forked from operator-framework/operator-sdk
/
scan.go
87 lines (75 loc) · 1.84 KB
/
scan.go
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// Copyright 2018 The Operator-SDK 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 yamlutil
import (
"bufio"
"bytes"
"io"
k8syaml "k8s.io/apimachinery/pkg/util/yaml"
)
const maxExecutiveEmpties = 100
// Scanner scans a yaml manifest file for manifest tokens delimited by "---".
// See bufio.Scanner for semantics.
type Scanner struct {
reader *k8syaml.YAMLReader
token []byte // Last token returned by split.
err error // Sticky error.
empties int // Count of successive empty tokens.
done bool // Scan has finished.
}
func NewYAMLScanner(b []byte) *Scanner {
r := bufio.NewReader(bytes.NewBuffer(b))
return &Scanner{reader: k8syaml.NewYAMLReader(r)}
}
func (s *Scanner) Err() error {
if s.err == io.EOF {
return nil
}
return s.err
}
func (s *Scanner) Scan() bool {
if s.done {
return false
}
var (
tok []byte
err error
)
for {
tok, err = s.reader.Read()
if err != nil {
if err == io.EOF {
s.done = true
}
s.err = err
return false
}
if len(bytes.TrimSpace(tok)) == 0 {
s.empties++
if s.empties > maxExecutiveEmpties {
panic("yaml.Scan: too many empty tokens without progressing")
}
continue
}
s.empties = 0
s.token = tok
return true
}
}
func (s *Scanner) Text() string {
return string(s.token)
}
func (s *Scanner) Bytes() []byte {
return s.token
}