From 2fabf8d8dbdaf8670c7b6c5ad6b9316d61c89531 Mon Sep 17 00:00:00 2001
From: EntireTwix <willkatz.dev@gmail.com>
Date: Sun, 11 Apr 2021 14:28:30 -0700
Subject: [PATCH] :racehorse: made AllUsers more effecient

---
 include/bank.hpp | 38 +++++++++++++++++++++++++++++---------
 1 file changed, 29 insertions(+), 9 deletions(-)

diff --git a/include/bank.hpp b/include/bank.hpp
index e2147a9..f56a905 100644
--- a/include/bank.hpp
+++ b/include/bank.hpp
@@ -29,14 +29,18 @@ private:
      */
     std::shared_mutex send_funds_l;
 
+    bool size_lock_flag = true;
+    Json::Value temp;
+
 public:
     std::string admin_pass;
 
     bool AddUser(const std::string &name, std::string &&init_pass)
     {
         std::unique_lock<std::shared_mutex> lock{size_lock};
+        size_lock_flag = true;
         return users.try_emplace_l(
-            name, [](User &) {}, std::move(init_pass));
+            name, [this](User &) { size_lock_flag = false; }, std::move(init_pass));
     }
     bool AdminAddUser(const std::string &attempt, std::string &&name, uint_fast32_t init_bal, std::string &&init_pass)
     {
@@ -47,18 +51,23 @@ public:
             state = users.try_emplace_l(
                 name, [](User &) {}, init_bal, std::move(init_pass));
         }
+        size_lock_flag += state;
         return state;
     }
 
     bool DelUser(const std::string &name, const std::string &attempt)
     {
         std::unique_lock<std::shared_mutex> lock{size_lock};
-        return users.erase_if(name, [&attempt](const User &u) { return (attempt == u.password); });
+        bool state = users.erase_if(name, [&attempt](const User &u) { return (attempt == u.password); });
+        size_lock_flag += state;
+        return state;
     }
     bool AdminDelUser(const std::string &name, const std::string &attempt)
     {
         std::unique_lock<std::shared_mutex> lock{size_lock};
-        return users.erase_if(name, [this, &attempt](const User &) { return (admin_pass == attempt); });
+        bool state = users.erase_if(name, [this, &attempt](const User &) { return (admin_pass == attempt); });
+        size_lock_flag += state;
+        return state;
     }
 
     bool SendFunds(const std::string &a_name, const std::string &b_name, uint_fast32_t amount, const std::string &attempt)
@@ -144,13 +153,24 @@ public:
 
     Json::Value AllUsers()
     {
-        Json::Value temp;
-        Json::UInt i = 0;
-        std::shared_lock<std::shared_mutex> lock{size_lock}; //gives readers of users the lock
-        for (const auto &u : users)
+        bool temp_flag = false;
         {
-            //we know it contains this key but we call this func to grab mutex
-            temp[i++] = u.first;
+            std::shared_lock<std::shared_mutex> lock{size_lock};
+            temp_flag = size_lock_flag;
+        }
+
+        if (!temp_flag)
+        {
+            temp = Json::Value();
+            Json::UInt i = 0;
+            for (const auto &u : users)
+            {
+                //we know it contains this key but we call this func to grab mutex
+                temp[i++] = u.first;
+            }
+            size_lock.unlock_shared();
+            std::unique_lock<std::shared_mutex> lock{size_lock};
+            size_lock_flag = false;
         }
         return temp;
     }