github.com/coreos/mantle@v0.13.0/update/generator/info.go (about)

     1  // Copyright 2016 CoreOS, Inc.
     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 generator
    16  
    17  import (
    18  	"crypto/sha256"
    19  	"io"
    20  	"os"
    21  
    22  	"github.com/golang/protobuf/proto"
    23  
    24  	"github.com/coreos/mantle/update/metadata"
    25  )
    26  
    27  func NewInstallInfo(r io.ReadSeeker) (*metadata.InstallInfo, error) {
    28  	sha := sha256.New()
    29  	size, err := io.Copy(sha, r)
    30  	if err != nil {
    31  		return nil, err
    32  	}
    33  
    34  	if _, err := r.Seek(0, os.SEEK_SET); err != nil {
    35  		return nil, err
    36  	}
    37  
    38  	return &metadata.InstallInfo{
    39  		Hash: sha.Sum(nil),
    40  		Size: proto.Uint64(uint64(size)),
    41  	}, nil
    42  }