From cd76a5bc57c991aef76cf43595315d64e11b7cf0 Mon Sep 17 00:00:00 2001
From: Igor Zolotarev <yngvar.antonsson@gmail.com>
Date: Thu, 23 Nov 2023 18:08:23 +0300
Subject: [PATCH] Add members.remove function

---
 membership.lua         | 26 +++++++++++++++++++++++++-
 membership/members.lua |  7 +++++++
 2 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/membership.lua b/membership.lua
index b640737..be08192 100755
--- a/membership.lua
+++ b/membership.lua
@@ -478,13 +478,17 @@ local function _protocol_step()
         local ack_data = wait_ack(uri, loop_now, opts.ACK_TIMEOUT_SECONDS * 1.0e6)
         if ack_data ~= nil then
             local member = members.get(uri)
+            if member == nil then
+                return
+            end
             -- calculate time difference between local time and member time
             local delta = _get_clock_delta(ack_data)
             members.set(uri, member.status, member.incarnation, { clock_delta = delta }) -- update timstamp
             return
         end
     end
-    if members.get(uri).status >= opts.DEAD then
+    local member = members.get(uri)
+    if member ~= nil and member.status >= opts.DEAD then
         -- still dead, do nothing
         return
     end
@@ -509,6 +513,9 @@ local function _protocol_step()
     end
     if sent_indirect > 0 and ack_data ~= nil then
         local member = members.get(uri)
+        if member == nil then
+            return
+        end
         -- calculate time difference between local time and member time
         local delta = _get_clock_delta(ack_data)
         members.set(uri, member.status, member.incarnation, { clock_delta = delta })
@@ -529,9 +536,11 @@ local function _protocol_step()
     end
 end
 
+local protocol_step_in_progress = fiber.cond()
 local function protocol_step()
     local t1 = fiber.clock()
     local ok, res = xpcall(_protocol_step, debug.traceback)
+    protocol_step_in_progress:signal()
     fiber.testcancel()
 
     if not ok then
@@ -929,6 +938,20 @@ local function set_payload(key, value)
     return true
 end
 
+--- Remove a member.
+-- @function remove_member
+-- @tparam uri string
+local function remove_member(uri)
+    checks('string')
+    protocol_step_in_progress:wait(60)
+    local member = members.get(uri)
+    if member == nil then
+        return
+    end
+
+    members.remove(uri)
+end
+
 do -- finish module loading
     opts.after_reload()
     events.after_reload()
@@ -949,6 +972,7 @@ return {
     probe_uri = probe_uri,
     add_member = add_member,
     get_member = get_member,
+    remove_member = remove_member,
     set_payload = set_payload,
 
 --- Encryption Functions.
diff --git a/membership/members.lua b/membership/members.lua
index b102ed5..510c9c1 100644
--- a/membership/members.lua
+++ b/membership/members.lua
@@ -117,4 +117,11 @@ function members.count()
     return count
 end
 
+function members.remove(uri)
+    checks('string')
+
+    _all_members[uri] = nil
+    rawget(_G, '__membership_stash')['members._all_members'][uri] = nil
+end
+
 return members