github.com/demonoid81/containerd@v1.3.4/metadata/boltutil/helpers.go (about)

     1  /*
     2     Copyright The containerd Authors.
     3  
     4     Licensed under the Apache License, Version 2.0 (the "License");
     5     you may not use this file except in compliance with the License.
     6     You may obtain a copy of the License at
     7  
     8         http://www.apache.org/licenses/LICENSE-2.0
     9  
    10     Unless required by applicable law or agreed to in writing, software
    11     distributed under the License is distributed on an "AS IS" BASIS,
    12     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13     See the License for the specific language governing permissions and
    14     limitations under the License.
    15  */
    16  
    17  package boltutil
    18  
    19  import (
    20  	"time"
    21  
    22  	"github.com/pkg/errors"
    23  	bolt "go.etcd.io/bbolt"
    24  )
    25  
    26  var (
    27  	bucketKeyAnnotations = []byte("annotations")
    28  	bucketKeyLabels      = []byte("labels")
    29  	bucketKeyCreatedAt   = []byte("createdat")
    30  	bucketKeyUpdatedAt   = []byte("updatedat")
    31  )
    32  
    33  // ReadLabels reads the labels key from the bucket
    34  // Uses the key "labels"
    35  func ReadLabels(bkt *bolt.Bucket) (map[string]string, error) {
    36  	return readMap(bkt, bucketKeyLabels)
    37  }
    38  
    39  // ReadAnnotations reads the OCI Descriptor Annotations key from the bucket
    40  // Uses the key "annotations"
    41  func ReadAnnotations(bkt *bolt.Bucket) (map[string]string, error) {
    42  	return readMap(bkt, bucketKeyAnnotations)
    43  }
    44  
    45  func readMap(bkt *bolt.Bucket, bucketName []byte) (map[string]string, error) {
    46  	lbkt := bkt.Bucket(bucketName)
    47  	if lbkt == nil {
    48  		return nil, nil
    49  	}
    50  	labels := map[string]string{}
    51  	if err := lbkt.ForEach(func(k, v []byte) error {
    52  		labels[string(k)] = string(v)
    53  		return nil
    54  	}); err != nil {
    55  		return nil, err
    56  	}
    57  	return labels, nil
    58  }
    59  
    60  // WriteLabels will write a new labels bucket to the provided bucket at key
    61  // bucketKeyLabels, replacing the contents of the bucket with the provided map.
    62  //
    63  // The provide map labels will be modified to have the final contents of the
    64  // bucket. Typically, this removes zero-value entries.
    65  // Uses the key "labels"
    66  func WriteLabels(bkt *bolt.Bucket, labels map[string]string) error {
    67  	return writeMap(bkt, bucketKeyLabels, labels)
    68  }
    69  
    70  // WriteAnnotations writes the OCI Descriptor Annotations
    71  func WriteAnnotations(bkt *bolt.Bucket, labels map[string]string) error {
    72  	return writeMap(bkt, bucketKeyAnnotations, labels)
    73  }
    74  
    75  func writeMap(bkt *bolt.Bucket, bucketName []byte, labels map[string]string) error {
    76  	// Remove existing labels to keep from merging
    77  	if lbkt := bkt.Bucket(bucketName); lbkt != nil {
    78  		if err := bkt.DeleteBucket(bucketName); err != nil {
    79  			return err
    80  		}
    81  	}
    82  
    83  	if len(labels) == 0 {
    84  		return nil
    85  	}
    86  
    87  	lbkt, err := bkt.CreateBucket(bucketName)
    88  	if err != nil {
    89  		return err
    90  	}
    91  
    92  	for k, v := range labels {
    93  		if v == "" {
    94  			delete(labels, k) // remove since we don't actually set it
    95  			continue
    96  		}
    97  
    98  		if err := lbkt.Put([]byte(k), []byte(v)); err != nil {
    99  			return errors.Wrapf(err, "failed to set label %q=%q", k, v)
   100  		}
   101  	}
   102  
   103  	return nil
   104  }
   105  
   106  // ReadTimestamps reads created and updated timestamps from a bucket.
   107  // Uses keys "createdat" and "updatedat"
   108  func ReadTimestamps(bkt *bolt.Bucket, created, updated *time.Time) error {
   109  	for _, f := range []struct {
   110  		b []byte
   111  		t *time.Time
   112  	}{
   113  		{bucketKeyCreatedAt, created},
   114  		{bucketKeyUpdatedAt, updated},
   115  	} {
   116  		v := bkt.Get(f.b)
   117  		if v != nil {
   118  			if err := f.t.UnmarshalBinary(v); err != nil {
   119  				return err
   120  			}
   121  		}
   122  	}
   123  	return nil
   124  }
   125  
   126  // WriteTimestamps writes created and updated timestamps to a bucket.
   127  // Uses keys "createdat" and "updatedat"
   128  func WriteTimestamps(bkt *bolt.Bucket, created, updated time.Time) error {
   129  	createdAt, err := created.MarshalBinary()
   130  	if err != nil {
   131  		return err
   132  	}
   133  	updatedAt, err := updated.MarshalBinary()
   134  	if err != nil {
   135  		return err
   136  	}
   137  	for _, v := range [][2][]byte{
   138  		{bucketKeyCreatedAt, createdAt},
   139  		{bucketKeyUpdatedAt, updatedAt},
   140  	} {
   141  		if err := bkt.Put(v[0], v[1]); err != nil {
   142  			return err
   143  		}
   144  	}
   145  
   146  	return nil
   147  }