syntax = "proto3";

package minikv;

// Internal volume service (coordinator → volume)

service VolumeInternal {

// 2PC write protocol

rpc Prepare(PrepareRequest) returns (PrepareResponse);

rpc Commit(CommitRequest) returns (CommitResponse);

rpc Abort(AbortRequest) returns (AbortResponse);

// Replication & repair

rpc Pull(PullRequest) returns (stream Chunk);

rpc Delete(DeleteRequest) returns (DeleteResponse);

// Health & admin

rpc Ping(PingRequest) returns (PingResponse);

rpc Stats(StatsRequest) returns (StatsResponse);

}

// Coordinator service (volume → coordinator, raft peers)

service CoordinatorInternal {

// Raft RPCs

rpc RequestVote(VoteRequest) returns (VoteResponse);

rpc AppendEntries(AppendRequest) returns (AppendResponse);

rpc InstallSnapshot(SnapshotRequest) returns (SnapshotResponse);

// Volume registration

rpc Join(JoinRequest) returns (JoinResponse);

rpc Heartbeat(HeartbeatRequest) returns (HeartbeatResponse);

// Range queries and batch operations

rpc Range(RangeRequest) returns (RangeResponse);

rpc Batch(BatchRequest) returns (BatchResponse);

}

// ===== Range Query Messages =====

message RangeRequest {

string start = 1;

string end = 2;

bool include_values = 3;

}

message RangeResponse {

repeated string keys = 1;

repeated bytes values = 2;

}

// ===== Batch Operation Messages =====

message BatchRequest {

repeated BatchOp ops = 1;

}

message BatchOp {

enum Type {

PUT = 0;

GET = 1;

DELETE = 2;

}

Type type = 1;

string key = 2;

bytes value = 3;

}

message BatchResponse {

repeated BatchResult results = 1;

}

message BatchResult {

bool ok = 1;

string key = 2;

bytes value = 3;

string error = 4;

}

// ===== 2PC Messages =====

message PrepareRequest {

string key = 1;

string upload_id = 2;

uint64 expected_size = 3;

string expected_blake3 = 4;

}

message PrepareResponse {

bool ok = 1;

string error = 2;

}

message CommitRequest {

string upload_id = 1;

string key = 2;

}

message CommitResponse {

bool ok = 1;

string error = 2;

}

message AbortRequest {

string upload_id = 1;

}

message AbortResponse {

bool ok = 1;

}

// ===== Replication Messages =====

message PullRequest {

string key = 1;

string source_url = 2;

}

message Chunk {

bytes data = 1;

}

message DeleteRequest {

string key = 1;

}

message DeleteResponse {

bool ok = 1;

string error = 2;

}

// ===== Health Messages =====

message PingRequest {}

message PingResponse {

string volume_id = 1;

uint64 uptime_secs = 2;

uint64 total_keys = 3;

uint64 total_bytes = 4;

}

message StatsRequest {}

message StatsResponse {

uint64 total_keys = 1;

uint64 total_bytes = 2;

uint64 free_bytes = 3;

repeated string shards = 4;

}

// ===== Raft Messages =====

message VoteRequest {

uint64 term = 1;

string candidate_id = 2;

uint64 last_log_index = 3;

uint64 last_log_term = 4;

}

message VoteResponse {

uint64 term = 1;

bool vote_granted = 2;

}

message AppendRequest {

uint64 term = 1;

string leader_id = 2;

uint64 prev_log_index = 3;

uint64 prev_log_term = 4;

repeated LogEntry entries = 5;

uint64 leader_commit = 6;

}

message AppendResponse {

uint64 term = 1;

bool success = 2;

uint64 conflict_index = 3;

}

message SnapshotRequest {

uint64 term = 1;

string leader_id = 2;

uint64 last_included_index = 3;

uint64 last_included_term = 4;

bytes data = 5;

}

message SnapshotResponse {

uint64 term = 1;

}

message LogEntry {

uint64 term = 1;

uint64 index = 2;

bytes data = 3;

}

// ===== Coordinator Messages =====

message JoinRequest {

string volume_id = 1;

string address = 2;

repeated string shards = 3;

}

message JoinResponse {

bool ok = 1;

string cluster_id = 2;

}

message HeartbeatRequest {

string volume_id = 1;

uint64 total_keys = 2;

uint64 total_bytes = 3;

uint64 free_bytes = 4;

}

message HeartbeatResponse {

bool ok = 1;

repeated string commands = 2; // e.g., ["compact_shard:0", "rebalance"]

}