Benchmark for k8s services (#2107)

* Benchmark for k8s services

* Adding k8s.io/client-go/kubernetes/fake dep
This commit is contained in:
Brad Beam
2018-09-29 10:43:09 -05:00
committed by Miek Gieben
parent 57197a49a4
commit a80ec6096f
199 changed files with 25884 additions and 11 deletions

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approvers:
- pwittrock
reviewers:
- mengqiy
- apelisse

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/*
Copyright 2017 The Kubernetes Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package mergepatch
import (
"errors"
"fmt"
"reflect"
)
var (
ErrBadJSONDoc = errors.New("invalid JSON document")
ErrNoListOfLists = errors.New("lists of lists are not supported")
ErrBadPatchFormatForPrimitiveList = errors.New("invalid patch format of primitive list")
ErrBadPatchFormatForRetainKeys = errors.New("invalid patch format of retainKeys")
ErrBadPatchFormatForSetElementOrderList = errors.New("invalid patch format of setElementOrder list")
ErrPatchContentNotMatchRetainKeys = errors.New("patch content doesn't match retainKeys list")
ErrUnsupportedStrategicMergePatchFormat = errors.New("strategic merge patch format is not supported")
)
func ErrNoMergeKey(m map[string]interface{}, k string) error {
return fmt.Errorf("map: %v does not contain declared merge key: %s", m, k)
}
func ErrBadArgType(expected, actual interface{}) error {
return fmt.Errorf("expected a %s, but received a %s",
reflect.TypeOf(expected),
reflect.TypeOf(actual))
}
func ErrBadArgKind(expected, actual interface{}) error {
var expectedKindString, actualKindString string
if expected == nil {
expectedKindString = "nil"
} else {
expectedKindString = reflect.TypeOf(expected).Kind().String()
}
if actual == nil {
actualKindString = "nil"
} else {
actualKindString = reflect.TypeOf(actual).Kind().String()
}
return fmt.Errorf("expected a %s, but received a %s", expectedKindString, actualKindString)
}
func ErrBadPatchType(t interface{}, m map[string]interface{}) error {
return fmt.Errorf("unknown patch type: %s in map: %v", t, m)
}
// IsPreconditionFailed returns true if the provided error indicates
// a precondition failed.
func IsPreconditionFailed(err error) bool {
_, ok := err.(ErrPreconditionFailed)
return ok
}
type ErrPreconditionFailed struct {
message string
}
func NewErrPreconditionFailed(target map[string]interface{}) ErrPreconditionFailed {
s := fmt.Sprintf("precondition failed for: %v", target)
return ErrPreconditionFailed{s}
}
func (err ErrPreconditionFailed) Error() string {
return err.message
}
type ErrConflict struct {
message string
}
func NewErrConflict(patch, current string) ErrConflict {
s := fmt.Sprintf("patch:\n%s\nconflicts with changes made from original to current:\n%s\n", patch, current)
return ErrConflict{s}
}
func (err ErrConflict) Error() string {
return err.message
}
// IsConflict returns true if the provided error indicates
// a conflict between the patch and the current configuration.
func IsConflict(err error) bool {
_, ok := err.(ErrConflict)
return ok
}

133
vendor/k8s.io/apimachinery/pkg/util/mergepatch/util.go generated vendored Normal file
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/*
Copyright 2017 The Kubernetes Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package mergepatch
import (
"fmt"
"reflect"
"github.com/davecgh/go-spew/spew"
"github.com/ghodss/yaml"
)
// PreconditionFunc asserts that an incompatible change is not present within a patch.
type PreconditionFunc func(interface{}) bool
// RequireKeyUnchanged returns a precondition function that fails if the provided key
// is present in the patch (indicating that its value has changed).
func RequireKeyUnchanged(key string) PreconditionFunc {
return func(patch interface{}) bool {
patchMap, ok := patch.(map[string]interface{})
if !ok {
return true
}
// The presence of key means that its value has been changed, so the test fails.
_, ok = patchMap[key]
return !ok
}
}
// RequireMetadataKeyUnchanged creates a precondition function that fails
// if the metadata.key is present in the patch (indicating its value
// has changed).
func RequireMetadataKeyUnchanged(key string) PreconditionFunc {
return func(patch interface{}) bool {
patchMap, ok := patch.(map[string]interface{})
if !ok {
return true
}
patchMap1, ok := patchMap["metadata"]
if !ok {
return true
}
patchMap2, ok := patchMap1.(map[string]interface{})
if !ok {
return true
}
_, ok = patchMap2[key]
return !ok
}
}
func ToYAMLOrError(v interface{}) string {
y, err := toYAML(v)
if err != nil {
return err.Error()
}
return y
}
func toYAML(v interface{}) (string, error) {
y, err := yaml.Marshal(v)
if err != nil {
return "", fmt.Errorf("yaml marshal failed:%v\n%v\n", err, spew.Sdump(v))
}
return string(y), nil
}
// HasConflicts returns true if the left and right JSON interface objects overlap with
// different values in any key. All keys are required to be strings. Since patches of the
// same Type have congruent keys, this is valid for multiple patch types. This method
// supports JSON merge patch semantics.
//
// NOTE: Numbers with different types (e.g. int(0) vs int64(0)) will be detected as conflicts.
// Make sure the unmarshaling of left and right are consistent (e.g. use the same library).
func HasConflicts(left, right interface{}) (bool, error) {
switch typedLeft := left.(type) {
case map[string]interface{}:
switch typedRight := right.(type) {
case map[string]interface{}:
for key, leftValue := range typedLeft {
rightValue, ok := typedRight[key]
if !ok {
continue
}
if conflict, err := HasConflicts(leftValue, rightValue); err != nil || conflict {
return conflict, err
}
}
return false, nil
default:
return true, nil
}
case []interface{}:
switch typedRight := right.(type) {
case []interface{}:
if len(typedLeft) != len(typedRight) {
return true, nil
}
for i := range typedLeft {
if conflict, err := HasConflicts(typedLeft[i], typedRight[i]); err != nil || conflict {
return conflict, err
}
}
return false, nil
default:
return true, nil
}
case string, float64, bool, int, int64, nil:
return !reflect.DeepEqual(left, right), nil
default:
return true, fmt.Errorf("unknown type: %v", reflect.TypeOf(left))
}
}

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/*
Copyright 2017 The Kubernetes Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package mergepatch
import (
"fmt"
"testing"
)
func TestHasConflicts(t *testing.T) {
testCases := []struct {
A interface{}
B interface{}
Ret bool
}{
{A: "hello", B: "hello", Ret: false},
{A: "hello", B: "hell", Ret: true},
{A: "hello", B: nil, Ret: true},
{A: "hello", B: 1, Ret: true},
{A: "hello", B: float64(1.0), Ret: true},
{A: "hello", B: false, Ret: true},
{A: 1, B: 1, Ret: false},
{A: nil, B: nil, Ret: false},
{A: false, B: false, Ret: false},
{A: float64(3), B: float64(3), Ret: false},
{A: "hello", B: []interface{}{}, Ret: true},
{A: []interface{}{1}, B: []interface{}{}, Ret: true},
{A: []interface{}{}, B: []interface{}{}, Ret: false},
{A: []interface{}{1}, B: []interface{}{1}, Ret: false},
{A: map[string]interface{}{}, B: []interface{}{1}, Ret: true},
{A: map[string]interface{}{}, B: map[string]interface{}{"a": 1}, Ret: false},
{A: map[string]interface{}{"a": 1}, B: map[string]interface{}{"a": 1}, Ret: false},
{A: map[string]interface{}{"a": 1}, B: map[string]interface{}{"a": 2}, Ret: true},
{A: map[string]interface{}{"a": 1}, B: map[string]interface{}{"b": 2}, Ret: false},
{
A: map[string]interface{}{"a": []interface{}{1}},
B: map[string]interface{}{"a": []interface{}{1}},
Ret: false,
},
{
A: map[string]interface{}{"a": []interface{}{1}},
B: map[string]interface{}{"a": []interface{}{}},
Ret: true,
},
{
A: map[string]interface{}{"a": []interface{}{1}},
B: map[string]interface{}{"a": 1},
Ret: true,
},
// Maps and lists with multiple entries.
{
A: map[string]interface{}{"a": 1, "b": 2},
B: map[string]interface{}{"a": 1, "b": 0},
Ret: true,
},
{
A: map[string]interface{}{"a": 1, "b": 2},
B: map[string]interface{}{"a": 1, "b": 2},
Ret: false,
},
{
A: map[string]interface{}{"a": 1, "b": 2},
B: map[string]interface{}{"a": 1, "b": 0, "c": 3},
Ret: true,
},
{
A: map[string]interface{}{"a": 1, "b": 2},
B: map[string]interface{}{"a": 1, "b": 2, "c": 3},
Ret: false,
},
{
A: map[string]interface{}{"a": []interface{}{1, 2}},
B: map[string]interface{}{"a": []interface{}{1, 0}},
Ret: true,
},
{
A: map[string]interface{}{"a": []interface{}{1, 2}},
B: map[string]interface{}{"a": []interface{}{1, 2}},
Ret: false,
},
// Numeric types are not interchangeable.
// Callers are expected to ensure numeric types are consistent in 'left' and 'right'.
{A: int(0), B: int64(0), Ret: true},
{A: int(0), B: float64(0), Ret: true},
{A: int64(0), B: float64(0), Ret: true},
// Other types are not interchangeable.
{A: int(0), B: "0", Ret: true},
{A: int(0), B: nil, Ret: true},
{A: int(0), B: false, Ret: true},
{A: "true", B: true, Ret: true},
{A: "null", B: nil, Ret: true},
}
for _, testCase := range testCases {
testStr := fmt.Sprintf("A = %#v, B = %#v", testCase.A, testCase.B)
// Run each test case multiple times if it passes because HasConflicts()
// uses map iteration, which returns keys in nondeterministic order.
for try := 0; try < 10; try++ {
out, err := HasConflicts(testCase.A, testCase.B)
if err != nil {
t.Errorf("%v: unexpected error: %v", testStr, err)
break
}
if out != testCase.Ret {
t.Errorf("%v: expected %t got %t", testStr, testCase.Ret, out)
break
}
out, err = HasConflicts(testCase.B, testCase.A)
if err != nil {
t.Errorf("%v: unexpected error: %v", testStr, err)
break
}
if out != testCase.Ret {
t.Errorf("%v: expected reversed %t got %t", testStr, testCase.Ret, out)
break
}
}
}
}

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approvers:
- pwittrock
reviewers:
- mengqiy
- apelisse

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/*
Copyright 2017 The Kubernetes Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package strategicpatch
import (
"fmt"
)
type LookupPatchMetaError struct {
Path string
Err error
}
func (e LookupPatchMetaError) Error() string {
return fmt.Sprintf("LookupPatchMetaError(%s): %v", e.Path, e.Err)
}
type FieldNotFoundError struct {
Path string
Field string
}
func (e FieldNotFoundError) Error() string {
return fmt.Sprintf("unable to find api field %q in %s", e.Field, e.Path)
}
type InvalidTypeError struct {
Path string
Expected string
Actual string
}
func (e InvalidTypeError) Error() string {
return fmt.Sprintf("invalid type for %s: got %q, expected %q", e.Path, e.Actual, e.Expected)
}

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/*
Copyright 2017 The Kubernetes Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package strategicpatch
import (
"errors"
"fmt"
"reflect"
"k8s.io/apimachinery/pkg/util/mergepatch"
forkedjson "k8s.io/apimachinery/third_party/forked/golang/json"
openapi "k8s.io/kube-openapi/pkg/util/proto"
)
type PatchMeta struct {
patchStrategies []string
patchMergeKey string
}
func (pm PatchMeta) GetPatchStrategies() []string {
if pm.patchStrategies == nil {
return []string{}
}
return pm.patchStrategies
}
func (pm PatchMeta) SetPatchStrategies(ps []string) {
pm.patchStrategies = ps
}
func (pm PatchMeta) GetPatchMergeKey() string {
return pm.patchMergeKey
}
func (pm PatchMeta) SetPatchMergeKey(pmk string) {
pm.patchMergeKey = pmk
}
type LookupPatchMeta interface {
// LookupPatchMetadataForStruct gets subschema and the patch metadata (e.g. patch strategy and merge key) for map.
LookupPatchMetadataForStruct(key string) (LookupPatchMeta, PatchMeta, error)
// LookupPatchMetadataForSlice get subschema and the patch metadata for slice.
LookupPatchMetadataForSlice(key string) (LookupPatchMeta, PatchMeta, error)
// Get the type name of the field
Name() string
}
type PatchMetaFromStruct struct {
T reflect.Type
}
func NewPatchMetaFromStruct(dataStruct interface{}) (PatchMetaFromStruct, error) {
t, err := getTagStructType(dataStruct)
return PatchMetaFromStruct{T: t}, err
}
var _ LookupPatchMeta = PatchMetaFromStruct{}
func (s PatchMetaFromStruct) LookupPatchMetadataForStruct(key string) (LookupPatchMeta, PatchMeta, error) {
fieldType, fieldPatchStrategies, fieldPatchMergeKey, err := forkedjson.LookupPatchMetadataForStruct(s.T, key)
if err != nil {
return nil, PatchMeta{}, err
}
return PatchMetaFromStruct{T: fieldType},
PatchMeta{
patchStrategies: fieldPatchStrategies,
patchMergeKey: fieldPatchMergeKey,
}, nil
}
func (s PatchMetaFromStruct) LookupPatchMetadataForSlice(key string) (LookupPatchMeta, PatchMeta, error) {
subschema, patchMeta, err := s.LookupPatchMetadataForStruct(key)
if err != nil {
return nil, PatchMeta{}, err
}
elemPatchMetaFromStruct := subschema.(PatchMetaFromStruct)
t := elemPatchMetaFromStruct.T
var elemType reflect.Type
switch t.Kind() {
// If t is an array or a slice, get the element type.
// If element is still an array or a slice, return an error.
// Otherwise, return element type.
case reflect.Array, reflect.Slice:
elemType = t.Elem()
if elemType.Kind() == reflect.Array || elemType.Kind() == reflect.Slice {
return nil, PatchMeta{}, errors.New("unexpected slice of slice")
}
// If t is an pointer, get the underlying element.
// If the underlying element is neither an array nor a slice, the pointer is pointing to a slice,
// e.g. https://github.com/kubernetes/kubernetes/blob/bc22e206c79282487ea0bf5696d5ccec7e839a76/staging/src/k8s.io/apimachinery/pkg/util/strategicpatch/patch_test.go#L2782-L2822
// If the underlying element is either an array or a slice, return its element type.
case reflect.Ptr:
t = t.Elem()
if t.Kind() == reflect.Array || t.Kind() == reflect.Slice {
t = t.Elem()
}
elemType = t
default:
return nil, PatchMeta{}, fmt.Errorf("expected slice or array type, but got: %s", s.T.Kind().String())
}
return PatchMetaFromStruct{T: elemType}, patchMeta, nil
}
func (s PatchMetaFromStruct) Name() string {
return s.T.Kind().String()
}
func getTagStructType(dataStruct interface{}) (reflect.Type, error) {
if dataStruct == nil {
return nil, mergepatch.ErrBadArgKind(struct{}{}, nil)
}
t := reflect.TypeOf(dataStruct)
// Get the underlying type for pointers
if t.Kind() == reflect.Ptr {
t = t.Elem()
}
if t.Kind() != reflect.Struct {
return nil, mergepatch.ErrBadArgKind(struct{}{}, dataStruct)
}
return t, nil
}
func GetTagStructTypeOrDie(dataStruct interface{}) reflect.Type {
t, err := getTagStructType(dataStruct)
if err != nil {
panic(err)
}
return t
}
type PatchMetaFromOpenAPI struct {
Schema openapi.Schema
}
func NewPatchMetaFromOpenAPI(s openapi.Schema) PatchMetaFromOpenAPI {
return PatchMetaFromOpenAPI{Schema: s}
}
var _ LookupPatchMeta = PatchMetaFromOpenAPI{}
func (s PatchMetaFromOpenAPI) LookupPatchMetadataForStruct(key string) (LookupPatchMeta, PatchMeta, error) {
if s.Schema == nil {
return nil, PatchMeta{}, nil
}
kindItem := NewKindItem(key, s.Schema.GetPath())
s.Schema.Accept(kindItem)
err := kindItem.Error()
if err != nil {
return nil, PatchMeta{}, err
}
return PatchMetaFromOpenAPI{Schema: kindItem.subschema},
kindItem.patchmeta, nil
}
func (s PatchMetaFromOpenAPI) LookupPatchMetadataForSlice(key string) (LookupPatchMeta, PatchMeta, error) {
if s.Schema == nil {
return nil, PatchMeta{}, nil
}
sliceItem := NewSliceItem(key, s.Schema.GetPath())
s.Schema.Accept(sliceItem)
err := sliceItem.Error()
if err != nil {
return nil, PatchMeta{}, err
}
return PatchMetaFromOpenAPI{Schema: sliceItem.subschema},
sliceItem.patchmeta, nil
}
func (s PatchMetaFromOpenAPI) Name() string {
schema := s.Schema
return schema.GetName()
}

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/*
Copyright 2017 The Kubernetes Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package strategicpatch
import (
"errors"
"strings"
"k8s.io/apimachinery/pkg/util/mergepatch"
openapi "k8s.io/kube-openapi/pkg/util/proto"
)
const (
patchStrategyOpenapiextensionKey = "x-kubernetes-patch-strategy"
patchMergeKeyOpenapiextensionKey = "x-kubernetes-patch-merge-key"
)
type LookupPatchItem interface {
openapi.SchemaVisitor
Error() error
Path() *openapi.Path
}
type kindItem struct {
key string
path *openapi.Path
err error
patchmeta PatchMeta
subschema openapi.Schema
hasVisitKind bool
}
func NewKindItem(key string, path *openapi.Path) *kindItem {
return &kindItem{
key: key,
path: path,
}
}
var _ LookupPatchItem = &kindItem{}
func (item *kindItem) Error() error {
return item.err
}
func (item *kindItem) Path() *openapi.Path {
return item.path
}
func (item *kindItem) VisitPrimitive(schema *openapi.Primitive) {
item.err = errors.New("expected kind, but got primitive")
}
func (item *kindItem) VisitArray(schema *openapi.Array) {
item.err = errors.New("expected kind, but got slice")
}
func (item *kindItem) VisitMap(schema *openapi.Map) {
item.err = errors.New("expected kind, but got map")
}
func (item *kindItem) VisitReference(schema openapi.Reference) {
if !item.hasVisitKind {
schema.SubSchema().Accept(item)
}
}
func (item *kindItem) VisitKind(schema *openapi.Kind) {
subschema, ok := schema.Fields[item.key]
if !ok {
item.err = FieldNotFoundError{Path: schema.GetPath().String(), Field: item.key}
return
}
mergeKey, patchStrategies, err := parsePatchMetadata(subschema.GetExtensions())
if err != nil {
item.err = err
return
}
item.patchmeta = PatchMeta{
patchStrategies: patchStrategies,
patchMergeKey: mergeKey,
}
item.subschema = subschema
}
type sliceItem struct {
key string
path *openapi.Path
err error
patchmeta PatchMeta
subschema openapi.Schema
hasVisitKind bool
}
func NewSliceItem(key string, path *openapi.Path) *sliceItem {
return &sliceItem{
key: key,
path: path,
}
}
var _ LookupPatchItem = &sliceItem{}
func (item *sliceItem) Error() error {
return item.err
}
func (item *sliceItem) Path() *openapi.Path {
return item.path
}
func (item *sliceItem) VisitPrimitive(schema *openapi.Primitive) {
item.err = errors.New("expected slice, but got primitive")
}
func (item *sliceItem) VisitArray(schema *openapi.Array) {
if !item.hasVisitKind {
item.err = errors.New("expected visit kind first, then visit array")
}
subschema := schema.SubType
item.subschema = subschema
}
func (item *sliceItem) VisitMap(schema *openapi.Map) {
item.err = errors.New("expected slice, but got map")
}
func (item *sliceItem) VisitReference(schema openapi.Reference) {
if !item.hasVisitKind {
schema.SubSchema().Accept(item)
} else {
item.subschema = schema.SubSchema()
}
}
func (item *sliceItem) VisitKind(schema *openapi.Kind) {
subschema, ok := schema.Fields[item.key]
if !ok {
item.err = FieldNotFoundError{Path: schema.GetPath().String(), Field: item.key}
return
}
mergeKey, patchStrategies, err := parsePatchMetadata(subschema.GetExtensions())
if err != nil {
item.err = err
return
}
item.patchmeta = PatchMeta{
patchStrategies: patchStrategies,
patchMergeKey: mergeKey,
}
item.hasVisitKind = true
subschema.Accept(item)
}
func parsePatchMetadata(extensions map[string]interface{}) (string, []string, error) {
ps, foundPS := extensions[patchStrategyOpenapiextensionKey]
var patchStrategies []string
var mergeKey, patchStrategy string
var ok bool
if foundPS {
patchStrategy, ok = ps.(string)
if ok {
patchStrategies = strings.Split(patchStrategy, ",")
} else {
return "", nil, mergepatch.ErrBadArgType(patchStrategy, ps)
}
}
mk, foundMK := extensions[patchMergeKeyOpenapiextensionKey]
if foundMK {
mergeKey, ok = mk.(string)
if !ok {
return "", nil, mergepatch.ErrBadArgType(mergeKey, mk)
}
}
return mergeKey, patchStrategies, nil
}

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approvers:
- pwittrock
reviewers:
- mengqiy
- apelisse

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// Copyright 2013 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package json is forked from the Go standard library to enable us to find the
// field of a struct that a given JSON key maps to.
package json
import (
"bytes"
"fmt"
"reflect"
"sort"
"strings"
"sync"
"unicode"
"unicode/utf8"
)
const (
patchStrategyTagKey = "patchStrategy"
patchMergeKeyTagKey = "patchMergeKey"
)
// Finds the patchStrategy and patchMergeKey struct tag fields on a given
// struct field given the struct type and the JSON name of the field.
// It returns field type, a slice of patch strategies, merge key and error.
// TODO: fix the returned errors to be introspectable.
func LookupPatchMetadataForStruct(t reflect.Type, jsonField string) (
elemType reflect.Type, patchStrategies []string, patchMergeKey string, e error) {
if t.Kind() == reflect.Ptr {
t = t.Elem()
}
if t.Kind() != reflect.Struct {
e = fmt.Errorf("merging an object in json but data type is not struct, instead is: %s",
t.Kind().String())
return
}
jf := []byte(jsonField)
// Find the field that the JSON library would use.
var f *field
fields := cachedTypeFields(t)
for i := range fields {
ff := &fields[i]
if bytes.Equal(ff.nameBytes, jf) {
f = ff
break
}
// Do case-insensitive comparison.
if f == nil && ff.equalFold(ff.nameBytes, jf) {
f = ff
}
}
if f != nil {
// Find the reflect.Value of the most preferential struct field.
tjf := t.Field(f.index[0])
// we must navigate down all the anonymously included structs in the chain
for i := 1; i < len(f.index); i++ {
tjf = tjf.Type.Field(f.index[i])
}
patchStrategy := tjf.Tag.Get(patchStrategyTagKey)
patchMergeKey = tjf.Tag.Get(patchMergeKeyTagKey)
patchStrategies = strings.Split(patchStrategy, ",")
elemType = tjf.Type
return
}
e = fmt.Errorf("unable to find api field in struct %s for the json field %q", t.Name(), jsonField)
return
}
// A field represents a single field found in a struct.
type field struct {
name string
nameBytes []byte // []byte(name)
equalFold func(s, t []byte) bool // bytes.EqualFold or equivalent
tag bool
// index is the sequence of indexes from the containing type fields to this field.
// it is a slice because anonymous structs will need multiple navigation steps to correctly
// resolve the proper fields
index []int
typ reflect.Type
omitEmpty bool
quoted bool
}
func (f field) String() string {
return fmt.Sprintf("{name: %s, type: %v, tag: %v, index: %v, omitEmpty: %v, quoted: %v}", f.name, f.typ, f.tag, f.index, f.omitEmpty, f.quoted)
}
func fillField(f field) field {
f.nameBytes = []byte(f.name)
f.equalFold = foldFunc(f.nameBytes)
return f
}
// byName sorts field by name, breaking ties with depth,
// then breaking ties with "name came from json tag", then
// breaking ties with index sequence.
type byName []field
func (x byName) Len() int { return len(x) }
func (x byName) Swap(i, j int) { x[i], x[j] = x[j], x[i] }
func (x byName) Less(i, j int) bool {
if x[i].name != x[j].name {
return x[i].name < x[j].name
}
if len(x[i].index) != len(x[j].index) {
return len(x[i].index) < len(x[j].index)
}
if x[i].tag != x[j].tag {
return x[i].tag
}
return byIndex(x).Less(i, j)
}
// byIndex sorts field by index sequence.
type byIndex []field
func (x byIndex) Len() int { return len(x) }
func (x byIndex) Swap(i, j int) { x[i], x[j] = x[j], x[i] }
func (x byIndex) Less(i, j int) bool {
for k, xik := range x[i].index {
if k >= len(x[j].index) {
return false
}
if xik != x[j].index[k] {
return xik < x[j].index[k]
}
}
return len(x[i].index) < len(x[j].index)
}
// typeFields returns a list of fields that JSON should recognize for the given type.
// The algorithm is breadth-first search over the set of structs to include - the top struct
// and then any reachable anonymous structs.
func typeFields(t reflect.Type) []field {
// Anonymous fields to explore at the current level and the next.
current := []field{}
next := []field{{typ: t}}
// Count of queued names for current level and the next.
count := map[reflect.Type]int{}
nextCount := map[reflect.Type]int{}
// Types already visited at an earlier level.
visited := map[reflect.Type]bool{}
// Fields found.
var fields []field
for len(next) > 0 {
current, next = next, current[:0]
count, nextCount = nextCount, map[reflect.Type]int{}
for _, f := range current {
if visited[f.typ] {
continue
}
visited[f.typ] = true
// Scan f.typ for fields to include.
for i := 0; i < f.typ.NumField(); i++ {
sf := f.typ.Field(i)
if sf.PkgPath != "" { // unexported
continue
}
tag := sf.Tag.Get("json")
if tag == "-" {
continue
}
name, opts := parseTag(tag)
if !isValidTag(name) {
name = ""
}
index := make([]int, len(f.index)+1)
copy(index, f.index)
index[len(f.index)] = i
ft := sf.Type
if ft.Name() == "" && ft.Kind() == reflect.Ptr {
// Follow pointer.
ft = ft.Elem()
}
// Record found field and index sequence.
if name != "" || !sf.Anonymous || ft.Kind() != reflect.Struct {
tagged := name != ""
if name == "" {
name = sf.Name
}
fields = append(fields, fillField(field{
name: name,
tag: tagged,
index: index,
typ: ft,
omitEmpty: opts.Contains("omitempty"),
quoted: opts.Contains("string"),
}))
if count[f.typ] > 1 {
// If there were multiple instances, add a second,
// so that the annihilation code will see a duplicate.
// It only cares about the distinction between 1 or 2,
// so don't bother generating any more copies.
fields = append(fields, fields[len(fields)-1])
}
continue
}
// Record new anonymous struct to explore in next round.
nextCount[ft]++
if nextCount[ft] == 1 {
next = append(next, fillField(field{name: ft.Name(), index: index, typ: ft}))
}
}
}
}
sort.Sort(byName(fields))
// Delete all fields that are hidden by the Go rules for embedded fields,
// except that fields with JSON tags are promoted.
// The fields are sorted in primary order of name, secondary order
// of field index length. Loop over names; for each name, delete
// hidden fields by choosing the one dominant field that survives.
out := fields[:0]
for advance, i := 0, 0; i < len(fields); i += advance {
// One iteration per name.
// Find the sequence of fields with the name of this first field.
fi := fields[i]
name := fi.name
for advance = 1; i+advance < len(fields); advance++ {
fj := fields[i+advance]
if fj.name != name {
break
}
}
if advance == 1 { // Only one field with this name
out = append(out, fi)
continue
}
dominant, ok := dominantField(fields[i : i+advance])
if ok {
out = append(out, dominant)
}
}
fields = out
sort.Sort(byIndex(fields))
return fields
}
// dominantField looks through the fields, all of which are known to
// have the same name, to find the single field that dominates the
// others using Go's embedding rules, modified by the presence of
// JSON tags. If there are multiple top-level fields, the boolean
// will be false: This condition is an error in Go and we skip all
// the fields.
func dominantField(fields []field) (field, bool) {
// The fields are sorted in increasing index-length order. The winner
// must therefore be one with the shortest index length. Drop all
// longer entries, which is easy: just truncate the slice.
length := len(fields[0].index)
tagged := -1 // Index of first tagged field.
for i, f := range fields {
if len(f.index) > length {
fields = fields[:i]
break
}
if f.tag {
if tagged >= 0 {
// Multiple tagged fields at the same level: conflict.
// Return no field.
return field{}, false
}
tagged = i
}
}
if tagged >= 0 {
return fields[tagged], true
}
// All remaining fields have the same length. If there's more than one,
// we have a conflict (two fields named "X" at the same level) and we
// return no field.
if len(fields) > 1 {
return field{}, false
}
return fields[0], true
}
var fieldCache struct {
sync.RWMutex
m map[reflect.Type][]field
}
// cachedTypeFields is like typeFields but uses a cache to avoid repeated work.
func cachedTypeFields(t reflect.Type) []field {
fieldCache.RLock()
f := fieldCache.m[t]
fieldCache.RUnlock()
if f != nil {
return f
}
// Compute fields without lock.
// Might duplicate effort but won't hold other computations back.
f = typeFields(t)
if f == nil {
f = []field{}
}
fieldCache.Lock()
if fieldCache.m == nil {
fieldCache.m = map[reflect.Type][]field{}
}
fieldCache.m[t] = f
fieldCache.Unlock()
return f
}
func isValidTag(s string) bool {
if s == "" {
return false
}
for _, c := range s {
switch {
case strings.ContainsRune("!#$%&()*+-./:<=>?@[]^_{|}~ ", c):
// Backslash and quote chars are reserved, but
// otherwise any punctuation chars are allowed
// in a tag name.
default:
if !unicode.IsLetter(c) && !unicode.IsDigit(c) {
return false
}
}
}
return true
}
const (
caseMask = ^byte(0x20) // Mask to ignore case in ASCII.
kelvin = '\u212a'
smallLongEss = '\u017f'
)
// foldFunc returns one of four different case folding equivalence
// functions, from most general (and slow) to fastest:
//
// 1) bytes.EqualFold, if the key s contains any non-ASCII UTF-8
// 2) equalFoldRight, if s contains special folding ASCII ('k', 'K', 's', 'S')
// 3) asciiEqualFold, no special, but includes non-letters (including _)
// 4) simpleLetterEqualFold, no specials, no non-letters.
//
// The letters S and K are special because they map to 3 runes, not just 2:
// * S maps to s and to U+017F 'ſ' Latin small letter long s
// * k maps to K and to U+212A '' Kelvin sign
// See http://play.golang.org/p/tTxjOc0OGo
//
// The returned function is specialized for matching against s and
// should only be given s. It's not curried for performance reasons.
func foldFunc(s []byte) func(s, t []byte) bool {
nonLetter := false
special := false // special letter
for _, b := range s {
if b >= utf8.RuneSelf {
return bytes.EqualFold
}
upper := b & caseMask
if upper < 'A' || upper > 'Z' {
nonLetter = true
} else if upper == 'K' || upper == 'S' {
// See above for why these letters are special.
special = true
}
}
if special {
return equalFoldRight
}
if nonLetter {
return asciiEqualFold
}
return simpleLetterEqualFold
}
// equalFoldRight is a specialization of bytes.EqualFold when s is
// known to be all ASCII (including punctuation), but contains an 's',
// 'S', 'k', or 'K', requiring a Unicode fold on the bytes in t.
// See comments on foldFunc.
func equalFoldRight(s, t []byte) bool {
for _, sb := range s {
if len(t) == 0 {
return false
}
tb := t[0]
if tb < utf8.RuneSelf {
if sb != tb {
sbUpper := sb & caseMask
if 'A' <= sbUpper && sbUpper <= 'Z' {
if sbUpper != tb&caseMask {
return false
}
} else {
return false
}
}
t = t[1:]
continue
}
// sb is ASCII and t is not. t must be either kelvin
// sign or long s; sb must be s, S, k, or K.
tr, size := utf8.DecodeRune(t)
switch sb {
case 's', 'S':
if tr != smallLongEss {
return false
}
case 'k', 'K':
if tr != kelvin {
return false
}
default:
return false
}
t = t[size:]
}
if len(t) > 0 {
return false
}
return true
}
// asciiEqualFold is a specialization of bytes.EqualFold for use when
// s is all ASCII (but may contain non-letters) and contains no
// special-folding letters.
// See comments on foldFunc.
func asciiEqualFold(s, t []byte) bool {
if len(s) != len(t) {
return false
}
for i, sb := range s {
tb := t[i]
if sb == tb {
continue
}
if ('a' <= sb && sb <= 'z') || ('A' <= sb && sb <= 'Z') {
if sb&caseMask != tb&caseMask {
return false
}
} else {
return false
}
}
return true
}
// simpleLetterEqualFold is a specialization of bytes.EqualFold for
// use when s is all ASCII letters (no underscores, etc) and also
// doesn't contain 'k', 'K', 's', or 'S'.
// See comments on foldFunc.
func simpleLetterEqualFold(s, t []byte) bool {
if len(s) != len(t) {
return false
}
for i, b := range s {
if b&caseMask != t[i]&caseMask {
return false
}
}
return true
}
// tagOptions is the string following a comma in a struct field's "json"
// tag, or the empty string. It does not include the leading comma.
type tagOptions string
// parseTag splits a struct field's json tag into its name and
// comma-separated options.
func parseTag(tag string) (string, tagOptions) {
if idx := strings.Index(tag, ","); idx != -1 {
return tag[:idx], tagOptions(tag[idx+1:])
}
return tag, tagOptions("")
}
// Contains reports whether a comma-separated list of options
// contains a particular substr flag. substr must be surrounded by a
// string boundary or commas.
func (o tagOptions) Contains(optionName string) bool {
if len(o) == 0 {
return false
}
s := string(o)
for s != "" {
var next string
i := strings.Index(s, ",")
if i >= 0 {
s, next = s[:i], s[i+1:]
}
if s == optionName {
return true
}
s = next
}
return false
}

View File

@@ -0,0 +1,30 @@
package json
import (
"reflect"
"testing"
)
func TestLookupPtrToStruct(t *testing.T) {
type Elem struct {
Key string
Value string
}
type Outer struct {
Inner []Elem `json:"inner" patchStrategy:"merge" patchMergeKey:"key"`
}
outer := &Outer{}
elemType, patchStrategies, patchMergeKey, err := LookupPatchMetadataForStruct(reflect.TypeOf(outer), "inner")
if err != nil {
t.Fatal(err)
}
if elemType != reflect.TypeOf([]Elem{}) {
t.Errorf("elemType = %v, want: %v", elemType, reflect.TypeOf([]Elem{}))
}
if !reflect.DeepEqual(patchStrategies, []string{"merge"}) {
t.Errorf("patchStrategies = %v, want: %v", patchStrategies, []string{"merge"})
}
if patchMergeKey != "key" {
t.Errorf("patchMergeKey = %v, want: %v", patchMergeKey, "key")
}
}