Files
kubesphere/vendor/github.com/open-policy-agent/opa/topdown/object.go
hongming 9769357005 update
Signed-off-by: hongming <talonwan@yunify.com>
2020-03-20 02:16:11 +08:00

140 lines
3.5 KiB
Go

// Copyright 2020 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.
package topdown
import (
"github.com/open-policy-agent/opa/ast"
"github.com/open-policy-agent/opa/topdown/builtins"
"github.com/open-policy-agent/opa/types"
)
func builtinObjectUnion(_ BuiltinContext, operands []*ast.Term, iter func(*ast.Term) error) error {
objA, err := builtins.ObjectOperand(operands[0].Value, 1)
if err != nil {
return err
}
objB, err := builtins.ObjectOperand(operands[1].Value, 2)
if err != nil {
return err
}
r := mergeWithOverwrite(objA, objB)
return iter(ast.NewTerm(r))
}
func builtinObjectRemove(_ BuiltinContext, operands []*ast.Term, iter func(*ast.Term) error) error {
// Expect an object and an array/set/object of keys
obj, err := builtins.ObjectOperand(operands[0].Value, 1)
if err != nil {
return err
}
// Build a set of keys to remove
keysToRemove, err := getObjectKeysParam(operands[1].Value)
if err != nil {
return err
}
r := ast.NewObject()
obj.Foreach(func(key *ast.Term, value *ast.Term) {
if !keysToRemove.Contains(key) {
r.Insert(key, value)
}
})
return iter(ast.NewTerm(r))
}
func builtinObjectFilter(_ BuiltinContext, operands []*ast.Term, iter func(*ast.Term) error) error {
// Expect an object and an array/set/object of keys
obj, err := builtins.ObjectOperand(operands[0].Value, 1)
if err != nil {
return err
}
// Build a new object from the supplied filter keys
keys, err := getObjectKeysParam(operands[1].Value)
if err != nil {
return err
}
filterObj := ast.NewObject()
keys.Foreach(func(key *ast.Term) {
filterObj.Insert(key, ast.NullTerm())
})
// Actually do the filtering
r, err := obj.Filter(filterObj)
if err != nil {
return err
}
return iter(ast.NewTerm(r))
}
func builtinObjectGet(_ BuiltinContext, operands []*ast.Term, iter func(*ast.Term) error) error {
object, err := builtins.ObjectOperand(operands[0].Value, 1)
if err != nil {
return err
}
if ret := object.Get(operands[1]); ret != nil {
return iter(ret)
}
return iter(operands[2])
}
// getObjectKeysParam returns a set of key values
// from a supplied ast array, object, set value
func getObjectKeysParam(arrayOrSet ast.Value) (ast.Set, error) {
keys := ast.NewSet()
switch v := arrayOrSet.(type) {
case ast.Array:
for _, f := range v {
keys.Add(f)
}
case ast.Set:
_ = v.Iter(func(f *ast.Term) error {
keys.Add(f)
return nil
})
case ast.Object:
_ = v.Iter(func(k *ast.Term, _ *ast.Term) error {
keys.Add(k)
return nil
})
default:
return nil, builtins.NewOperandTypeErr(2, arrayOrSet, ast.TypeName(types.Object{}), ast.TypeName(types.S), ast.TypeName(types.Array{}))
}
return keys, nil
}
func mergeWithOverwrite(objA, objB ast.Object) ast.Object {
merged, _ := objA.MergeWith(objB, func(v1, v2 *ast.Term) (*ast.Term, bool) {
originalValueObj, ok2 := v1.Value.(ast.Object)
updateValueObj, ok1 := v2.Value.(ast.Object)
if !ok1 || !ok2 {
// If we can't merge, stick with the right-hand value
return v2, false
}
// Recursively update the existing value
merged := mergeWithOverwrite(originalValueObj, updateValueObj)
return ast.NewTerm(merged), false
})
return merged
}
func init() {
RegisterBuiltinFunc(ast.ObjectUnion.Name, builtinObjectUnion)
RegisterBuiltinFunc(ast.ObjectRemove.Name, builtinObjectRemove)
RegisterBuiltinFunc(ast.ObjectFilter.Name, builtinObjectFilter)
RegisterBuiltinFunc(ast.ObjectGet.Name, builtinObjectGet)
}