BuildLitLenTree() public méthode

public BuildLitLenTree ( ) : InflaterHuffmanTree
Résultat InflaterHuffmanTree
Exemple #1
0
        /// <summary>
        /// Decodes the deflated stream.
        /// </summary>
        /// <returns>
        /// false if more input is needed, or if finished.
        /// </returns>
        /// <exception cref="SharpZipBaseException">
        /// if deflated stream is invalid.
        /// </exception>
        private bool Decode()
        {
            switch (mode)
            {
            case DECODE_HEADER:
                return(DecodeHeader());

            case DECODE_DICT:
                return(DecodeDict());

            case DECODE_CHKSUM:
                return(DecodeChksum());

            case DECODE_BLOCKS:
                if (isLastBlock)
                {
                    if (noHeader)
                    {
                        mode = FINISHED;
                        return(false);
                    }
                    else
                    {
                        input.SkipToByteBoundary();
                        neededBits = 32;
                        mode       = DECODE_CHKSUM;
                        return(true);
                    }
                }

                int type = input.PeekBits(3);
                if (type < 0)
                {
                    return(false);
                }
                input.DropBits(3);

                if ((type & 1) != 0)
                {
                    isLastBlock = true;
                }
                switch (type >> 1)
                {
                case DeflaterConstants.STORED_BLOCK:
                    input.SkipToByteBoundary();
                    mode = DECODE_STORED_LEN1;
                    break;

                case DeflaterConstants.STATIC_TREES:
                    litlenTree = InflaterHuffmanTree.defLitLenTree;
                    distTree   = InflaterHuffmanTree.defDistTree;
                    mode       = DECODE_HUFFMAN;
                    break;

                case DeflaterConstants.DYN_TREES:
                    dynHeader = new InflaterDynHeader();
                    mode      = DECODE_DYN_HEADER;
                    break;

                default:
                    throw new SharpZipBaseException("Unknown block type " + type);
                }
                return(true);

            case DECODE_STORED_LEN1:
            {
                if ((uncomprLen = input.PeekBits(16)) < 0)
                {
                    return(false);
                }
                input.DropBits(16);
                mode = DECODE_STORED_LEN2;
            }
                goto case DECODE_STORED_LEN2;                         /* fall through */

            case DECODE_STORED_LEN2:
            {
                int nlen = input.PeekBits(16);
                if (nlen < 0)
                {
                    return(false);
                }
                input.DropBits(16);
                if (nlen != (uncomprLen ^ 0xffff))
                {
                    throw new SharpZipBaseException("broken uncompressed block");
                }
                mode = DECODE_STORED;
            }
                goto case DECODE_STORED;                        /* fall through */

            case DECODE_STORED:
            {
                int more = outputWindow.CopyStored(input, uncomprLen);
                uncomprLen -= more;
                if (uncomprLen == 0)
                {
                    mode = DECODE_BLOCKS;
                    return(true);
                }
                return(!input.IsNeedingInput);
            }

            case DECODE_DYN_HEADER:
                if (!dynHeader.Decode(input))
                {
                    return(false);
                }

                litlenTree = dynHeader.BuildLitLenTree();
                distTree   = dynHeader.BuildDistTree();
                mode       = DECODE_HUFFMAN;
                goto case DECODE_HUFFMAN;                         /* fall through */

            case DECODE_HUFFMAN:
            case DECODE_HUFFMAN_LENBITS:
            case DECODE_HUFFMAN_DIST:
            case DECODE_HUFFMAN_DISTBITS:
                return(DecodeHuffman());

            case FINISHED:
                return(false);

            default:
                throw new SharpZipBaseException("Inflater.Decode unknown mode");
            }
        }
Exemple #2
0
        private bool Decode()
        {
            switch (mode)
            {
            case 0:
                return(DecodeHeader());

            case 1:
                return(DecodeDict());

            case 11:
                return(DecodeChksum());

            case 2:
            {
                if (isLastBlock)
                {
                    if (noHeader)
                    {
                        mode = 12;
                        return(false);
                    }
                    input.SkipToByteBoundary();
                    neededBits = 32;
                    mode       = 11;
                    return(true);
                }
                int num = input.PeekBits(3);
                if (num < 0)
                {
                    return(false);
                }
                input.DropBits(3);
                if (((uint)num & (true ? 1u : 0u)) != 0)
                {
                    isLastBlock = true;
                }
                switch (num >> 1)
                {
                case 0:
                    input.SkipToByteBoundary();
                    mode = 3;
                    break;

                case 1:
                    litlenTree = InflaterHuffmanTree.defLitLenTree;
                    distTree   = InflaterHuffmanTree.defDistTree;
                    mode       = 7;
                    break;

                case 2:
                    dynHeader = new InflaterDynHeader();
                    mode      = 6;
                    break;

                default:
                    throw new SharpZipBaseException(string.Concat((object)"Unknown block type ", (object)num));
                }
                return(true);
            }

            case 3:
                if ((uncomprLen = input.PeekBits(16)) < 0)
                {
                    return(false);
                }
                input.DropBits(16);
                mode = 4;
                goto case 4;

            case 4:
            {
                int num3 = input.PeekBits(16);
                if (num3 < 0)
                {
                    return(false);
                }
                input.DropBits(16);
                if (num3 != (uncomprLen ^ 0xFFFF))
                {
                    throw new SharpZipBaseException("broken uncompressed block");
                }
                mode = 5;
                goto case 5;
            }

            case 5:
            {
                int num2 = outputWindow.CopyStored(input, uncomprLen);
                uncomprLen -= num2;
                if (uncomprLen == 0)
                {
                    mode = 2;
                    return(true);
                }
                return(!input.IsNeedingInput);
            }

            case 6:
                if (!dynHeader.Decode(input))
                {
                    return(false);
                }
                litlenTree = dynHeader.BuildLitLenTree();
                distTree   = dynHeader.BuildDistTree();
                mode       = 7;
                goto case 7;

            case 7:
            case 8:
            case 9:
            case 10:
                return(DecodeHuffman());

            case 12:
                return(false);

            default:
                throw new SharpZipBaseException("Inflater.Decode unknown mode");
            }
        }
Exemple #3
0
        /// <summary>
        /// Decodes the deflated stream.
        /// </summary>
        /// <returns>
        /// false if more input is needed, or if finished.
        /// </returns>
        /// <exception cref="SharpZipBaseException">
        /// if deflated stream is invalid.
        /// </exception>
        private bool Decode()
        {
            switch (mode)
            {
            case DECODE_HEADER:
                return(DecodeHeader());

            case DECODE_DICT:
                return(DecodeDict());

            case DECODE_CHKSUM:
                return(DecodeChksum());

            case DECODE_BLOCKS:
                if (isLastBlock)
                {
                    if (noHeader)
                    {
                        mode = FINISHED;
                        return(false);
                    }
                    else
                    {
                        input.SkipToByteBoundary();
                        neededBits = 32;
                        mode       = DECODE_CHKSUM;
                        return(true);
                    }
                }

                int blockType;
                if (!ReadHeader(ref isLastBlock, out blockType))
                {
                    return(false);
                }
                switch (blockType)
                {
                case STORED_BLOCK:
                    input.SkipToByteBoundary();
                    mode = DECODE_STORED_LEN1;
                    break;

                case STATIC_TREES:
                    litlenTree = InflaterHuffmanTree.defLitLenTree;
                    distTree   = InflaterHuffmanTree.defDistTree;
                    mode       = DECODE_HUFFMAN;
                    break;

                case DYN_TREES:
                    dynHeader = new InflaterDynHeader();
                    mode      = DECODE_DYN_HEADER;
                    break;

                default:
                    throw new SharpZipBaseException("Unknown block type " + blockType);
                }
                return(true);

            case DECODE_STORED_LEN1:
                if (!DecodeStoredLength())
                {
                    return(false);
                }
                mode = DECODE_STORED;
                goto case DECODE_STORED;                         // fall through

            case DECODE_STORED:
            {
                int more = outputWindow.CopyStored(input, uncomprLen);
                uncomprLen -= more;
                if (uncomprLen == 0)
                {
                    mode = DECODE_BLOCKS;
                    return(true);
                }
                return(!input.IsNeedingInput);
            }

            case DECODE_DYN_HEADER:
                if (!dynHeader.Decode(input))
                {
                    return(false);
                }

                litlenTree = dynHeader.BuildLitLenTree();
                distTree   = dynHeader.BuildDistTree();
                mode       = DECODE_HUFFMAN;
                goto case DECODE_HUFFMAN;                         // fall through

            case DECODE_HUFFMAN:
            case DECODE_HUFFMAN_LENBITS:
            case DECODE_HUFFMAN_DIST:
            case DECODE_HUFFMAN_DISTBITS:
                return(DecodeHuffman());

            case FINISHED:
                return(false);

            default:
                throw new SharpZipBaseException("Inflater.Decode unknown mode");
            }
        }
Exemple #4
0
        /// <summary>
        /// Decodes the deflated stream.
        /// </summary>
        /// <returns>
        /// false if more input is needed, or if finished.
        /// </returns>
        /// <exception cref="SharpZipBaseException">
        /// if deflated stream is invalid.
        /// </exception>
        private bool Decode()
        {
            switch (mode) {
                case DECODE_HEADER:
                    return DecodeHeader();

                case DECODE_DICT:
                    return DecodeDict();

                case DECODE_CHKSUM:
                    return DecodeChksum();
                
                case DECODE_BLOCKS:
                    if (isLastBlock) {
                        if (noHeader) {
                            mode = FINISHED;
                            return false;
                        } else {
                            input.SkipToByteBoundary();
                            neededBits = 32;
                            mode = DECODE_CHKSUM;
                            return true;
                        }
                    }
                    
                    int type = input.PeekBits(3);
                    if (type < 0) {
                        return false;
                    }
                    input.DropBits(3);
                    
                    if ((type & 1) != 0) {
                        isLastBlock = true;
                    }
                    switch (type >> 1){
                        case DeflaterConstants.STORED_BLOCK:
                            input.SkipToByteBoundary();
                            mode = DECODE_STORED_LEN1;
                            break;
                        case DeflaterConstants.STATIC_TREES:
                            litlenTree = InflaterHuffmanTree.defLitLenTree;
                            distTree = InflaterHuffmanTree.defDistTree;
                            mode = DECODE_HUFFMAN;
                            break;
                        case DeflaterConstants.DYN_TREES:
                            dynHeader = new InflaterDynHeader();
                            mode = DECODE_DYN_HEADER;
                            break;
                        default:
                            throw new SharpZipBaseException("Unknown block type " + type);
                    }
                    return true;
                
                case DECODE_STORED_LEN1: 
                {
                    if ((uncomprLen = input.PeekBits(16)) < 0) {
                        return false;
                    }
                    input.DropBits(16);
                    mode = DECODE_STORED_LEN2;
                }
                    goto case DECODE_STORED_LEN2; // fall through
                    
                case DECODE_STORED_LEN2: 
                {
                    int nlen = input.PeekBits(16);
                    if (nlen < 0) {
                        return false;
                    }
                    input.DropBits(16);
                    if (nlen != (uncomprLen ^ 0xffff)) {
                        throw new SharpZipBaseException("broken uncompressed block");
                    }
                    mode = DECODE_STORED;
                }
                    goto case DECODE_STORED; // fall through
                    
                case DECODE_STORED: 
                {
                    int more = outputWindow.CopyStored(input, uncomprLen);
                    uncomprLen -= more;
                    if (uncomprLen == 0) {
                        mode = DECODE_BLOCKS;
                        return true;
                    }
                    return !input.IsNeedingInput;
                }
                
                case DECODE_DYN_HEADER:
                    if (!dynHeader.Decode(input)) {
                        return false;
                    }
                    
                    litlenTree = dynHeader.BuildLitLenTree();
                    distTree = dynHeader.BuildDistTree();
                    mode = DECODE_HUFFMAN;
                    goto case DECODE_HUFFMAN; // fall through
                    
                case DECODE_HUFFMAN:
                case DECODE_HUFFMAN_LENBITS:
                case DECODE_HUFFMAN_DIST:
                case DECODE_HUFFMAN_DISTBITS:
                    return DecodeHuffman();
                
                case FINISHED:
                    return false;
                
                default:
                    throw new SharpZipBaseException("Inflater.Decode unknown mode");
            }
        }
Exemple #5
0
        /// <summary>
        /// Decodes the deflated stream.
        /// </summary>
        /// <returns>
        /// false if more input is needed, or if finished.
        /// </returns>
        /// <exception cref="SharpZipBaseException">
        /// if deflated stream is invalid.
        /// </exception>
        private bool Decode()
        {
            switch (mode) {
                case DECODE_HEADER:
                    return DecodeHeader();

                case DECODE_DICT:
                    return DecodeDict();

                case DECODE_CHKSUM:
                    return DecodeChksum();

                case DECODE_BLOCKS:
                    if (isLastBlock) {
                        if (noHeader) {
                            mode = FINISHED;
                            return false;
                        } else {
                            input.SkipToByteBoundary();
                            neededBits = 32;
                            mode = DECODE_CHKSUM;
                            return true;
                        }
                    }

                    int blockType;
                    if (!ReadHeader(ref isLastBlock, out blockType)) {
                        return false;
                    }
                    switch (blockType){
                        case STORED_BLOCK:
                            input.SkipToByteBoundary();
                            mode = DECODE_STORED_LEN1;
                            break;
                        case STATIC_TREES:
                            litlenTree = InflaterHuffmanTree.defLitLenTree;
                            distTree = InflaterHuffmanTree.defDistTree;
                            mode = DECODE_HUFFMAN;
                            break;
                        case DYN_TREES:
                            dynHeader = new InflaterDynHeader();
                            mode = DECODE_DYN_HEADER;
                            break;
                        default:
                            throw new SharpZipBaseException("Unknown block type " + blockType);
                    }
                    return true;

                case DECODE_STORED_LEN1:
                    if (!DecodeStoredLength()) {
                        return false;
                    }
                    mode = DECODE_STORED;
                    goto case DECODE_STORED; // fall through

                case DECODE_STORED:
                {
                    int more = outputWindow.CopyStored(input, uncomprLen);
                    uncomprLen -= more;
                    if (uncomprLen == 0) {
                        mode = DECODE_BLOCKS;
                        return true;
                    }
                    return !input.IsNeedingInput;
                }

                case DECODE_DYN_HEADER:
                    if (!dynHeader.Decode(input)) {
                        return false;
                    }

                    litlenTree = dynHeader.BuildLitLenTree();
                    distTree = dynHeader.BuildDistTree();
                    mode = DECODE_HUFFMAN;
                    goto case DECODE_HUFFMAN; // fall through

                case DECODE_HUFFMAN:
                case DECODE_HUFFMAN_LENBITS:
                case DECODE_HUFFMAN_DIST:
                case DECODE_HUFFMAN_DISTBITS:
                    return DecodeHuffman();

                case FINISHED:
                    return false;

                default:
                    throw new SharpZipBaseException("Inflater.Decode unknown mode");
            }
        }