github.com/alibaba/sealer@v0.8.6-0.20220430115802-37a2bdaa8173/pkg/image/cache/layer.go (about)

     1  // Copyright © 2021 Alibaba Group Holding Ltd.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package cache
    16  
    17  import (
    18  	"strings"
    19  
    20  	"github.com/opencontainers/go-digest"
    21  )
    22  
    23  type Layer struct {
    24  	// cacheID for layerdb/layersid/cacheID, we will load the content only for COPY layer
    25  	CacheID string `json:"cache_id"`
    26  	// same as v1Layer type
    27  	Type string `json:"type"`
    28  	// same as v1Layer value
    29  	Value string `json:"value"`
    30  }
    31  
    32  func (l *Layer) String() string {
    33  	return strings.TrimSpace(l.CacheID) + ":" + strings.TrimSpace(l.Type) + ":" + strings.TrimSpace(l.Value)
    34  }
    35  
    36  func (l *Layer) ChainID(parentID ChainID) (ChainID, error) {
    37  	if parentID.String() == "" {
    38  		return ChainID(digest.FromString(l.String())), nil
    39  	}
    40  	return ChainID(digest.FromString(parentID.String() + ":" + l.String())), nil
    41  }