syntax = "proto3";
package mpp;

import "gogoproto/gogo.proto";
import "coprocessor.proto";
import "metapb.proto";
import "kvrpcpb.proto";

option (gogoproto.marshaler_all) = true;
option (gogoproto.sizer_all) = true;
option (gogoproto.unmarshaler_all) = true;

option java_package = "org.tikv.kvproto";

// TaskMeta contains meta of a mpp plan, including query's ts and task address.
message TaskMeta {
	uint64 start_ts = 1; // start ts of a query
	int64 task_id = 2; // if task id is -1 , it indicates a tidb task.
	int64 partition_id = 3; // Only used for hash partition
	string address = 4; // target address of this task.
	uint64 gather_id = 5; // used to distinguish different gathers in the mpp query.
	uint64 query_ts = 6; // timestamp when start to execute query, used for TiFlash miniTSO schedule.
	uint64 local_query_id = 7; // unique local query_id if tidb don't restart. So we can use gather_id + query_ts + local_query_id + server_id to represent a global unique query.
	uint64 server_id = 8; // TiDB server id
	int64 mpp_version = 9; // mpp version
	uint32 keyspace_id = 10; // keyspace id of the request
	string coordinator_address = 11; // coordinator_address of this query
	bool report_execution_summary = 12; // Only when coordinator_address is not empty, this flag can be true. When set to true, TiFlash only report execution summary through ReportMPPTaskStatus service, don't include summaries in MppDataPacket
	kvrpcpb.APIVersion api_version = 16; // API version of the request
	string resource_group_name = 17;
	uint64 connection_id = 18; // This is the session id between a client and tidb
	string connection_alias = 19; // This is the session alias between a client and tidb
}

message IsAliveRequest {
}

message IsAliveResponse {
	bool available = 1;
	int64 mpp_version = 2;
}

// Dipsatch the task request to different tiflash servers.
message DispatchTaskRequest {
	TaskMeta meta = 1;
	bytes encoded_plan = 2;
	int64 timeout = 3;
	repeated coprocessor.RegionInfo regions = 4; 
	// If this task contains table scan, we still need their region info.
	int64 schema_ver = 5;
	// Used for partition table scan
	repeated coprocessor.TableRegions table_regions = 6;
}

// Get response of DispatchTaskRequest.
message DispatchTaskResponse {
	Error error = 1;
	repeated metapb.Region retry_regions = 2;
}

// CancelTaskRequest closes the execution of a task.
message CancelTaskRequest {
	TaskMeta meta = 1;
	Error error = 2;
}

message CancelTaskResponse {
	Error error = 1;
}

// ReportTaskStatus reports the execution status of a task.
// when TiFlash reports status to TiDB, ReportTaskStatusRequest serialize tipb.TiFlashExecutionInfo into data;
message ReportTaskStatusRequest {
	TaskMeta meta = 1;
	bytes data = 2;
	Error error = 3;
}

message ReportTaskStatusResponse {
	Error error = 1;
}

// build connection between different tasks. Data is sent by the tasks that are closer to the data sources.
message EstablishMPPConnectionRequest {
	TaskMeta sender_meta = 1; // node closer to the source
	TaskMeta receiver_meta = 2; // node closer to the tidb mpp gather.
}

// when TiFlash sends data to TiDB, Data packets wrap tipb.SelectResponse, i.e., serialize tipb.SelectResponse into data;
// when TiFlash sends data to TiFlash, data blocks are serialized into chunks, and the execution_summaries in tipb.SelectResponse are serialized into data only for the last packet.
message MPPDataPacket {
	bytes data = 1;
	Error error = 2;
	repeated bytes chunks = 3;
	repeated uint64 stream_ids = 4;
	int64 version = 5; // version of data packet format
}

message Error {
	int32 code = 1;
	string msg = 2;
	int64 mpp_version = 3;
}