rpc.proto

syntax = "proto3";
package raft_rpc;

message rpc_Entry {
    int32 term = 1;
    int32 index = 2; // （wrong！even empty AE, we must send prelog_index）we can't put index in ae rpc, because: if we want to send an empty HB, we only need the term in ae
    string msg = 3;

}

message AppendEntryRpc {
    int32 term = 1;
    int32 prelog_term = 2;
    int32 commit_index = 3;
    int32 lsn = 4;
    string ip = 5;
    int32 port = 6;
    repeated rpc_Entry entry = 7;
    int32 prelog_index = 8; //though entry has index, prelog_index can be caculated with index, however we still must have prelog_index because empty AE needs it to let itself verified by follower

}


message Resp_AppendEntryRpc {
    bool ok = 1;
    int32 term = 2;
    int32 lsn = 3;
    string ip = 4;
    int32 port = 5;
    /* why we must known the context of rpc (specifically, when received a resp_rpc, we must known the call rpc), why? here is the scene:
 * Scene 1:
 *    P and F steady with [0], P haven't send any empty AE as HB, client apply [1], P AE with [1], P received resp_ae,
 *    ok:1, last_send_index: 1, follower_saved_index: 0, entry size: 2. P should add nextIndex to 2.
 * Scene 2:
 *    P and F steady with [0], P send empty AE as HB, client apply [1], P received resp_ae,
 *    ok:1, last_send_index: 1, follower_saved_index: 0, entry size: 2. It is completely same with scene 1, but P should add nextIndex to 2,
 *    P should stay nextIndex to 1, and immediately trigger the next AE to send rpc_ae with entry [1].
 *    That's why we need extra information (the call of AE)
 */
    bool is_empty_ae = 6;
}


message RequestVoteRpc {
    int32 term = 1;
    int32 latest_index = 2;
    int32 latest_term = 3;
    int32 lsn = 4;
    string ip = 5;
    int32 port = 6;
}


message Resp_RequestVoteRpc {
    bool ok = 1;
    int32 term = 2;
    int32 lsn = 3;
    string ip = 4;
    int32 port = 5;
}