +194,24 @@ func parseOutput(q *query.Basic) (Command, bool, error) {
 		return nil, false, nil
 	}
 
+	var typeValue string
+	query.VisitField(q.ToParseTree(), query.FieldType, func(value string, _ bool, _ query.Annotation) {
+		typeValue = value
+	})
+
 	var selector string
 	query.VisitField(q.ToParseTree(), query.FieldSelect, func(value string, _ bool, _ query.Annotation) {
 		selector = value
 	})
 
 	// The default separator is newline and cannot be changed currently.
-	return &Output{SearchPattern: matchPattern, OutputPattern: right, Separator: "\n", Selector: selector}, true, nil
+	return &Output{
+		SearchPattern: matchPattern,
+		OutputPattern: right,
+		Separator:     "\n",
+		TypeValue:     typeValue,
+		Selector:      selector,
+	}, true, nil
 }
 
 func parseMatchOnly(q *query.Basic) (Command, bool, error) {