示例#1
0
        /// <summary>
        /// Skips n decompressed bytes in the stream.
        /// </summary>
        /// <param name="n">The number of bytes to skip.</param>
        public long Skip(long n)
        {
            int len = 512;

            if (n < len)
            {
                len = (int)n;
            }
            byte[] tmp = new byte[len];
            return((long)ZLibUtil.ReadInput(this, tmp, 0, tmp.Length));
        }
示例#2
0
        ///<summary>
        /// Reverse the first count bits of a code, using straightforward code (a faster
        /// method would use a table)
        ///</summary>
        private static int bi_reverse(int code, int len)
        {
            int res = 0;

            do
            {
                res  |= code & 1;
                code  = ZLibUtil.URShift(code, 1);
                res <<= 1;
            }while (--len > 0);
            return(ZLibUtil.URShift(res, 1));
        }
示例#3
0
 /// <summary>
 /// Mapping from a distance to a distance code. dist is the distance - 1 and
 /// must not have side effects. _dist_code[256] and _dist_code[257] are never
 /// used.
 /// </summary>
 internal static int d_code(int dist)
 {
     return((dist) < 256 ? ZLibUtil._dist_code[dist] : ZLibUtil._dist_code[256 + (ZLibUtil.URShift((dist), 7))]);
 }
示例#4
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));
                }
            }
        }
示例#5
0
        /// <summary>
        /// Given a list of code lengths and a maximum table size, make a set of
        /// tables to decode that set of codes.
        /// </summary>
        /// <returns>Return (int)ZLibResultCode.Z_OK on success, (int)ZLibResultCode.Z_DATA_ERROR if the given code set is incomplete (the tables are still built in this case), (int)ZLibResultCode.Z_DATA_ERROR if the input is invalid (an over-subscribed set of lengths), or (int)ZLibResultCode.Z_DATA_ERROR if not enough memory.
        /// </returns>
        private static int huft_build(int[] b, int bindex, int n, int s, int[] d, int[] e, int[] t, int[] m, int[] hp, int[] hn, int[] v)
        {
            int a;                                   // counter for codes of length k

            int[] c = new int[InfTreeUtil.BMAX + 1]; // bit length count table
            int   f;                                 // i repeats in table every internalFlush entries
            int   g;                                 // maximum code length
            int   h;                                 // table level
            int   i;                                 // counter, current code
            int   j;                                 // counter
            int   k;                                 // number of bits in current code
            int   l;                                 // bits per table (returned in m)
            int   mask;                              // (1 << windowBits) - 1, to avoid cc -O bug on HP
            int   p;                                 // pointer into c[], buffer[], or v[]
            int   q;                                 // points to current table

            int[] r = new int[3];                    // table entry for structure assignment
            int[] u = new int[InfTreeUtil.BMAX];     // table stack
            int   w;                                 // bits before this table == (l * h)

            int[] x = new int[InfTreeUtil.BMAX + 1]; // bit offsets, then code stack
            int   xp;                                // pointer into x
            int   y;                                 // number of dummy codes added
            int   z;                                 // number of entries in current table

            // Generate counts for each bit length

            p = 0; i = n;
            do
            {
                c[b[bindex + p]]++; p++; i--;                 // assume all entries <= BMAX
            }while (i != 0);

            if (c[0] == n)
            {
                // null input--all zero length codes
                t[0] = -1;
                m[0] = 0;
                return((int)ZLibResultCode.Z_OK);
            }

            // Find minimum and maximum length, bound *m by those
            l = m[0];
            for (j = 1; j <= InfTreeUtil.BMAX; j++)
            {
                if (c[j] != 0)
                {
                    break;
                }
            }
            k = j;             // minimum code length
            if (l < j)
            {
                l = j;
            }
            for (i = InfTreeUtil.BMAX; i != 0; i--)
            {
                if (c[i] != 0)
                {
                    break;
                }
            }
            g = i;             // maximum code length
            if (l > i)
            {
                l = i;
            }
            m[0] = l;

            // Adjust last length count to fill out codes, if needed
            for (y = 1 << j; j < i; j++, y <<= 1)
            {
                if ((y -= c[j]) < 0)
                {
                    return((int)ZLibResultCode.Z_DATA_ERROR);
                }
            }
            if ((y -= c[i]) < 0)
            {
                return((int)ZLibResultCode.Z_DATA_ERROR);
            }
            c[i] += y;

            // Generate starting offsets into the value table for each length
            x[1] = j = 0;
            p    = 1; xp = 2;
            while (--i != 0)
            {
                // note that i == g from above
                x[xp] = (j += c[p]);
                xp++;
                p++;
            }

            // Make a table of values in order of bit lengths
            i = 0; p = 0;
            do
            {
                if ((j = b[bindex + p]) != 0)
                {
                    v[x[j]++] = i;
                }
                p++;
            }while (++i < n);
            n = x[g];             // set n to length of v

            // Generate the Huffman codes and for each, make the table entries
            x[0] = i = 0;      // first Huffman code is zero
            p    = 0;          // grab values in bit order
            h    = -1;         // no tables yet--level -1
            w    = -l;         // bits decoded == (l * h)
            u[0] = 0;          // just to keep compilers happy
            q    = 0;          // ditto
            z    = 0;          // ditto

            // go through the bit lengths (k already is bits in shortest code)
            for (; k <= g; k++)
            {
                a = c[k];
                while (a-- != 0)
                {
                    // here i is the Huffman code of length k bits for value *p
                    // make tables up to required level
                    while (k > w + l)
                    {
                        h++;
                        w += l;                         // previous table always l bits
                        // compute minimum size table less than or equal to l bits
                        z = g - w;
                        z = (z > l)?l:z;                         // table size upper limit
                        if ((f = 1 << (j = k - w)) > a + 1)
                        {
                            // try a k-windowBits bit table
                            // too few codes for k-windowBits bit table
                            f -= (a + 1);                             // deduct codes from patterns left
                            xp = k;
                            if (j < z)
                            {
                                while (++j < z)
                                {
                                    // try smaller tables up to z bits
                                    if ((f <<= 1) <= c[++xp])
                                    {
                                        break;                                      // enough codes to use up j bits
                                    }
                                    f -= c[xp];                                     // else deduct codes from patterns
                                }
                            }
                        }
                        z = 1 << j;                         // table entries for j-bit table

                        // allocate new table
                        if (hn[0] + z > InfTreeUtil.MANY)
                        {
                            // (note: doesn't matter for fixed)
                            return((int)ZLibResultCode.Z_DATA_ERROR); // overflow of MANY
                        }
                        u[h]   = q = hn[0];                           // DEBUG
                        hn[0] += z;

                        // connect to last table, if there is one
                        if (h != 0)
                        {
                            x[h] = i;                                    // save pattern for backing up
                            r[0] = (byte)j;                              // bits in this table
                            r[1] = (byte)l;                              // bits to dump before this table
                            j    = ZLibUtil.URShift(i, (w - l));
                            r[2] = (int)(q - u[h - 1] - j);              // offset to this table
                            Array.Copy(r, 0, hp, (u[h - 1] + j) * 3, 3); // connect to last table
                        }
                        else
                        {
                            t[0] = q;                             // first table is returned result
                        }
                    }

                    // set up table entry in r
                    r[1] = (byte)(k - w);
                    if (p >= n)
                    {
                        r[0] = 128 + 64;                         // out of values--invalid code
                    }
                    else if (v[p] < s)
                    {
                        r[0] = (byte)(v[p] < 256?0:32 + 64);   // 256 is End-of-block
                        r[2] = v[p++];                         // simple code is just the value
                    }
                    else
                    {
                        r[0] = (byte)(e[v[p] - s] + 16 + 64);                          // non-simple--look up in lists
                        r[2] = d[v[p++] - s];
                    }

                    // fill code-like entries with r
                    f = 1 << (k - w);
                    for (j = ZLibUtil.URShift(i, w); j < z; j += f)
                    {
                        Array.Copy(r, 0, hp, (q + j) * 3, 3);
                    }

                    // backwards increment the k-bit code i
                    for (j = 1 << (k - 1); (i & j) != 0; j = ZLibUtil.URShift(j, 1))
                    {
                        i ^= j;
                    }
                    i ^= j;

                    // backup over finished tables
                    mask = (1 << w) - 1;                     // needed on HP, cc -O bug
                    while ((i & mask) != x[h])
                    {
                        h--;                         // don't need to update q
                        w   -= l;
                        mask = (1 << w) - 1;
                    }
                }
            }
            // Return (int)ZLibResultCode.Z_DATA_ERROR if we were given an incomplete table
            return(y != 0 && g != 1 ? (int)ZLibResultCode.Z_BUF_ERROR : (int)ZLibResultCode.Z_OK);
        }
示例#6
0
        /// <summary>
        /// Block processing method
        /// </summary>
        /// <param name="s">An instance of the InfBlocks class</param>
        /// <param name="z">A ZStream object</param>
        /// <param name="r">A result code</param>
        internal int proc(InfBlocks s, ZStream z, int r)
        {
            int j;             // temporary storage
            //int[] t; // temporary pointer
            int tindex;        // temporary pointer
            int e;             // extra bits or operation
            int b = 0;         // bit buffer
            int k = 0;         // bits in bit buffer
            int p = 0;         // input data pointer
            int n;             // bytes available there
            int q;             // output Window WritePos pointer
            int m;             // bytes to End of Window or ReadPos pointer
            int f;             // pointer to copy strings from

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

            // process input and output based on current state
            while (true)
            {
                switch (mode)
                {
                // waiting for "i:"=input, "o:"=output, "x:"=nothing
                case  InflateCodesMode.START:                          // x: set up for  InflateCodesMode.LEN
                    if (m >= 258 && n >= 10)
                    {
                        s.BitB     = b; s.BitK = k;
                        z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
                        s.WritePos = q;
                        r          = inflate_fast(lbits, dbits, ltree, ltree_index, dtree, dtree_index, s, z);

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

                        if (r != (int)ZLibResultCode.Z_OK)
                        {
                            mode = r == (int)ZLibResultCode.Z_STREAM_END? InflateCodesMode.WASH: InflateCodesMode.BADCODE;
                            break;
                        }
                    }
                    need       = lbits;
                    tree       = ltree;
                    tree_index = ltree_index;

                    mode = InflateCodesMode.LEN;
                    goto case InflateCodesMode.LEN;

                case  InflateCodesMode.LEN:                          // i: get length/literal/eob next
                    j = need;

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

                    tindex = (tree_index + (b & ZLibUtil.inflate_mask[j])) * 3;

                    b  = ZLibUtil.URShift(b, (tree[tindex + 1]));
                    k -= (tree[tindex + 1]);

                    e = tree[tindex];

                    if (e == 0)
                    {
                        // literal
                        lit  = tree[tindex + 2];
                        mode = InflateCodesMode.LIT;
                        break;
                    }
                    if ((e & 16) != 0)
                    {
                        // length
                        get_Renamed = e & 15;
                        count       = tree[tindex + 2];
                        mode        = InflateCodesMode.LENEXT;
                        break;
                    }
                    if ((e & 64) == 0)
                    {
                        // next table
                        need       = e;
                        tree_index = tindex / 3 + tree[tindex + 2];
                        break;
                    }
                    if ((e & 32) != 0)
                    {
                        // End of block
                        mode = InflateCodesMode.WASH;
                        break;
                    }
                    mode  = InflateCodesMode.BADCODE;                             // invalid code
                    z.msg = "invalid literal/length code";
                    r     = (int)ZLibResultCode.Z_DATA_ERROR;

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


                case  InflateCodesMode.LENEXT:                          // i: getting length extra (have base)
                    j = get_Renamed;

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

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

                    b >>= j;
                    k  -= j;

                    need       = dbits;
                    tree       = dtree;
                    tree_index = dtree_index;
                    mode       = InflateCodesMode.DIST;
                    goto case InflateCodesMode.DIST;

                case  InflateCodesMode.DIST:                          // i: get distance next
                    j = need;

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

                    tindex = (tree_index + (b & ZLibUtil.inflate_mask[j])) * 3;

                    b >>= tree[tindex + 1];
                    k  -= tree[tindex + 1];

                    e = (tree[tindex]);
                    if ((e & 16) != 0)
                    {
                        // distance
                        get_Renamed = e & 15;
                        dist        = tree[tindex + 2];
                        mode        = InflateCodesMode.DISTEXT;
                        break;
                    }
                    if ((e & 64) == 0)
                    {
                        // next table
                        need       = e;
                        tree_index = tindex / 3 + tree[tindex + 2];
                        break;
                    }
                    mode  = InflateCodesMode.BADCODE;                             // invalid code
                    z.msg = "invalid distance code";
                    r     = (int)ZLibResultCode.Z_DATA_ERROR;

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


                case  InflateCodesMode.DISTEXT:                          // i: getting distance extra
                    j = get_Renamed;

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

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

                    b >>= j;
                    k  -= j;

                    mode = InflateCodesMode.COPY;
                    goto case InflateCodesMode.COPY;

                case  InflateCodesMode.COPY:                          // o: copying bytes in Window, waiting for space
                    f = q - dist;
                    while (f < 0)
                    {
                        // modulo Window size-"while" instead
                        f += s.End;                                 // of "if" handles invalid distances
                    }
                    while (count != 0)
                    {
                        if (m == 0)
                        {
                            if (q == s.End && s.ReadPos != 0)
                            {
                                q = 0; m = q < s.ReadPos?s.ReadPos - q - 1:s.End - q;
                            }
                            if (m == 0)
                            {
                                s.WritePos = q; r = s.inflate_flush(z, r);
                                q          = s.WritePos; m = q < s.ReadPos?s.ReadPos - q - 1:s.End - q;

                                if (q == s.End && s.ReadPos != 0)
                                {
                                    q = 0; m = q < s.ReadPos?s.ReadPos - q - 1:s.End - q;
                                }

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

                        s.Window[q++] = s.Window[f++]; m--;

                        if (f == s.End)
                        {
                            f = 0;
                        }
                        count--;
                    }
                    mode = InflateCodesMode.START;
                    break;

                case  InflateCodesMode.LIT:                          // o: got literal, waiting for output space
                    if (m == 0)
                    {
                        if (q == s.End && s.ReadPos != 0)
                        {
                            q = 0; m = q < s.ReadPos?s.ReadPos - q - 1:s.End - q;
                        }
                        if (m == 0)
                        {
                            s.WritePos = q; r = s.inflate_flush(z, r);
                            q          = s.WritePos; m = q < s.ReadPos?s.ReadPos - q - 1:s.End - q;

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

                    s.Window[q++] = (byte)lit; m--;

                    mode = InflateCodesMode.START;
                    break;

                case  InflateCodesMode.WASH:                          // o: got eob, possibly more output
                    if (k > 7)
                    {
                        // return unused byte, if any
                        k -= 8;
                        n++;
                        p--;                                 // can always return one
                    }

                    s.WritePos = q; r = s.inflate_flush(z, r);
                    q          = s.WritePos; m = q < s.ReadPos?s.ReadPos - q - 1:s.End - q;

                    if (s.ReadPos != s.WritePos)
                    {
                        s.BitB     = b; s.BitK = k;
                        z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
                        s.WritePos = q;
                        return(s.inflate_flush(z, r));
                    }
                    mode = InflateCodesMode.END;
                    goto case InflateCodesMode.END;

                case  InflateCodesMode.END:
                    r          = (int)ZLibResultCode.Z_STREAM_END;
                    s.BitB     = b; s.BitK = k;
                    z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
                    s.WritePos = q;
                    return(s.inflate_flush(z, r));


                case  InflateCodesMode.BADCODE:                          // x: got error

                    r = (int)ZLibResultCode.Z_DATA_ERROR;

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


                default:
                    r = (int)ZLibResultCode.Z_STREAM_ERROR;

                    s.BitB     = b; s.BitK = k;
                    z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
                    s.WritePos = q;
                    return(s.inflate_flush(z, r));
                }
            }
        }
示例#7
0
        /// <summary>
        /// Reads a number of decompressed bytes into the specified byte array.
        /// </summary>
        /// <param name="buffer">The array used to store decompressed bytes.</param>
        /// <param name="offset">The location in the array to begin reading.</param>
        /// <param name="count">The number of decompressed bytes to read.</param>
        /// <returns>The number of bytes that were decompressed into the byte array.</returns>
        /// <example> The following code demonstrates how to use the <c>ZInputStream</c> to decompresses data
        /// <code>
        /// [C#]
        /// private void decompressFile(string inFile, string outFile)
        ///	{
        ///	  /* Create a file to store decompressed data */
        ///		System.IO.FileStream decompressedFile = new System.IO.FileStream(@"c:\data\decompressed.dat", System.IO.FileMode.Create);
        ///		/* Open a file containing compressed data */
        ///		System.IO.FileStream compressedFile = new System.IO.FileStream(@"c:\data\compressed.dat", System.IO.FileMode.Open);
        ///		/* Create ZInputStream for decompression */
        ///		ZInputStream decompressionStream = new ZInputStream(compressedFile);
        ///
        ///		try
        ///		{
        ///				byte[] buffer = new byte[2000];
        ///				int len;
        ///				/* Read and decompress data */
        ///				while ((len = decompressionStream.Read(buffer, 0, 2000)) > 0)
        ///				{
        ///				  /* Store decompressed data */
        ///					decompressedFile.Write(buffer, 0, len);
        ///				}
        ///		}
        ///		finally
        ///		{
        ///			decompressionStream.Close();
        ///			decompressedFile.Close();
        ///			compressedFile.Close();
        ///		}
        ///	}
        /// </code>
        /// </example>
        public override int Read(byte[] buffer, int offset, int count)
        {
            if (count == 0)
            {
                return(0);
            }

            if (this.needCopyArrays && ZLibUtil.CopyLargeArrayToSmall.GetRemainingDataSize() > 0)
            {
                return(ZLibUtil.CopyLargeArrayToSmall.CopyData());
            }
            else
            {
                this.needCopyArrays = false;
            }

            bool call_finish = false;
            int  err;

            z.next_out       = buffer;
            z.next_out_index = offset;
            z.avail_out      = count;
            do
            {
                if ((z.avail_in == 0) && (!nomoreinput))
                {
                    // if buffer is empty and more input is available, refill it
                    z.next_in_index = 0;
                    z.avail_in      = ZLibUtil.ReadInput(_stream, buf, 0, ZLibUtil.zLibBufSize); //(ZLibUtil.zLibBufSize<z._avail_out ? ZLibUtil.zLibBufSize : z._avail_out));
                    if (z.avail_in == -1)
                    {
                        z.avail_in  = 0;
                        nomoreinput = true;
                    }
                }
                if ((z.avail_in == 0) && nomoreinput)
                {
                    call_finish = true;
                    break;
                }

                err = z.inflate(flush);
                if (nomoreinput && (err == (int)ZLibResultCode.Z_BUF_ERROR))
                {
                    return(-1);
                }
                if (err != (int)ZLibResultCode.Z_OK && err != (int)ZLibResultCode.Z_STREAM_END)
                {
                    throw new ZStreamException("inflating: " + z.msg);
                }
                if (nomoreinput && (z.avail_out == count))
                {
                    return(-1);
                }
            }while (z.avail_out == count && err == (int)ZLibResultCode.Z_OK);
            if (call_finish)
            {
                return(Finish(buffer, offset, count));
            }
            return(count - z.avail_out);
        }