Exemple #1
0
        // 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

            // 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;
                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] + (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;
                        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++];
                                        c--; // minimum count is three,
                                        s.window[q++] = s.window[r++];
                                        c--; // so unroll loop a little
                                    }
                                    else
                                    {
                                        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
                                        {
                                            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
                                {
                                    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]);
                                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]);
                        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;
        }
Exemple #2
0
        // 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

            // 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;
                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] + (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;
                        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++];
                                        c--; // minimum count is three,
                                        s.window[q++] = s.window[r++];
                                        c--; // so unroll loop a little
                                    }
                                    else
                                    {
                                        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
                                        {
                                            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
                                {
                                    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]);
                                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]);
                        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);
        }
Exemple #3
0
        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 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 = SupportClass.URShift(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_Renamed = 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_Renamed;

                        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_Renamed = 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_Renamed;

                        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);
                }
            }
        }
Exemple #4
0
        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 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  = SupportClass.URShift(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_Renamed = 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_Renamed;

                    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_Renamed = 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_Renamed;

                    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));
                }
            }
        }