SQLite performance test code

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Threading;
using SQLite;

namespace ConcurrencyTests {
  public class ConcurrentSelectTests {
    private const int ENTRY_COUNT = 50000;

    private string m_databaseFileName;

    private void SetUp(bool fillTable) {
      this.m_databaseFileName = @"d:\concurrency.db";
      if (File.Exists(this.m_databaseFileName)) {
        File.Delete(this.m_databaseFileName);
      }

      var db = DatabaseConnection.OpenFileDb(this.m_databaseFileName, DatabaseAccessMode.ReadWrite);

      db.Execute("CREATE TABLE tests (id INTEGER PRIMARY KEY AUTOINCREMENT, val2 INTEGER, val3 INTEGER, val4 INTEGER, val5 INTEGER)");

      Stmt stmt = db.Compile("INSERT INTO tests (val2, val3, val4, val5) VALUES (?, ?, ?, ?)");
      Random rnd = new Random();

      // NOTE: Strangely, if the table is empty the single
      //   connection version is slower than the multi connection version. If the table is filled,
      //   the single connection version is much faster.
      if (fillTable) {
        db.Execute("BEGIN TRANSACTION");

        for (int x = 0; x < ENTRY_COUNT; x++) {
          stmt.ClearBindings();
          stmt.MultiBind(rnd.Next(), rnd.Next(), rnd.Next(), rnd.Next());
          stmt.Execute();
        }

        db.Execute("COMMIT TRANSACTION");
      }

      db.Close();
    }

    public void TestSameConnection(DatabaseAccessMode accessMode, bool fillTable, int threadCount, int selectCount) {
      Console.WriteLine("Testing with one connections (" + accessMode + ") and " + (fillTable ? "filled" : "empty") + " table...");

      SetUp(fillTable);

      Stopwatch stopwatch = Stopwatch.StartNew();
      var db = DatabaseConnection.OpenFileDb(this.m_databaseFileName, accessMode);

      List<QueryThread> threads = new List<QueryThread>();
      for (int x = 0; x < threadCount; x++) {
        threads.Add(QueryThread.Start(db, x, selectCount));
      }

      foreach (QueryThread thread in threads) {
        thread.Join();
      }

      db.Close();

      stopwatch.Stop();

      Console.WriteLine("Elapsed: {0:0.0} s", stopwatch.Elapsed.TotalSeconds);
    }

    public void TestDifferentConnections(DatabaseAccessMode accessMode, bool fillTable, int threadCount, int selectCount) {
      Console.WriteLine("Testing with one connections (" + accessMode + ") and " + (fillTable ? "filled" : "empty") + " table...");

      SetUp(fillTable);

      Stopwatch stopwatch = Stopwatch.StartNew();
      List<QueryThread> threads = new List<QueryThread>();
      for (int x = 0; x < threadCount; x++) {
        var db = DatabaseConnection.OpenFileDb(this.m_databaseFileName, accessMode);
        threads.Add(QueryThread.Start(db, x, selectCount));
      }

      foreach (QueryThread thread in threads) {
        thread.Join();
        thread.m_stmt.DatabaseConnection.Close();
      }

      stopwatch.Stop();

      Console.WriteLine("Elapsed: {0:0.0} s", stopwatch.Elapsed.TotalSeconds);
    }

    private class QueryThread {
      private const string SELECT_SQL = "SELECT * FROM tests WHERE id = ?";

      public readonly Stmt m_stmt;

      private readonly Thread m_thread;
      private readonly int m_selectCount;

      private QueryThread(DatabaseConnection db, int num, int selectCount) {
        this.m_stmt = db.Compile(SELECT_SQL);
        this.m_thread = new Thread(this.Run);
        this.m_thread.Name = "Query Thread " + num;
        this.m_selectCount = selectCount;
      }

      public static QueryThread Start(DatabaseConnection db, int num, int selectCount) {
        QueryThread queryThread = new QueryThread(db, num, selectCount);
        queryThread.m_thread.Start();

        return queryThread;
      }

      public void Join() {
        this.m_thread.Join();
      }

      private void Run() {
        Random rnd = new Random();

        int dummy = 0;

        for (int x = 0; x < this.m_selectCount; x++) {
          int id = rnd.Next(ENTRY_COUNT);

          this.m_stmt.ClearBindings();
          this.m_stmt.Bind(1, id);

          foreach (ResultRow resultRow in this.m_stmt.Query()) {
            for (int col = 0; col < resultRow.ColumnCount; col++) {
              dummy += resultRow.GetColumnAsInt(col);
            }
          }
        }
      }
    }
  }
}