Import of https://github.com/ciena/voltctl at commit 40d61fbf3f910ed4017cf67c9c79e8e1f82a33a5
Change-Id: I8464c59e60d76cb8612891db3303878975b5416c
diff --git a/vendor/k8s.io/apimachinery/pkg/util/errors/errors.go b/vendor/k8s.io/apimachinery/pkg/util/errors/errors.go
new file mode 100644
index 0000000..88e9376
--- /dev/null
+++ b/vendor/k8s.io/apimachinery/pkg/util/errors/errors.go
@@ -0,0 +1,201 @@
+/*
+Copyright 2015 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 errors
+
+import (
+ "errors"
+ "fmt"
+)
+
+// MessageCountMap contains occurrence for each error message.
+type MessageCountMap map[string]int
+
+// Aggregate represents an object that contains multiple errors, but does not
+// necessarily have singular semantic meaning.
+type Aggregate interface {
+ error
+ Errors() []error
+}
+
+// NewAggregate converts a slice of errors into an Aggregate interface, which
+// is itself an implementation of the error interface. If the slice is empty,
+// this returns nil.
+// It will check if any of the element of input error list is nil, to avoid
+// nil pointer panic when call Error().
+func NewAggregate(errlist []error) Aggregate {
+ if len(errlist) == 0 {
+ return nil
+ }
+ // In case of input error list contains nil
+ var errs []error
+ for _, e := range errlist {
+ if e != nil {
+ errs = append(errs, e)
+ }
+ }
+ if len(errs) == 0 {
+ return nil
+ }
+ return aggregate(errs)
+}
+
+// This helper implements the error and Errors interfaces. Keeping it private
+// prevents people from making an aggregate of 0 errors, which is not
+// an error, but does satisfy the error interface.
+type aggregate []error
+
+// Error is part of the error interface.
+func (agg aggregate) Error() string {
+ if len(agg) == 0 {
+ // This should never happen, really.
+ return ""
+ }
+ if len(agg) == 1 {
+ return agg[0].Error()
+ }
+ result := fmt.Sprintf("[%s", agg[0].Error())
+ for i := 1; i < len(agg); i++ {
+ result += fmt.Sprintf(", %s", agg[i].Error())
+ }
+ result += "]"
+ return result
+}
+
+// Errors is part of the Aggregate interface.
+func (agg aggregate) Errors() []error {
+ return []error(agg)
+}
+
+// Matcher is used to match errors. Returns true if the error matches.
+type Matcher func(error) bool
+
+// FilterOut removes all errors that match any of the matchers from the input
+// error. If the input is a singular error, only that error is tested. If the
+// input implements the Aggregate interface, the list of errors will be
+// processed recursively.
+//
+// This can be used, for example, to remove known-OK errors (such as io.EOF or
+// os.PathNotFound) from a list of errors.
+func FilterOut(err error, fns ...Matcher) error {
+ if err == nil {
+ return nil
+ }
+ if agg, ok := err.(Aggregate); ok {
+ return NewAggregate(filterErrors(agg.Errors(), fns...))
+ }
+ if !matchesError(err, fns...) {
+ return err
+ }
+ return nil
+}
+
+// matchesError returns true if any Matcher returns true
+func matchesError(err error, fns ...Matcher) bool {
+ for _, fn := range fns {
+ if fn(err) {
+ return true
+ }
+ }
+ return false
+}
+
+// filterErrors returns any errors (or nested errors, if the list contains
+// nested Errors) for which all fns return false. If no errors
+// remain a nil list is returned. The resulting silec will have all
+// nested slices flattened as a side effect.
+func filterErrors(list []error, fns ...Matcher) []error {
+ result := []error{}
+ for _, err := range list {
+ r := FilterOut(err, fns...)
+ if r != nil {
+ result = append(result, r)
+ }
+ }
+ return result
+}
+
+// Flatten takes an Aggregate, which may hold other Aggregates in arbitrary
+// nesting, and flattens them all into a single Aggregate, recursively.
+func Flatten(agg Aggregate) Aggregate {
+ result := []error{}
+ if agg == nil {
+ return nil
+ }
+ for _, err := range agg.Errors() {
+ if a, ok := err.(Aggregate); ok {
+ r := Flatten(a)
+ if r != nil {
+ result = append(result, r.Errors()...)
+ }
+ } else {
+ if err != nil {
+ result = append(result, err)
+ }
+ }
+ }
+ return NewAggregate(result)
+}
+
+// CreateAggregateFromMessageCountMap converts MessageCountMap Aggregate
+func CreateAggregateFromMessageCountMap(m MessageCountMap) Aggregate {
+ if m == nil {
+ return nil
+ }
+ result := make([]error, 0, len(m))
+ for errStr, count := range m {
+ var countStr string
+ if count > 1 {
+ countStr = fmt.Sprintf(" (repeated %v times)", count)
+ }
+ result = append(result, fmt.Errorf("%v%v", errStr, countStr))
+ }
+ return NewAggregate(result)
+}
+
+// Reduce will return err or, if err is an Aggregate and only has one item,
+// the first item in the aggregate.
+func Reduce(err error) error {
+ if agg, ok := err.(Aggregate); ok && err != nil {
+ switch len(agg.Errors()) {
+ case 1:
+ return agg.Errors()[0]
+ case 0:
+ return nil
+ }
+ }
+ return err
+}
+
+// AggregateGoroutines runs the provided functions in parallel, stuffing all
+// non-nil errors into the returned Aggregate.
+// Returns nil if all the functions complete successfully.
+func AggregateGoroutines(funcs ...func() error) Aggregate {
+ errChan := make(chan error, len(funcs))
+ for _, f := range funcs {
+ go func(f func() error) { errChan <- f() }(f)
+ }
+ errs := make([]error, 0)
+ for i := 0; i < cap(errChan); i++ {
+ if err := <-errChan; err != nil {
+ errs = append(errs, err)
+ }
+ }
+ return NewAggregate(errs)
+}
+
+// ErrPreconditionViolated is returned when the precondition is violated
+var ErrPreconditionViolated = errors.New("precondition is violated")