From 65a954b681a017201546675efcf5d55dd0a90fc9 Mon Sep 17 00:00:00 2001
From: Marcus Holland-Moritz <github@mhxnet.de>
Date: Sat, 18 Nov 2023 22:13:30 +0100
Subject: [PATCH] refactor: naming in multi_queue_block_merger

---
 include/dwarfs/multi_queue_block_merger.h | 72 ++++++++++++-----------
 1 file changed, 37 insertions(+), 35 deletions(-)

diff --git a/include/dwarfs/multi_queue_block_merger.h b/include/dwarfs/multi_queue_block_merger.h
index 0f8e7ab6..5223f1c9 100644
--- a/include/dwarfs/multi_queue_block_merger.h
+++ b/include/dwarfs/multi_queue_block_merger.h
@@ -41,16 +41,18 @@ class multi_queue_block_merger : public block_merger<SourceT, BlockT> {
   using source_type = SourceT;
   using block_type = BlockT;
 
-  multi_queue_block_merger(size_t num_active_slots, size_t max_queued_blocks,
-                           std::vector<source_type> const& sources,
-                           std::function<void(block_type)> on_block_merged)
+  multi_queue_block_merger(
+      size_t num_active_slots, size_t max_queued_blocks,
+      std::vector<source_type> const& sources,
+      std::function<void(block_type)> on_block_merged_callback)
       : num_queueable_{max_queued_blocks}
-      , sources_{sources.begin(), sources.end()}
-      , active_(num_active_slots)
-      , on_block_merged_{on_block_merged} {
-    for (size_t i = 0; i < active_.size() && !sources_.empty(); ++i) {
-      active_[i] = sources_.front();
-      sources_.pop_front();
+      , source_queue_{sources.begin(), sources.end()}
+      , active_slots_(num_active_slots)
+      , on_block_merged_callback_{on_block_merged_callback} {
+    for (size_t i = 0; i < active_slots_.size() && !source_queue_.empty();
+         ++i) {
+      active_slots_[i] = source_queue_.front();
+      source_queue_.pop_front();
     }
   }
 
@@ -62,7 +64,7 @@ class multi_queue_block_merger : public block_merger<SourceT, BlockT> {
 
     --num_queueable_;
 
-    queues_[src].emplace(std::move(blk), is_last);
+    block_queues_[src].emplace(std::move(blk), is_last);
 
     while (try_merge_block()) {
     }
@@ -72,16 +74,16 @@ class multi_queue_block_merger : public block_merger<SourceT, BlockT> {
 
  private:
   size_t source_distance(source_type src) const {
-    auto ix = active_index_;
+    auto ix = active_slot_index_;
     size_t distance{0};
 
-    while (active_[ix] && active_[ix].value() != src) {
+    while (active_slots_[ix] && active_slots_[ix].value() != src) {
       ++distance;
-      ix = (ix + 1) % active_.size();
+      ix = (ix + 1) % active_slots_.size();
 
-      if (ix == active_index_) {
-        auto it = std::find(begin(sources_), end(sources_), src);
-        distance += std::distance(begin(sources_), it);
+      if (ix == active_slot_index_) {
+        auto it = std::find(begin(source_queue_), end(source_queue_), src);
+        distance += std::distance(begin(source_queue_), it);
         break;
       }
     }
@@ -90,54 +92,54 @@ class multi_queue_block_merger : public block_merger<SourceT, BlockT> {
   }
 
   bool try_merge_block() {
-    auto const ix = active_index_;
+    auto const ix = active_slot_index_;
 
-    assert(active_[ix]);
+    assert(active_slots_[ix]);
 
-    auto src = active_[ix].value();
-    auto it = queues_.find(src);
+    auto src = active_slots_[ix].value();
+    auto it = block_queues_.find(src);
 
-    if (it == queues_.end() || it->second.empty()) {
+    if (it == block_queues_.end() || it->second.empty()) {
       return false;
     }
 
     auto [blk, is_last] = std::move(it->second.front());
     it->second.pop();
 
-    on_block_merged_(std::move(blk));
+    on_block_merged_callback_(std::move(blk));
 
     ++num_queueable_;
 
     if (is_last) {
-      queues_.erase(it);
+      block_queues_.erase(it);
       update_active(ix);
     }
 
     do {
-      active_index_ = (active_index_ + 1) % active_.size();
-    } while (active_index_ != ix && !active_[active_index_]);
+      active_slot_index_ = (active_slot_index_ + 1) % active_slots_.size();
+    } while (active_slot_index_ != ix && !active_slots_[active_slot_index_]);
 
-    return active_index_ != ix || active_[active_index_];
+    return active_slot_index_ != ix || active_slots_[active_slot_index_];
   }
 
   void update_active(size_t ix) {
-    if (!sources_.empty()) {
-      active_[ix] = sources_.front();
-      sources_.pop_front();
+    if (!source_queue_.empty()) {
+      active_slots_[ix] = source_queue_.front();
+      source_queue_.pop_front();
     } else {
-      active_[ix].reset();
+      active_slots_[ix].reset();
     }
   }
 
   std::mutex mx_;
   std::condition_variable cv_;
-  size_t active_index_{0};
+  size_t active_slot_index_{0};
   size_t num_queueable_;
   std::unordered_map<source_type, std::queue<std::pair<block_type, bool>>>
-      queues_;
-  std::deque<source_type> sources_;
-  std::vector<std::optional<source_type>> active_;
-  std::function<void(block_type)> on_block_merged_;
+      block_queues_;
+  std::deque<source_type> source_queue_;
+  std::vector<std::optional<source_type>> active_slots_;
+  std::function<void(block_type)> on_block_merged_callback_;
 };
 
 } // namespace dwarfs