Combine SqlQuery into IDatabaseBackend

ClassiCube · May 25, 2022 · 9a86929 · 9a86929
1 parent 7952de4
commit 9a86929
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Showing 6 changed files with 92 additions and 108 deletions.
diff --git a/MCGalaxy/Database/ColumnDesc.cs b/MCGalaxy/Database/ColumnDesc.cs
@@ -17,10 +17,11 @@
  */
 using System;
 
-namespace MCGalaxy.SQL {
-
+namespace MCGalaxy.SQL 
+{
     /// <summary> Describes a column for an SQL create statement. </summary>
-    public struct ColumnDesc {
+    public struct ColumnDesc 
+    {
         public readonly string Column;
         public readonly ColumnType Type;
         public readonly ushort MaxLength;
@@ -57,7 +58,8 @@ public ColumnDesc(string col, ColumnType type, ushort maxLen)
         };
     }
 
-    public enum ColumnType {
+    public enum ColumnType 
+    {
         UInt8, UInt16, UInt24, UInt32, UInt64,
         Int8, Int16, Int24, Int32, Int64,
         Integer, DateTime, Char, VarChar

diff --git a/MCGalaxy/Database/Database.cs b/MCGalaxy/Database/Database.cs
@@ -20,12 +20,14 @@
 using System.Data;
 using System.IO;
 
-namespace MCGalaxy.SQL {
+namespace MCGalaxy.SQL 
+{
     /// <summary> Callback function invoked on a row returned from an SQL query. </summary>
     public delegate object ReaderCallback(IDataRecord record, object arg);
 
     /// <summary> Abstracts a SQL database management engine. </summary>
-    public static class Database {
+    public static class Database 
+    {
         public static IDatabaseBackend Backend;
         public const string DateFormat = "yyyy-MM-dd HH:mm:ss";        
 
@@ -175,13 +177,15 @@ public static class Database {
 
         internal static object Do(string sql, bool createDB, object arg,
                                   ReaderCallback callback, params object[] args) {
+            IDatabaseBackend db = Backend;
             Exception e = null;
+
             for (int i = 0; i < 10; i++) {
                 try {
                     if (callback != null) {
-                        arg = SqlQuery.Iterate(sql, args, arg, callback);
+                        arg = db.Iterate(sql, args, arg, callback);
                     } else {
-                        SqlQuery.Execute(sql, args, createDB);
+                        db.Execute(sql, args, createDB);
                     }
 
                     return arg;
@@ -195,6 +199,7 @@ public static class Database {
         }
         #endregion
 
+
         internal static bool ValidNameChar(char c) {
             return 
                 c > ' '   && c != '"' && c != '%' && c != '&'  &&

diff --git a/MCGalaxy/Database/IDatabaseBackend.cs b/MCGalaxy/Database/IDatabaseBackend.cs
@@ -21,11 +21,11 @@
 using System.IO;
 using System.Text;
 
-namespace MCGalaxy.SQL {
-
-    /// <summary> Simple abstraction for a database management system. </summary>
-    public abstract class IDatabaseBackend {
-
+namespace MCGalaxy.SQL 
+{    
+    /// <summary> Abstracts a SQL based database management system </summary>
+    public abstract class IDatabaseBackend 
+    {        
         /// <summary> Whether this backend enforces the character length in VARCHAR columns. </summary>
         public abstract bool EnforcesTextLength { get; }        
         /// <summary> Whether this backend supports multiple database schemas. </summary>
@@ -135,14 +135,79 @@ public abstract class IDatabaseBackend {
             sql.Append(" `").Append(table).Append("` ");
             sql.Append('(').Append(columns).Append(')');
 
-            string[] names = SqlQuery.GetNames(args.Length);
+            string[] names = GetNames(args.Length);
             sql.Append(" VALUES (");
-            for (int i = 0; i < args.Length; i++) {
+            for (int i = 0; i < args.Length; i++) 
+            {
                 sql.Append(names[i]);
                 if (i < args.Length - 1) sql.Append(", ");
                 else sql.Append(")");
             }
             return sql.ToString();
         }
+
+
+        #region Raw SQL functions
+
+        /// <summary> Executes an SQL command that does not return any results. </summary>
+        public void Execute(string sql, object[] parameters, bool createDB) {
+            using (IDbConnection conn = CreateConnection()) {
+                conn.Open();
+                if (!createDB && MultipleSchema)
+                    conn.ChangeDatabase(Server.Config.MySQLDatabaseName);
+
+                using (IDbCommand cmd = CreateCommand(sql, conn)) {
+                    FillParams(cmd, parameters);
+                    cmd.ExecuteNonQuery();
+                }
+                conn.Close();
+            }
+        }
+
+        /// <summary> Excecutes an SQL query, invoking a callback on the returned rows one by one. </summary>        
+        public object Iterate(string sql, object[] parameters, object arg, ReaderCallback callback) {
+            using (IDbConnection conn = CreateConnection()) {
+                conn.Open();
+                if (MultipleSchema)
+                    conn.ChangeDatabase(Server.Config.MySQLDatabaseName);
+
+                using (IDbCommand cmd = CreateCommand(sql, conn)) {
+                    FillParams(cmd, parameters);
+                    using (IDataReader reader = cmd.ExecuteReader()) {
+                        while (reader.Read()) { arg = callback(reader, arg); }
+                    }
+                }
+                conn.Close();
+            }
+            return arg;
+        }
+
+
+        /// <summary> Adds IDbDataParameter for each argument to the given command. </summary>
+        public void FillParams(IDbCommand cmd, object[] parameters) {
+            if (parameters == null || parameters.Length == 0) return;
+
+            string[] names = GetNames(parameters.Length);
+            for (int i = 0; i < parameters.Length; i++) 
+            {
+                IDbDataParameter arg = CreateParameter();
+                arg.ParameterName = names[i];
+                arg.Value         = parameters[i];
+                cmd.Parameters.Add(arg);
+            }
+        }
+
+        volatile static string[] ids;
+        internal static string[] GetNames(int count) {
+            // Avoid allocation overhead from string concat every query by caching
+            string[] names = ids;
+            if (names == null || count > names.Length) {
+                names = new string[count];
+                for (int i = 0; i < names.Length; i++) { names[i] = "@" + i; }
+                ids = names;
+            }
+            return names;
+        }
+        #endregion
     }
 }
diff --git a/MCGalaxy/Database/SqlQuery.cs b/MCGalaxy/Database/SqlQuery.cs
diff --git a/MCGalaxy/Database/SqlTransaction.cs b/MCGalaxy/Database/SqlTransaction.cs
@@ -18,9 +18,10 @@
 using System;
 using System.Data;
 
-namespace MCGalaxy.SQL {
-
-    public sealed class SqlTransaction : IDisposable {
+namespace MCGalaxy.SQL 
+{    
+    public sealed class SqlTransaction : IDisposable 
+    {
         internal IDbConnection conn;
         internal IDbTransaction transaction;
 
@@ -66,7 +67,7 @@ public sealed class SqlTransaction : IDisposable {
             try {
                 using (IDbCommand cmd = db.CreateCommand(sql, conn)) {
                     cmd.Transaction = transaction;
-                    SqlQuery.FillParams(cmd, args);
+                    db.FillParams(cmd, args);
                     cmd.ExecuteNonQuery();
                     return true;
                 }

diff --git a/MCGalaxy/MCGalaxy_.csproj b/MCGalaxy/MCGalaxy_.csproj
@@ -396,7 +396,6 @@
     <Compile Include="Database\ColumnDesc.cs" />
     <Compile Include="Database\IDatabaseBackend.cs" />
     <Compile Include="Database\Backends\MySQL.cs" />
-    <Compile Include="Database\SqlQuery.cs" />
     <Compile Include="Database\PlayerData.cs" />
     <Compile Include="Database\Stats\OfflineStat.cs" />
     <Compile Include="Database\Stats\OnlineStat.cs" />