Ejemplo n.º 1
0
        /// <summary>
        /// copy as much as possible from the sliding Window to the output area
        /// </summary>
        internal int inflate_flush(ZStream z, int r)
        {
            int n;
            int p;
            int q;

            // local copies of source and destination pointers
            p = z.next_out_index;
            q = ReadPos;

            // compute number of bytes to copy as far as End of Window
            n = (int)((q <= WritePos?WritePos:End) - q);
            if (n > z.avail_out)
            {
                n = z.avail_out;
            }
            if (n != 0 && r == (int)ZLibResultCode.Z_BUF_ERROR)
            {
                r = (int)ZLibResultCode.Z_OK;
            }

            // update counters
            z.avail_out -= n;
            z.total_out += n;

            // update check information
            if (this.needCheck)
            {
                z.adler = check = Adler32.GetAdler32Checksum(check, Window, q, n);
            }

            // copy as far as End of Window
            Array.Copy(Window, q, z.next_out, p, n);
            p += n;
            q += n;

            // see if more to copy at beginning of Window
            if (q == End)
            {
                // wrap pointers
                q = 0;
                if (WritePos == End)
                {
                    WritePos = 0;
                }

                // compute bytes to copy
                n = WritePos - q;
                if (n > z.avail_out)
                {
                    n = z.avail_out;
                }
                if (n != 0 && r == (int)ZLibResultCode.Z_BUF_ERROR)
                {
                    r = (int)ZLibResultCode.Z_OK;
                }

                // update counters
                z.avail_out -= n;
                z.total_out += n;

                // update check information
                if (this.needCheck)
                {
                    z.adler = check = Adler32.GetAdler32Checksum(check, Window, q, n);
                }

                // copy
                Array.Copy(Window, q, z.next_out, p, n);
                p += n;
                q += n;
            }

            // update pointers
            z.next_out_index = p;
            ReadPos          = q;

            // done
            return(r);
        }
Ejemplo n.º 2
0
        /// <summary>
        /// Block processing functions
        /// </summary>
        internal int proc(ZStream z, int r)
        {
            int t; // temporary storage
            int b; // bit buffer
            int k; // bits in bit buffer
            int p; // input data pointer
            int n; // bytes available there
            int q; // output Window WritePos pointer
            int m; // bytes to End of Window or ReadPos pointer

            // copy input/output information to locals (UPDATE macro restores)
            {
                p = z.next_in_index; n = z.avail_in; b = BitB; k = BitK;
            }
            {
                q = WritePos; m = (int)(q < ReadPos ? ReadPos - q - 1 : End - q);
            }

            // process input based on current state
            while (true)
            {
                switch (mode)
                {
                case InflateBlockMode.TYPE:

                    while (k < (3))
                    {
                        if (n != 0)
                        {
                            r = (int)ZLibResultCode.Z_OK;
                        }
                        else
                        {
                            BitB        = b; BitK = k;
                            z.avail_in  = n;
                            z.total_in += p - z.next_in_index; z.next_in_index = p;
                            WritePos    = q;
                            return(inflate_flush(z, r));
                        }
                        ;
                        n--;
                        b |= (z.next_in[p++] & 0xff) << k;
                        k += 8;
                    }
                    t    = (int)(b & 7);
                    last = t & 1;

                    switch (ZLibUtil.URShift(t, 1))
                    {
                    case 0:          // stored
                    {
                        b = ZLibUtil.URShift(b, (3)); k -= (3);
                    }
                        t = k & 7;         // go to byte boundary
                        {
                            b = ZLibUtil.URShift(b, (t)); k -= (t);
                        }
                        mode = InflateBlockMode.LENS;         // get length of stored block
                        break;

                    case 1:          // fixed
                    {
                        int[]   bl = new int[1];
                        int[]   bd = new int[1];
                        int[][] tl = new int[1][];
                        int[][] td = new int[1][];

                        InfTree.inflate_trees_fixed(bl, bd, tl, td, z);
                        codes = new InfCodes(bl[0], bd[0], tl[0], td[0], z);
                    }
                        {
                            b = ZLibUtil.URShift(b, (3)); k -= (3);
                        }

                        mode = InflateBlockMode.CODES;
                        break;

                    case 2:          // dynamic
                    {
                        b = ZLibUtil.URShift(b, (3)); k -= (3);
                    }

                        mode = InflateBlockMode.TABLE;
                        break;

                    case 3:          // illegal
                    {
                        b = ZLibUtil.URShift(b, (3)); k -= (3);
                    }
                        mode  = InflateBlockMode.BAD;
                        z.msg = "invalid block type";
                        r     = (int)ZLibResultCode.Z_DATA_ERROR;

                        BitB       = b; BitK = k;
                        z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
                        WritePos   = q;
                        return(inflate_flush(z, r));
                    }
                    break;

                case InflateBlockMode.LENS:

                    while (k < (32))
                    {
                        if (n != 0)
                        {
                            r = (int)ZLibResultCode.Z_OK;
                        }
                        else
                        {
                            BitB        = b; BitK = k;
                            z.avail_in  = n;
                            z.total_in += p - z.next_in_index; z.next_in_index = p;
                            WritePos    = q;
                            return(inflate_flush(z, r));
                        }
                        ;
                        n--;
                        b |= (z.next_in[p++] & 0xff) << k;
                        k += 8;
                    }

                    if (((ZLibUtil.URShift((~b), 16)) & 0xffff) != (b & 0xffff))
                    {
                        mode  = InflateBlockMode.BAD;
                        z.msg = "invalid stored block lengths";
                        r     = (int)ZLibResultCode.Z_DATA_ERROR;

                        BitB       = b; BitK = k;
                        z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
                        WritePos   = q;
                        return(inflate_flush(z, r));
                    }
                    left = (b & 0xffff);
                    b    = k = 0;  // dump bits
                    mode = (left != 0) ? InflateBlockMode.STORED : (last != 0 ? InflateBlockMode.DRY : InflateBlockMode.TYPE);
                    break;

                case InflateBlockMode.STORED:
                    if (n == 0)
                    {
                        BitB       = b; BitK = k;
                        z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
                        WritePos   = q;
                        return(inflate_flush(z, r));
                    }

                    if (m == 0)
                    {
                        if (q == End && ReadPos != 0)
                        {
                            q = 0; m = (int)(q < ReadPos ? ReadPos - q - 1 : End - q);
                        }
                        if (m == 0)
                        {
                            WritePos = q;
                            r        = inflate_flush(z, r);
                            q        = WritePos; m = (int)(q < ReadPos ? ReadPos - q - 1 : End - q);
                            if (q == End && ReadPos != 0)
                            {
                                q = 0; m = (int)(q < ReadPos ? ReadPos - q - 1 : End - q);
                            }
                            if (m == 0)
                            {
                                BitB       = b; BitK = k;
                                z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
                                WritePos   = q;
                                return(inflate_flush(z, r));
                            }
                        }
                    }
                    r = (int)ZLibResultCode.Z_OK;

                    t = left;
                    if (t > n)
                    {
                        t = n;
                    }
                    if (t > m)
                    {
                        t = m;
                    }
                    Array.Copy(z.next_in, p, Window, q, t);
                    p += t; n -= t;
                    q += t; m -= t;
                    if ((left -= t) != 0)
                    {
                        break;
                    }
                    mode = last != 0 ? InflateBlockMode.DRY : InflateBlockMode.TYPE;
                    break;

                case InflateBlockMode.TABLE:

                    while (k < (14))
                    {
                        if (n != 0)
                        {
                            r = (int)ZLibResultCode.Z_OK;
                        }
                        else
                        {
                            BitB        = b; BitK = k;
                            z.avail_in  = n;
                            z.total_in += p - z.next_in_index; z.next_in_index = p;
                            WritePos    = q;
                            return(inflate_flush(z, r));
                        }
                        ;
                        n--;
                        b |= (z.next_in[p++] & 0xff) << k;
                        k += 8;
                    }

                    table = t = (b & 0x3fff);
                    if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29)
                    {
                        mode  = InflateBlockMode.BAD;
                        z.msg = "too many length or distance symbols";
                        r     = (int)ZLibResultCode.Z_DATA_ERROR;

                        BitB       = b; BitK = k;
                        z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
                        WritePos   = q;
                        return(inflate_flush(z, r));
                    }
                    t     = 258 + (t & 0x1f) + ((t >> 5) & 0x1f);
                    blens = new int[t];
                    {
                        b = ZLibUtil.URShift(b, (14)); k -= (14);
                    }

                    index = 0;
                    mode  = InflateBlockMode.BTREE;
                    goto case InflateBlockMode.BTREE;

                case InflateBlockMode.BTREE:
                    while (index < 4 + (ZLibUtil.URShift(table, 10)))
                    {
                        while (k < (3))
                        {
                            if (n != 0)
                            {
                                r = (int)ZLibResultCode.Z_OK;
                            }
                            else
                            {
                                BitB        = b; BitK = k;
                                z.avail_in  = n;
                                z.total_in += p - z.next_in_index; z.next_in_index = p;
                                WritePos    = q;
                                return(inflate_flush(z, r));
                            }
                            ;
                            n--;
                            b |= (z.next_in[p++] & 0xff) << k;
                            k += 8;
                        }

                        blens[ZLibUtil.border[index++]] = b & 7;

                        {
                            b = ZLibUtil.URShift(b, (3)); k -= (3);
                        }
                    }

                    while (index < 19)
                    {
                        blens[ZLibUtil.border[index++]] = 0;
                    }

                    bb[0] = 7;
                    t     = InfTree.inflate_trees_bits(blens, bb, tb, hufts, z);
                    if (t != (int)ZLibResultCode.Z_OK)
                    {
                        r = t;
                        if (r == (int)ZLibResultCode.Z_DATA_ERROR)
                        {
                            blens = null;
                            mode  = InflateBlockMode.BAD;
                        }

                        BitB       = b; BitK = k;
                        z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
                        WritePos   = q;
                        return(inflate_flush(z, r));
                    }

                    index = 0;
                    mode  = InflateBlockMode.DTREE;
                    goto case InflateBlockMode.DTREE;

                case InflateBlockMode.DTREE:
                    while (true)
                    {
                        t = table;
                        if (!(index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f)))
                        {
                            break;
                        }


                        int i, j, c;

                        t = bb[0];

                        while (k < (t))
                        {
                            if (n != 0)
                            {
                                r = (int)ZLibResultCode.Z_OK;
                            }
                            else
                            {
                                BitB        = b; BitK = k;
                                z.avail_in  = n;
                                z.total_in += p - z.next_in_index; z.next_in_index = p;
                                WritePos    = q;
                                return(inflate_flush(z, r));
                            }
                            ;
                            n--;
                            b |= (z.next_in[p++] & 0xff) << k;
                            k += 8;
                        }

                        t = hufts[(tb[0] + (b & ZLibUtil.inflate_mask[t])) * 3 + 1];
                        c = hufts[(tb[0] + (b & ZLibUtil.inflate_mask[t])) * 3 + 2];

                        if (c < 16)
                        {
                            b = ZLibUtil.URShift(b, (t)); k -= (t);
                            blens[index++] = c;
                        }
                        else
                        {
                            // c == 16..18
                            i = c == 18 ? 7 : c - 14;
                            j = c == 18 ? 11 : 3;

                            while (k < (t + i))
                            {
                                if (n != 0)
                                {
                                    r = (int)ZLibResultCode.Z_OK;
                                }
                                else
                                {
                                    BitB        = b; BitK = k;
                                    z.avail_in  = n;
                                    z.total_in += p - z.next_in_index; z.next_in_index = p;
                                    WritePos    = q;
                                    return(inflate_flush(z, r));
                                }
                                ;
                                n--;
                                b |= (z.next_in[p++] & 0xff) << k;
                                k += 8;
                            }

                            b = ZLibUtil.URShift(b, (t)); k -= (t);

                            j += (b & ZLibUtil.inflate_mask[i]);

                            b = ZLibUtil.URShift(b, (i)); k -= (i);

                            i = index;
                            t = table;
                            if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) || (c == 16 && i < 1))
                            {
                                blens = null;
                                mode  = InflateBlockMode.BAD;
                                z.msg = "invalid bit length repeat";
                                r     = (int)ZLibResultCode.Z_DATA_ERROR;

                                BitB       = b; BitK = k;
                                z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
                                WritePos   = q;
                                return(inflate_flush(z, r));
                            }

                            c = c == 16 ? blens[i - 1] : 0;
                            do
                            {
                                blens[i++] = c;
                            }while (--j != 0);
                            index = i;
                        }
                    }

                    tb[0] = -1;
                    {
                        int[] bl = new int[1];
                        int[] bd = new int[1];
                        int[] tl = new int[1];
                        int[] td = new int[1];


                        bl[0] = 9;     // must be <= 9 for lookahead assumptions
                        bd[0] = 6;     // must be <= 9 for lookahead assumptions
                        t     = table;
                        t     = InfTree.inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f), blens, bl, bd, tl, td, hufts, z);
                        if (t != (int)ZLibResultCode.Z_OK)
                        {
                            if (t == (int)ZLibResultCode.Z_DATA_ERROR)
                            {
                                blens = null;
                                mode  = InflateBlockMode.BAD;
                            }
                            r = t;

                            BitB       = b; BitK = k;
                            z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
                            WritePos   = q;
                            return(inflate_flush(z, r));
                        }

                        codes = new InfCodes(bl[0], bd[0], hufts, tl[0], hufts, td[0], z);
                    }
                    blens = null;
                    mode  = InflateBlockMode.CODES;
                    goto case InflateBlockMode.CODES;

                case InflateBlockMode.CODES:
                    BitB       = b; BitK = k;
                    z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
                    WritePos   = q;

                    if ((r = codes.proc(this, z, r)) != (int)ZLibResultCode.Z_STREAM_END)
                    {
                        return(inflate_flush(z, r));
                    }
                    r = (int)ZLibResultCode.Z_OK;
                    codes.free(z);

                    p = z.next_in_index; n = z.avail_in; b = BitB; k = BitK;
                    q = WritePos; m = (int)(q < ReadPos ? ReadPos - q - 1 : End - q);

                    if (last == 0)
                    {
                        mode = InflateBlockMode.TYPE;
                        break;
                    }
                    mode = InflateBlockMode.DRY;
                    goto case InflateBlockMode.DRY;

                case InflateBlockMode.DRY:
                    WritePos = q;
                    r        = inflate_flush(z, r);
                    q        = WritePos; m = (int)(q < ReadPos ? ReadPos - q - 1 : End - q);
                    if (ReadPos != WritePos)
                    {
                        BitB       = b; BitK = k;
                        z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
                        WritePos   = q;
                        return(inflate_flush(z, r));
                    }
                    mode = InflateBlockMode.DONE;
                    goto case InflateBlockMode.DONE;

                case InflateBlockMode.DONE:
                    r = (int)ZLibResultCode.Z_STREAM_END;

                    BitB       = b; BitK = k;
                    z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
                    WritePos   = q;
                    return(inflate_flush(z, r));

                case InflateBlockMode.BAD:
                    r = (int)ZLibResultCode.Z_DATA_ERROR;

                    BitB       = b; BitK = k;
                    z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
                    WritePos   = q;
                    return(inflate_flush(z, r));


                default:
                    r = (int)ZLibResultCode.Z_STREAM_ERROR;

                    BitB       = b; BitK = k;
                    z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
                    WritePos   = q;
                    return(inflate_flush(z, r));
                }
            }
        }