#pragma once

#include "source/common/protobuf/protobuf.h"

#if defined(ENVOY_ENABLE_FULL_PROTOS)

namespace Envoy {

namespace DeterministicProtoHash {

// Note: this ignores unknown fields and unrecognized types in Any fields.

// An alternative approach might treat such fields as "raw data" and include

// them in the hash, which would risk breaking the deterministic behavior,

// versus this way risks ignoring significant data.

//

// Ignoring unknown fields was chosen as the implementation because the

// TextFormat-based hashing this replaces was explicitly ignoring unknown

// fields.

//

// If this is used as part of making a hash table, it may result in

// collisions if unknown fields are present and are not ignored by the

// corresponding comparator. A `MessageDifferencer` can be configured to

// ignore unknown fields, or not to.

uint64_t hash(const Protobuf::Message& message);

} // namespace DeterministicProtoHash

} // namespace Envoy

#endif