protocol.proto

syntax = "proto3";
package pb;

// import "github.com/gogo/protobuf/gogoproto/gogo.proto";

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

// How messages are delivered to the STAN cluster
message PubMsg {
  string clientID = 1; // ClientID
  string guid = 2;     // guid
  string subject = 3;  // subject
  string reply = 4;    // optional reply
  bytes data = 5;      // payload

  bytes sha256 = 10; // optional sha256 of data
}

// Used to ACK to publishers
message PubAck {
  string guid = 1;  // guid
  string error = 2; // err string, empty/omitted if no error
}

// Msg struct. Sequence is assigned for global ordering by
// the cluster after the publisher has been acknowledged.
message MsgProto {
  uint64 sequence =
      1; // globally ordered sequence number for the subject's channel
  string subject = 2;   // subject
  string reply = 3;     // optional reply
  bytes data = 4;       // payload
  int64 timestamp = 5;  // received timestamp
  bool redelivered = 6; // Flag specifying if the message is being redelivered

  uint32 CRC32 = 10; // optional IEEE CRC32
}

// Ack will deliver an ack for a delivered msg.
message Ack {
  string subject = 1;  // Subject
  uint64 sequence = 2; // Sequence to acknowledge
}

// Connection Request
message ConnectRequest {
  string clientID = 1;       // Client name/identifier.
  string heartbeatInbox = 2; // Inbox for server initiated heartbeats.
}

// Response to a client connect
message ConnectResponse {
  string pubPrefix = 1;   // Prefix to use when publishing to this STAN cluster
  string subRequests = 2; // Subject to use for subscription requests
  string unsubRequests = 3;    // Subject to use for unsubscribe requests
  string closeRequests = 4;    // Subject for closing the stan connection
  string error = 5;            // err string, empty/omitted if no error
  string subCloseRequests = 6; // Subject to use for subscription close requests

  string publicKey = 100; // Possibly used to sign acks, etc.
}

// Enum for start position type.
enum StartPosition {
  NewOnly = 0;
  LastReceived = 1;
  TimeDeltaStart = 2;
  SequenceStart = 3;
  First = 4;
}

// Protocol for a client to subscribe
message SubscriptionRequest {
  string clientID = 1;     // ClientID
  string subject = 2;      // Formal subject to subscribe to, e.g. foo.bar
  string qGroup = 3;       // Optional queue group
  string inbox = 4;        // Inbox subject to deliver messages on
  int32 maxInFlight = 5;   // Maximum inflight messages without an ack allowed
  int32 ackWaitInSecs = 6; // Timeout for receiving an ack from the client
  string durableName =
      7; // Optional durable name which survives client restarts
  StartPosition startPosition = 10; // Start position
  uint64 startSequence = 11;        // Optional start sequence number
  int64 startTimeDelta = 12;        // Optional start time
}

// Response for SubscriptionRequest and UnsubscribeRequests
message SubscriptionResponse {
  string ackInbox = 2; // ackInbox for sending acks
  string error = 3;    // err string, empty/omitted if no error
}

// Protocol for a clients to unsubscribe. Will return a SubscriptionResponse
message UnsubscribeRequest {
  string clientID = 1; // ClientID
  string subject = 2;  // subject for the subscription
  string inbox = 3;    // Inbox subject to identify subscription
  string durableName =
      4; // Optional durable name which survives client restarts
}

// Protocol for a client to close a connection
message CloseRequest {
  string clientID = 1; // Client name provided to Connect() requests
}

// Response for CloseRequest
message CloseResponse {
  string error = 1; // err string, empty/omitted if no error
}