From 3ce34c5c14645c5d0ef2eb42ea39e4c09a350c0d Mon Sep 17 00:00:00 2001
From: Pavel Artsishevsky <polter.rnd@gmail.com>
Date: Mon, 25 Nov 2024 15:25:00 +0100
Subject: [PATCH] Remove queue from SinkDriver::update_effective_sinks()

Signed-off-by: Pavel Artsishevsky <polter.rnd@gmail.com>
---
 include/slimlog/sink-inl.h | 69 +++++++++++++++++++-------------------
 1 file changed, 35 insertions(+), 34 deletions(-)

diff --git a/include/slimlog/sink-inl.h b/include/slimlog/sink-inl.h
index 4d85087..c958c64 100644
--- a/include/slimlog/sink-inl.h
+++ b/include/slimlog/sink-inl.h
@@ -17,10 +17,9 @@
 #include <slimlog/policy.h>
 
 #include <algorithm> // IWYU pragma: keep
-#include <exception>
 #include <initializer_list>
+#include <iterator>
 #include <memory>
-#include <queue>
 #include <string_view>
 #include <unordered_map>
 #include <unordered_set>
@@ -63,16 +62,12 @@ SinkDriver<Logger, ThreadingPolicy>::SinkDriver(const Logger* logger, SinkDriver
 template<typename Logger, typename ThreadingPolicy>
 SinkDriver<Logger, ThreadingPolicy>::~SinkDriver()
 {
-    try {
-        const typename ThreadingPolicy::WriteLock lock(m_mutex);
-        for (auto* child : m_children) {
-            child->set_parent(m_parent);
-        }
-        if (m_parent) {
-            m_parent->remove_child(this);
-        }
-    } catch (...) {
-        std::terminate();
+    const typename ThreadingPolicy::WriteLock lock(m_mutex);
+    for (auto* child : m_children) {
+        child->set_parent(m_parent);
+    }
+    if (m_parent) {
+        m_parent->remove_child(this);
     }
 }
 
@@ -154,33 +149,39 @@ auto SinkDriver<Logger, ThreadingPolicy>::remove_child(SinkDriver* child) -> voi
 template<typename Logger, typename ThreadingPolicy>
 auto SinkDriver<Logger, ThreadingPolicy>::update_effective_sinks() -> void
 {
-    // Queue for level order traversal
-    std::queue<SinkDriver*> nodes;
-    nodes.push(this);
-    while (!nodes.empty()) {
-        auto* node = nodes.front();
-        if (node->m_parent) {
-            node->m_effective_sinks = node->m_parent->m_effective_sinks;
-            for (const auto& [sink, enabled] : node->m_sinks) {
-                if (enabled) {
-                    node->m_effective_sinks.insert_or_assign(sink.get(), node->m_logger);
-                } else {
-                    node->m_effective_sinks.erase(sink.get());
-                }
+    SinkDriver* current = this;
+    while (current) {
+        // Update the current node's effective sinks
+        current->m_effective_sinks = current->m_parent ? current->m_parent->m_effective_sinks
+                                                       : decltype(current->m_effective_sinks)();
+        for (const auto& [sink, enabled] : current->m_sinks) {
+            if (enabled) {
+                current->m_effective_sinks.insert_or_assign(sink.get(), current->m_logger);
+            } else {
+                current->m_effective_sinks.erase(sink.get());
             }
-        } else {
-            node->m_effective_sinks.clear();
-            for (const auto& [sink, enabled] : node->m_sinks) {
-                if (enabled) {
-                    node->m_effective_sinks.emplace(sink.get(), node->m_logger);
+        }
+
+        // Find the next node in level order
+        SinkDriver* next = nullptr;
+        if (current->m_children.empty()) {
+            // Move to the next sibling or parent's sibling
+            SinkDriver* parent = current->m_parent;
+            SinkDriver* prev = current;
+            while (parent && !next) {
+                if (auto prev_it = parent->m_children.find(prev);
+                    std::distance(prev_it, parent->m_children.end()) > 1) {
+                    next = *std::next(prev_it);
                 }
+                prev = parent;
+                parent = parent->m_parent != this ? parent->m_parent : nullptr;
             }
+        } else {
+            // Nove to next level
+            next = *current->m_children.begin();
         }
-        nodes.pop();
 
-        for (auto* child : node->m_children) {
-            nodes.push(child);
-        }
+        current = next;
     }
 }