syntax = "proto3";
package mvccpb;

import "gogoproto/gogo.proto";

option (gogoproto.marshaler_all) = true;
option (gogoproto.sizer_all) = true;
option (gogoproto.unmarshaler_all) = true;
option (gogoproto.goproto_getters_all) = false;
option (gogoproto.goproto_enum_prefix_all) = false;

message KeyValue {
  // key is the key in bytes. An empty key is not allowed.
  bytes key = 1;
  // create_revision is the revision of last creation on this key.
  int64 create_revision = 2;
  // mod_revision is the revision of last modification on this key.
  int64 mod_revision = 3;
  // version is the version of the key. A deletion resets
  // the version to zero and any modification of the key
  // increases its version.
  int64 version = 4;
  // value is the value held by the key, in bytes.
  bytes value = 5;
  // lease is the ID of the lease that attached to key.
  // When the attached lease expires, the key will be deleted.
  // If lease is 0, then no lease is attached to the key.
  int64 lease = 6;
}

message Event {
  enum EventType {
    PUT = 0;
    DELETE = 1;
  }
  // type is the kind of event. If type is a PUT, it indicates
  // new data has been stored to the key. If type is a DELETE,
  // it indicates the key was deleted.
  EventType type = 1;
  // kv holds the KeyValue for the event.
  // A PUT event contains current kv pair.
  // A PUT event with kv.Version=1 indicates the creation of a key.
  // A DELETE/EXPIRE event contains the deleted key with
  // its modification revision set to the revision of deletion.
  KeyValue kv = 2;

  // prev_kv holds the key-value pair before the event happens.
  KeyValue prev_kv = 3;
}