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Diffstat (limited to 'vendor/k8s.io/apimachinery/pkg/util/strategicpatch/patch.go')
| -rw-r--r-- | vendor/k8s.io/apimachinery/pkg/util/strategicpatch/patch.go | 2115 |
1 files changed, 2115 insertions, 0 deletions
diff --git a/vendor/k8s.io/apimachinery/pkg/util/strategicpatch/patch.go b/vendor/k8s.io/apimachinery/pkg/util/strategicpatch/patch.go new file mode 100644 index 000000000..8884c738e --- /dev/null +++ b/vendor/k8s.io/apimachinery/pkg/util/strategicpatch/patch.go @@ -0,0 +1,2115 @@ +/* +Copyright 2014 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" + "reflect" + "sort" + "strings" + + "k8s.io/apimachinery/pkg/util/json" + "k8s.io/apimachinery/pkg/util/mergepatch" + forkedjson "k8s.io/apimachinery/third_party/forked/golang/json" +) + +// An alternate implementation of JSON Merge Patch +// (https://tools.ietf.org/html/rfc7386) which supports the ability to annotate +// certain fields with metadata that indicates whether the elements of JSON +// lists should be merged or replaced. +// +// For more information, see the PATCH section of docs/devel/api-conventions.md. +// +// Some of the content of this package was borrowed with minor adaptations from +// evanphx/json-patch and openshift/origin. + +const ( + directiveMarker = "$patch" + deleteDirective = "delete" + replaceDirective = "replace" + mergeDirective = "merge" + + retainKeysStrategy = "retainKeys" + + deleteFromPrimitiveListDirectivePrefix = "$deleteFromPrimitiveList" + retainKeysDirective = "$" + retainKeysStrategy + setElementOrderDirectivePrefix = "$setElementOrder" +) + +// JSONMap is a representations of JSON object encoded as map[string]interface{} +// where the children can be either map[string]interface{}, []interface{} or +// primitive type). +// Operating on JSONMap representation is much faster as it doesn't require any +// json marshaling and/or unmarshaling operations. +type JSONMap map[string]interface{} + +type DiffOptions struct { + // SetElementOrder determines whether we generate the $setElementOrder parallel list. + SetElementOrder bool + // IgnoreChangesAndAdditions indicates if we keep the changes and additions in the patch. + IgnoreChangesAndAdditions bool + // IgnoreDeletions indicates if we keep the deletions in the patch. + IgnoreDeletions bool + // We introduce a new value retainKeys for patchStrategy. + // It indicates that all fields needing to be preserved must be + // present in the `retainKeys` list. + // And the fields that are present will be merged with live object. + // All the missing fields will be cleared when patching. + BuildRetainKeysDirective bool +} + +type MergeOptions struct { + // MergeParallelList indicates if we are merging the parallel list. + // We don't merge parallel list when calling mergeMap() in CreateThreeWayMergePatch() + // which is called client-side. + // We merge parallel list iff when calling mergeMap() in StrategicMergeMapPatch() + // which is called server-side + MergeParallelList bool + // IgnoreUnmatchedNulls indicates if we should process the unmatched nulls. + IgnoreUnmatchedNulls bool +} + +// The following code is adapted from github.com/openshift/origin/pkg/util/jsonmerge. +// Instead of defining a Delta that holds an original, a patch and a set of preconditions, +// the reconcile method accepts a set of preconditions as an argument. + +// CreateTwoWayMergePatch creates a patch that can be passed to StrategicMergePatch from an original +// document and a modified document, which are passed to the method as json encoded content. It will +// return a patch that yields the modified document when applied to the original document, or an error +// if either of the two documents is invalid. +func CreateTwoWayMergePatch(original, modified []byte, dataStruct interface{}, fns ...mergepatch.PreconditionFunc) ([]byte, error) { + originalMap := map[string]interface{}{} + if len(original) > 0 { + if err := json.Unmarshal(original, &originalMap); err != nil { + return nil, mergepatch.ErrBadJSONDoc + } + } + + modifiedMap := map[string]interface{}{} + if len(modified) > 0 { + if err := json.Unmarshal(modified, &modifiedMap); err != nil { + return nil, mergepatch.ErrBadJSONDoc + } + } + + patchMap, err := CreateTwoWayMergeMapPatch(originalMap, modifiedMap, dataStruct, fns...) + if err != nil { + return nil, err + } + + return json.Marshal(patchMap) +} + +// CreateTwoWayMergeMapPatch creates a patch from an original and modified JSON objects, +// encoded JSONMap. +// The serialized version of the map can then be passed to StrategicMergeMapPatch. +func CreateTwoWayMergeMapPatch(original, modified JSONMap, dataStruct interface{}, fns ...mergepatch.PreconditionFunc) (JSONMap, error) { + t, err := getTagStructType(dataStruct) + if err != nil { + return nil, err + } + + diffOptions := DiffOptions{ + SetElementOrder: true, + } + patchMap, err := diffMaps(original, modified, t, diffOptions) + if err != nil { + return nil, err + } + + // Apply the preconditions to the patch, and return an error if any of them fail. + for _, fn := range fns { + if !fn(patchMap) { + return nil, mergepatch.NewErrPreconditionFailed(patchMap) + } + } + + return patchMap, nil +} + +// Returns a (recursive) strategic merge patch that yields modified when applied to original. +// Including: +// - Adding fields to the patch present in modified, missing from original +// - Setting fields to the patch present in modified and original with different values +// - Delete fields present in original, missing from modified through +// - IFF map field - set to nil in patch +// - IFF list of maps && merge strategy - use deleteDirective for the elements +// - IFF list of primitives && merge strategy - use parallel deletion list +// - IFF list of maps or primitives with replace strategy (default) - set patch value to the value in modified +// - Build $retainKeys directive for fields with retainKeys patch strategy +func diffMaps(original, modified map[string]interface{}, t reflect.Type, diffOptions DiffOptions) (map[string]interface{}, error) { + patch := map[string]interface{}{} + // Get the underlying type for pointers + if t.Kind() == reflect.Ptr { + t = t.Elem() + } + // This will be used to build the $retainKeys directive sent in the patch + retainKeysList := make([]interface{}, 0, len(modified)) + + // Compare each value in the modified map against the value in the original map + for key, modifiedValue := range modified { + // Get the underlying type for pointers + if diffOptions.BuildRetainKeysDirective && modifiedValue != nil { + retainKeysList = append(retainKeysList, key) + } + + originalValue, ok := original[key] + if !ok { + // Key was added, so add to patch + if !diffOptions.IgnoreChangesAndAdditions { + patch[key] = modifiedValue + } + continue + } + + // The patch may have a patch directive + // TODO: figure out if we need this. This shouldn't be needed by apply. When would the original map have patch directives in it? + foundDirectiveMarker, err := handleDirectiveMarker(key, originalValue, modifiedValue, patch) + if err != nil { + return nil, err + } + if foundDirectiveMarker { + continue + } + + if reflect.TypeOf(originalValue) != reflect.TypeOf(modifiedValue) { + // Types have changed, so add to patch + if !diffOptions.IgnoreChangesAndAdditions { + patch[key] = modifiedValue + } + continue + } + + // Types are the same, so compare values + switch originalValueTyped := originalValue.(type) { + case map[string]interface{}: + modifiedValueTyped := modifiedValue.(map[string]interface{}) + err = handleMapDiff(key, originalValueTyped, modifiedValueTyped, patch, t, diffOptions) + case []interface{}: + modifiedValueTyped := modifiedValue.([]interface{}) + err = handleSliceDiff(key, originalValueTyped, modifiedValueTyped, patch, t, diffOptions) + default: + replacePatchFieldIfNotEqual(key, originalValue, modifiedValue, patch, diffOptions) + } + if err != nil { + return nil, err + } + } + + updatePatchIfMissing(original, modified, patch, diffOptions) + // Insert the retainKeysList iff there are values present in the retainKeysList and + // either of the following is true: + // - the patch is not empty + // - there are additional field in original that need to be cleared + if len(retainKeysList) > 0 && + (len(patch) > 0 || hasAdditionalNewField(original, modified)) { + patch[retainKeysDirective] = sortScalars(retainKeysList) + } + return patch, nil +} + +// handleDirectiveMarker handles how to diff directive marker between 2 objects +func handleDirectiveMarker(key string, originalValue, modifiedValue interface{}, patch map[string]interface{}) (bool, error) { + if key == directiveMarker { + originalString, ok := originalValue.(string) + if !ok { + return false, fmt.Errorf("invalid value for special key: %s", directiveMarker) + } + modifiedString, ok := modifiedValue.(string) + if !ok { + return false, fmt.Errorf("invalid value for special key: %s", directiveMarker) + } + if modifiedString != originalString { + patch[directiveMarker] = modifiedValue + } + return true, nil + } + return false, nil +} + +// handleMapDiff diff between 2 maps `originalValueTyped` and `modifiedValue`, +// puts the diff in the `patch` associated with `key` +// key is the key associated with originalValue and modifiedValue. +// originalValue, modifiedValue are the old and new value respectively.They are both maps +// patch is the patch map that contains key and the updated value, and it is the parent of originalValue, modifiedValue +// diffOptions contains multiple options to control how we do the diff. +func handleMapDiff(key string, originalValue, modifiedValue, patch map[string]interface{}, + t reflect.Type, diffOptions DiffOptions) error { + fieldType, fieldPatchStrategies, _, err := forkedjson.LookupPatchMetadata(t, key) + if err != nil { + // We couldn't look up metadata for the field + // If the values are identical, this doesn't matter, no patch is needed + if reflect.DeepEqual(originalValue, modifiedValue) { + return nil + } + // Otherwise, return the error + return err + } + retainKeys, patchStrategy, err := extractRetainKeysPatchStrategy(fieldPatchStrategies) + if err != nil { + return err + } + diffOptions.BuildRetainKeysDirective = retainKeys + switch patchStrategy { + // The patch strategic from metadata tells us to replace the entire object instead of diffing it + case replaceDirective: + if !diffOptions.IgnoreChangesAndAdditions { + patch[key] = modifiedValue + } + default: + patchValue, err := diffMaps(originalValue, modifiedValue, fieldType, diffOptions) + if err != nil { + return err + } + // Maps were not identical, use provided patch value + if len(patchValue) > 0 { + patch[key] = patchValue + } + } + return nil +} + +// handleSliceDiff diff between 2 slices `originalValueTyped` and `modifiedValue`, +// puts the diff in the `patch` associated with `key` +// key is the key associated with originalValue and modifiedValue. +// originalValue, modifiedValue are the old and new value respectively.They are both slices +// patch is the patch map that contains key and the updated value, and it is the parent of originalValue, modifiedValue +// diffOptions contains multiple options to control how we do the diff. +func handleSliceDiff(key string, originalValue, modifiedValue []interface{}, patch map[string]interface{}, + t reflect.Type, diffOptions DiffOptions) error { + fieldType, fieldPatchStrategies, fieldPatchMergeKey, err := forkedjson.LookupPatchMetadata(t, key) + if err != nil { + // We couldn't look up metadata for the field + // If the values are identical, this doesn't matter, no patch is needed + if reflect.DeepEqual(originalValue, modifiedValue) { + return nil + } + // Otherwise, return the error + return err + } + retainKeys, patchStrategy, err := extractRetainKeysPatchStrategy(fieldPatchStrategies) + if err != nil { + return err + } + switch patchStrategy { + // Merge the 2 slices using mergePatchKey + case mergeDirective: + diffOptions.BuildRetainKeysDirective = retainKeys + addList, deletionList, setOrderList, err := diffLists(originalValue, modifiedValue, fieldType.Elem(), fieldPatchMergeKey, diffOptions) + if err != nil { + return err + } + if len(addList) > 0 { + patch[key] = addList + } + // generate a parallel list for deletion + if len(deletionList) > 0 { + parallelDeletionListKey := fmt.Sprintf("%s/%s", deleteFromPrimitiveListDirectivePrefix, key) + patch[parallelDeletionListKey] = deletionList + } + if len(setOrderList) > 0 { + parallelSetOrderListKey := fmt.Sprintf("%s/%s", setElementOrderDirectivePrefix, key) + patch[parallelSetOrderListKey] = setOrderList + } + default: + replacePatchFieldIfNotEqual(key, originalValue, modifiedValue, patch, diffOptions) + } + return nil +} + +// replacePatchFieldIfNotEqual updates the patch if original and modified are not deep equal +// if diffOptions.IgnoreChangesAndAdditions is false. +// original is the old value, maybe either the live cluster object or the last applied configuration +// modified is the new value, is always the users new config +func replacePatchFieldIfNotEqual(key string, original, modified interface{}, + patch map[string]interface{}, diffOptions DiffOptions) { + if diffOptions.IgnoreChangesAndAdditions { + // Ignoring changes - do nothing + return + } + if reflect.DeepEqual(original, modified) { + // Contents are identical - do nothing + return + } + // Create a patch to replace the old value with the new one + patch[key] = modified +} + +// updatePatchIfMissing iterates over `original` when ignoreDeletions is false. +// Clear the field whose key is not present in `modified`. +// original is the old value, maybe either the live cluster object or the last applied configuration +// modified is the new value, is always the users new config +func updatePatchIfMissing(original, modified, patch map[string]interface{}, diffOptions DiffOptions) { + if diffOptions.IgnoreDeletions { + // Ignoring deletion - do nothing + return + } + // Add nils for deleted values + for key := range original { + if _, found := modified[key]; !found { + patch[key] = nil + } + } +} + +// validateMergeKeyInLists checks if each map in the list has the mentryerge key. +func validateMergeKeyInLists(mergeKey string, lists ...[]interface{}) error { + for _, list := range lists { + for _, item := range list { + m, ok := item.(map[string]interface{}) + if !ok { + return mergepatch.ErrBadArgType(m, item) + } + if _, ok = m[mergeKey]; !ok { + return mergepatch.ErrNoMergeKey(m, mergeKey) + } + } + } + return nil +} + +// normalizeElementOrder sort `patch` list by `patchOrder` and sort `serverOnly` list by `serverOrder`. +// Then it merges the 2 sorted lists. +// It guarantee the relative order in the patch list and in the serverOnly list is kept. +// `patch` is a list of items in the patch, and `serverOnly` is a list of items in the live object. +// `patchOrder` is the order we want `patch` list to have and +// `serverOrder` is the order we want `serverOnly` list to have. +// kind is the kind of each item in the lists `patch` and `serverOnly`. +func normalizeElementOrder(patch, serverOnly, patchOrder, serverOrder []interface{}, mergeKey string, kind reflect.Kind) ([]interface{}, error) { + patch, err := normalizeSliceOrder(patch, patchOrder, mergeKey, kind) + if err != nil { + return nil, err + } + serverOnly, err = normalizeSliceOrder(serverOnly, serverOrder, mergeKey, kind) + if err != nil { + return nil, err + } + all := mergeSortedSlice(serverOnly, patch, serverOrder, mergeKey, kind) + + return all, nil +} + +// mergeSortedSlice merges the 2 sorted lists by serverOrder with best effort. +// It will insert each item in `left` list to `right` list. In most cases, the 2 lists will be interleaved. +// The relative order of left and right are guaranteed to be kept. +// They have higher precedence than the order in the live list. +// The place for a item in `left` is found by: +// scan from the place of last insertion in `right` to the end of `right`, +// the place is before the first item that is greater than the item we want to insert. +// example usage: using server-only items as left and patch items as right. We insert server-only items +// to patch list. We use the order of live object as record for comparision. +func mergeSortedSlice(left, right, serverOrder []interface{}, mergeKey string, kind reflect.Kind) []interface{} { + // Returns if l is less than r, and if both have been found. + // If l and r both present and l is in front of r, l is less than r. + less := func(l, r interface{}) (bool, bool) { + li := index(serverOrder, l, mergeKey, kind) + ri := index(serverOrder, r, mergeKey, kind) + if li >= 0 && ri >= 0 { + return li < ri, true + } else { + return false, false + } + } + + // left and right should be non-overlapping. + size := len(left) + len(right) + i, j := 0, 0 + s := make([]interface{}, size, size) + + for k := 0; k < size; k++ { + if i >= len(left) && j < len(right) { + // have items left in `right` list + s[k] = right[j] + j++ + } else if j >= len(right) && i < len(left) { + // have items left in `left` list + s[k] = left[i] + i++ + } else { + // compare them if i and j are both in bound + less, foundBoth := less(left[i], right[j]) + if foundBoth && less { + s[k] = left[i] + i++ + } else { + s[k] = right[j] + j++ + } + } + } + return s +} + +// index returns the index of the item in the given items, or -1 if it doesn't exist +// l must NOT be a slice of slices, this should be checked before calling. +func index(l []interface{}, valToLookUp interface{}, mergeKey string, kind reflect.Kind) int { + var getValFn func(interface{}) interface{} + // Get the correct `getValFn` based on item `kind`. + // It should return the value of merge key for maps and + // return the item for other kinds. + switch kind { + case reflect.Map: + getValFn = func(item interface{}) interface{} { + typedItem, ok := item.(map[string]interface{}) + if !ok { + return nil + } + val := typedItem[mergeKey] + return val + } + default: + getValFn = func(item interface{}) interface{} { + return item + } + } + + for i, v := range l { + if getValFn(valToLookUp) == getValFn(v) { + return i + } + } + return -1 +} + +// extractToDeleteItems takes a list and +// returns 2 lists: one contains items that should be kept and the other contains items to be deleted. +func extractToDeleteItems(l []interface{}) ([]interface{}, []interface{}, error) { + var nonDelete, toDelete []interface{} + for _, v := range l { + m, ok := v.(map[string]interface{}) + if !ok { + return nil, nil, mergepatch.ErrBadArgType(m, v) + } + + directive, foundDirective := m[directiveMarker] + if foundDirective && directive == deleteDirective { + toDelete = append(toDelete, v) + } else { + nonDelete = append(nonDelete, v) + } + } + return nonDelete, toDelete, nil +} + +// normalizeSliceOrder sort `toSort` list by `order` +func normalizeSliceOrder(toSort, order []interface{}, mergeKey string, kind reflect.Kind) ([]interface{}, error) { + var toDelete []interface{} + if kind == reflect.Map { + // make sure each item in toSort, order has merge key + err := validateMergeKeyInLists(mergeKey, toSort, order) + if err != nil { + return nil, err + } + toSort, toDelete, err = extractToDeleteItems(toSort) + } + + sort.SliceStable(toSort, func(i, j int) bool { + if ii := index(order, toSort[i], mergeKey, kind); ii >= 0 { + if ij := index(order, toSort[j], mergeKey, kind); ij >= 0 { + return ii < ij + } + } + return true + }) + toSort = append(toSort, toDelete...) + return toSort, nil +} + +// Returns a (recursive) strategic merge patch, a parallel deletion list if necessary and +// another list to set the order of the list +// Only list of primitives with merge strategy will generate a parallel deletion list. +// These two lists should yield modified when applied to original, for lists with merge semantics. +func diffLists(original, modified []interface{}, t reflect.Type, mergeKey string, diffOptions DiffOptions) ([]interface{}, []interface{}, []interface{}, error) { + if len(original) == 0 { + // Both slices are empty - do nothing + if len(modified) == 0 || diffOptions.IgnoreChangesAndAdditions { + return nil, nil, nil, nil + } + + // Old slice was empty - add all elements from the new slice + return modified, nil, nil, nil + } + + elementType, err := sliceElementType(original, modified) + if err != nil { + return nil, nil, nil, err + } + + var patchList, deleteList, setOrderList []interface{} + kind := elementType.Kind() + switch kind { + case reflect.Map: + patchList, deleteList, err = diffListsOfMaps(original, modified, t, mergeKey, diffOptions) + patchList, err = normalizeSliceOrder(patchList, modified, mergeKey, kind) + orderSame, err := isOrderSame(original, modified, mergeKey) + if err != nil { + return nil, nil, nil, err + } + // append the deletions to the end of the patch list. + patchList = append(patchList, deleteList...) + deleteList = nil + // generate the setElementOrder list when there are content changes or order changes + if diffOptions.SetElementOrder && + ((!diffOptions.IgnoreChangesAndAdditions && (len(patchList) > 0 || !orderSame)) || + (!diffOptions.IgnoreDeletions && len(patchList) > 0)) { + // Generate a list of maps that each item contains only the merge key. + setOrderList = make([]interface{}, len(modified)) + for i, v := range modified { + typedV := v.(map[string]interface{}) + setOrderList[i] = map[string]interface{}{ + mergeKey: typedV[mergeKey], + } + } + } + case reflect.Slice: + // Lists of Lists are not permitted by the api + return nil, nil, nil, mergepatch.ErrNoListOfLists + default: + patchList, deleteList, err = diffListsOfScalars(original, modified, diffOptions) + patchList, err = normalizeSliceOrder(patchList, modified, mergeKey, kind) + // generate the setElementOrder list when there are content changes or order changes + if diffOptions.SetElementOrder && ((!diffOptions.IgnoreDeletions && len(deleteList) > 0) || + (!diffOptions.IgnoreChangesAndAdditions && !reflect.DeepEqual(original, modified))) { + setOrderList = modified + } + } + return patchList, deleteList, setOrderList, err +} + +// isOrderSame checks if the order in a list has changed +func isOrderSame(original, modified []interface{}, mergeKey string) (bool, error) { + if len(original) != len(modified) { + return false, nil + } + for i, modifiedItem := range modified { + equal, err := mergeKeyValueEqual(original[i], modifiedItem, mergeKey) + if err != nil || !equal { + return equal, err + } + } + return true, nil +} + +// diffListsOfScalars returns 2 lists, the first one is addList and the second one is deletionList. +// Argument diffOptions.IgnoreChangesAndAdditions controls if calculate addList. true means not calculate. +// Argument diffOptions.IgnoreDeletions controls if calculate deletionList. true means not calculate. +// original may be changed, but modified is guaranteed to not be changed +func diffListsOfScalars(original, modified []interface{}, diffOptions DiffOptions) ([]interface{}, []interface{}, error) { + modifiedCopy := make([]interface{}, len(modified)) + copy(modifiedCopy, modified) + // Sort the scalars for easier calculating the diff + originalScalars := sortScalars(original) + modifiedScalars := sortScalars(modifiedCopy) + + originalIndex, modifiedIndex := 0, 0 + addList := []interface{}{} + deletionList := []interface{}{} + + for { + originalInBounds := originalIndex < len(originalScalars) + modifiedInBounds := modifiedIndex < len(modifiedScalars) + if !originalInBounds && !modifiedInBounds { + break + } + // we need to compare the string representation of the scalar, + // because the scalar is an interface which doesn't support either < or > + // And that's how func sortScalars compare scalars. + var originalString, modifiedString string + var originalValue, modifiedValue interface{} + if originalInBounds { + originalValue = originalScalars[originalIndex] + originalString = fmt.Sprintf("%v", originalValue) + } + if modifiedInBounds { + modifiedValue = modifiedScalars[modifiedIndex] + modifiedString = fmt.Sprintf("%v", modifiedValue) + } + + originalV, modifiedV := compareListValuesAtIndex(originalInBounds, modifiedInBounds, originalString, modifiedString) + switch { + case originalV == nil && modifiedV == nil: + originalIndex++ + modifiedIndex++ + case originalV != nil && modifiedV == nil: + if !diffOptions.IgnoreDeletions { + deletionList = append(deletionList, originalValue) + } + originalIndex++ + case originalV == nil && modifiedV != nil: + if !diffOptions.IgnoreChangesAndAdditions { + addList = append(addList, modifiedValue) + } + modifiedIndex++ + default: + return nil, nil, fmt.Errorf("Unexpected returned value from compareListValuesAtIndex: %v and %v", originalV, modifiedV) + } + } + + return addList, deduplicateScalars(deletionList), nil +} + +// If first return value is non-nil, list1 contains an element not present in list2 +// If second return value is non-nil, list2 contains an element not present in list1 +func compareListValuesAtIndex(list1Inbounds, list2Inbounds bool, list1Value, list2Value string) (interface{}, interface{}) { + bothInBounds := list1Inbounds && list2Inbounds + switch { + // scalars are identical + case bothInBounds && list1Value == list2Value: + return nil, nil + // only list2 is in bound + case !list1Inbounds: + fallthrough + // list2 has additional scalar + case bothInBounds && list1Value > list2Value: + return nil, list2Value + // only original is in bound + case !list2Inbounds: + fallthrough + // original has additional scalar + case bothInBounds && list1Value < list2Value: + return list1Value, nil + default: + return nil, nil + } +} + +// diffListsOfMaps takes a pair of lists and +// returns a (recursive) strategic merge patch list contains additions and changes and +// a deletion list contains deletions +func diffListsOfMaps(original, modified []interface{}, t reflect.Type, mergeKey string, diffOptions DiffOptions) ([]interface{}, []interface{}, error) { + patch := make([]interface{}, 0, len(modified)) + deletionList := make([]interface{}, 0, len(original)) + + originalSorted, err := sortMergeListsByNameArray(original, t, mergeKey, false) + if err != nil { + return nil, nil, err + } + modifiedSorted, err := sortMergeListsByNameArray(modified, t, mergeKey, false) + if err != nil { + return nil, nil, err + } + + originalIndex, modifiedIndex := 0, 0 + for { + originalInBounds := originalIndex < len(originalSorted) + modifiedInBounds := modifiedIndex < len(modifiedSorted) + bothInBounds := originalInBounds && modifiedInBounds + if !originalInBounds && !modifiedInBounds { + break + } + + var originalElementMergeKeyValueString, modifiedElementMergeKeyValueString string + var originalElementMergeKeyValue, modifiedElementMergeKeyValue interface{} + var originalElement, modifiedElement map[string]interface{} + if originalInBounds { + originalElement, originalElementMergeKeyValue, err = getMapAndMergeKeyValueByIndex(originalIndex, mergeKey, originalSorted) + if err != nil { + return nil, nil, err + } + originalElementMergeKeyValueString = fmt.Sprintf("%v", originalElementMergeKeyValue) + } + if modifiedInBounds { + modifiedElement, modifiedElementMergeKeyValue, err = getMapAndMergeKeyValueByIndex(modifiedIndex, mergeKey, modifiedSorted) + if err != nil { + return nil, nil, err + } + modifiedElementMergeKeyValueString = fmt.Sprintf("%v", modifiedElementMergeKeyValue) + } + + switch { + case bothInBounds && ItemMatchesOriginalAndModifiedSlice(originalElementMergeKeyValueString, modifiedElementMergeKeyValueString): + // Merge key values are equal, so recurse + patchValue, err := diffMaps(originalElement, modifiedElement, t, diffOptions) + if err != nil { + return nil, nil, err + } + if len(patchValue) > 0 { + patchValue[mergeKey] = modifiedElementMergeKeyValue + patch = append(patch, patchValue) + } + originalIndex++ + modifiedIndex++ + // only modified is in bound + case !originalInBounds: + fallthrough + // modified has additional map + case bothInBounds && ItemAddedToModifiedSlice(originalElementMergeKeyValueString, modifiedElementMergeKeyValueString): + if !diffOptions.IgnoreChangesAndAdditions { + patch = append(patch, modifiedElement) + } + modifiedIndex++ + // only original is in bound + case !modifiedInBounds: + fallthrough + // original has additional map + case bothInBounds && ItemRemovedFromModifiedSlice(originalElementMergeKeyValueString, modifiedElementMergeKeyValueString): + if !diffOptions.IgnoreDeletions { + // Item was deleted, so add delete directive + deletionList = append(deletionList, CreateDeleteDirective(mergeKey, originalElementMergeKeyValue)) + } + originalIndex++ + } + } + + return patch, deletionList, nil +} + +// getMapAndMergeKeyValueByIndex return a map in the list and its merge key value given the index of the map. +func getMapAndMergeKeyValueByIndex(index int, mergeKey string, listOfMaps []interface{}) (map[string]interface{}, interface{}, error) { + m, ok := listOfMaps[index].(map[string]interface{}) + if !ok { + return nil, nil, mergepatch.ErrBadArgType(m, listOfMaps[index]) + } + + val, ok := m[mergeKey] + if !ok { + return nil, nil, mergepatch.ErrNoMergeKey(m, mergeKey) + } + return m, val, nil +} + +// StrategicMergePatch applies a strategic merge patch. The patch and the original document +// must be json encoded content. A patch can be created from an original and a modified document +// by calling CreateStrategicMergePatch. +func StrategicMergePatch(original, patch []byte, dataStruct interface{}) ([]byte, error) { + originalMap, err := handleUnmarshal(original) + if err != nil { + return nil, err + } + patchMap, err := handleUnmarshal(patch) + if err != nil { + return nil, err + } + + result, err := StrategicMergeMapPatch(originalMap, patchMap, dataStruct) + if err != nil { + return nil, err + } + + return json.Marshal(result) +} + +func handleUnmarshal(j []byte) (map[string]interface{}, error) { + if j == nil { + j = []byte("{}") + } + + m := map[string]interface{}{} + err := json.Unmarshal(j, &m) + if err != nil { + return nil, mergepatch.ErrBadJSONDoc + } + return m, nil +} + +// StrategicMergePatch applies a strategic merge patch. The original and patch documents +// must be JSONMap. A patch can be created from an original and modified document by +// calling CreateTwoWayMergeMapPatch. +// Warning: the original and patch JSONMap objects are mutated by this function and should not be reused. +func StrategicMergeMapPatch(original, patch JSONMap, dataStruct interface{}) (JSONMap, error) { + t, err := getTagStructType(dataStruct) + if err != nil { + return nil, err + } + mergeOptions := MergeOptions{ + MergeParallelList: true, + IgnoreUnmatchedNulls: true, + } + return mergeMap(original, patch, t, mergeOptions) +} + +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 +} + +// handleDirectiveInMergeMap handles the patch directive when merging 2 maps. +func handleDirectiveInMergeMap(directive interface{}, patch map[string]interface{}) (map[string]interface{}, error) { + if directive == replaceDirective { + // If the patch contains "$patch: replace", don't merge it, just use the + // patch directly. Later on, we can add a single level replace that only + // affects the map that the $patch is in. + delete(patch, directiveMarker) + return patch, nil + } + + if directive == deleteDirective { + // If the patch contains "$patch: delete", don't merge it, just return + // an empty map. + return map[string]interface{}{}, nil + } + + return nil, mergepatch.ErrBadPatchType(directive, patch) +} + +func containsDirectiveMarker(item interface{}) bool { + m, ok := item.(map[string]interface{}) + if ok { + if _, foundDirectiveMarker := m[directiveMarker]; foundDirectiveMarker { + return true + } + } + return false +} + +func mergeKeyValueEqual(left, right interface{}, mergeKey string) (bool, error) { + if len(mergeKey) == 0 { + return left == right, nil + } + typedLeft, ok := left.(map[string]interface{}) + if !ok { + return false, mergepatch.ErrBadArgType(typedLeft, left) + } + typedRight, ok := right.(map[string]interface{}) + if !ok { + return false, mergepatch.ErrBadArgType(typedRight, right) + } + mergeKeyLeft, ok := typedLeft[mergeKey] + if !ok { + return false, mergepatch.ErrNoMergeKey(typedLeft, mergeKey) + } + mergeKeyRight, ok := typedRight[mergeKey] + if !ok { + return false, mergepatch.ErrNoMergeKey(typedRight, mergeKey) + } + return mergeKeyLeft == mergeKeyRight, nil +} + +// extractKey trims the prefix and return the original key +func extractKey(s, prefix string) (string, error) { + substrings := strings.SplitN(s, "/", 2) + if len(substrings) <= 1 || substrings[0] != prefix { + switch prefix { + case deleteFromPrimitiveListDirectivePrefix: + return "", mergepatch.ErrBadPatchFormatForPrimitiveList + case setElementOrderDirectivePrefix: + return "", mergepatch.ErrBadPatchFormatForSetElementOrderList + default: + return "", fmt.Errorf("fail to find unknown prefix %q in %s\n", prefix, s) + } + } + return substrings[1], nil +} + +// validatePatchUsingSetOrderList verifies: +// the relative order of any two items in the setOrderList list matches that in the patch list. +// the items in the patch list must be a subset or the same as the $setElementOrder list (deletions are ignored). +func validatePatchWithSetOrderList(patchList, setOrderList interface{}, mergeKey string) error { + typedSetOrderList, ok := setOrderList.([]interface{}) + if !ok { + return mergepatch.ErrBadPatchFormatForSetElementOrderList + } + typedPatchList, ok := patchList.([]interface{}) + if !ok { + return mergepatch.ErrBadPatchFormatForSetElementOrderList + } + if len(typedSetOrderList) == 0 || len(typedPatchList) == 0 { + return nil + } + + var nonDeleteList, toDeleteList []interface{} + var err error + if len(mergeKey) > 0 { + nonDeleteList, toDeleteList, err = extractToDeleteItems(typedPatchList) + if err != nil { + return err + } + } else { + nonDeleteList = typedPatchList + } + + patchIndex, setOrderIndex := 0, 0 + for patchIndex < len(nonDeleteList) && setOrderIndex < len(typedSetOrderList) { + if containsDirectiveMarker(nonDeleteList[patchIndex]) { + patchIndex++ + continue + } + mergeKeyEqual, err := mergeKeyValueEqual(nonDeleteList[patchIndex], typedSetOrderList[setOrderIndex], mergeKey) + if err != nil { + return err + } + if mergeKeyEqual { + patchIndex++ + } + setOrderIndex++ + } + // If patchIndex is inbound but setOrderIndex if out of bound mean there are items mismatching between the patch list and setElementOrder list. + // the second check is is a sanity check, and should always be true if the first is true. + if patchIndex < len(nonDeleteList) && setOrderIndex >= len(typedSetOrderList) { + return fmt.Errorf("The order in patch list:\n%v\n doesn't match %s list:\n%v\n", typedPatchList, setElementOrderDirectivePrefix, setOrderList) + } + typedPatchList = append(nonDeleteList, toDeleteList...) + return nil +} + +// preprocessDeletionListForMerging preprocesses the deletion list. +// it returns shouldContinue, isDeletionList, noPrefixKey +func preprocessDeletionListForMerging(key string, original map[string]interface{}, + patchVal interface{}, mergeDeletionList bool) (bool, bool, string, error) { + // If found a parallel list for deletion and we are going to merge the list, + // overwrite the key to the original key and set flag isDeleteList + foundParallelListPrefix := strings.HasPrefix(key, deleteFromPrimitiveListDirectivePrefix) + if foundParallelListPrefix { + if !mergeDeletionList { + original[key] = patchVal + return true, false, "", nil + } + originalKey, err := extractKey(key, deleteFromPrimitiveListDirectivePrefix) + return false, true, originalKey, err + } + return false, false, "", nil +} + +// applyRetainKeysDirective looks for a retainKeys directive and applies to original +// - if no directive exists do nothing +// - if directive is found, clear keys in original missing from the directive list +// - validate that all keys present in the patch are present in the retainKeys directive +// note: original may be another patch request, e.g. applying the add+modified patch to the deletions patch. In this case it may have directives +func applyRetainKeysDirective(original, patch map[string]interface{}, options MergeOptions) error { + retainKeysInPatch, foundInPatch := patch[retainKeysDirective] + if !foundInPatch { + return nil + } + // cleanup the directive + delete(patch, retainKeysDirective) + + if !options.MergeParallelList { + // If original is actually a patch, make sure the retainKeys directives are the same in both patches if present in both. + // If not present in the original patch, copy from the modified patch. + retainKeysInOriginal, foundInOriginal := original[retainKeysDirective] + if foundInOriginal { + if !reflect.DeepEqual(retainKeysInOriginal, retainKeysInPatch) { + // This error actually should never happen. + return fmt.Errorf("%v and %v are not deep equal: this may happen when calculating the 3-way diff patch", retainKeysInOriginal, retainKeysInPatch) + } + } else { + original[retainKeysDirective] = retainKeysInPatch + } + return nil + } + + retainKeysList, ok := retainKeysInPatch.([]interface{}) + if !ok { + return mergepatch.ErrBadPatchFormatForRetainKeys + } + + // validate patch to make sure all fields in the patch are present in the retainKeysList. + // The map is used only as a set, the value is never referenced + m := map[interface{}]struct{}{} + for _, v := range retainKeysList { + m[v] = struct{}{} + } + for k, v := range patch { + if v == nil || strings.HasPrefix(k, deleteFromPrimitiveListDirectivePrefix) || + strings.HasPrefix(k, setElementOrderDirectivePrefix) { + continue + } + // If there is an item present in the patch but not in the retainKeys list, + // the patch is invalid. + if _, found := m[k]; !found { + return mergepatch.ErrBadPatchFormatForRetainKeys + } + } + + // clear not present fields + for k := range original { + if _, found := m[k]; !found { + delete(original, k) + } + } + return nil +} + +// mergePatchIntoOriginal processes $setElementOrder list. +// When not merging the directive, it will make sure $setElementOrder list exist only in original. +// When merging the directive, it will try to find the $setElementOrder list and +// its corresponding patch list, validate it and merge it. +// Then, sort them by the relative order in setElementOrder, patch list and live list. +// The precedence is $setElementOrder > order in patch list > order in live list. +// This function will delete the item after merging it to prevent process it again in the future. +// Ref: https://git.k8s.io/community/contributors/design-proposals/preserve-order-in-strategic-merge-patch.md +func mergePatchIntoOriginal(original, patch map[string]interface{}, t reflect.Type, mergeOptions MergeOptions) error { + for key, patchV := range patch { + // Do nothing if there is no ordering directive + if !strings.HasPrefix(key, setElementOrderDirectivePrefix) { + continue + } + + setElementOrderInPatch := patchV + // Copies directive from the second patch (`patch`) to the first patch (`original`) + // and checks they are equal and delete the directive in the second patch + if !mergeOptions.MergeParallelList { + setElementOrderListInOriginal, ok := original[key] + if ok { + // check if the setElementOrder list in original and the one in patch matches + if !reflect.DeepEqual(setElementOrderListInOriginal, setElementOrderInPatch) { + return mergepatch.ErrBadPatchFormatForSetElementOrderList + } + } else { + // move the setElementOrder list from patch to original + original[key] = setElementOrderInPatch + } + } + delete(patch, key) + + var ( + ok bool + originalFieldValue, patchFieldValue, merged []interface{} + patchStrategy, mergeKey string + patchStrategies []string + fieldType reflect.Type + ) + typedSetElementOrderList, ok := setElementOrderInPatch.([]interface{}) + if !ok { + return mergepatch.ErrBadArgType(typedSetElementOrderList, setElementOrderInPatch) + } + // Trim the setElementOrderDirectivePrefix to get the key of the list field in original. + originalKey, err := extractKey(key, setElementOrderDirectivePrefix) + if err != nil { + return err + } + // try to find the list with `originalKey` in `original` and `modified` and merge them. + originalList, foundOriginal := original[originalKey] + patchList, foundPatch := patch[originalKey] + if foundOriginal { + originalFieldValue, ok = originalList.([]interface{}) + if !ok { + return mergepatch.ErrBadArgType(originalFieldValue, originalList) + } + } + if foundPatch { + patchFieldValue, ok = patchList.([]interface{}) + if !ok { + return mergepatch.ErrBadArgType(patchFieldValue, patchList) + } + } + fieldType, patchStrategies, mergeKey, err = forkedjson.LookupPatchMetadata(t, originalKey) + if err != nil { + return err + } + _, patchStrategy, err = extractRetainKeysPatchStrategy(patchStrategies) + if err != nil { + return err + } + // Check for consistency between the element order list and the field it applies to + err = validatePatchWithSetOrderList(patchFieldValue, typedSetElementOrderList, mergeKey) + if err != nil { + return err + } + + switch { + case foundOriginal && !foundPatch: + // no change to list contents + merged = originalFieldValue + case !foundOriginal && foundPatch: + // list was added + merged = patchFieldValue + case foundOriginal && foundPatch: + merged, err = mergeSliceHandler(originalList, patchList, fieldType, + patchStrategy, mergeKey, false, mergeOptions) + if err != nil { + return err + } + case !foundOriginal && !foundPatch: + continue + } + + // Split all items into patch items and server-only items and then enforce the order. + var patchItems, serverOnlyItems []interface{} + if len(mergeKey) == 0 { + // Primitives doesn't need merge key to do partitioning. + patchItems, serverOnlyItems = partitionPrimitivesByPresentInList(merged, typedSetElementOrderList) + + } else { + // Maps need merge key to do partitioning. + patchItems, serverOnlyItems, err = partitionMapsByPresentInList(merged, typedSetElementOrderList, mergeKey) + if err != nil { + return err + } + } + + elementType, err := sliceElementType(originalFieldValue, patchFieldValue) + if err != nil { + return err + } + kind := elementType.Kind() + // normalize merged list + // typedSetElementOrderList contains all the relative order in typedPatchList, + // so don't need to use typedPatchList + both, err := normalizeElementOrder(patchItems, serverOnlyItems, typedSetElementOrderList, originalFieldValue, mergeKey, kind) + if err != nil { + return err + } + original[originalKey] = both + // delete patch list from patch to prevent process again in the future + delete(patch, originalKey) + } + return nil +} + +// partitionPrimitivesByPresentInList partitions elements into 2 slices, the first containing items present in partitionBy, the other not. +func partitionPrimitivesByPresentInList(original, partitionBy []interface{}) ([]interface{}, []interface{}) { + patch := make([]interface{}, 0, len(original)) + serverOnly := make([]interface{}, 0, len(original)) + inPatch := map[interface{}]bool{} + for _, v := range partitionBy { + inPatch[v] = true + } + for _, v := range original { + if !inPatch[v] { + serverOnly = append(serverOnly, v) + } else { + patch = append(patch, v) + } + } + return patch, serverOnly +} + +// partitionMapsByPresentInList partitions elements into 2 slices, the first containing items present in partitionBy, the other not. +func partitionMapsByPresentInList(original, partitionBy []interface{}, mergeKey string) ([]interface{}, []interface{}, error) { + patch := make([]interface{}, 0, len(original)) + serverOnly := make([]interface{}, 0, len(original)) + for _, v := range original { + typedV, ok := v.(map[string]interface{}) + if !ok { + return nil, nil, mergepatch.ErrBadArgType(typedV, v) + } + mergeKeyValue, foundMergeKey := typedV[mergeKey] + if !foundMergeKey { + return nil, nil, mergepatch.ErrNoMergeKey(typedV, mergeKey) + } + _, _, found, err := findMapInSliceBasedOnKeyValue(partitionBy, mergeKey, mergeKeyValue) + if err != nil { + return nil, nil, err + } + if !found { + serverOnly = append(serverOnly, v) + } else { + patch = append(patch, v) + } + } + return patch, serverOnly, nil +} + +// Merge fields from a patch map into the original map. Note: This may modify +// both the original map and the patch because getting a deep copy of a map in +// golang is highly non-trivial. +// flag mergeOptions.MergeParallelList controls if using the parallel list to delete or keeping the list. +// If patch contains any null field (e.g. field_1: null) that is not +// present in original, then to propagate it to the end result use +// mergeOptions.IgnoreUnmatchedNulls == false. +func mergeMap(original, patch map[string]interface{}, t reflect.Type, mergeOptions MergeOptions) (map[string]interface{}, error) { + if v, ok := patch[directiveMarker]; ok { + return handleDirectiveInMergeMap(v, patch) + } + + // nil is an accepted value for original to simplify logic in other places. + // If original is nil, replace it with an empty map and then apply the patch. + if original == nil { + original = map[string]interface{}{} + } + + err := applyRetainKeysDirective(original, patch, mergeOptions) + if err != nil { + return nil, err + } + + // Process $setElementOrder list and other lists sharing the same key. + // When not merging the directive, it will make sure $setElementOrder list exist only in original. + // When merging the directive, it will process $setElementOrder and its patch list together. + // This function will delete the merged elements from patch so they will not be reprocessed + err = mergePatchIntoOriginal(original, patch, t, mergeOptions) + if err != nil { + return nil, err + } + + // Start merging the patch into the original. + for k, patchV := range patch { + skipProcessing, isDeleteList, noPrefixKey, err := preprocessDeletionListForMerging(k, original, patchV, mergeOptions.MergeParallelList) + if err != nil { + return nil, err + } + if skipProcessing { + continue + } + if len(noPrefixKey) > 0 { + k = noPrefixKey + } + + // If the value of this key is null, delete the key if it exists in the + // original. Otherwise, check if we want to preserve it or skip it. + // Preserving the null value is useful when we want to send an explicit + // delete to the API server. + if patchV == nil { + if _, ok := original[k]; ok { + delete(original, k) + } + if mergeOptions.IgnoreUnmatchedNulls { + continue + } + } + + _, ok := original[k] + if !ok { + // If it's not in the original document, just take the patch value. + original[k] = patchV + continue + } + + // If the data type is a pointer, resolve the element. + if t.Kind() == reflect.Ptr { + t = t.Elem() + } + + originalType := reflect.TypeOf(original[k]) + patchType := reflect.TypeOf(patchV) + if originalType != patchType { + original[k] = patchV + continue + } + // If they're both maps or lists, recurse into the value. + // First find the fieldPatchStrategy and fieldPatchMergeKey. + fieldType, fieldPatchStrategies, fieldPatchMergeKey, err := forkedjson.LookupPatchMetadata(t, k) + if err != nil { + return nil, err + } + _, patchStrategy, err := extractRetainKeysPatchStrategy(fieldPatchStrategies) + if err != nil { + return nil, err + } + + switch originalType.Kind() { + case reflect.Map: + + original[k], err = mergeMapHandler(original[k], patchV, fieldType, patchStrategy, mergeOptions) + case reflect.Slice: + original[k], err = mergeSliceHandler(original[k], patchV, fieldType, patchStrategy, fieldPatchMergeKey, isDeleteList, mergeOptions) + default: + original[k] = patchV + } + if err != nil { + return nil, err + } + } + return original, nil +} + +// mergeMapHandler handles how to merge `patchV` whose key is `key` with `original` respecting +// fieldPatchStrategy and mergeOptions. +func mergeMapHandler(original, patch interface{}, fieldType reflect.Type, + fieldPatchStrategy string, mergeOptions MergeOptions) (map[string]interface{}, error) { + typedOriginal, typedPatch, err := mapTypeAssertion(original, patch) + if err != nil { + return nil, err + } + + if fieldPatchStrategy != replaceDirective { + return mergeMap(typedOriginal, typedPatch, fieldType, mergeOptions) + } else { + return typedPatch, nil + } +} + +// mergeSliceHandler handles how to merge `patchV` whose key is `key` with `original` respecting +// fieldPatchStrategy, fieldPatchMergeKey, isDeleteList and mergeOptions. +func mergeSliceHandler(original, patch interface{}, fieldType reflect.Type, + fieldPatchStrategy, fieldPatchMergeKey string, isDeleteList bool, mergeOptions MergeOptions) ([]interface{}, error) { + typedOriginal, typedPatch, err := sliceTypeAssertion(original, patch) + if err != nil { + return nil, err + } + + if fieldPatchStrategy == mergeDirective { + elemType := fieldType.Elem() + return mergeSlice(typedOriginal, typedPatch, elemType, fieldPatchMergeKey, mergeOptions, isDeleteList) + } else { + return typedPatch, nil + } +} + +// Merge two slices together. Note: This may modify both the original slice and +// the patch because getting a deep copy of a slice in golang is highly +// non-trivial. +func mergeSlice(original, patch []interface{}, elemType reflect.Type, mergeKey string, mergeOptions MergeOptions, isDeleteList bool) ([]interface{}, error) { + if len(original) == 0 && len(patch) == 0 { + return original, nil + } + + // All the values must be of the same type, but not a list. + t, err := sliceElementType(original, patch) + if err != nil { + return nil, err + } + + var merged []interface{} + kind := t.Kind() + // If the elements are not maps, merge the slices of scalars. + if kind != reflect.Map { + if mergeOptions.MergeParallelList && isDeleteList { + return deleteFromSlice(original, patch), nil + } + // Maybe in the future add a "concat" mode that doesn't + // deduplicate. + both := append(original, patch...) + merged = deduplicateScalars(both) + + } else { + if mergeKey == "" { + return nil, fmt.Errorf("cannot merge lists without merge key for type %s", elemType.Kind().String()) + } + + original, patch, err = mergeSliceWithSpecialElements(original, patch, mergeKey) + if err != nil { + return nil, err + } + + merged, err = mergeSliceWithoutSpecialElements(original, patch, mergeKey, elemType, mergeOptions) + if err != nil { + return nil, err + } + } + + // enforce the order + var patchItems, serverOnlyItems []interface{} + if len(mergeKey) == 0 { + patchItems, serverOnlyItems = partitionPrimitivesByPresentInList(merged, patch) + } else { + patchItems, serverOnlyItems, err = partitionMapsByPresentInList(merged, patch, mergeKey) + if err != nil { + return nil, err + } + } + return normalizeElementOrder(patchItems, serverOnlyItems, patch, original, mergeKey, kind) +} + +// mergeSliceWithSpecialElements handles special elements with directiveMarker +// before merging the slices. It returns a updated `original` and a patch without special elements. +// original and patch must be slices of maps, they should be checked before calling this function. +func mergeSliceWithSpecialElements(original, patch []interface{}, mergeKey string) ([]interface{}, []interface{}, error) { + patchWithoutSpecialElements := []interface{}{} + replace := false + for _, v := range patch { + typedV := v.(map[string]interface{}) + patchType, ok := typedV[directiveMarker] + if !ok { + patchWithoutSpecialElements = append(patchWithoutSpecialElements, v) + } else { + switch patchType { + case deleteDirective: + mergeValue, ok := typedV[mergeKey] + if ok { + var err error + original, err = deleteMatchingEntries(original, mergeKey, mergeValue) + if err != nil { + return nil, nil, err + } + } else { + return nil, nil, mergepatch.ErrNoMergeKey(typedV, mergeKey) + } + case replaceDirective: + replace = true + // Continue iterating through the array to prune any other $patch elements. + case mergeDirective: + return nil, nil, fmt.Errorf("merging lists cannot yet be specified in the patch") + default: + return nil, nil, mergepatch.ErrBadPatchType(patchType, typedV) + } + } + } + if replace { + return patchWithoutSpecialElements, nil, nil + } + return original, patchWithoutSpecialElements, nil +} + +// delete all matching entries (based on merge key) from a merging list +func deleteMatchingEntries(original []interface{}, mergeKey string, mergeValue interface{}) ([]interface{}, error) { + for { + _, originalKey, found, err := findMapInSliceBasedOnKeyValue(original, mergeKey, mergeValue) + if err != nil { + return nil, err + } + + if !found { + break + } + // Delete the element at originalKey. + original = append(original[:originalKey], original[originalKey+1:]...) + } + return original, nil +} + +// mergeSliceWithoutSpecialElements merges slices with non-special elements. +// original and patch must be slices of maps, they should be checked before calling this function. +func mergeSliceWithoutSpecialElements(original, patch []interface{}, mergeKey string, elemType reflect.Type, mergeOptions MergeOptions) ([]interface{}, error) { + for _, v := range patch { + typedV := v.(map[string]interface{}) + mergeValue, ok := typedV[mergeKey] + if !ok { + return nil, mergepatch.ErrNoMergeKey(typedV, mergeKey) + } + + // If we find a value with this merge key value in original, merge the + // maps. Otherwise append onto original. + originalMap, originalKey, found, err := findMapInSliceBasedOnKeyValue(original, mergeKey, mergeValue) + if err != nil { + return nil, err + } + + if found { + var mergedMaps interface{} + var err error + // Merge into original. + mergedMaps, err = mergeMap(originalMap, typedV, elemType, mergeOptions) + if err != nil { + return nil, err + } + + original[originalKey] = mergedMaps + } else { + original = append(original, v) + } + } + return original, nil +} + +// deleteFromSlice uses the parallel list to delete the items in a list of scalars +func deleteFromSlice(current, toDelete []interface{}) []interface{} { + toDeleteMap := map[interface{}]interface{}{} + processed := make([]interface{}, 0, len(current)) + for _, v := range toDelete { + toDeleteMap[v] = true + } + for _, v := range current { + if _, found := toDeleteMap[v]; !found { + processed = append(processed, v) + } + } + return processed +} + +// This method no longer panics if any element of the slice is not a map. +func findMapInSliceBasedOnKeyValue(m []interface{}, key string, value interface{}) (map[string]interface{}, int, bool, error) { + for k, v := range m { + typedV, ok := v.(map[string]interface{}) + if !ok { + return nil, 0, false, fmt.Errorf("value for key %v is not a map.", k) + } + + valueToMatch, ok := typedV[key] + if ok && valueToMatch == value { + return typedV, k, true, nil + } + } + + return nil, 0, false, nil +} + +// This function takes a JSON map and sorts all the lists that should be merged +// by key. This is needed by tests because in JSON, list order is significant, +// but in Strategic Merge Patch, merge lists do not have significant order. +// Sorting the lists allows for order-insensitive comparison of patched maps. +func sortMergeListsByName(mapJSON []byte, dataStruct interface{}) ([]byte, error) { + var m map[string]interface{} + err := json.Unmarshal(mapJSON, &m) + if err != nil { + return nil, err + } + + newM, err := sortMergeListsByNameMap(m, reflect.TypeOf(dataStruct)) + if err != nil { + return nil, err + } + + return json.Marshal(newM) +} + +// Function sortMergeListsByNameMap recursively sorts the merge lists by its mergeKey in a map. +func sortMergeListsByNameMap(s map[string]interface{}, t reflect.Type) (map[string]interface{}, error) { + newS := map[string]interface{}{} + for k, v := range s { + if k == retainKeysDirective { + typedV, ok := v.([]interface{}) + if !ok { + return nil, mergepatch.ErrBadPatchFormatForRetainKeys + } + v = sortScalars(typedV) + } else if strings.HasPrefix(k, deleteFromPrimitiveListDirectivePrefix) { + typedV, ok := v.([]interface{}) + if !ok { + return nil, mergepatch.ErrBadPatchFormatForPrimitiveList + } + v = sortScalars(typedV) + } else if strings.HasPrefix(k, setElementOrderDirectivePrefix) { + _, ok := v.([]interface{}) + if !ok { + return nil, mergepatch.ErrBadPatchFormatForSetElementOrderList + } + } else if k != directiveMarker { + fieldType, fieldPatchStrategies, fieldPatchMergeKey, err := forkedjson.LookupPatchMetadata(t, k) + if err != nil { + return nil, err + } + _, patchStrategy, err := extractRetainKeysPatchStrategy(fieldPatchStrategies) + if err != nil { + return nil, err + } + + // If v is a map or a merge slice, recurse. + if typedV, ok := v.(map[string]interface{}); ok { + var err error + v, err = sortMergeListsByNameMap(typedV, fieldType) + if err != nil { + return nil, err + } + } else if typedV, ok := v.([]interface{}); ok { + if patchStrategy == mergeDirective { + var err error + v, err = sortMergeListsByNameArray(typedV, fieldType.Elem(), fieldPatchMergeKey, true) + if err != nil { + return nil, err + } + } + } + } + + newS[k] = v + } + + return newS, nil +} + +// Function sortMergeListsByNameMap recursively sorts the merge lists by its mergeKey in an array. +func sortMergeListsByNameArray(s []interface{}, elemType reflect.Type, mergeKey string, recurse bool) ([]interface{}, error) { + if len(s) == 0 { + return s, nil + } + + // We don't support lists of lists yet. + t, err := sliceElementType(s) + if err != nil { + return nil, err + } + + // If the elements are not maps... + if t.Kind() != reflect.Map { + // Sort the elements, because they may have been merged out of order. + return deduplicateAndSortScalars(s), nil + } + + // Elements are maps - if one of the keys of the map is a map or a + // list, we may need to recurse into it. + newS := []interface{}{} + for _, elem := range s { + if recurse { + typedElem := elem.(map[string]interface{}) + newElem, err := sortMergeListsByNameMap(typedElem, elemType) + if err != nil { + return nil, err + } + + newS = append(newS, newElem) + } else { + newS = append(newS, elem) + } + } + + // Sort the maps. + newS = sortMapsBasedOnField(newS, mergeKey) + return newS, nil +} + +func sortMapsBasedOnField(m []interface{}, fieldName string) []interface{} { + mapM := mapSliceFromSlice(m) + ss := SortableSliceOfMaps{mapM, fieldName} + sort.Sort(ss) + newS := sliceFromMapSlice(ss.s) + return newS +} + +func mapSliceFromSlice(m []interface{}) []map[string]interface{} { + newM := []map[string]interface{}{} + for _, v := range m { + vt := v.(map[string]interface{}) + newM = append(newM, vt) + } + + return newM +} + +func sliceFromMapSlice(s []map[string]interface{}) []interface{} { + newS := []interface{}{} + for _, v := range s { + newS = append(newS, v) + } + + return newS +} + +type SortableSliceOfMaps struct { + s []map[string]interface{} + k string // key to sort on +} + +func (ss SortableSliceOfMaps) Len() int { + return len(ss.s) +} + +func (ss SortableSliceOfMaps) Less(i, j int) bool { + iStr := fmt.Sprintf("%v", ss.s[i][ss.k]) + jStr := fmt.Sprintf("%v", ss.s[j][ss.k]) + return sort.StringsAreSorted([]string{iStr, jStr}) +} + +func (ss SortableSliceOfMaps) Swap(i, j int) { + tmp := ss.s[i] + ss.s[i] = ss.s[j] + ss.s[j] = tmp +} + +func deduplicateAndSortScalars(s []interface{}) []interface{} { + s = deduplicateScalars(s) + return sortScalars(s) +} + +func sortScalars(s []interface{}) []interface{} { + ss := SortableSliceOfScalars{s} + sort.Sort(ss) + return ss.s +} + +func deduplicateScalars(s []interface{}) []interface{} { + // Clever algorithm to deduplicate. + length := len(s) - 1 + for i := 0; i < length; i++ { + for j := i + 1; j <= length; j++ { + if s[i] == s[j] { + s[j] = s[length] + s = s[0:length] + length-- + j-- + } + } + } + + return s +} + +type SortableSliceOfScalars struct { + s []interface{} +} + +func (ss SortableSliceOfScalars) Len() int { + return len(ss.s) +} + +func (ss SortableSliceOfScalars) Less(i, j int) bool { + iStr := fmt.Sprintf("%v", ss.s[i]) + jStr := fmt.Sprintf("%v", ss.s[j]) + return sort.StringsAreSorted([]string{iStr, jStr}) +} + +func (ss SortableSliceOfScalars) Swap(i, j int) { + tmp := ss.s[i] + ss.s[i] = ss.s[j] + ss.s[j] = tmp +} + +// Returns the type of the elements of N slice(s). If the type is different, +// another slice or undefined, returns an error. +func sliceElementType(slices ...[]interface{}) (reflect.Type, error) { + var prevType reflect.Type + for _, s := range slices { + // Go through elements of all given slices and make sure they are all the same type. + for _, v := range s { + currentType := reflect.TypeOf(v) + if prevType == nil { + prevType = currentType + // We don't support lists of lists yet. + if prevType.Kind() == reflect.Slice { + return nil, mergepatch.ErrNoListOfLists + } + } else { + if prevType != currentType { + return nil, fmt.Errorf("list element types are not identical: %v", fmt.Sprint(slices)) + } + prevType = currentType + } + } + } + + if prevType == nil { + return nil, fmt.Errorf("no elements in any of the given slices") + } + + return prevType, nil +} + +// MergingMapsHaveConflicts 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 strategic merge patch semantics. +func MergingMapsHaveConflicts(left, right map[string]interface{}, dataStruct interface{}) (bool, error) { + t, err := getTagStructType(dataStruct) + if err != nil { + return true, err + } + + return mergingMapFieldsHaveConflicts(left, right, t, "", "") +} + +func mergingMapFieldsHaveConflicts( + left, right interface{}, + fieldType reflect.Type, + fieldPatchStrategy, fieldPatchMergeKey string, +) (bool, error) { + switch leftType := left.(type) { + case map[string]interface{}: + rightType, ok := right.(map[string]interface{}) + if !ok { + return true, nil + } + leftMarker, okLeft := leftType[directiveMarker] + rightMarker, okRight := rightType[directiveMarker] + // if one or the other has a directive marker, + // then we need to consider that before looking at the individual keys, + // since a directive operates on the whole map. + if okLeft || okRight { + // if one has a directive marker and the other doesn't, + // then we have a conflict, since one is deleting or replacing the whole map, + // and the other is doing things to individual keys. + if okLeft != okRight { + return true, nil + } + // if they both have markers, but they are not the same directive, + // then we have a conflict because they're doing different things to the map. + if leftMarker != rightMarker { + return true, nil + } + } + if fieldPatchStrategy == replaceDirective { + return false, nil + } + // Check the individual keys. + return mapsHaveConflicts(leftType, rightType, fieldType) + + case []interface{}: + rightType, ok := right.([]interface{}) + if !ok { + return true, nil + } + return slicesHaveConflicts(leftType, rightType, fieldType, fieldPatchStrategy, fieldPatchMergeKey) + + case string, float64, bool, int, int64, nil: + return !reflect.DeepEqual(left, right), nil + default: + return true, fmt.Errorf("unknown type: %v", reflect.TypeOf(left)) + } +} + +func mapsHaveConflicts(typedLeft, typedRight map[string]interface{}, structType reflect.Type) (bool, error) { + for key, leftValue := range typedLeft { + if key != directiveMarker && key != retainKeysDirective { + if rightValue, ok := typedRight[key]; ok { + fieldType, fieldPatchStrategies, fieldPatchMergeKey, err := forkedjson.LookupPatchMetadata(structType, key) + if err != nil { + return true, err + } + _, patchStrategy, err := extractRetainKeysPatchStrategy(fieldPatchStrategies) + if err != nil { + return true, err + } + + if hasConflicts, err := mergingMapFieldsHaveConflicts(leftValue, rightValue, + fieldType, patchStrategy, fieldPatchMergeKey); hasConflicts { + return true, err + } + } + } + } + + return false, nil +} + +func slicesHaveConflicts( + typedLeft, typedRight []interface{}, + fieldType reflect.Type, + fieldPatchStrategy, fieldPatchMergeKey string, +) (bool, error) { + elementType, err := sliceElementType(typedLeft, typedRight) + if err != nil { + return true, err + } + + valueType := fieldType.Elem() + if fieldPatchStrategy == mergeDirective { + // Merging lists of scalars have no conflicts by definition + // So we only need to check further if the elements are maps + if elementType.Kind() != reflect.Map { + return false, nil + } + + // Build a map for each slice and then compare the two maps + leftMap, err := sliceOfMapsToMapOfMaps(typedLeft, fieldPatchMergeKey) + if err != nil { + return true, err + } + + rightMap, err := sliceOfMapsToMapOfMaps(typedRight, fieldPatchMergeKey) + if err != nil { + return true, err + } + + return mapsOfMapsHaveConflicts(leftMap, rightMap, valueType) + } + + // Either we don't have type information, or these are non-merging lists + if len(typedLeft) != len(typedRight) { + return true, nil + } + + // Sort scalar slices to prevent ordering issues + // We have no way to sort non-merging lists of maps + if elementType.Kind() != reflect.Map { + typedLeft = deduplicateAndSortScalars(typedLeft) + typedRight = deduplicateAndSortScalars(typedRight) + } + + // Compare the slices element by element in order + // This test will fail if the slices are not sorted + for i := range typedLeft { + if hasConflicts, err := mergingMapFieldsHaveConflicts(typedLeft[i], typedRight[i], valueType, "", ""); hasConflicts { + return true, err + } + } + + return false, nil +} + +func sliceOfMapsToMapOfMaps(slice []interface{}, mergeKey string) (map[string]interface{}, error) { + result := make(map[string]interface{}, len(slice)) + for _, value := range slice { + typedValue, ok := value.(map[string]interface{}) + if !ok { + return nil, fmt.Errorf("invalid element type in merging list:%v", slice) + } + + mergeValue, ok := typedValue[mergeKey] + if !ok { + return nil, fmt.Errorf("cannot find merge key `%s` in merging list element:%v", mergeKey, typedValue) + } + + result[fmt.Sprintf("%s", mergeValue)] = typedValue + } + + return result, nil +} + +func mapsOfMapsHaveConflicts(typedLeft, typedRight map[string]interface{}, structType reflect.Type) (bool, error) { + for key, leftValue := range typedLeft { + if rightValue, ok := typedRight[key]; ok { + if hasConflicts, err := mergingMapFieldsHaveConflicts(leftValue, rightValue, structType, "", ""); hasConflicts { + return true, err + } + } + } + + return false, nil +} + +// CreateThreeWayMergePatch reconciles a modified configuration with an original configuration, +// while preserving any changes or deletions made to the original configuration in the interim, +// and not overridden by the current configuration. All three documents must be passed to the +// method as json encoded content. It will return a strategic merge patch, or an error if any +// of the documents is invalid, or if there are any preconditions that fail against the modified +// configuration, or, if overwrite is false and there are conflicts between the modified and current +// configurations. Conflicts are defined as keys changed differently from original to modified +// than from original to current. In other words, a conflict occurs if modified changes any key +// in a way that is different from how it is changed in current (e.g., deleting it, changing its +// value). We also propagate values fields that do not exist in original but are explicitly +// defined in modified. +func CreateThreeWayMergePatch(original, modified, current []byte, dataStruct interface{}, overwrite bool, fns ...mergepatch.PreconditionFunc) ([]byte, error) { + originalMap := map[string]interface{}{} + if len(original) > 0 { + if err := json.Unmarshal(original, &originalMap); err != nil { + return nil, mergepatch.ErrBadJSONDoc + } + } + + modifiedMap := map[string]interface{}{} + if len(modified) > 0 { + if err := json.Unmarshal(modified, &modifiedMap); err != nil { + return nil, mergepatch.ErrBadJSONDoc + } + } + + currentMap := map[string]interface{}{} + if len(current) > 0 { + if err := json.Unmarshal(current, ¤tMap); err != nil { + return nil, mergepatch.ErrBadJSONDoc + } + } + + t, err := getTagStructType(dataStruct) + if err != nil { + return nil, err + } + + // The patch is the difference from current to modified without deletions, plus deletions + // from original to modified. To find it, we compute deletions, which are the deletions from + // original to modified, and delta, which is the difference from current to modified without + // deletions, and then apply delta to deletions as a patch, which should be strictly additive. + deltaMapDiffOptions := DiffOptions{ + IgnoreDeletions: true, + SetElementOrder: true, + } + deltaMap, err := diffMaps(currentMap, modifiedMap, t, deltaMapDiffOptions) + if err != nil { + return nil, err + } + deletionsMapDiffOptions := DiffOptions{ + SetElementOrder: true, + IgnoreChangesAndAdditions: true, + } + deletionsMap, err := diffMaps(originalMap, modifiedMap, t, deletionsMapDiffOptions) + if err != nil { + return nil, err + } + + mergeOptions := MergeOptions{} + patchMap, err := mergeMap(deletionsMap, deltaMap, t, mergeOptions) + if err != nil { + return nil, err + } + + // Apply the preconditions to the patch, and return an error if any of them fail. + for _, fn := range fns { + if !fn(patchMap) { + return nil, mergepatch.NewErrPreconditionFailed(patchMap) + } + } + + // If overwrite is false, and the patch contains any keys that were changed differently, + // then return a conflict error. + if !overwrite { + changeMapDiffOptions := DiffOptions{} + changedMap, err := diffMaps(originalMap, currentMap, t, changeMapDiffOptions) + if err != nil { + return nil, err + } + + hasConflicts, err := MergingMapsHaveConflicts(patchMap, changedMap, dataStruct) + if err != nil { + return nil, err + } + + if hasConflicts { + return nil, mergepatch.NewErrConflict(mergepatch.ToYAMLOrError(patchMap), mergepatch.ToYAMLOrError(changedMap)) + } + } + + return json.Marshal(patchMap) +} + +func ItemAddedToModifiedSlice(original, modified string) bool { return original > modified } + +func ItemRemovedFromModifiedSlice(original, modified string) bool { return original < modified } + +func ItemMatchesOriginalAndModifiedSlice(original, modified string) bool { return original == modified } + +func CreateDeleteDirective(mergeKey string, mergeKeyValue interface{}) map[string]interface{} { + return map[string]interface{}{mergeKey: mergeKeyValue, directiveMarker: deleteDirective} +} + +func mapTypeAssertion(original, patch interface{}) (map[string]interface{}, map[string]interface{}, error) { + typedOriginal, ok := original.(map[string]interface{}) + if !ok { + return nil, nil, mergepatch.ErrBadArgType(typedOriginal, original) + } + typedPatch, ok := patch.(map[string]interface{}) + if !ok { + return nil, nil, mergepatch.ErrBadArgType(typedPatch, patch) + } + return typedOriginal, typedPatch, nil +} + +func sliceTypeAssertion(original, patch interface{}) ([]interface{}, []interface{}, error) { + typedOriginal, ok := original.([]interface{}) + if !ok { + return nil, nil, mergepatch.ErrBadArgType(typedOriginal, original) + } + typedPatch, ok := patch.([]interface{}) + if !ok { + return nil, nil, mergepatch.ErrBadArgType(typedPatch, patch) + } + return typedOriginal, typedPatch, nil +} + +// extractRetainKeysPatchStrategy process patch strategy, which is a string may contains multiple +// patch strategies seperated by ",". It returns a boolean var indicating if it has +// retainKeys strategies and a string for the other strategy. +func extractRetainKeysPatchStrategy(strategies []string) (bool, string, error) { + switch len(strategies) { + case 0: + return false, "", nil + case 1: + singleStrategy := strategies[0] + switch singleStrategy { + case retainKeysStrategy: + return true, "", nil + default: + return false, singleStrategy, nil + } + case 2: + switch { + case strategies[0] == retainKeysStrategy: + return true, strategies[1], nil + case strategies[1] == retainKeysStrategy: + return true, strategies[0], nil + default: + return false, "", fmt.Errorf("unexpected patch strategy: %v", strategies) + } + default: + return false, "", fmt.Errorf("unexpected patch strategy: %v", strategies) + } +} + +// hasAdditionalNewField returns if original map has additional key with non-nil value than modified. +func hasAdditionalNewField(original, modified map[string]interface{}) bool { + for k, v := range original { + if v == nil { + continue + } + if _, found := modified[k]; !found { + return true + } + } + return false +} |