From 78e321f4ad797e55faa5b635bac3e94240800602 Mon Sep 17 00:00:00 2001
From: YuQing <384681@qq.com>
Date: Thu, 21 Apr 2022 11:29:43 +0800
Subject: [PATCH] election quorum support sf_election_quorum_auto

---
 src/sf_configs.c |  2 ++
 src/sf_configs.h | 24 +++++++++++++++++++++++-
 src/sf_types.h   |  5 +++--
 3 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/src/sf_configs.c b/src/sf_configs.c
index f088515..4f02ee2 100644
--- a/src/sf_configs.c
+++ b/src/sf_configs.c
@@ -128,6 +128,8 @@ int sf_load_quorum_config_ex(SFElectionQuorum *quorum,
             "quorum", ini_ctx->context);
     if (str == NULL) {
         *quorum = def_quorum;
+    } else if (strncasecmp(str, "auto", 4) == 0) {
+        *quorum = sf_election_quorum_auto;
     } else if (strncasecmp(str, "any", 3) == 0) {
         *quorum = sf_election_quorum_any;
     } else if (strncasecmp(str, "majority", 8) == 0) {
diff --git a/src/sf_configs.h b/src/sf_configs.h
index b8887ac..a0a71ee 100644
--- a/src/sf_configs.h
+++ b/src/sf_configs.h
@@ -92,6 +92,8 @@ static inline const char *sf_get_quorum_caption(
         const SFElectionQuorum quorum)
 {
     switch (quorum) {
+        case sf_election_quorum_auto:
+            return "auto";
         case sf_election_quorum_any:
             return "any";
         case sf_election_quorum_majority:
@@ -101,11 +103,31 @@ static inline const char *sf_get_quorum_caption(
     }
 }
 
+static inline bool sf_election_quorum_check(const SFElectionQuorum quorum,
+        const int total_count, const int active_count)
+{
+    switch (quorum) {
+        case sf_election_quorum_any:
+            return active_count > 0;
+        case sf_election_quorum_auto:
+            if (total_count % 2 == 0) {  //same as sf_election_quorum_any
+                return active_count > 0;
+            }
+            //continue
+        case sf_election_quorum_majority:
+            if (active_count == total_count) {
+                return true;
+            } else {
+                return active_count > total_count / 2;
+            }
+    }
+}
+
 #define sf_load_read_rule_config(rule, ini_ctx) \
     sf_load_read_rule_config_ex(rule, ini_ctx, sf_data_read_rule_master_only)
 
 #define sf_load_quorum_config(quorum, ini_ctx) \
-    sf_load_quorum_config_ex(quorum, ini_ctx, sf_election_quorum_majority)
+    sf_load_quorum_config_ex(quorum, ini_ctx, sf_election_quorum_auto)
 
 #define SF_NET_RETRY_FINISHED(retry_times, counter, result)  \
         !((SF_IS_RETRIABLE_ERROR(result) && ((retry_times > 0 &&  \
diff --git a/src/sf_types.h b/src/sf_types.h
index ec3f3ba..2062e93 100644
--- a/src/sf_types.h
+++ b/src/sf_types.h
@@ -245,8 +245,9 @@ typedef struct sf_synchronize_context {
 } SFSynchronizeContext;
 
 typedef enum sf_election_quorum {
-    sf_election_quorum_any = 1,
-    sf_election_quorum_majority
+    sf_election_quorum_auto,
+    sf_election_quorum_any,
+    sf_election_quorum_majority,
 } SFElectionQuorum;
 
 #endif