internal int inflateInit(ZStream z, int w)
        {
            z.msg  = null;
            blocks = null;

            // handle undocumented nowrap option (no zlib header or check)
            nowrap = 0;
            if (w < 0)
            {
                w      = -w;
                nowrap = 1;
            }

            // set window size
            if (w < 8 || w > 15)
            {
                inflateEnd(z);
                return(Z_STREAM_ERROR);
            }
            wbits = w;

            z.istate.blocks = new InfBlocks(z,
                                            z.istate.nowrap != 0 ? null : this,
                                            1 << w);

            // reset state
            inflateReset(z);
            return(Z_OK);
        }
 internal int inflateEnd(ZStream z)
 {
     if (blocks != null)
     {
         blocks.free(z);
     }
     blocks = null;
     //    ZFREE(z, z->state);
     return(Z_OK);
 }
        // Called with number of bytes left to write in window at least 258
        // (the maximum string length) and number of input bytes available
        // at least ten.  The ten bytes are six bytes for the longest length/
        // distance pair plus four bytes for overloading the bit buffer.

        internal int inflate_fast(int bl, int bd,
                                  int[] tl, int tl_index,
                                  int[] td, int td_index,
                                  InfBlocks s, ZStream z)
        {
            int t;                // temporary pointer

            int[] tp;             // temporary pointer
            int   tp_index;       // temporary pointer
            int   e;              // extra bits or operation
            int   b;              // bit buffer
            int   k;              // bits in bit buffer
            int   p;              // input data pointer
            int   n;              // bytes available there
            int   q;              // output window write pointer
            int   m;              // bytes to end of window or read pointer
            int   ml;             // mask for literal/length tree
            int   md;             // mask for distance tree
            int   c;              // bytes to copy
            int   d;              // distance back to copy from
            int   r;              // copy source pointer

            int tp_index_t_3;     // (tp_index+t)*3

            // load input, output, bit values
            p = z.next_in_index; n = z.avail_in; b = s.bitb; k = s.bitk;
            q = s.write; m = q < s.read?s.read - q - 1:s.end - q;

            // initialize masks
            ml = inflate_mask[bl];
            md = inflate_mask[bd];

            // do until not enough input or output space for fast loop
            do                            // assume called with m >= 258 && n >= 10
            // get literal/length code
            {
                while (k < (20))        // max bits for literal/length code
                {
                    n--;
                    b |= (z.next_in[p++] & 0xff) << k; k += 8;
                }

                t            = b & ml;
                tp           = tl;
                tp_index     = tl_index;
                tp_index_t_3 = (tp_index + t) * 3;
                if ((e = tp[tp_index_t_3]) == 0)
                {
                    b >>= (tp[tp_index_t_3 + 1]); k -= (tp[tp_index_t_3 + 1]);

                    s.window[q++] = (byte)tp[tp_index_t_3 + 2];
                    m--;
                    continue;
                }
                do
                {
                    b >>= (tp[tp_index_t_3 + 1]); k -= (tp[tp_index_t_3 + 1]);

                    if ((e & 16) != 0)
                    {
                        e &= 15;
                        c  = tp[tp_index_t_3 + 2] + ((int)b & inflate_mask[e]);

                        b >>= e; k -= e;

                        // decode distance base of block to copy
                        while (k < (15))            // max bits for distance code
                        {
                            n--;
                            b |= (z.next_in[p++] & 0xff) << k; k += 8;
                        }

                        t            = b & md;
                        tp           = td;
                        tp_index     = td_index;
                        tp_index_t_3 = (tp_index + t) * 3;
                        e            = tp[tp_index_t_3];

                        do
                        {
                            b >>= (tp[tp_index_t_3 + 1]); k -= (tp[tp_index_t_3 + 1]);

                            if ((e & 16) != 0)
                            {
                                // get extra bits to add to distance base
                                e &= 15;
                                while (k < (e))          // get extra bits (up to 13)
                                {
                                    n--;
                                    b |= (z.next_in[p++] & 0xff) << k; k += 8;
                                }

                                d = tp[tp_index_t_3 + 2] + (b & inflate_mask[e]);

                                b >>= (e); k -= (e);

                                // do the copy
                                m -= c;
                                if (q >= d)                 // offset before dest
                                //  just copy
                                {
                                    r = q - d;
                                    if (q - r > 0 && 2 > (q - r))
                                    {
                                        s.window[q++] = s.window[r++]; // minimum count is three,
                                        s.window[q++] = s.window[r++]; // so unroll loop a little
                                        c            -= 2;
                                    }
                                    else
                                    {
                                        System.Array.Copy(s.window, r, s.window, q, 2);
                                        q += 2; r += 2; c -= 2;
                                    }
                                }
                                else                   // else offset after destination
                                {
                                    r = q - d;
                                    do
                                    {
                                        r += s.end;        // force pointer in window
                                    }while(r < 0);         // covers invalid distances
                                    e = s.end - r;
                                    if (c > e)             // if source crosses,
                                    {
                                        c -= e;            // wrapped copy
                                        if (q - r > 0 && e > (q - r))
                                        {
                                            do
                                            {
                                                s.window[q++] = s.window[r++];
                                            }while(--e != 0);
                                        }
                                        else
                                        {
                                            System.Array.Copy(s.window, r, s.window, q, e);
                                            q += e; r += e; e = 0;
                                        }
                                        r = 0;                  // copy rest from start of window
                                    }
                                }

                                // copy all or what's left
                                if (q - r > 0 && c > (q - r))
                                {
                                    do
                                    {
                                        s.window[q++] = s.window[r++];
                                    }while(--c != 0);
                                }
                                else
                                {
                                    System.Array.Copy(s.window, r, s.window, q, c);
                                    q += c; r += c; c = 0;
                                }
                                break;
                            }
                            else if ((e & 64) == 0)
                            {
                                t           += tp[tp_index_t_3 + 2];
                                t           += (b & inflate_mask[e]);
                                tp_index_t_3 = (tp_index + t) * 3;
                                e            = tp[tp_index_t_3];
                            }
                            else
                            {
                                z.msg = "invalid distance code";

                                c = z.avail_in - n; c = (k >> 3) < c?k >> 3:c; n += c; p -= c; k -= c << 3;

                                s.bitb     = b; s.bitk = k;
                                z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
                                s.write    = q;

                                return(Z_DATA_ERROR);
                            }
                        }while(true);
                        break;
                    }

                    if ((e & 64) == 0)
                    {
                        t           += tp[tp_index_t_3 + 2];
                        t           += (b & inflate_mask[e]);
                        tp_index_t_3 = (tp_index + t) * 3;
                        if ((e = tp[tp_index_t_3]) == 0)
                        {
                            b >>= (tp[tp_index_t_3 + 1]); k -= (tp[tp_index_t_3 + 1]);

                            s.window[q++] = (byte)tp[tp_index_t_3 + 2];
                            m--;
                            break;
                        }
                    }
                    else if ((e & 32) != 0)
                    {
                        c = z.avail_in - n; c = (k >> 3) < c?k >> 3:c; n += c; p -= c; k -= c << 3;

                        s.bitb     = b; s.bitk = k;
                        z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
                        s.write    = q;

                        return(Z_STREAM_END);
                    }
                    else
                    {
                        z.msg = "invalid literal/length code";

                        c = z.avail_in - n; c = (k >> 3) < c?k >> 3:c; n += c; p -= c; k -= c << 3;

                        s.bitb     = b; s.bitk = k;
                        z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
                        s.write    = q;

                        return(Z_DATA_ERROR);
                    }
                }while(true);
            }while(m >= 258 && n >= 10);

            // not enough input or output--restore pointers and return
            c = z.avail_in - n; c = (k >> 3) < c?k >> 3:c; n += c; p -= c; k -= c << 3;

            s.bitb     = b; s.bitk = k;
            z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
            s.write    = q;

            return(Z_OK);
        }
        internal int proc(InfBlocks s, ZStream z, int r)
        {
            int j;              // temporary storage
            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 write pointer
            int m;              // bytes to end of window or read 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.write; m = q < s.read?s.read - 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 START:             // x: set up for 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.write    = 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.write; m = q < s.read?s.read - q - 1:s.end - q;

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

                    mode = LEN;
                    goto case LEN;

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

                    while (k < (j))
                    {
                        if (n != 0)
                        {
                            r = 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.write    = q;
                            return(s.inflate_flush(z, r));
                        }
                        n--;
                        b |= (z.next_in[p++] & 0xff) << k;
                        k += 8;
                    }

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

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

                    e = tree[tindex];

                    if (e == 0)                   // literal
                    {
                        lit  = tree[tindex + 2];
                        mode = LIT;
                        break;
                    }
                    if ((e & 16) != 0)             // length
                    {
                        get  = e & 15;
                        len  = tree[tindex + 2];
                        mode = 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 = WASH;
                        break;
                    }
                    mode  = BADCODE;           // invalid code
                    z.msg = "invalid literal/length code";
                    r     = 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.write    = q;
                    return(s.inflate_flush(z, r));

                case LENEXT:            // i: getting length extra (have base)
                    j = get;

                    while (k < (j))
                    {
                        if (n != 0)
                        {
                            r = 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.write    = q;
                            return(s.inflate_flush(z, r));
                        }
                        n--; b |= (z.next_in[p++] & 0xff) << k;
                        k      += 8;
                    }

                    len += (b & inflate_mask[j]);

                    b >>= j;
                    k  -= j;

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

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

                    while (k < (j))
                    {
                        if (n != 0)
                        {
                            r = 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.write    = q;
                            return(s.inflate_flush(z, r));
                        }
                        n--; b |= (z.next_in[p++] & 0xff) << k;
                        k      += 8;
                    }

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

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

                    e = (tree[tindex]);
                    if ((e & 16) != 0)                 // distance
                    {
                        get  = e & 15;
                        dist = tree[tindex + 2];
                        mode = DISTEXT;
                        break;
                    }
                    if ((e & 64) == 0)             // next table
                    {
                        need       = e;
                        tree_index = tindex / 3 + tree[tindex + 2];
                        break;
                    }
                    mode  = BADCODE;           // invalid code
                    z.msg = "invalid distance code";
                    r     = 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.write    = q;
                    return(s.inflate_flush(z, r));

                case DISTEXT:           // i: getting distance extra
                    j = get;

                    while (k < (j))
                    {
                        if (n != 0)
                        {
                            r = 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.write    = q;
                            return(s.inflate_flush(z, r));
                        }
                        n--; b |= (z.next_in[p++] & 0xff) << k;
                        k      += 8;
                    }

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

                    b >>= j;
                    k  -= j;

                    mode = COPY;
                    goto case COPY;

                case 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 (len != 0)
                    {
                        if (m == 0)
                        {
                            if (q == s.end && s.read != 0)
                            {
                                q = 0; m = q < s.read?s.read - q - 1:s.end - q;
                            }
                            if (m == 0)
                            {
                                s.write = q; r = s.inflate_flush(z, r);
                                q       = s.write; m = q < s.read?s.read - q - 1:s.end - q;

                                if (q == s.end && s.read != 0)
                                {
                                    q = 0; m = q < s.read?s.read - 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.write    = q;
                                    return(s.inflate_flush(z, r));
                                }
                            }
                        }

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

                        if (f == s.end)
                        {
                            f = 0;
                        }
                        len--;
                    }
                    mode = START;
                    break;

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

                            if (q == s.end && s.read != 0)
                            {
                                q = 0; m = q < s.read?s.read - 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.write    = q;
                                return(s.inflate_flush(z, r));
                            }
                        }
                    }
                    r = Z_OK;

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

                    mode = START;
                    break;

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

                    s.write = q; r = s.inflate_flush(z, r);
                    q       = s.write; m = q < s.read?s.read - q - 1:s.end - q;

                    if (s.read != s.write)
                    {
                        s.bitb     = b; s.bitk = k;
                        z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
                        s.write    = q;
                        return(s.inflate_flush(z, r));
                    }
                    mode = END;
                    goto case END;

                case END:
                    r          = 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.write    = q;
                    return(s.inflate_flush(z, r));

                case BADCODE:           // x: got error

                    r = 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.write    = q;
                    return(s.inflate_flush(z, r));

                default:
                    r = 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.write    = q;
                    return(s.inflate_flush(z, r));
                }
            }
        }