go.chromium.org/luci@v0.0.0-20240309015107-7cdc2e660f33/resultdb/internal/invocations/graph/source_hash.go (about)

     1  // Copyright 2022 The LUCI Authors.
     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 graph contains methods to explore reachable invocations.
    16  package graph
    17  
    18  import (
    19  	"crypto/sha256"
    20  	"encoding/hex"
    21  
    22  	"go.chromium.org/luci/resultdb/pbutil"
    23  	pb "go.chromium.org/luci/resultdb/proto/v1"
    24  )
    25  
    26  // SourceHash stores a 12 byte hash of sources, as raw bytes.
    27  // To display, use the String() method.
    28  type SourceHash string
    29  
    30  const (
    31  	EmptySourceHash SourceHash = ""
    32  )
    33  
    34  func (h SourceHash) String() string {
    35  	return hex.EncodeToString([]byte(h))
    36  }
    37  
    38  // HashSources returns a hash of the given code sources proto,
    39  // which can be used as a key in maps.
    40  func HashSources(s *pb.Sources) SourceHash {
    41  	h := sha256.New()
    42  	b := pbutil.MustMarshal(s)
    43  	_, err := h.Write(b)
    44  	if err != nil {
    45  		panic(err)
    46  	}
    47  	return SourceHash(string(h.Sum(nil)[:12]))
    48  }