private ZLibStatus ProcessCodes(InfBlocks s, ZStream z, ZLibStatus r)
{
int j; // temporary storage
int tindex; // temporary pointer
int e; // extra bits or operation
int b = 0; // bit buffer
int k = 0; // bits in bit buffer
int p = 0; // input data pointer
int n; // bytes available there
int q; // output window write pointer
int m; // bytes to end of window or read pointer
int f; // pointer to copy strings from
// copy input/output information to locals (UPDATE macro restores)
p = z.next_in_index; n = z.avail_in; b = s.bitb; k = s.bitk;
q = s.write; m = q < s.read ? s.read - q - 1 : s.end - q;
// process input and output based on current state
while (true)
{
switch (this._mode)
{
// waiting for "i:"=input, "o:"=output, "x:"=nothing
case InflateCodeMode.START: // x: set up for InflateCodeMode.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 = this.InflateFast(this._lbits, this._dbits, this._ltree, this._ltreeIndex, this._dtree, this._dtreeIndex, 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 != ZLibStatus.Z_OK)
{
this._mode = r == ZLibStatus.Z_STREAM_END ? InflateCodeMode.WASH : InflateCodeMode.BADCODE;
break;
}
}
this._need = this._lbits;
this._tree = this._ltree;
this._treeIndex = this._ltreeIndex;
this._mode = InflateCodeMode.LEN;
goto case InflateCodeMode.LEN;
case InflateCodeMode.LEN: // i: get length/literal/eob next
j = this._need;
while (k < (j))
{
if (n != 0) r = ZLibStatus.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.InflateFlush(z, r);
}
n--;
b |= (z.next_in[p++] & 0xff) << k;
k += 8;
}
tindex = (this._treeIndex + (b & inflate_mask[j])) * 3;
b >>= (this._tree[tindex + 1]);
k -= (this._tree[tindex + 1]);
e = this._tree[tindex];
if (e == 0)
{ // literal
this._lit = this._tree[tindex + 2];
this._mode = InflateCodeMode.LIT;
break;
}
if ((e & 16) != 0)
{ // length
this._get = e & 15;
this._len = this._tree[tindex + 2];
this._mode = InflateCodeMode.LENEXT;
break;
}
if ((e & 64) == 0)
{ // next table
this._need = e;
this._treeIndex = tindex / 3 + this._tree[tindex + 2];
break;
}
if ((e & 32) != 0)
{ // end of block
this._mode = InflateCodeMode.WASH;
break;
}
this._mode = InflateCodeMode.BADCODE; // invalid code
z.msg = "invalid literal/length code";
r = ZLibStatus.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.InflateFlush(z, r);
case InflateCodeMode.LENEXT: // i: getting length extra (have base)
j = this._get;
while (k < (j))
{
if (n != 0) r = ZLibStatus.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.InflateFlush(z, r);
}
n--; b |= (z.next_in[p++] & 0xff) << k;
k += 8;
}
this._len += (b & inflate_mask[j]);
b >>= j;
k -= j;
this._need = this._dbits;
this._tree = this._dtree;
this._treeIndex = this._dtreeIndex;
this._mode = InflateCodeMode.DIST;
goto case InflateCodeMode.DIST;
case InflateCodeMode.DIST: // i: get distance next
j = this._need;
while (k < (j))
{
if (n != 0) r = ZLibStatus.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.InflateFlush(z, r);
}
n--; b |= (z.next_in[p++] & 0xff) << k;
k += 8;
}
tindex = (this._treeIndex + (b & inflate_mask[j])) * 3;
b >>= this._tree[tindex + 1];
k -= this._tree[tindex + 1];
e = (this._tree[tindex]);
if ((e & 16) != 0)
{ // distance
this._get = e & 15;
this._dist = this._tree[tindex + 2];
this._mode = InflateCodeMode.DISTEXT;
break;
}
if ((e & 64) == 0)
{ // next table
this._need = e;
this._treeIndex = tindex / 3 + this._tree[tindex + 2];
break;
}
this._mode = InflateCodeMode.BADCODE; // invalid code
z.msg = "invalid distance code";
r = ZLibStatus.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.InflateFlush(z, r);
case InflateCodeMode.DISTEXT: // i: getting distance extra
j = this._get;
while (k < (j))
{
if (n != 0) r = ZLibStatus.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.InflateFlush(z, r);
}
n--; b |= (z.next_in[p++] & 0xff) << k;
k += 8;
}
this._dist += (b & inflate_mask[j]);
b >>= j;
k -= j;
this._mode = InflateCodeMode.COPY;
goto case InflateCodeMode.COPY;
case InflateCodeMode.COPY: // o: copying bytes in window, waiting for space
f = q - this._dist;
while (f < 0)
{ // modulo window size-"while" instead
f += s.end; // of "if" handles invalid distances
}
while (this._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.InflateFlush(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.InflateFlush(z, r);
}
}
}
s.window[q++] = s.window[f++]; m--;
if (f == s.end)
f = 0;
this._len--;
}
this._mode = InflateCodeMode.START;
break;
case InflateCodeMode.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.InflateFlush(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.InflateFlush(z, r);
}
}
}
r = ZLibStatus.Z_OK;
s.window[q++] = (byte)this._lit; m--;
this._mode = InflateCodeMode.START;
break;
case InflateCodeMode.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.InflateFlush(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.InflateFlush(z, r);
}
this._mode = InflateCodeMode.END;
goto case InflateCodeMode.END;
case InflateCodeMode.END:
r = ZLibStatus.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.InflateFlush(z, r);
case InflateCodeMode.BADCODE: // x: got error
r = ZLibStatus.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.InflateFlush(z, r);
default:
r = ZLibStatus.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.InflateFlush(z, r);
}
}
}
