Click here to Skip to main content
15,860,972 members
Articles / Database Development / NoSQL

RaptorDB - the Key Value Store

Rate me:
Please Sign up or sign in to vote.
4.89/5 (118 votes)
22 Jan 2012CPOL22 min read 904.9K   9.9K   266  
Smallest, fastest embedded nosql persisted dictionary using b+tree or MurMur hash indexing. (Now with Hybrid WAH bitmap indexes)
using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using System.Text;

namespace RaptorDB
{
    public class SafeDictionary<TKey, TValue>
    {
        private readonly object _Padlock = new object();
        private readonly Dictionary<TKey, TValue> _Dictionary = new Dictionary<TKey, TValue>();

        public SafeDictionary(int capacity)
        {
            _Dictionary = new Dictionary<TKey, TValue>(capacity);
        }

        public SafeDictionary(int capacity, IEqualityComparer<TKey> comp)
        {
            _Dictionary = new Dictionary<TKey, TValue>(capacity, comp);
        }

        public SafeDictionary()
        {
            _Dictionary = new Dictionary<TKey, TValue>();
        }

        public bool TryGetValue(TKey key, out TValue value)
        {
            return _Dictionary.TryGetValue(key, out value);
        }

        public TValue this[TKey key]
        {
            get
            {
                return _Dictionary[key];
            }
            set
            {
                _Dictionary[key] = value;
            }
        }

        public ICollection<KeyValuePair<TKey, TValue>> GetList()
        {
            return (ICollection<KeyValuePair<TKey, TValue>>)_Dictionary;
        }

        public IEnumerator<KeyValuePair<TKey, TValue>> GetEnumerator()
        {
            return ((ICollection<KeyValuePair<TKey, TValue>>)_Dictionary).GetEnumerator();
        }

        public void Add(TKey key, TValue value)
        {
            lock (_Padlock)
            {
                if (_Dictionary.ContainsKey(key) == false)
                    _Dictionary.Add(key, value);
                else
                    _Dictionary[key] = value;
            }
        }

        public void Remove(TKey key)
        {
            lock (_Padlock)
            {
                _Dictionary.Remove(key);
            }
        }
    }

    //------------------------------------------------------------------------------------------------------------------

    internal static class FastDateTime
    {
        public static TimeSpan LocalUtcOffset;

        public static DateTime Now
        {
            get { return DateTime.UtcNow + LocalUtcOffset; }
        }

        static FastDateTime()
        {
            LocalUtcOffset = TimeZone.CurrentTimeZone.GetUtcOffset(DateTime.Now);
        }
    }

    //------------------------------------------------------------------------------------------------------------------

    public static class Helper
    {
        public static MurmurHash2Unsafe MurMur = new MurmurHash2Unsafe();

        //[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
        //private class MEMORYSTATUSEX
        //{
        //    public uint dwLength;
        //    public uint dwMemoryLoad;
        //    public ulong ullTotalPhys;
        //    public ulong ullAvailPhys;
        //    public ulong ullTotalPageFile;
        //    public ulong ullAvailPageFile;
        //    public ulong ullTotalVirtual;
        //    public ulong ullAvailVirtual;
        //    public ulong ullAvailExtendedVirtual;
        //    public MEMORYSTATUSEX()
        //    {
        //        this.dwLength = (uint)Marshal.SizeOf(typeof(MEMORYSTATUSEX));
        //    }
        //}

        //[return: MarshalAs(UnmanagedType.Bool)]
        //[DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
        //private static extern bool GlobalMemoryStatusEx([In, Out] MEMORYSTATUSEX lpBuffer);

        //internal static int GetFreeMemory()
        //{
        //    ulong installedMemory = 0;
        //    MEMORYSTATUSEX memStatus = new MEMORYSTATUSEX();
        //    if (GlobalMemoryStatusEx(memStatus))
        //    {
        //        installedMemory = memStatus.ullAvailPhys >> 20;
        //    }
        //    return (int)installedMemory;
        //}

        internal static unsafe int ToInt32(byte[] value, int startIndex, bool reverse)
        {
            if (reverse)
            {
                byte[] b = new byte[4];
                Buffer.BlockCopy(value, startIndex, b, 0, 4);
                Array.Reverse(b);
                return ToInt32(b, 0);
            }

            return ToInt32(value, startIndex);
        }

        internal static unsafe int ToInt32(byte[] value, int startIndex)
        {
            fixed (byte* numRef = &(value[startIndex]))
            {
                return *((int*)numRef);
            }
        }

        internal static unsafe long ToInt64(byte[] value, int startIndex, bool reverse)
        {
            if (reverse)
            {
                byte[] b = new byte[8];
                Buffer.BlockCopy(value, startIndex, b, 0, 8);
                Array.Reverse(b);
                return ToInt64(b, 0);
            }
            return ToInt64(value, startIndex);
        }

        internal static unsafe long ToInt64(byte[] value, int startIndex)
        {
            fixed (byte* numRef = &(value[startIndex]))
            {
                return *(((long*)numRef));
            }
        }

        internal static unsafe short ToInt16(byte[] value, int startIndex, bool reverse)
        {
            if (reverse)
            {
                byte[] b = new byte[2];
                Buffer.BlockCopy(value, startIndex, b, 0, 2);
                Array.Reverse(b);
                return ToInt16(b, 0);
            }
            return ToInt16(value, startIndex);
        }

        internal static unsafe short ToInt16(byte[] value, int startIndex)
        {
            fixed (byte* numRef = &(value[startIndex]))
            {
                return *(((short*)numRef));
            }
        }

        internal static unsafe byte[] GetBytes(long num, bool reverse)
        {
            byte[] buffer = new byte[8];
            fixed (byte* numRef = buffer)
            {
                *((long*)numRef) = num;
            }
            if (reverse)
                Array.Reverse(buffer);
            return buffer;
        }

        public static unsafe byte[] GetBytes(int num, bool reverse)
        {
            byte[] buffer = new byte[4];
            fixed (byte* numRef = buffer)
            {
                *((int*)numRef) = num;
            }
            if (reverse)
                Array.Reverse(buffer);
            return buffer;
        }

        internal unsafe static int CompareUnSafe(byte[] left, byte[] right)
        {
            int c = left.Length;
            if (c > right.Length)
                c = right.Length;
            fixed (byte* p1 = left, p2 = right)
            {
                for (int i = 0; i < c; i++)
                {
                    int a = p1[i];
                    int b = p2[i];
                    if (a != b)
                    {
                        return a - b;
                    }
                }
            }
            return left.Length - right.Length;
        }

        public static int CompareSafe(byte[] left, byte[] right)
        {
            int c = left.Length;
            if (c > right.Length)
                c = right.Length;
            for (int i = 0; i < c; i++)
            {
                int a = left[i];
                int b = right[i];
                if (a != b)
                {
                    return a - b;
                }
            }
            return left.Length - right.Length;
        }

        public static int CompareMemCmp(byte[] left, byte[] right)
        {
            int c = left.Length;
            if (c > right.Length)
                c = right.Length;
            return memcmp(left, right, c);
        }

        [DllImport("msvcrt.dll", CallingConvention = CallingConvention.Cdecl)]
        private static extern int memcmp(byte[] arr1, byte[] arr2, int cnt);

        internal static byte[] GetBytes(string s)
        {
            return Encoding.UTF8.GetBytes(s);

            //byte[] b = new byte[s.Length];
            //char[] cc = s.ToCharArray();
            //int l = cc.Length;
            //for (int i = 0; i < l; i++)//foreach (char c in s)
            //    b[i] = (byte)cc[i];// c;
            //return b;
        }

        internal static string GetString(byte[] bytes)
        {
            return Encoding.UTF8.GetString(bytes);
            //char[] cc = new char[bytes.Length];
            //int i=0;
            //foreach (byte b in bytes)
            //    cc[i++] = (char)b;

            //return new string(cc);
        }

        internal static string GetString(byte[] buffer, int index, short keylength)
        {
            return Encoding.UTF8.GetString(buffer, index, keylength);
            //char[] cc = new char[keylength];

            //for (int i = 0; i < keylength; i++)
            //    cc[i] = (char)buffer[index + i];

            //return new string(cc);
        }
    }
}

By viewing downloads associated with this article you agree to the Terms of Service and the article's licence.

If a file you wish to view isn't highlighted, and is a text file (not binary), please let us know and we'll add colourisation support for it.

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


Written By
Architect -
United Kingdom United Kingdom
Mehdi first started programming when he was 8 on BBC+128k machine in 6512 processor language, after various hardware and software changes he eventually came across .net and c# which he has been using since v1.0.
He is formally educated as a system analyst Industrial engineer, but his programming passion continues.

* Mehdi is the 5th person to get 6 out of 7 Platinum's on Code-Project (13th Jan'12)
* Mehdi is the 3rd person to get 7 out of 7 Platinum's on Code-Project (26th Aug'16)

Comments and Discussions