internal int Initialize(ZlibCodec codec, CompressionLevel level, int bits, CompressionStrategy compressionStrategy)
{
return Initialize(codec, level, bits, MEM_LEVEL_DEFAULT, compressionStrategy);
}
internal int Initialize(ZlibCodec codec, CompressionLevel level, int windowBits, int memLevel, CompressionStrategy strategy)
{
_codec = codec;
_codec.Message = null;
// validation
if (windowBits < 9 || windowBits > 15)
throw new ZlibException("windowBits must be in the range 9..15.");
if (memLevel < 1 || memLevel > MEM_LEVEL_MAX)
throw new ZlibException(String.Format("memLevel must be in the range 1.. {0}", MEM_LEVEL_MAX));
_codec.dstate = this;
w_bits = windowBits;
w_size = 1 << w_bits;
w_mask = w_size - 1;
hash_bits = memLevel + 7;
hash_size = 1 << hash_bits;
hash_mask = hash_size - 1;
hash_shift = ((hash_bits + MIN_MATCH - 1) / MIN_MATCH);
window = new byte[w_size * 2];
prev = new short[w_size];
head = new short[hash_size];
// for memLevel==8, this will be 16384, 16k
lit_bufsize = 1 << (memLevel + 6);
// Use a single array as the buffer for data pending compression,
// the output distance codes, and the output length codes (aka tree).
// orig comment: This works just fine since the average
// output size for (length,distance) codes is <= 24 bits.
pending = new byte[lit_bufsize * 4];
_distanceOffset = lit_bufsize;
_lengthOffset = (1 + 2) * lit_bufsize;
// So, for memLevel 8, the length of the pending buffer is 65536. 64k.
// The first 16k are pending bytes.
// The middle slice, of 32k, is used for distance codes.
// The final 16k are length codes.
this.compressionLevel = level;
this.compressionStrategy = strategy;
Reset();
return ZlibConstants.Z_OK;
}
private InflateBlockMode mode; // current inflate_block mode
#endregion Fields
#region Constructors
internal InflateBlocks(ZlibCodec codec, System.Object checkfn, int w)
{
_codec = codec;
hufts = new int[MANY * 3];
window = new byte[w];
end = w;
this.checkfn = checkfn;
mode = InflateBlockMode.TYPE;
Reset();
}
internal int Initialize(ZlibCodec codec, CompressionLevel level)
{
return Initialize(codec, level, ZlibConstants.WindowBitsMax);
}
internal int Initialize(ZlibCodec codec, int w)
{
_codec = codec;
_codec.Message = 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)
{
End();
throw new ZlibException("Bad window size.");
//return ZlibConstants.Z_STREAM_ERROR;
}
wbits = w;
blocks = new InflateBlocks(codec,
HandleRfc1950HeaderBytes ? this : null,
1 << w);
// reset state
Reset();
return ZlibConstants.Z_OK;
}
// Returns true if inflate is currently at the end of a block generated
// by Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP
// implementation to provide an additional safety check. PPP uses Z_SYNC_FLUSH
// but removes the length bytes of the resulting empty stored block. When
// decompressing, PPP checks that at the end of input packet, inflate is
// waiting for these length bytes.
internal int SyncPoint(ZlibCodec z)
{
return blocks.SyncPoint();
}
// 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 InflateFast(int bl, int bd, int[] tl, int tl_index, int[] td, int td_index, InflateBlocks s, ZlibCodec 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.NextIn; n = z.AvailableBytesIn; b = s.bitb; k = s.bitk;
q = s.writeAt; m = q < s.readAt ? s.readAt - q - 1 : s.end - q;
// initialize masks
ml = InternalInflateConstants.InflateMask[bl];
md = InternalInflateConstants.InflateMask[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.InputBuffer[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 & InternalInflateConstants.InflateMask[e]);
b >>= e; k -= e;
// decode distance base of block to copy
while (k < 15)
{
// max bits for distance code
n--;
b |= (z.InputBuffer[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.InputBuffer[p++] & 0xff) << k; k += 8;
}
d = tp[tp_index_t_3 + 2] + (b & InternalInflateConstants.InflateMask[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 & InternalInflateConstants.InflateMask[e]);
tp_index_t_3 = (tp_index + t) * 3;
e = tp[tp_index_t_3];
}
else
{
z.Message = "invalid distance code";
c = z.AvailableBytesIn - n; c = (k >> 3) < c ? k >> 3 : c; n += c; p -= c; k -= (c << 3);
s.bitb = b; s.bitk = k;
z.AvailableBytesIn = n; z.TotalBytesIn += p - z.NextIn; z.NextIn = p;
s.writeAt = q;
return ZlibConstants.Z_DATA_ERROR;
}
}
while (true);
break;
}
if ((e & 64) == 0)
{
t += tp[tp_index_t_3 + 2];
t += (b & InternalInflateConstants.InflateMask[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.AvailableBytesIn - n; c = (k >> 3) < c ? k >> 3 : c; n += c; p -= c; k -= (c << 3);
s.bitb = b; s.bitk = k;
z.AvailableBytesIn = n; z.TotalBytesIn += p - z.NextIn; z.NextIn = p;
s.writeAt = q;
return ZlibConstants.Z_STREAM_END;
}
else
{
z.Message = "invalid literal/length code";
c = z.AvailableBytesIn - n; c = (k >> 3) < c ? k >> 3 : c; n += c; p -= c; k -= (c << 3);
s.bitb = b; s.bitk = k;
z.AvailableBytesIn = n; z.TotalBytesIn += p - z.NextIn; z.NextIn = p;
s.writeAt = q;
return ZlibConstants.Z_DATA_ERROR;
}
}
while (true);
}
while (m >= 258 && n >= 10);
// not enough input or output--restore pointers and return
c = z.AvailableBytesIn - n; c = (k >> 3) < c ? k >> 3 : c; n += c; p -= c; k -= (c << 3);
s.bitb = b; s.bitk = k;
z.AvailableBytesIn = n; z.TotalBytesIn += p - z.NextIn; z.NextIn = p;
s.writeAt = q;
return ZlibConstants.Z_OK;
}
internal int inflate_trees_dynamic(int nl, int nd, int[] c, int[] bl, int[] bd, int[] tl, int[] td, int[] hp, ZlibCodec z)
{
int result;
// build literal/length tree
initWorkArea(288);
hn[0] = 0;
result = huft_build(c, 0, nl, 257, cplens, cplext, tl, bl, hp, hn, v);
if (result != Z_OK || bl[0] == 0)
{
if (result == Z_DATA_ERROR)
{
z.Message = "oversubscribed literal/length tree";
}
else if (result != Z_MEM_ERROR)
{
z.Message = "incomplete literal/length tree";
result = Z_DATA_ERROR;
}
return result;
}
// build distance tree
initWorkArea(288);
result = huft_build(c, nl, nd, 0, cpdist, cpdext, td, bd, hp, hn, v);
if (result != Z_OK || (bd[0] == 0 && nl > 257))
{
if (result == Z_DATA_ERROR)
{
z.Message = "oversubscribed distance tree";
}
else if (result == Z_BUF_ERROR)
{
z.Message = "incomplete distance tree";
result = Z_DATA_ERROR;
}
else if (result != Z_MEM_ERROR)
{
z.Message = "empty distance tree with lengths";
result = Z_DATA_ERROR;
}
return result;
}
return Z_OK;
}
internal int inflate_trees_bits(int[] c, int[] bb, int[] tb, int[] hp, ZlibCodec z)
{
int result;
initWorkArea(19);
hn[0] = 0;
result = huft_build(c, 0, 19, 19, null, null, tb, bb, hp, hn, v);
if (result == Z_DATA_ERROR)
{
z.Message = "oversubscribed dynamic bit lengths tree";
}
else if (result == Z_BUF_ERROR || bb[0] == 0)
{
z.Message = "incomplete dynamic bit lengths tree";
result = Z_DATA_ERROR;
}
return result;
}
internal static int inflate_trees_fixed(int[] bl, int[] bd, int[][] tl, int[][] td, ZlibCodec z)
{
bl[0] = fixed_bl;
bd[0] = fixed_bd;
tl[0] = fixed_tl;
td[0] = fixed_td;
return Z_OK;
}
private void end()
{
if (z == null)
return;
if (_wantCompress)
{
_z.EndDeflate();
}
else
{
_z.EndInflate();
}
_z = null;
}