From 45a5d2d07bb1956edde412d20f8fa7ff02a86e77 Mon Sep 17 00:00:00 2001
From: "Alexander A. Klimov" <alexander.klimov@icinga.com>
Date: Wed, 18 Sep 2024 17:45:00 +0200
Subject: [PATCH] ApiListener::UpdateObjectAuthority(): distribute auth. by
 object's host

Pin child objects of hosts (HOST!...) to the same endpoint as the host.
This reduces cross-object action latency withing the same host.
If all endpoints know this algorithm, we can use it.
---
 lib/remote/apilistener-authority.cpp | 27 ++++++++++++++++++++++++---
 lib/remote/apilistener.cpp           |  4 +++-
 lib/remote/apilistener.hpp           |  1 +
 3 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/lib/remote/apilistener-authority.cpp b/lib/remote/apilistener-authority.cpp
index f33a1905bf1..35f7a997928 100644
--- a/lib/remote/apilistener-authority.cpp
+++ b/lib/remote/apilistener-authority.cpp
@@ -25,6 +25,7 @@ void ApiListener::UpdateObjectAuthority()
 
 	std::vector<Endpoint::Ptr> endpoints;
 	Endpoint::Ptr my_endpoint;
+	int hostChildrenInheritObjectAuthority = 0;
 
 	if (my_zone) {
 		my_endpoint = Endpoint::GetLocalEndpoint();
@@ -51,6 +52,12 @@ void ApiListener::UpdateObjectAuthority()
 				return a->GetName() < b->GetName();
 			}
 		);
+
+		for (auto& endpoint : endpoints) {
+			if (endpoint == my_endpoint || endpoint->GetCapabilities() & (uint_fast64_t)ApiCapabilities::HostChildrenInheritObjectAuthority) {
+				++hostChildrenInheritObjectAuthority;
+			}
+		}
 	}
 
 	for (const Type::Ptr& type : Type::GetAllTypes()) {
@@ -65,10 +72,24 @@ void ApiListener::UpdateObjectAuthority()
 
 			bool authority;
 
-			if (!my_zone)
+			if (my_zone) {
+				auto name (object->GetName());
+
+				// If all endpoints know this algorithm, we can use it.
+				if (hostChildrenInheritObjectAuthority == endpoints.size()) {
+					auto exclamation (name.FindFirstOf('!'));
+
+					// Pin child objects of hosts (HOST!...) to the same endpoint as the host.
+					// This reduces cross-object action latency withing the same host.
+					if (exclamation != String::NPos) {
+						name = name.SubStr(0, exclamation);
+					}
+				}
+
+				authority = endpoints[Utility::SDBM(name) % endpoints.size()] == my_endpoint;
+			} else {
 				authority = true;
-			else
-				authority = endpoints[Utility::SDBM(object->GetName()) % endpoints.size()] == my_endpoint;
+			}
 
 #ifdef I2_DEBUG
 // 			//Enable on demand, causes heavy logging on each run.
diff --git a/lib/remote/apilistener.cpp b/lib/remote/apilistener.cpp
index f740fe13baf..0c6835cc154 100644
--- a/lib/remote/apilistener.cpp
+++ b/lib/remote/apilistener.cpp
@@ -644,7 +644,9 @@ static const auto l_AppVersionInt (([]() -> unsigned long {
 })());
 
 static const auto l_MyCapabilities (
-	(uint_fast64_t)ApiCapabilities::ExecuteArbitraryCommand | (uint_fast64_t)ApiCapabilities::IfwApiCheckCommand
+	(uint_fast64_t)ApiCapabilities::ExecuteArbitraryCommand
+	| (uint_fast64_t)ApiCapabilities::IfwApiCheckCommand
+	| (uint_fast64_t)ApiCapabilities::HostChildrenInheritObjectAuthority
 );
 
 /**
diff --git a/lib/remote/apilistener.hpp b/lib/remote/apilistener.hpp
index fced0a8afb1..9a54d374b39 100644
--- a/lib/remote/apilistener.hpp
+++ b/lib/remote/apilistener.hpp
@@ -69,6 +69,7 @@ enum class ApiCapabilities : uint_fast64_t
 {
 	ExecuteArbitraryCommand = 1u << 0u,
 	IfwApiCheckCommand = 1u << 1u,
+	HostChildrenInheritObjectAuthority = 1u << 2u,
 };
 
 /**