election: Add a possible callback when becoming a follower v2 SUPERSEDED

Louis Solofrizzo: 1
 election: Add a possible callback when becoming a follower

 2 files changed, 20 insertions(+), 1 deletions(-)

[PATCH v2] election: Add a possible callback when becoming a follower Export this patch

Signed-off-by: Louis Solofrizzo <lsolofrizzo@scaleway.com>
---
 libfloat.h |  7 +++++++
 raft.c     | 14 +++++++++++++-
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/libfloat.h b/libfloat.h
index e5494b7..cfaa156 100644
--- a/libfloat.h
+++ b/libfloat.h
@@ -105,6 +105,13 @@ struct libfloat_ctx_s {
      */
     void (*become_leader_cb)(struct libfloat_ctx_s *);
 
+    /*!
+     * \brief Callback when becoming follower of a cluster
+     *
+     * \param[in] struct libfloat_ctx_s * - Cluster context
+     */
+    void (*become_follower_cb)(struct libfloat_ctx_s *);
+
     /*!
      * \brief Send a "is leader healthy" to a node
      *
diff --git a/raft.c b/raft.c
index 8f10661..8148c96 100644
--- a/raft.c
+++ b/raft.c
@@ -36,11 +36,23 @@ void __libfloat_become_candidate(libfloat_ctx_t *ctx, libfloat_elections_args_t
 
 void __libfloat_become_follower(libfloat_ctx_t *ctx, libfloat_elections_args_t *args)
 {
+    if (ctx->state == RAFT_STATE_FOLLOWER)
+        return;
+
+    if (ctx->become_follower_cb != NULL && ctx->state == RAFT_STATE_LEADER)
+    {
+        /* Only call this when we loose leadership */
+        ctx->become_follower_cb(ctx);
+    }
+
+    ctx->state = RAFT_STATE_FOLLOWER;
+
     DEBUG(ctx, "Becoming follower: reason=%s", args->reason);
     ctx->abort_send_snapshot(ctx);
-    ctx->state = RAFT_STATE_FOLLOWER;
+
     ctx->election_timeout_rand = ctx->conf.election_timeout + ctx->rand() % ctx->conf.election_timeout;
     ctx->stat.leader_election_time = 0;
+
     libfloat_vote_for(ctx, 0);
 }
 
-- 
2.38.1