Fixed BigInteger Random Number Generator<\/p>\n\n\n\n
using System;\nusing System.Security.Cryptography;\npublic class FixedBigIntegerRandomNumberGenerator : RandomNumberGenerator\n{\n private readonly int _bitWidthHold;\n private readonly byte[] _buffer;\n private readonly JitterCacheRng _crng;\n private readonly BigDecimal _dBi;\n private readonly FixedBigInteger _maxValueHold = new FixedBigInteger(0, 0);\n public FixedBigIntegerRandomNumberGenerator(int bitWidth)\n {\n if (bitWidth < 32)\n bitWidth = 32;\n var maxValue = GetMaxValue(bitWidth);\n var vdp = maxValue.GetDecimalPlaces();\n if (vdp > BigDecimal.MaxPrecision)\n BigDecimal.MaxPrecision = vdp;\n _bitWidthHold = bitWidth;\n if (_bitWidthHold < 32)\n _bitWidthHold = 32;\n _maxValueHold = maxValue;\n _dBi = BigDecimal.One \/ (BigDecimal) maxValue;\n _buffer = new byte[_bitWidthHold >> 3];\n _crng = new JitterCacheRng(1000000);\n }\n public FixedBigIntegerRandomNumberGenerator(int bitWidth, int cacheSize)\n {\n if (bitWidth < 32)\n bitWidth = 32;\n var maxValue = GetMaxValue(bitWidth);\n var vdp = maxValue.GetDecimalPlaces();\n if (vdp > BigDecimal.MaxPrecision)\n BigDecimal.MaxPrecision = vdp;\n _bitWidthHold = bitWidth;\n if (_bitWidthHold < 32)\n _bitWidthHold = 32;\n _maxValueHold = maxValue;\n _dBi = BigDecimal.One \/ (BigDecimal) maxValue;\n _buffer = new byte[_bitWidthHold >> 3];\n _crng = new JitterCacheRng(cacheSize);\n }\n public bool OddsOnly\n {\n get;\n set;\n }\n public bool Unsigned\n {\n get;\n set;\n }\n protected override void Dispose(bool disposing)\n {\n _crng.Dispose();\n }\n private FixedBigInteger GetMaxValue(int bitWidth)\n {\n var r = new FixedBigInteger(0, bitWidth);\n for (var i = 0; i < r.Data.Length; ++i)\n r.Data[i] = uint.MaxValue;\n r.Data[r.Data.Length - 1] = int.MaxValue;\n return r;\n }\n private FixedBigInteger GetMaxValue()\n {\n var r = new FixedBigInteger(0, _bitWidthHold);\n for (var i = 0; i < r.Data.Length; ++i)\n r.Data[i] = uint.MaxValue;\n r.Data[r.Data.Length - 1] = int.MaxValue;\n return r;\n }\n private BigDecimal Sample()\n {\n FixedBigInteger Internal()\n {\n _crng.GetBytes(_buffer);\n var n = new FixedBigInteger(_buffer, _bitWidthHold);\n return !OddsOnly ? n : n | 1;\n }\n var s = (BigDecimal) Internal() * _dBi;\n if (s.Sign == -1)\n s = s * -1;\n if (s.IsZero)\n throw new Exception(\"Sample is zero. SEE: MaxPrecision in BigDecimal.cs. Default value is 308.\");\n return s;\n }\n public FixedBigInteger Next(FixedBigInteger minValue, FixedBigInteger maxValue)\n {\n var sa = Sample();\n var fi = (BigDecimal) (maxValue - minValue + minValue);\n var n = new FixedBigInteger(sa * fi, 0);\n n = !OddsOnly ? n : n | 1;\n if (Unsigned)\n return n.Sign < 0 ? new FixedBigInteger(1, n.Data, 0) : n;\n var buffer = new byte[1];\n _crng.GetBytes(buffer);\n if (buffer[0] > 127)\n return n.Sign < 0 ? n : new FixedBigInteger(-1, n.Data, 0);\n return n.Sign < 0 ? new FixedBigInteger(1, n.Data, 0) : n;\n }\n public FixedBigInteger Next(FixedBigInteger maxValue)\n {\n return Next(0, maxValue);\n }\n public FixedBigInteger Next()\n {\n return Next(0, _maxValueHold);\n }\n public override void GetBytes(byte[] data)\n {\n if (data == null)\n throw new ArgumentException(\"The buffer cannot be null.\");\n _crng.GetBytes(data);\n }\n public void NextBytes(byte[] buffer)\n {\n if (buffer == null)\n throw new ArgumentNullException(\"The buffer cannot be null.\");\n for (var index = 0; index < buffer.Length; ++index)\n buffer[index] = (byte) (Sample() * byte.MaxValue);\n }\n public FixedBigInteger[] Next(FixedBigInteger minValue, FixedBigInteger maxValue, int arraySize)\n {\n var array = new FixedBigInteger[arraySize];\n for (var i = 0; i < arraySize; ++i)\n array[i] = Next(minValue, maxValue);\n return array;\n }\n public char[] GetNextCharArray(int size)\n {\n var ca = new char[size];\n var ptr = 0;\n do\n {\n ca[ptr++] = (char) Next(32, 128);\n } while (ptr < size);\n return ca;\n }\n public byte[] GetNextByteArray(int size)\n {\n var ba = new byte[size];\n _crng.GetBytes(ba);\n return ba;\n }\n public string GetRandomString(int minLen, int maxLen)\n {\n if (minLen == maxLen)\n return new string(GetNextCharArray(minLen));\n return new string(GetNextCharArray((int) Next((uint) minLen, (uint) maxLen)));\n }\n}<\/pre>\n","protected":false},"excerpt":{"rendered":"Fixed BigInteger Random Number Generator<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[2],"tags":[],"_links":{"self":[{"href":"https:\/\/michaeljohnsteiner.com\/index.php\/wp-json\/wp\/v2\/posts\/42"}],"collection":[{"href":"https:\/\/michaeljohnsteiner.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/michaeljohnsteiner.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/michaeljohnsteiner.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/michaeljohnsteiner.com\/index.php\/wp-json\/wp\/v2\/comments?post=42"}],"version-history":[{"count":1,"href":"https:\/\/michaeljohnsteiner.com\/index.php\/wp-json\/wp\/v2\/posts\/42\/revisions"}],"predecessor-version":[{"id":43,"href":"https:\/\/michaeljohnsteiner.com\/index.php\/wp-json\/wp\/v2\/posts\/42\/revisions\/43"}],"wp:attachment":[{"href":"https:\/\/michaeljohnsteiner.com\/index.php\/wp-json\/wp\/v2\/media?parent=42"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/michaeljohnsteiner.com\/index.php\/wp-json\/wp\/v2\/categories?post=42"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/michaeljohnsteiner.com\/index.php\/wp-json\/wp\/v2\/tags?post=42"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}