namespace WhiteRabbit { // Anagram representation optimized for MD5 internal unsafe struct PhraseSet { public fixed uint Buffer[8 * Constants.PhrasesPerSet]; public PhraseSet(byte[][] words, int[][] permutations, int offset, int numberOfCharacters) { fixed (uint* bufferPointer = this.Buffer) { var length = numberOfCharacters + words.Length - 1; for (var i = 0; i < Constants.PhrasesPerSet; i++) { var permutation = permutations[offset + i]; var startPointer = bufferPointer + i * 8; byte[] currentWord; var j = 0; var wordIndex = 0; var currentPointer = (byte*)startPointer; byte* lastPointer = currentPointer + length; for (; currentPointer < lastPointer; currentPointer++) { currentWord = words[permutation[wordIndex]]; *currentPointer = currentWord[j]; j++; // 0xffffffff if greater than or equal, 0 if less than var comparisonResult = unchecked((int)((((uint)j - (uint)currentWord.Length) >> 31) - 1)); j = (comparisonResult & 0) | (~comparisonResult & j); wordIndex = (comparisonResult & (wordIndex + 1)) | (~comparisonResult & wordIndex); } *currentPointer = 128; startPointer[7] = (uint)(length << 3); } } } public byte[] GetBytes(int number) { System.Diagnostics.Debug.Assert(number < Constants.PhrasesPerSet); fixed(uint* bufferPointer = this.Buffer) { var phrasePointer = bufferPointer + 8 * number; var length = phrasePointer[7] >> 3; var result = new byte[length]; for (var i = 0; i < length; i++) { result[i] = ((byte*)phrasePointer)[i]; } return result; } } } }