Пример #1
0
 internal void Free(ZStream z)
 {
     //  ZFREE(z, c);
 }
Пример #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.

        static 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
                                    {
                                        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]);
                                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);
        }
Пример #3
0
 internal InfCodes(ZStream z, InfBlocks s)
 {
     this.z = z;
     this.s = s;
 }