Initial QSfera import

Server/vendor/github.com/open-policy-agent/opa/v1/ast/json/json.go

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+// Copyright 2023 The OPA Authors.  All rights reserved.
+// Use of this source code is governed by an Apache2
+// license that can be found in the LICENSE file.
+
+// This package provides options for JSON marshalling of AST nodes, and location
+// data in particular. Since location data occupies a significant portion of the
+// AST when included, it is excluded by default. The options provided here allow
+// changing that behavior — either for all nodes or for specific types. Since
+// JSONMarshaller implementations have access only to the node being marshaled,
+// our options are to either attach these settings to *all* nodes in the AST, or
+// to provide them via global state. The former is perhaps a little more elegant,
+// and is what we went with initially. The cost of attaching these settings to
+// every node however turned out to be non-negligible, and given that the number
+// of users who have an interest in AST serialization are likely to be few, we
+// have since switched to using global state, as provided here. Note that this
+// is mostly to provide an equivalent feature to what we had before, should
+// anyone depend on that. Users who need fine-grained control over AST
+// serialization are recommended to use external libraries for that purpose,
+// such as `github.com/json-iterator/go`.
+package json
+
+import "sync"
+
+// Options defines the options for JSON operations,
+// currently only marshaling can be configured
+type Options struct {
+	MarshalOptions MarshalOptions
+}
+
+// MarshalOptions defines the options for JSON marshaling,
+// currently only toggling the marshaling of location information is supported
+type MarshalOptions struct {
+	// IncludeLocation toggles the marshaling of location information
+	IncludeLocation NodeToggle
+	// IncludeLocationText additionally/optionally includes the text of the location
+	IncludeLocationText bool
+	// ExcludeLocationFile additionally/optionally excludes the file of the location
+	// Note that this is inverted (i.e. not "include" as the default needs to remain false)
+	ExcludeLocationFile bool
+}
+
+// NodeToggle is a generic struct to allow the toggling of
+// settings for different ast node types
+type NodeToggle struct {
+	Term           bool
+	Package        bool
+	Comment        bool
+	Import         bool
+	Rule           bool
+	Head           bool
+	Expr           bool
+	SomeDecl       bool
+	Every          bool
+	With           bool
+	Annotations    bool
+	AnnotationsRef bool
+}
+
+// configuredJSONOptions synchronizes access to the global JSON options
+type configuredJSONOptions struct {
+	options Options
+	lock    sync.RWMutex
+}
+
+var options = &configuredJSONOptions{
+	options: Defaults(),
+}
+
+// SetOptions sets the global options for marshalling AST nodes to JSON
+func SetOptions(opts Options) {
+	options.lock.Lock()
+	defer options.lock.Unlock()
+	options.options = opts
+}
+
+// GetOptions returns (a copy of) the global options for marshalling AST nodes to JSON
+func GetOptions() Options {
+	options.lock.RLock()
+	defer options.lock.RUnlock()
+	return options.options
+}
+
+// Defaults returns the default JSON options, which is to exclude location
+// information in serialized JSON AST.
+func Defaults() Options {
+	return Options{
+		MarshalOptions: MarshalOptions{
+			IncludeLocation: NodeToggle{
+				Term:           false,
+				Package:        false,
+				Comment:        false,
+				Import:         false,
+				Rule:           false,
+				Head:           false,
+				Expr:           false,
+				SomeDecl:       false,
+				Every:          false,
+				With:           false,
+				Annotations:    false,
+				AnnotationsRef: false,
+			},
+			IncludeLocationText: false,
+			ExcludeLocationFile: false,
+		},
+	}
+}