https://github.com/cerbos/protoc-gen-go-hashpb

Generate hash functions for protocol buffer messages
https://github.com/cerbos/protoc-gen-go-hashpb

go golang hash protobuf protobuf-plugin protocol-buffers

Last synced: about 2 months ago
JSON representation

Generate hash functions for protocol buffer messages

• Host: GitHub
• URL: https://github.com/cerbos/protoc-gen-go-hashpb
• Owner: cerbos
• License: apache-2.0
• Created: 2022-01-20T17:58:40.000Z (almost 3 years ago)
• Default Branch: main
• Last Pushed: 2024-08-02T07:27:51.000Z (5 months ago)
• Last Synced: 2024-08-02T09:07:02.403Z (5 months ago)
• Topics: go, golang, hash, protobuf, protobuf-plugin, protocol-buffers
• Language: Go
• Homepage:
• Size: 620 KB
• Stars: 6
• Watchers: 3
• Forks: 6
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

README

        
# protoc-gen-go-hashpb

A protobuf plugin to generate hash functions for messages.

Hashing messages encoded using Protocol Buffers is tricky because there is [no guarantee that the serialized form is stable](https://developers.google.com/protocol-buffers/docs/encoding) between different implementations, architectures, or even library versions.

This plugin generates a hash function that does a depth-first traversal of the populated values (including default values) of the message in field number order and feeds it to the provided `hash.Hash` implementation. Map values are accessed in key order as well. Because of this deterministic traversal order, the hash generated for two identical protobuf messages should be the same.

NOTE: While we have tested this plugin quite extensively, some edge cases may remain. Use at your own risk.

## Install

Download the latest binary for your environment from https://github.com/cerbos/protoc-gen-go-hashpb/releases.

Alternatively, install from source:

```shell

go install github.com/cerbos/protoc-gen-go-hashpb@latest

```

## Usage

### Generate code

With `protoc`:

```shell

protoc --plugin protoc-gen-go-hashpb=${GOBIN}/protoc-gen-go-hashpb --go_out=. --go-hashpb_out=. *.proto

```

### Calculate hashes using generated code

```go

func hashMyProto(m *mypb.MyMsg) uint64 {

    digest := xxhash.New() // any hash.Hash implementation would work

    m.HashPB(digest, nil)

    return digest.Sum64()

}

```

You can exclude certain fields from being included in the hash. The field name must be fully qualified.

```go

ignore := map[string]struct{}{"fully.qualified.package.Message.field_name1": {}, "fully.qualified.package.Message.field_name2":{}}

digest := xxhash.New() // any hash.Hash implementation would work

m.HashPB(digest, ignore)

```