Пример #1
0
 /// <summary>Detects whether or not the specified Node is the leaf or not</summary>
 /// <param name="node">The Node to be checked</param>
 /// <returns> True if Leaf, False if not</returns>
 public bool IsLeaf(HuffmanNode node)
 {
     return(node.Left == null && node.Right == null);
 }
Пример #2
0
        /// <summary>Compressses the file into a Byte array</summary>
        /// <param name="id"></param>
        /// <returns> The byte array of the file</returns>
        public byte[] compress(string iContent)
        {
            content     = iContent;
            frequencies = new Dictionary <char, HuffmanNode>();

            foreach (char c in content)
            {
                if (frequencies.ContainsKey(c))
                {
                    frequencies[c].Frequency = frequencies[c].Frequency + 1;
                }
                else
                {
                    frequencies.Add(c, new HuffmanNode()
                    {
                        Frequency = 1, Symbol = c
                    });
                }
            }

            HuffTree = TreeConstruction(frequencies);
            HuffBase = HuffTree.First().Value;

            List <string> result = new List <string>();

            int[] disctFrequencies = frequencies.Select(f => f.Value.Frequency).Distinct().ToArray();

            if (frequencies.ContainsKey('\n'))
            {
                int newLineFreq = frequencies.Where(i => i.Key == '\n').Select(fr => fr.Value.Frequency).ToList()[0];
                result.Add(newLineFreq + "lb");
            }

            if (frequencies.ContainsKey(':'))
            {
                int newLineFreq = frequencies.Where(i => i.Key == ':').Select(fr => fr.Value.Frequency).ToList()[0];
                result.Add(":" + newLineFreq + "DD");
            }


            foreach (int freq in disctFrequencies)
            {
                List <char> sameFreq = frequencies.Where(i => i.Value.Frequency == freq && i.Key != '\n' && i.Key != ':').Select(fr => fr.Key).ToList();
                result.Add(":" + freq + string.Join("", sameFreq));
            }

            // Adds the Delimiter
            result.Add("###");

            string[]    arrayResult = result.ToArray();
            List <byte> bytesTest   = new List <byte>();

            //for (int i = 0; i < arrayResult.Length; i++)
            //{
            //    Console.WriteLine(arrayResult[i]);
            //    char[] charArray = arrayResult[i].ToCharArray();

            //        List<byte> characters = charArray.Select(s => (byte)s).ToList();
            //        bytesTest.AddRange(characters);

            //}

            bytesTest.AddRange(String.Join("", arrayResult).ToCharArray().Select(s => (byte)s).ToList());

            byte[] resultTest = bytesTest.ToArray();


            var    str  = System.Text.Encoding.Default.GetString(resultTest);
            string res  = Encoding.UTF8.GetString(resultTest, 0, resultTest.Length);
            string res2 = Encoding.ASCII.GetString(resultTest, 0, resultTest.Length);
            string res3 = Encoding.Unicode.GetString(resultTest, 0, resultTest.Length);



            //  Console.WriteLine(str);
            Console.WriteLine(res);

            List <bool> encodedSource = new List <bool>();

            for (int i = 0; i < content.Length; i++)
            {
                List <bool> encodedSymbol = HuffBase.Find(content[i], new List <bool>());
                encodedSource.AddRange(encodedSymbol);
            }

            BitArray bits = new BitArray(encodedSource.ToArray());

            var oneBit = bits[2];

            byte[] bytes = new byte[bits.Length / 8 + (bits.Length % 8 == 0 ? 0 : 1)];
            bits.CopyTo(bytes, 0);

            var comindedBytes = new List <byte>();

            comindedBytes.AddRange(resultTest);
            comindedBytes.AddRange(bytes);

            string res4 = Encoding.UTF8.GetString(bytes, 0, bytes.Length);
            string res5 = Encoding.ASCII.GetString(bytes, 0, bytes.Length);
            string res6 = Encoding.Unicode.GetString(bytes, 0, bytes.Length);
            string res7 = Encoding.Default.GetString(bytes, 0, bytes.Length);
            string res8 = Encoding.BigEndianUnicode.GetString(bytes, 0, bytes.Length);
            string res9 = Encoding.Unicode.GetString(bytes, 0, bytes.Length);

            return(comindedBytes.ToArray());
        }
Пример #3
0
        /// <summary>Decompresses the file contents provided.</summary>
        /// <param name="fileContent">Byte array of the file to be decompressed</param>
        /// <returns> String of the content of the file</returns>
        public string decompress(byte[] fileContent)
        {
            var str = System.Text.Encoding.Default.GetString(fileContent);

            string[] fileParts = str.Split(new string[] { "###" }, StringSplitOptions.None);



            string[] items = fileParts[0].Split(":");


            frequencies = new Dictionary <char, HuffmanNode>();

            foreach (string item in items)
            {
                string digits        = new String(item.TakeWhile(Char.IsDigit).ToArray());
                string indiviualItem = item.Replace(digits, "");



                if (indiviualItem == "lb")
                {
                    frequencies.Add('\n', new HuffmanNode()
                    {
                        Frequency = Convert.ToInt32(digits), Symbol = '\n'
                    });
                }
                if (indiviualItem == "DD")
                {
                    frequencies.Add(':', new HuffmanNode()
                    {
                        Frequency = Convert.ToInt32(digits), Symbol = ':'
                    });
                }

                if (indiviualItem != "DD" && indiviualItem != "lb")
                {
                    char[] invidualItems = indiviualItem.ToArray();

                    foreach (char symbol in indiviualItem)
                    {
                        frequencies.Add(symbol, new HuffmanNode()
                        {
                            Frequency = Convert.ToInt32(digits), Symbol = symbol
                        });
                    }
                }
            }


            HuffTree = TreeConstruction(frequencies);
            HuffBase = HuffTree.First().Value;


            BitArray bits = new BitArray(fileContent);

            HuffmanNode current = this.HuffBase;
            string      decoded = "";

            foreach (bool bit in bits)
            {
                if (bit)
                {
                    if (current.Right != null)
                    {
                        current = current.Right;
                    }
                }
                else
                {
                    if (current.Left != null)
                    {
                        current = current.Left;
                    }
                }

                if (IsLeaf(current))
                {
                    decoded += current.Symbol;
                    current  = this.HuffBase;
                }
            }

            return(decoded);
        }