From b72ecfbc8ee042ce24219489f6a852145a98b831 Mon Sep 17 00:00:00 2001
From: Walter Karas <wkaras@verizonmedia.com>
Date: Thu, 6 Jan 2022 17:18:10 -0600
Subject: [PATCH] Clean up of next hop HostRecord class.

---
 include/tscore/ConsistentHash.h              |  4 +-
 proxy/http/remap/NextHopSelectionStrategy.cc |  6 +-
 proxy/http/remap/NextHopSelectionStrategy.h  | 75 ++++++--------------
 3 files changed, 25 insertions(+), 60 deletions(-)

diff --git a/include/tscore/ConsistentHash.h b/include/tscore/ConsistentHash.h
index 75d979c0aed..9fe7a237246 100644
--- a/include/tscore/ConsistentHash.h
+++ b/include/tscore/ConsistentHash.h
@@ -32,8 +32,8 @@
  */
 
 struct ATSConsistentHashNode {
-  std::atomic<bool> available;
-  char *name;
+  std::atomic<bool> available{true};
+  char *name{nullptr};
 };
 
 std::ostream &operator<<(std::ostream &os, ATSConsistentHashNode &thing);
diff --git a/proxy/http/remap/NextHopSelectionStrategy.cc b/proxy/http/remap/NextHopSelectionStrategy.cc
index f3b507c3064..6a39028a3ea 100644
--- a/proxy/http/remap/NextHopSelectionStrategy.cc
+++ b/proxy/http/remap/NextHopSelectionStrategy.cc
@@ -211,7 +211,7 @@ NextHopSelectionStrategy::Init(ts::Yaml::Map &n)
             std::vector<std::shared_ptr<HostRecord>> hosts_inner;
 
             for (unsigned int hst = 0; hst < hosts_list.size(); ++hst) {
-              std::shared_ptr<HostRecord> host_rec = std::make_shared<HostRecord>(hosts_list[hst].as<HostRecord>());
+              std::shared_ptr<HostRecord> host_rec = std::make_shared<HostRecord>(hosts_list[hst].as<HostRecordCfg>());
               host_rec->group_index                = grp;
               host_rec->host_index                 = hst;
               if ((self_host == host_rec->hostname) || mach->is_self(host_rec->hostname.c_str())) {
@@ -311,9 +311,9 @@ NextHopSelectionStrategy::responseIsRetryable(int64_t sm_id, HttpTransact::Curre
 
 namespace YAML
 {
-template <> struct convert<HostRecord> {
+template <> struct convert<HostRecordCfg> {
   static bool
-  decode(const Node &node, HostRecord &nh)
+  decode(const Node &node, HostRecordCfg &nh)
   {
     ts::Yaml::Map map{node};
     ts::Yaml::Map *mmap{&map};
diff --git a/proxy/http/remap/NextHopSelectionStrategy.h b/proxy/http/remap/NextHopSelectionStrategy.h
index 628c01d55f8..1f931cd275e 100644
--- a/proxy/http/remap/NextHopSelectionStrategy.h
+++ b/proxy/http/remap/NextHopSelectionStrategy.h
@@ -23,6 +23,8 @@
 
 #pragma once
 
+#include <utility>
+
 #include "ts/parentselectdefs.h"
 #include "ParentSelection.h"
 #include "HttpTransact.h"
@@ -103,64 +105,27 @@ struct NHProtocol {
   std::string health_check_url;
 };
 
-struct HostRecord : ATSConsistentHashNode {
-  std::mutex _mutex;
+struct HostRecordCfg {
   std::string hostname;
-  std::atomic<time_t> failedAt;
-  std::atomic<uint32_t> failCount;
-  std::atomic<time_t> upAt;
-  float weight;
-  std::string hash_string;
-  int host_index;
-  int group_index;
-  bool self = false;
   std::vector<std::shared_ptr<NHProtocol>> protocols;
+  float weight{0};
+  std::string hash_string;
+};
 
-  // construct without locking the _mutex.
-  HostRecord()
-  {
-    hostname    = "";
-    failedAt    = 0;
-    failCount   = 0;
-    upAt        = 0;
-    weight      = 0;
-    hash_string = "";
-    host_index  = -1;
-    group_index = -1;
-    available   = true;
-  }
-
-  // copy constructor to avoid copying the _mutex.
-  HostRecord(const HostRecord &o)
-  {
-    hostname    = o.hostname;
-    failedAt    = o.failedAt.load();
-    failCount   = o.failCount.load();
-    upAt        = o.upAt.load();
-    weight      = o.weight;
-    hash_string = o.hash_string;
-    host_index  = -1;
-    group_index = -1;
-    available   = true;
-    protocols   = o.protocols;
-  }
-
-  // assign without copying the _mutex.
-  HostRecord &
-  operator=(const HostRecord &o)
-  {
-    hostname    = o.hostname;
-    failedAt    = o.failedAt.load();
-    failCount   = o.failCount.load();
-    upAt        = o.upAt.load();
-    weight      = o.weight;
-    hash_string = o.hash_string;
-    host_index  = o.host_index;
-    group_index = o.group_index;
-    available   = o.available.load();
-    protocols   = o.protocols;
-    return *this;
-  }
+struct HostRecord : public ATSConsistentHashNode, public HostRecordCfg {
+  std::mutex _mutex;
+  std::atomic<time_t> failedAt{0};
+  std::atomic<uint32_t> failCount{0};
+  std::atomic<time_t> upAt{0};
+  int host_index{-1};
+  int group_index{-1};
+  bool self{false};
+
+  explicit HostRecord(HostRecordCfg &&o) : HostRecordCfg(std::move(o)) {}
+
+  // No copying or moving.
+  HostRecord(const HostRecord &) = delete;
+  HostRecord &operator=(const HostRecord &) = delete;
 
   // locks the record when marking this host down.
   void