chore: define remote_engine grpc service

proto/Cargo.toml

@@ -12,6 +12,7 @@ workspace = true
 
 [dependencies]
 prost = { workspace = true }
+tonic = { workspace = true }
 
 [build-dependencies]
 protoc-bin-vendored = "3.0.0"

proto/build.rs

@@ -15,6 +15,7 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
             "protos/table_requests.proto",
             "protos/wal_on_mq.proto",
             "protos/oss_cache.proto",
+            "protos/remote_engine.proto",
         ],
         &["protos"],
     )?;

proto/protos/remote_engine.proto

@@ -0,0 +1,82 @@
+// Copyright 2022 CeresDB Project Authors. Licensed under Apache-2.0.
+
+syntax = "proto3";
+package remote_engine;
+
+import "common.proto";
+
+message ResponseHeader {
+  uint32 code = 1;
+  string error = 2;
+}
+
+service RemoteEngineService {
+  rpc Read(ReadRequest) returns (stream ReadResponse) {}
+  rpc Write(WriteRequest) returns (WriteResponse) {}
+}
+
+message TableIdentifier {
+  string catalog = 1;
+  string schema = 2;
+  string table = 3;
+}
+
+message ReadOptions {
+  uint64 batch_size = 1;
+  uint64 read_parallelism = 2;
+}
+
+message Projection {
+  repeated uint64 idx = 1;
+}
+
+message ProjectedSchema {
+  common.TableSchema table_schema = 1;
+  Projection projection = 2;
+}
+
+message Predicate {
+  repeated bytes exprs = 1;
+  common.TimeRange time_range = 2;
+}
+
+enum ReadOrder {
+  None = 0;
+  Asc = 1;
+  Desc = 2;
+}
+
+message TableReadRequest {
+  uint64 request_id = 1;
+  ReadOptions opts = 2;
+  ProjectedSchema projected_schema = 3;
+  Predicate predicate = 4;
+  ReadOrder order = 5;
+}
+
+message ReadRequest {
+  TableIdentifier table = 1;
+  TableReadRequest read_request = 2;
+}
+
+message ReadResponse {
+  ResponseHeader header = 1;
+  repeated bytes rows = 2;
+}
+
+message RowGroup {
+  common.TableSchema table_schema = 1;
+  repeated bytes rows = 2;
+  int64 min_timestamp = 3;
+  int64 max_timestamp = 4;
+}
+
+message WriteRequest {
+  TableIdentifier table = 1;
+  RowGroup row_group = 2;
+}
+
+message WriteResponse {
+  ResponseHeader header = 1;
+  uint64 affected_rows = 2;
+}

proto/src/lib.rs

@@ -12,3 +12,4 @@ pub mod sst;
 pub mod sys_catalog;
 pub mod table_requests;
 pub mod wal_on_mq;
+pub mod remote_engine;