fix(Core/DatabseWorkerPool): implement DatabaseIncompatibleVersion to…

… better support MariaDB (azerothcore#18201)

* fix(Core): Rework Database Version Check for MariaDB support

* incorporate "smarter" version comparison

* rename function to be more accurate

* Factor magic numbers into defines. Revise comments

* clean up triple newline

* Doxygenify the docs

* remove blankspace

---------

Co-authored-by: Kitzunu <[email protected]>

src/server/database/Database/DatabaseWorkerPool.cpp

@@ -33,20 +33,14 @@
 #include "WorldDatabase.h"
 #include <limits>
 #include <mysqld_error.h>
+#include <sstream>
+#include <vector>
 
 #ifdef ACORE_DEBUG
 #include <boost/stacktrace.hpp>
 #include <sstream>
 #endif
 
-#if MARIADB_VERSION_ID >= 100600
-#define MIN_MYSQL_SERVER_VERSION 100500u
-#define MIN_MYSQL_CLIENT_VERSION 30203u
-#else
-#define MIN_MYSQL_SERVER_VERSION 50700u
-#define MIN_MYSQL_CLIENT_VERSION 50700u
-#endif
-
 class PingOperation : public SQLOperation
 {
     //! Operation for idle delaythreads
@@ -377,6 +371,63 @@ void DatabaseWorkerPool<T>::KeepAlive()
         Enqueue(new PingOperation);
 }
 
+/**
+* @brief Returns true if the version string given is incompatible
+*
+* Intended to be used with mysql_get_server_info()'s output as the source
+*
+* DatabaseIncompatibleVersion("8.0.35") => false
+* DatabaseIncompatibleVersion("5.6.6") => true
+* DatabaseIncompatibleVersion("5.5.5-10.5.5-MariaDB") => false
+* DatabaseIncompatibleVersion("5.5.5-10.4.0-MariaDB") => true
+*
+* Adapted from stackoverflow response
+* https://stackoverflow.com/a/2941508
+*
+* @param mysqlVersion The output from GetServerInfo()/mysql_get_server_info()
+* @return Returns true if the Server version is incompatible
+*/
+bool DatabaseIncompatibleVersion(std::string const mysqlVersion)
+{
+    // anon func to turn a version string into an array of uint8
+    // "1.2.3" => [1, 2, 3]
+    auto parse = [](std::string const& input)
+    {
+        std::vector<uint8> result;
+        std::istringstream parser(input);
+        result.push_back(parser.get());
+        for (int i = 1; i < 3; i++)
+        {
+            // Skip period
+            parser.get();
+            // Append int from parser to output
+            result.push_back(parser.get());
+        }
+        return result;
+    };
+
+    // default to values for MySQL
+    uint8 offset = 0;
+    std::string minVersion = MIN_MYSQL_SERVER_VERSION;
+
+    // If the version string contains "MariaDB", use that
+    if (mysqlVersion.find("MariaDB") != std::string::npos)
+    {
+        // All MariaDB 10.X versions have a prefix of 5.5.5 from the
+        // mysql_get_server_info() function. To make matters more
+        // annoying, this is removed in MariaDB 11.X
+        if (mysqlVersion.rfind("5.5.5-", 0) == 0)
+            offset = 6;
+        minVersion = MIN_MARIADB_SERVER_VERSION;
+    }
+
+    auto parsedMySQLVersion = parse(mysqlVersion.substr(offset));
+    auto parsedMinVersion = parse(minVersion);
+
+    return std::lexicographical_compare(parsedMySQLVersion.begin(), parsedMySQLVersion.end(),
+                                        parsedMinVersion.begin(), parsedMinVersion.end());
+}
+
 template <class T>
 uint32 DatabaseWorkerPool<T>::OpenConnections(InternalIndex type, uint8 numConnections)
 {
@@ -402,10 +453,10 @@ uint32 DatabaseWorkerPool<T>::OpenConnections(InternalIndex type, uint8 numConne
             _connections[type].clear();
             return error;
         }
-        else if (connection->GetServerVersion() < MIN_MYSQL_SERVER_VERSION)
+        else if (DatabaseIncompatibleVersion(connection->GetServerInfo()))
         {
             LOG_ERROR("sql.driver", "AzerothCore does not support MySQL versions below 5.7 or MariaDB versions below 10.5.\n\nFound server version: {}. Server compiled with: {}.",
-                connection->GetServerVersion(), MYSQL_VERSION_ID);
+                connection->GetServerInfo(), MYSQL_VERSION_ID);
             return 1;
         }
         else

src/server/database/Database/DatabaseWorkerPool.h

@@ -24,6 +24,34 @@
 #include <array>
 #include <vector>
 
+/** @file DatabaseWorkerPool.h */
+
+/**
+* @def MIN_MYSQL_CLIENT_VERSION
+* The minimum MariaDB Client Version
+* MARIADB_VERSION_ID is defined if using libmariadbclient instead of libmysqlclient
+*/
+#if MARIADB_VERSION_ID >= 100600
+#define MIN_MYSQL_CLIENT_VERSION 30203u
+#else
+/**
+* @def MIN_MYSQL_CLIENT_VERSION
+* The minimum MySQL Client Version
+*/
+#define MIN_MYSQL_CLIENT_VERSION 50700u
+#endif
+
+/**
+* @def MIN_MYSQL_SERVER_VERSION
+* The minimum MySQL Server Version
+*/
+#define MIN_MYSQL_SERVER_VERSION "5.7.0"
+/**
+* @def MIN_MARIADB_SERVER_VERSION
+* The minimum MariaDB Server Version
+*/
+#define MIN_MARIADB_SERVER_VERSION "10.5.0"
+
 template <typename T>
 class ProducerConsumerQueue;
 

src/server/database/Database/MySQLConnection.cpp

@@ -27,8 +27,8 @@
 #include "Timer.h"
 #include "Tokenize.h"
 #include "Transaction.h"
-#include "Util.h"
 #include <errmsg.h>
+#include <mysql.h>
 #include <mysqld_error.h>
 
 MySQLConnectionInfo::MySQLConnectionInfo(std::string_view infoString)
@@ -486,6 +486,11 @@ uint32 MySQLConnection::GetServerVersion() const
     return mysql_get_server_version(m_Mysql);
 }
 
+std::string MySQLConnection::GetServerInfo() const
+{
+    return mysql_get_server_info(m_Mysql);
+}
+
 MySQLPreparedStatement* MySQLConnection::GetPreparedStatement(uint32 index)
 {
     ASSERT(index < m_stmts.size(), "Tried to access invalid prepared statement index {} (max index {}) on database `{}`, connection type: {}",

src/server/database/Database/MySQLConnection.h

@@ -94,6 +94,7 @@ friend class PingOperation;
     void Unlock();
 
     [[nodiscard]] uint32 GetServerVersion() const;
+    [[nodiscard]] std::string GetServerInfo() const;
     MySQLPreparedStatement* GetPreparedStatement(uint32 index);
     void PrepareStatement(uint32 index, std::string_view sql, ConnectionFlags flags);