From 5a16660af11c84dd1ae442c46f1f7c0351b5f6a0 Mon Sep 17 00:00:00 2001
From: Steve Dee <steve@smartercode.net>
Date: Fri, 17 Jan 2014 12:13:46 -0800
Subject: [PATCH] Skeleton for raft

---
 include/v/vere.h | 13 +++++++
 v/loop.c         |  1 +
 v/raft.c         | 88 +++++++++++++++++++++++++++++++++++++++++++++++-
 3 files changed, 101 insertions(+), 1 deletion(-)

diff --git a/include/v/vere.h b/include/v/vere.h
index fca1cfb3ac..de2c000961 100644
--- a/include/v/vere.h
+++ b/include/v/vere.h
@@ -382,6 +382,13 @@
         struct _u2_utty* nex_u;             //  next in host list
       } u2_utty;
 
+    /* u2_raft: raft state.
+    */
+      typedef struct {
+        uv_tcp_t   wax_u;
+        uv_timer_t tim_u;
+      } u2_raft;
+
     /* u2_rnam: raft peer name.
     */
       typedef struct _u2_rnam {
@@ -436,6 +443,7 @@
         u2_cttp*   ctp_u;                   //  http connections
         u2_utty*   uty_u;                   //  all terminals 
         u2_utty*   tem_u;                   //  main terminal (1)
+        u2_raft    raf_u;                   //  raft event log
         u2_ulog    lug_u;                   //  event log
         u2_ames    sam_u;                   //  packet interface
         u2_save    sav_u;                   //  autosave
@@ -998,3 +1006,8 @@
       */
         u2_bean
         u2_raft_readopt(u2_ropt* rop_u, const c3_c* arg_c);
+
+      /* u2_raft_io_init(): initialize raft I/O.
+      */
+        void
+        u2_raft_io_init(void);
diff --git a/v/loop.c b/v/loop.c
index d6e19b4d0d..317131b751 100644
--- a/v/loop.c
+++ b/v/loop.c
@@ -161,6 +161,7 @@ u2_loop_signal_memory()
 static void
 _lo_init()
 {
+  u2_raft_io_init();
   u2_unix_io_init();
   u2_ames_io_init();
   u2_term_io_init();
diff --git a/v/raft.c b/v/raft.c
index ec06fb7b86..1ac74c3276 100644
--- a/v/raft.c
+++ b/v/raft.c
@@ -11,9 +11,18 @@
 #include "all.h"
 #include "v/vere.h"
 
+
+/* _raft_election_rand(): pseudorandom component of election timeout.
+*/
+static c3_w
+_raft_election_rand()
+{
+  return ((float) rand() / RAND_MAX) * 150;
+}
+
 /* _raft_readname(): parse a raft host:port peer name.
 */
-u2_bean
+static u2_bean
 _raft_readname(u2_ropt* rop_u, const c3_c* str_c, c3_w siz_w)
 {
   u2_rnam* nam_u = malloc(sizeof(*nam_u));
@@ -62,3 +71,80 @@ u2_raft_readopt(u2_ropt* rop_u, const c3_c* arg_c)
   }
   return _raft_readname(rop_u, arg_c, strlen(arg_c));
 }
+
+static void
+_raft_listen_cb(uv_stream_t* wax_u, c3_i sas_i)
+{
+}
+
+static void
+_raft_time_cb(uv_timer_t* tim_u, c3_i sas_i)
+{
+  u2_raft* raf_u = tim_u->data;
+  //uL(fprintf(uH, "raft: time\n"));
+}
+
+/* _raft_foll_init(): begin, follower mode.
+*/
+static void
+_raft_foll_init(u2_raft* raf_u)
+{
+  uL(fprintf(uH, "raft: starting follower\n"));
+
+  if ( 0 != uv_tcp_init(u2L, &raf_u->wax_u) ) {
+    uL(fprintf(uH, "raft: init: %s\n", uv_strerror(uv_last_error(u2L))));
+    c3_assert(0);
+  }
+
+  // Bind the listener.
+  {
+    struct sockaddr_in add_u;
+
+    memset(&add_u, 0, sizeof(add_u));
+    add_u.sin_family = AF_INET;
+    add_u.sin_addr.s_addr = htonl(INADDR_ANY);
+    add_u.sin_port = htons(u2_Host.ops_u.rop_u.por_s);
+
+    if ( 0 != uv_tcp_bind(&raf_u->wax_u, add_u) ) {
+      uL(fprintf(uH, "raft: bind: %s\n", uv_strerror(uv_last_error(u2L))));
+      c3_assert(0);
+    }
+    else {
+      if ( 0 != uv_listen((uv_stream_t*)&raf_u->wax_u, 16, _raft_listen_cb) ) {
+        uL(fprintf(uH, "raft: listen: %s\n", uv_strerror(uv_last_error(u2L))));
+        c3_assert(0);
+      }
+      else {
+        uL(fprintf(uH, "raft: on TCP %d\n", u2_Host.ops_u.rop_u.por_s));
+      }
+    }
+  }
+
+  // Start the initial election timeout.
+  {
+    uv_timer_init(u2L, &raf_u->tim_u);
+    raf_u->tim_u.data = raf_u;
+    uv_timer_start(&raf_u->tim_u, _raft_time_cb, _raft_election_rand(), 0);
+  }
+}
+
+/* _raft_lone_init(): begin, single-instance mode.
+*/
+static void
+_raft_lone_init(u2_raft* raf_u)
+{
+  uL(fprintf(uH, "raft: single-instance mode\n"));
+}
+
+void
+u2_raft_io_init()
+{
+  u2_raft* raf_u = &u2_Host.raf_u;
+
+  if ( 0 == u2_Host.ops_u.rop_u.por_s ) {
+    _raft_lone_init(raf_u);
+  }
+  else {
+    _raft_foll_init(raf_u);
+  }
+}