diff options
Diffstat (limited to 'vendor/k8s.io/apimachinery/pkg/runtime/serializer/recognizer/recognizer.go')
-rw-r--r-- | vendor/k8s.io/apimachinery/pkg/runtime/serializer/recognizer/recognizer.go | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/vendor/k8s.io/apimachinery/pkg/runtime/serializer/recognizer/recognizer.go b/vendor/k8s.io/apimachinery/pkg/runtime/serializer/recognizer/recognizer.go new file mode 100644 index 000000000..38497ab53 --- /dev/null +++ b/vendor/k8s.io/apimachinery/pkg/runtime/serializer/recognizer/recognizer.go @@ -0,0 +1,127 @@ +/* +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 recognizer + +import ( + "bufio" + "bytes" + "fmt" + "io" + + "k8s.io/apimachinery/pkg/runtime" + "k8s.io/apimachinery/pkg/runtime/schema" +) + +type RecognizingDecoder interface { + runtime.Decoder + // RecognizesData should return true if the input provided in the provided reader + // belongs to this decoder, or an error if the data could not be read or is ambiguous. + // Unknown is true if the data could not be determined to match the decoder type. + // Decoders should assume that they can read as much of peek as they need (as the caller + // provides) and may return unknown if the data provided is not sufficient to make a + // a determination. When peek returns EOF that may mean the end of the input or the + // end of buffered input - recognizers should return the best guess at that time. + RecognizesData(peek io.Reader) (ok, unknown bool, err error) +} + +// NewDecoder creates a decoder that will attempt multiple decoders in an order defined +// by: +// +// 1. The decoder implements RecognizingDecoder and identifies the data +// 2. All other decoders, and any decoder that returned true for unknown. +// +// The order passed to the constructor is preserved within those priorities. +func NewDecoder(decoders ...runtime.Decoder) runtime.Decoder { + return &decoder{ + decoders: decoders, + } +} + +type decoder struct { + decoders []runtime.Decoder +} + +var _ RecognizingDecoder = &decoder{} + +func (d *decoder) RecognizesData(peek io.Reader) (bool, bool, error) { + var ( + lastErr error + anyUnknown bool + ) + data, _ := bufio.NewReaderSize(peek, 1024).Peek(1024) + for _, r := range d.decoders { + switch t := r.(type) { + case RecognizingDecoder: + ok, unknown, err := t.RecognizesData(bytes.NewBuffer(data)) + if err != nil { + lastErr = err + continue + } + anyUnknown = anyUnknown || unknown + if !ok { + continue + } + return true, false, nil + } + } + return false, anyUnknown, lastErr +} + +func (d *decoder) Decode(data []byte, gvk *schema.GroupVersionKind, into runtime.Object) (runtime.Object, *schema.GroupVersionKind, error) { + var ( + lastErr error + skipped []runtime.Decoder + ) + + // try recognizers, record any decoders we need to give a chance later + for _, r := range d.decoders { + switch t := r.(type) { + case RecognizingDecoder: + buf := bytes.NewBuffer(data) + ok, unknown, err := t.RecognizesData(buf) + if err != nil { + lastErr = err + continue + } + if unknown { + skipped = append(skipped, t) + continue + } + if !ok { + continue + } + return r.Decode(data, gvk, into) + default: + skipped = append(skipped, t) + } + } + + // try recognizers that returned unknown or didn't recognize their data + for _, r := range skipped { + out, actual, err := r.Decode(data, gvk, into) + if err != nil { + lastErr = err + continue + } + return out, actual, nil + } + + if lastErr == nil { + lastErr = fmt.Errorf("no serialization format matched the provided data") + } + return nil, nil, lastErr +} |