proto: support queue

This patch adds the `push` field to `ExecuteRequest` and introduces
`aeon_queue.proto` module.

Needed for tarantool/aeon#488

Author: ImeevMA

aeon_crud.proto

@@ -43,6 +43,24 @@ service CRUDService {
 // Transactionally executes a set of read and write operations.
 
 message ExecuteRequest {
+  // Message queue push section in a transaction request.
+  message Push {
+    // Definition of messages pushed to a shard-local queue.
+    message Message {
+      // Topic of the message.
+      string topic = 1;
+      // Data of the message.
+      Value data = 2;
+      // Time to live of the message.
+      double ttl = 3;
+    }
+    // Push function.
+    string func = 1;
+    // Additional argument to the push function.
+    Value func_arg = 2;
+    // Messages to send if the push function is not provided.
+    repeated Message messages = 3;
+  }
   // Array of read operations.
   repeated Operation read_set = 1;
   // Array of write operations.
@@ -89,6 +107,8 @@ message ExecuteRequest {
   // Map : space name -> tuple format.
   // Contains formats of all provided tuples. Optional.
   map<string, TupleFormat> tuple_formats = 6;
+  // Description of messages to push when executing a transaction.
+  Push push = 7;
 }
 
 message ExecuteResponse {

aeon_queue.proto

@@ -0,0 +1,105 @@
+syntax = "proto3";
+
+import "aeon_error.proto";
+import "aeon_value.proto";
+
+package aeon;
+
+// Queue API to Aeon - a distributed database based on Tarantool.
+service QueueService {
+  // Takes messages from a shard-local queue.
+  rpc TakeMessages(TakeMessagesRequest) returns (TakeMessagesResponse) {}
+
+  // Releases messages.
+  rpc ReleaseMessages(ReleaseMessagesRequest)
+      returns (ReleaseMessagesResponse) {}
+
+  // Returns the oldest message for all storages, or the oldest message
+  // for each storage.
+  rpc GetOldestMessages(GetOldestMessagesRequest)
+      returns (GetOldestMessagesResponse) {}
+}
+
+// The difinition of messages returned by the `take_messages()` and
+// `get_oldest_messages()`.
+message Message {
+  // Shard name.
+  string shard = 1;
+  // LSN of the message.
+  uint64 lsn = 2;
+  // Data of the message.
+  Value data = 3;
+}
+
+// Message queue consumer reference.
+message ConsumerRef {
+  // Shard of the message queue consumer.
+  string shard = 1;
+  // Topic of the message queue consumer.
+  string topic = 2;
+  // Name of the consumer.
+  string consumer = 3;
+}
+
+// Request for the `take_messages()`.
+message TakeMessagesRequest {
+  // Topic of the messages.
+  string topic = 1;
+  // Consumer of the messages.
+  string consumer = 2;
+  // Max number of returned messages.
+  uint64 limit = 3;
+  // Time to live of the request.
+  double ttl = 4;
+  // Exclusivity of `take_messages()`.
+  bool exclusive = 5;
+  // The timeout for the request.
+  double timeout = 6;
+}
+
+// Response of the `take_messages()`.
+message TakeMessagesResponse {
+  // Error information. Set only on failure.
+  Error error = 1;
+  // Returned messages.
+  repeated Message messages = 2;
+  // Reference to queue consumer.
+  ConsumerRef ref = 3;
+  // True if these messages have already been requested by this consumer,
+  // false otherwise.
+  bool taken_earlier = 4;
+}
+
+// Request for the `release_messages()`.
+message ReleaseMessagesRequest {
+  // Reference to queue consumer.
+  ConsumerRef ref = 1;
+  // If the flag is set, queue.take_messages() won't return released
+  // messages to consumers anymore.
+  bool done = 2;
+}
+
+// Response of the `release_messages()`.
+message ReleaseMessagesResponse {
+  // Error information. Set only on failure.
+  Error error = 1;
+  // True if messages were already released, false otherwise.
+  bool released_earlier = 2;
+}
+
+// Request for the `get_oldest_messages()`.
+message GetOldestMessagesRequest {
+  // Topic of messages to get.
+  string topic = 1;
+  // True if the oldest messages for each shard should be returned,
+  // false if the oldest messages for all shards should be returned.
+  bool for_each_shard = 2;
+}
+
+// Response of the `get_oldest_messages()`.
+message GetOldestMessagesResponse {
+  // Error information. Set only on failure.
+  Error error = 1;
+  // Returned messages.
+  repeated Message messages = 2;
+}