/// <summary>
/// Skips n decompressed bytes in the stream.
/// </summary>
/// <param name="n">The number of bytes to skip.</param>
public long Skip(long n)
{
int len = 512;
if (n < len)
{
len = (int)n;
}
byte[] tmp = new byte[len];
return((long)ZLibUtil.ReadInput(this, tmp, 0, tmp.Length));
}
///<summary>
/// Reverse the first count bits of a code, using straightforward code (a faster
/// method would use a table)
///</summary>
private static int bi_reverse(int code, int len)
{
int res = 0;
do
{
res |= code & 1;
code = ZLibUtil.URShift(code, 1);
res <<= 1;
}while (--len > 0);
return(ZLibUtil.URShift(res, 1));
}
/// <summary>
/// Block processing functions
/// </summary>
internal int proc(ZStream z, int r)
{
int t; // temporary storage
int b; // bit buffer
int k; // bits in bit buffer
int p; // input data pointer
int n; // bytes available there
int q; // output Window WritePos pointer
int m; // bytes to End of Window or ReadPos pointer
// copy input/output information to locals (UPDATE macro restores)
{
p = z.next_in_index; n = z.avail_in; b = BitB; k = BitK;
}
{
q = WritePos; m = (int)(q < ReadPos ? ReadPos - q - 1 : End - q);
}
// process input based on current state
while (true)
{
switch (mode)
{
case InflateBlockMode.TYPE:
while (k < (3))
{
if (n != 0)
{
r = (int)ZLibResultCode.Z_OK;
}
else
{
BitB = b; BitK = k;
z.avail_in = n;
z.total_in += p - z.next_in_index; z.next_in_index = p;
WritePos = q;
return(inflate_flush(z, r));
}
;
n--;
b |= (z.next_in[p++] & 0xff) << k;
k += 8;
}
t = (int)(b & 7);
last = t & 1;
switch (ZLibUtil.URShift(t, 1))
{
case 0: // stored
{
b = ZLibUtil.URShift(b, (3)); k -= (3);
}
t = k & 7; // go to byte boundary
{
b = ZLibUtil.URShift(b, (t)); k -= (t);
}
mode = InflateBlockMode.LENS; // get length of stored block
break;
case 1: // fixed
{
int[] bl = new int[1];
int[] bd = new int[1];
int[][] tl = new int[1][];
int[][] td = new int[1][];
InfTree.inflate_trees_fixed(bl, bd, tl, td, z);
codes = new InfCodes(bl[0], bd[0], tl[0], td[0], z);
}
{
b = ZLibUtil.URShift(b, (3)); k -= (3);
}
mode = InflateBlockMode.CODES;
break;
case 2: // dynamic
{
b = ZLibUtil.URShift(b, (3)); k -= (3);
}
mode = InflateBlockMode.TABLE;
break;
case 3: // illegal
{
b = ZLibUtil.URShift(b, (3)); k -= (3);
}
mode = InflateBlockMode.BAD;
z.msg = "invalid block type";
r = (int)ZLibResultCode.Z_DATA_ERROR;
BitB = b; BitK = k;
z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
WritePos = q;
return(inflate_flush(z, r));
}
break;
case InflateBlockMode.LENS:
while (k < (32))
{
if (n != 0)
{
r = (int)ZLibResultCode.Z_OK;
}
else
{
BitB = b; BitK = k;
z.avail_in = n;
z.total_in += p - z.next_in_index; z.next_in_index = p;
WritePos = q;
return(inflate_flush(z, r));
}
;
n--;
b |= (z.next_in[p++] & 0xff) << k;
k += 8;
}
if (((ZLibUtil.URShift((~b), 16)) & 0xffff) != (b & 0xffff))
{
mode = InflateBlockMode.BAD;
z.msg = "invalid stored block lengths";
r = (int)ZLibResultCode.Z_DATA_ERROR;
BitB = b; BitK = k;
z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
WritePos = q;
return(inflate_flush(z, r));
}
left = (b & 0xffff);
b = k = 0; // dump bits
mode = (left != 0) ? InflateBlockMode.STORED : (last != 0 ? InflateBlockMode.DRY : InflateBlockMode.TYPE);
break;
case InflateBlockMode.STORED:
if (n == 0)
{
BitB = b; BitK = k;
z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
WritePos = q;
return(inflate_flush(z, r));
}
if (m == 0)
{
if (q == End && ReadPos != 0)
{
q = 0; m = (int)(q < ReadPos ? ReadPos - q - 1 : End - q);
}
if (m == 0)
{
WritePos = q;
r = inflate_flush(z, r);
q = WritePos; m = (int)(q < ReadPos ? ReadPos - q - 1 : End - q);
if (q == End && ReadPos != 0)
{
q = 0; m = (int)(q < ReadPos ? ReadPos - q - 1 : End - q);
}
if (m == 0)
{
BitB = b; BitK = k;
z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
WritePos = q;
return(inflate_flush(z, r));
}
}
}
r = (int)ZLibResultCode.Z_OK;
t = left;
if (t > n)
{
t = n;
}
if (t > m)
{
t = m;
}
Array.Copy(z.next_in, p, Window, q, t);
p += t; n -= t;
q += t; m -= t;
if ((left -= t) != 0)
{
break;
}
mode = last != 0 ? InflateBlockMode.DRY : InflateBlockMode.TYPE;
break;
case InflateBlockMode.TABLE:
while (k < (14))
{
if (n != 0)
{
r = (int)ZLibResultCode.Z_OK;
}
else
{
BitB = b; BitK = k;
z.avail_in = n;
z.total_in += p - z.next_in_index; z.next_in_index = p;
WritePos = q;
return(inflate_flush(z, r));
}
;
n--;
b |= (z.next_in[p++] & 0xff) << k;
k += 8;
}
table = t = (b & 0x3fff);
if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29)
{
mode = InflateBlockMode.BAD;
z.msg = "too many length or distance symbols";
r = (int)ZLibResultCode.Z_DATA_ERROR;
BitB = b; BitK = k;
z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
WritePos = q;
return(inflate_flush(z, r));
}
t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f);
blens = new int[t];
{
b = ZLibUtil.URShift(b, (14)); k -= (14);
}
index = 0;
mode = InflateBlockMode.BTREE;
goto case InflateBlockMode.BTREE;
case InflateBlockMode.BTREE:
while (index < 4 + (ZLibUtil.URShift(table, 10)))
{
while (k < (3))
{
if (n != 0)
{
r = (int)ZLibResultCode.Z_OK;
}
else
{
BitB = b; BitK = k;
z.avail_in = n;
z.total_in += p - z.next_in_index; z.next_in_index = p;
WritePos = q;
return(inflate_flush(z, r));
}
;
n--;
b |= (z.next_in[p++] & 0xff) << k;
k += 8;
}
blens[ZLibUtil.border[index++]] = b & 7;
{
b = ZLibUtil.URShift(b, (3)); k -= (3);
}
}
while (index < 19)
{
blens[ZLibUtil.border[index++]] = 0;
}
bb[0] = 7;
t = InfTree.inflate_trees_bits(blens, bb, tb, hufts, z);
if (t != (int)ZLibResultCode.Z_OK)
{
r = t;
if (r == (int)ZLibResultCode.Z_DATA_ERROR)
{
blens = null;
mode = InflateBlockMode.BAD;
}
BitB = b; BitK = k;
z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
WritePos = q;
return(inflate_flush(z, r));
}
index = 0;
mode = InflateBlockMode.DTREE;
goto case InflateBlockMode.DTREE;
case InflateBlockMode.DTREE:
while (true)
{
t = table;
if (!(index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f)))
{
break;
}
int i, j, c;
t = bb[0];
while (k < (t))
{
if (n != 0)
{
r = (int)ZLibResultCode.Z_OK;
}
else
{
BitB = b; BitK = k;
z.avail_in = n;
z.total_in += p - z.next_in_index; z.next_in_index = p;
WritePos = q;
return(inflate_flush(z, r));
}
;
n--;
b |= (z.next_in[p++] & 0xff) << k;
k += 8;
}
t = hufts[(tb[0] + (b & ZLibUtil.inflate_mask[t])) * 3 + 1];
c = hufts[(tb[0] + (b & ZLibUtil.inflate_mask[t])) * 3 + 2];
if (c < 16)
{
b = ZLibUtil.URShift(b, (t)); k -= (t);
blens[index++] = c;
}
else
{
// c == 16..18
i = c == 18 ? 7 : c - 14;
j = c == 18 ? 11 : 3;
while (k < (t + i))
{
if (n != 0)
{
r = (int)ZLibResultCode.Z_OK;
}
else
{
BitB = b; BitK = k;
z.avail_in = n;
z.total_in += p - z.next_in_index; z.next_in_index = p;
WritePos = q;
return(inflate_flush(z, r));
}
;
n--;
b |= (z.next_in[p++] & 0xff) << k;
k += 8;
}
b = ZLibUtil.URShift(b, (t)); k -= (t);
j += (b & ZLibUtil.inflate_mask[i]);
b = ZLibUtil.URShift(b, (i)); k -= (i);
i = index;
t = table;
if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) || (c == 16 && i < 1))
{
blens = null;
mode = InflateBlockMode.BAD;
z.msg = "invalid bit length repeat";
r = (int)ZLibResultCode.Z_DATA_ERROR;
BitB = b; BitK = k;
z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
WritePos = q;
return(inflate_flush(z, r));
}
c = c == 16 ? blens[i - 1] : 0;
do
{
blens[i++] = c;
}while (--j != 0);
index = i;
}
}
tb[0] = -1;
{
int[] bl = new int[1];
int[] bd = new int[1];
int[] tl = new int[1];
int[] td = new int[1];
bl[0] = 9; // must be <= 9 for lookahead assumptions
bd[0] = 6; // must be <= 9 for lookahead assumptions
t = table;
t = InfTree.inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f), blens, bl, bd, tl, td, hufts, z);
if (t != (int)ZLibResultCode.Z_OK)
{
if (t == (int)ZLibResultCode.Z_DATA_ERROR)
{
blens = null;
mode = InflateBlockMode.BAD;
}
r = t;
BitB = b; BitK = k;
z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
WritePos = q;
return(inflate_flush(z, r));
}
codes = new InfCodes(bl[0], bd[0], hufts, tl[0], hufts, td[0], z);
}
blens = null;
mode = InflateBlockMode.CODES;
goto case InflateBlockMode.CODES;
case InflateBlockMode.CODES:
BitB = b; BitK = k;
z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
WritePos = q;
if ((r = codes.proc(this, z, r)) != (int)ZLibResultCode.Z_STREAM_END)
{
return(inflate_flush(z, r));
}
r = (int)ZLibResultCode.Z_OK;
codes.free(z);
p = z.next_in_index; n = z.avail_in; b = BitB; k = BitK;
q = WritePos; m = (int)(q < ReadPos ? ReadPos - q - 1 : End - q);
if (last == 0)
{
mode = InflateBlockMode.TYPE;
break;
}
mode = InflateBlockMode.DRY;
goto case InflateBlockMode.DRY;
case InflateBlockMode.DRY:
WritePos = q;
r = inflate_flush(z, r);
q = WritePos; m = (int)(q < ReadPos ? ReadPos - q - 1 : End - q);
if (ReadPos != WritePos)
{
BitB = b; BitK = k;
z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
WritePos = q;
return(inflate_flush(z, r));
}
mode = InflateBlockMode.DONE;
goto case InflateBlockMode.DONE;
case InflateBlockMode.DONE:
r = (int)ZLibResultCode.Z_STREAM_END;
BitB = b; BitK = k;
z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
WritePos = q;
return(inflate_flush(z, r));
case InflateBlockMode.BAD:
r = (int)ZLibResultCode.Z_DATA_ERROR;
BitB = b; BitK = k;
z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
WritePos = q;
return(inflate_flush(z, r));
default:
r = (int)ZLibResultCode.Z_STREAM_ERROR;
BitB = b; BitK = k;
z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
WritePos = q;
return(inflate_flush(z, r));
}
}
}
/// <summary>
/// Given a list of code lengths and a maximum table size, make a set of
/// tables to decode that set of codes.
/// </summary>
/// <returns>Return (int)ZLibResultCode.Z_OK on success, (int)ZLibResultCode.Z_DATA_ERROR if the given code set is incomplete (the tables are still built in this case), (int)ZLibResultCode.Z_DATA_ERROR if the input is invalid (an over-subscribed set of lengths), or (int)ZLibResultCode.Z_DATA_ERROR if not enough memory.
/// </returns>
private static int huft_build(int[] b, int bindex, int n, int s, int[] d, int[] e, int[] t, int[] m, int[] hp, int[] hn, int[] v)
{
int a; // counter for codes of length k
int[] c = new int[InfTreeUtil.BMAX + 1]; // bit length count table
int f; // i repeats in table every internalFlush entries
int g; // maximum code length
int h; // table level
int i; // counter, current code
int j; // counter
int k; // number of bits in current code
int l; // bits per table (returned in m)
int mask; // (1 << windowBits) - 1, to avoid cc -O bug on HP
int p; // pointer into c[], buffer[], or v[]
int q; // points to current table
int[] r = new int[3]; // table entry for structure assignment
int[] u = new int[InfTreeUtil.BMAX]; // table stack
int w; // bits before this table == (l * h)
int[] x = new int[InfTreeUtil.BMAX + 1]; // bit offsets, then code stack
int xp; // pointer into x
int y; // number of dummy codes added
int z; // number of entries in current table
// Generate counts for each bit length
p = 0; i = n;
do
{
c[b[bindex + p]]++; p++; i--; // assume all entries <= BMAX
}while (i != 0);
if (c[0] == n)
{
// null input--all zero length codes
t[0] = -1;
m[0] = 0;
return((int)ZLibResultCode.Z_OK);
}
// Find minimum and maximum length, bound *m by those
l = m[0];
for (j = 1; j <= InfTreeUtil.BMAX; j++)
{
if (c[j] != 0)
{
break;
}
}
k = j; // minimum code length
if (l < j)
{
l = j;
}
for (i = InfTreeUtil.BMAX; i != 0; i--)
{
if (c[i] != 0)
{
break;
}
}
g = i; // maximum code length
if (l > i)
{
l = i;
}
m[0] = l;
// Adjust last length count to fill out codes, if needed
for (y = 1 << j; j < i; j++, y <<= 1)
{
if ((y -= c[j]) < 0)
{
return((int)ZLibResultCode.Z_DATA_ERROR);
}
}
if ((y -= c[i]) < 0)
{
return((int)ZLibResultCode.Z_DATA_ERROR);
}
c[i] += y;
// Generate starting offsets into the value table for each length
x[1] = j = 0;
p = 1; xp = 2;
while (--i != 0)
{
// note that i == g from above
x[xp] = (j += c[p]);
xp++;
p++;
}
// Make a table of values in order of bit lengths
i = 0; p = 0;
do
{
if ((j = b[bindex + p]) != 0)
{
v[x[j]++] = i;
}
p++;
}while (++i < n);
n = x[g]; // set n to length of v
// Generate the Huffman codes and for each, make the table entries
x[0] = i = 0; // first Huffman code is zero
p = 0; // grab values in bit order
h = -1; // no tables yet--level -1
w = -l; // bits decoded == (l * h)
u[0] = 0; // just to keep compilers happy
q = 0; // ditto
z = 0; // ditto
// go through the bit lengths (k already is bits in shortest code)
for (; k <= g; k++)
{
a = c[k];
while (a-- != 0)
{
// here i is the Huffman code of length k bits for value *p
// make tables up to required level
while (k > w + l)
{
h++;
w += l; // previous table always l bits
// compute minimum size table less than or equal to l bits
z = g - w;
z = (z > l)?l:z; // table size upper limit
if ((f = 1 << (j = k - w)) > a + 1)
{
// try a k-windowBits bit table
// too few codes for k-windowBits bit table
f -= (a + 1); // deduct codes from patterns left
xp = k;
if (j < z)
{
while (++j < z)
{
// try smaller tables up to z bits
if ((f <<= 1) <= c[++xp])
{
break; // enough codes to use up j bits
}
f -= c[xp]; // else deduct codes from patterns
}
}
}
z = 1 << j; // table entries for j-bit table
// allocate new table
if (hn[0] + z > InfTreeUtil.MANY)
{
// (note: doesn't matter for fixed)
return((int)ZLibResultCode.Z_DATA_ERROR); // overflow of MANY
}
u[h] = q = hn[0]; // DEBUG
hn[0] += z;
// connect to last table, if there is one
if (h != 0)
{
x[h] = i; // save pattern for backing up
r[0] = (byte)j; // bits in this table
r[1] = (byte)l; // bits to dump before this table
j = ZLibUtil.URShift(i, (w - l));
r[2] = (int)(q - u[h - 1] - j); // offset to this table
Array.Copy(r, 0, hp, (u[h - 1] + j) * 3, 3); // connect to last table
}
else
{
t[0] = q; // first table is returned result
}
}
// set up table entry in r
r[1] = (byte)(k - w);
if (p >= n)
{
r[0] = 128 + 64; // out of values--invalid code
}
else if (v[p] < s)
{
r[0] = (byte)(v[p] < 256?0:32 + 64); // 256 is End-of-block
r[2] = v[p++]; // simple code is just the value
}
else
{
r[0] = (byte)(e[v[p] - s] + 16 + 64); // non-simple--look up in lists
r[2] = d[v[p++] - s];
}
// fill code-like entries with r
f = 1 << (k - w);
for (j = ZLibUtil.URShift(i, w); j < z; j += f)
{
Array.Copy(r, 0, hp, (q + j) * 3, 3);
}
// backwards increment the k-bit code i
for (j = 1 << (k - 1); (i & j) != 0; j = ZLibUtil.URShift(j, 1))
{
i ^= j;
}
i ^= j;
// backup over finished tables
mask = (1 << w) - 1; // needed on HP, cc -O bug
while ((i & mask) != x[h])
{
h--; // don't need to update q
w -= l;
mask = (1 << w) - 1;
}
}
}
// Return (int)ZLibResultCode.Z_DATA_ERROR if we were given an incomplete table
return(y != 0 && g != 1 ? (int)ZLibResultCode.Z_BUF_ERROR : (int)ZLibResultCode.Z_OK);
}
/// <summary>
/// Reads a number of decompressed bytes into the specified byte array.
/// </summary>
/// <param name="buffer">The array used to store decompressed bytes.</param>
/// <param name="offset">The location in the array to begin reading.</param>
/// <param name="count">The number of decompressed bytes to read.</param>
/// <returns>The number of bytes that were decompressed into the byte array.</returns>
/// <example> The following code demonstrates how to use the <c>ZInputStream</c> to decompresses data
/// <code>
/// [C#]
/// private void decompressFile(string inFile, string outFile)
/// {
/// /* Create a file to store decompressed data */
/// System.IO.FileStream decompressedFile = new System.IO.FileStream(@"c:\data\decompressed.dat", System.IO.FileMode.Create);
/// /* Open a file containing compressed data */
/// System.IO.FileStream compressedFile = new System.IO.FileStream(@"c:\data\compressed.dat", System.IO.FileMode.Open);
/// /* Create ZInputStream for decompression */
/// ZInputStream decompressionStream = new ZInputStream(compressedFile);
///
/// try
/// {
/// byte[] buffer = new byte[2000];
/// int len;
/// /* Read and decompress data */
/// while ((len = decompressionStream.Read(buffer, 0, 2000)) > 0)
/// {
/// /* Store decompressed data */
/// decompressedFile.Write(buffer, 0, len);
/// }
/// }
/// finally
/// {
/// decompressionStream.Close();
/// decompressedFile.Close();
/// compressedFile.Close();
/// }
/// }
/// </code>
/// </example>
public override int Read(byte[] buffer, int offset, int count)
{
if (count == 0)
{
return(0);
}
if (this.needCopyArrays && ZLibUtil.CopyLargeArrayToSmall.GetRemainingDataSize() > 0)
{
return(ZLibUtil.CopyLargeArrayToSmall.CopyData());
}
else
{
this.needCopyArrays = false;
}
bool call_finish = false;
int err;
z.next_out = buffer;
z.next_out_index = offset;
z.avail_out = count;
do
{
if ((z.avail_in == 0) && (!nomoreinput))
{
// if buffer is empty and more input is available, refill it
z.next_in_index = 0;
z.avail_in = ZLibUtil.ReadInput(_stream, buf, 0, ZLibUtil.zLibBufSize); //(ZLibUtil.zLibBufSize<z._avail_out ? ZLibUtil.zLibBufSize : z._avail_out));
if (z.avail_in == -1)
{
z.avail_in = 0;
nomoreinput = true;
}
}
if ((z.avail_in == 0) && nomoreinput)
{
call_finish = true;
break;
}
err = z.inflate(flush);
if (nomoreinput && (err == (int)ZLibResultCode.Z_BUF_ERROR))
{
return(-1);
}
if (err != (int)ZLibResultCode.Z_OK && err != (int)ZLibResultCode.Z_STREAM_END)
{
throw new ZStreamException("inflating: " + z.msg);
}
if (nomoreinput && (z.avail_out == count))
{
return(-1);
}
}while (z.avail_out == count && err == (int)ZLibResultCode.Z_OK);
if (call_finish)
{
return(Finish(buffer, offset, count));
}
return(count - z.avail_out);
}
/// <summary>
/// Block processing method
/// </summary>
/// <param name="s">An instance of the InfBlocks class</param>
/// <param name="z">A ZStream object</param>
/// <param name="r">A result code</param>
internal int proc(InfBlocks s, ZStream z, int r)
{
int j; // temporary storage
//int[] t; // temporary pointer
int tindex; // temporary pointer
int e; // extra bits or operation
int b = 0; // bit buffer
int k = 0; // bits in bit buffer
int p = 0; // input data pointer
int n; // bytes available there
int q; // output Window WritePos pointer
int m; // bytes to End of Window or ReadPos pointer
int f; // pointer to copy strings from
// copy input/output information to locals (UPDATE macro restores)
p = z.next_in_index; n = z.avail_in; b = s.BitB; k = s.BitK;
q = s.WritePos; m = q < s.ReadPos?s.ReadPos - q - 1:s.End - q;
// process input and output based on current state
while (true)
{
switch (mode)
{
// waiting for "i:"=input, "o:"=output, "x:"=nothing
case InflateCodesMode.START: // x: set up for InflateCodesMode.LEN
if (m >= 258 && n >= 10)
{
s.BitB = b; s.BitK = k;
z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
s.WritePos = q;
r = inflate_fast(lbits, dbits, ltree, ltree_index, dtree, dtree_index, s, z);
p = z.next_in_index; n = z.avail_in; b = s.BitB; k = s.BitK;
q = s.WritePos; m = q < s.ReadPos?s.ReadPos - q - 1:s.End - q;
if (r != (int)ZLibResultCode.Z_OK)
{
mode = r == (int)ZLibResultCode.Z_STREAM_END? InflateCodesMode.WASH: InflateCodesMode.BADCODE;
break;
}
}
need = lbits;
tree = ltree;
tree_index = ltree_index;
mode = InflateCodesMode.LEN;
goto case InflateCodesMode.LEN;
case InflateCodesMode.LEN: // i: get length/literal/eob next
j = need;
while (k < (j))
{
if (n != 0)
{
r = (int)ZLibResultCode.Z_OK;
}
else
{
s.BitB = b; s.BitK = k;
z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
s.WritePos = q;
return(s.inflate_flush(z, r));
}
n--;
b |= (z.next_in[p++] & 0xff) << k;
k += 8;
}
tindex = (tree_index + (b & ZLibUtil.inflate_mask[j])) * 3;
b = ZLibUtil.URShift(b, (tree[tindex + 1]));
k -= (tree[tindex + 1]);
e = tree[tindex];
if (e == 0)
{
// literal
lit = tree[tindex + 2];
mode = InflateCodesMode.LIT;
break;
}
if ((e & 16) != 0)
{
// length
get_Renamed = e & 15;
count = tree[tindex + 2];
mode = InflateCodesMode.LENEXT;
break;
}
if ((e & 64) == 0)
{
// next table
need = e;
tree_index = tindex / 3 + tree[tindex + 2];
break;
}
if ((e & 32) != 0)
{
// End of block
mode = InflateCodesMode.WASH;
break;
}
mode = InflateCodesMode.BADCODE; // invalid code
z.msg = "invalid literal/length code";
r = (int)ZLibResultCode.Z_DATA_ERROR;
s.BitB = b; s.BitK = k;
z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
s.WritePos = q;
return(s.inflate_flush(z, r));
case InflateCodesMode.LENEXT: // i: getting length extra (have base)
j = get_Renamed;
while (k < (j))
{
if (n != 0)
{
r = (int)ZLibResultCode.Z_OK;
}
else
{
s.BitB = b; s.BitK = k;
z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
s.WritePos = q;
return(s.inflate_flush(z, r));
}
n--; b |= (z.next_in[p++] & 0xff) << k;
k += 8;
}
count += (b & ZLibUtil.inflate_mask[j]);
b >>= j;
k -= j;
need = dbits;
tree = dtree;
tree_index = dtree_index;
mode = InflateCodesMode.DIST;
goto case InflateCodesMode.DIST;
case InflateCodesMode.DIST: // i: get distance next
j = need;
while (k < (j))
{
if (n != 0)
{
r = (int)ZLibResultCode.Z_OK;
}
else
{
s.BitB = b; s.BitK = k;
z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
s.WritePos = q;
return(s.inflate_flush(z, r));
}
n--; b |= (z.next_in[p++] & 0xff) << k;
k += 8;
}
tindex = (tree_index + (b & ZLibUtil.inflate_mask[j])) * 3;
b >>= tree[tindex + 1];
k -= tree[tindex + 1];
e = (tree[tindex]);
if ((e & 16) != 0)
{
// distance
get_Renamed = e & 15;
dist = tree[tindex + 2];
mode = InflateCodesMode.DISTEXT;
break;
}
if ((e & 64) == 0)
{
// next table
need = e;
tree_index = tindex / 3 + tree[tindex + 2];
break;
}
mode = InflateCodesMode.BADCODE; // invalid code
z.msg = "invalid distance code";
r = (int)ZLibResultCode.Z_DATA_ERROR;
s.BitB = b; s.BitK = k;
z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
s.WritePos = q;
return(s.inflate_flush(z, r));
case InflateCodesMode.DISTEXT: // i: getting distance extra
j = get_Renamed;
while (k < (j))
{
if (n != 0)
{
r = (int)ZLibResultCode.Z_OK;
}
else
{
s.BitB = b; s.BitK = k;
z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
s.WritePos = q;
return(s.inflate_flush(z, r));
}
n--; b |= (z.next_in[p++] & 0xff) << k;
k += 8;
}
dist += (b & ZLibUtil.inflate_mask[j]);
b >>= j;
k -= j;
mode = InflateCodesMode.COPY;
goto case InflateCodesMode.COPY;
case InflateCodesMode.COPY: // o: copying bytes in Window, waiting for space
f = q - dist;
while (f < 0)
{
// modulo Window size-"while" instead
f += s.End; // of "if" handles invalid distances
}
while (count != 0)
{
if (m == 0)
{
if (q == s.End && s.ReadPos != 0)
{
q = 0; m = q < s.ReadPos?s.ReadPos - q - 1:s.End - q;
}
if (m == 0)
{
s.WritePos = q; r = s.inflate_flush(z, r);
q = s.WritePos; m = q < s.ReadPos?s.ReadPos - q - 1:s.End - q;
if (q == s.End && s.ReadPos != 0)
{
q = 0; m = q < s.ReadPos?s.ReadPos - q - 1:s.End - q;
}
if (m == 0)
{
s.BitB = b; s.BitK = k;
z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
s.WritePos = q;
return(s.inflate_flush(z, r));
}
}
}
s.Window[q++] = s.Window[f++]; m--;
if (f == s.End)
{
f = 0;
}
count--;
}
mode = InflateCodesMode.START;
break;
case InflateCodesMode.LIT: // o: got literal, waiting for output space
if (m == 0)
{
if (q == s.End && s.ReadPos != 0)
{
q = 0; m = q < s.ReadPos?s.ReadPos - q - 1:s.End - q;
}
if (m == 0)
{
s.WritePos = q; r = s.inflate_flush(z, r);
q = s.WritePos; m = q < s.ReadPos?s.ReadPos - q - 1:s.End - q;
if (q == s.End && s.ReadPos != 0)
{
q = 0; m = q < s.ReadPos?s.ReadPos - q - 1:s.End - q;
}
if (m == 0)
{
s.BitB = b; s.BitK = k;
z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
s.WritePos = q;
return(s.inflate_flush(z, r));
}
}
}
r = (int)ZLibResultCode.Z_OK;
s.Window[q++] = (byte)lit; m--;
mode = InflateCodesMode.START;
break;
case InflateCodesMode.WASH: // o: got eob, possibly more output
if (k > 7)
{
// return unused byte, if any
k -= 8;
n++;
p--; // can always return one
}
s.WritePos = q; r = s.inflate_flush(z, r);
q = s.WritePos; m = q < s.ReadPos?s.ReadPos - q - 1:s.End - q;
if (s.ReadPos != s.WritePos)
{
s.BitB = b; s.BitK = k;
z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
s.WritePos = q;
return(s.inflate_flush(z, r));
}
mode = InflateCodesMode.END;
goto case InflateCodesMode.END;
case InflateCodesMode.END:
r = (int)ZLibResultCode.Z_STREAM_END;
s.BitB = b; s.BitK = k;
z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
s.WritePos = q;
return(s.inflate_flush(z, r));
case InflateCodesMode.BADCODE: // x: got error
r = (int)ZLibResultCode.Z_DATA_ERROR;
s.BitB = b; s.BitK = k;
z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
s.WritePos = q;
return(s.inflate_flush(z, r));
default:
r = (int)ZLibResultCode.Z_STREAM_ERROR;
s.BitB = b; s.BitK = k;
z.avail_in = n; z.total_in += p - z.next_in_index; z.next_in_index = p;
s.WritePos = q;
return(s.inflate_flush(z, r));
}
}
}
/// <summary>
/// Mapping from a distance to a distance code. dist is the distance - 1 and
/// must not have side effects. _dist_code[256] and _dist_code[257] are never
/// used.
/// </summary>
internal static int d_code(int dist)
{
return((dist) < 256 ? ZLibUtil._dist_code[dist] : ZLibUtil._dist_code[256 + (ZLibUtil.URShift((dist), 7))]);
}