|
private inflate_flush ( |
||
| z | ||
| r | int | |
| return | int | |
internal int inflate_flush(ZStream z, int r){
int n;
int p;
int q;
// local copies of source and destination pointers
p = z.next_out_index;
q = read;
// compute number of bytes to copy as far as end of window
n = (int)((q <= write ? write : end) - q);
if (n > z.avail_out) n = z.avail_out;
if (n!=0 && r == Z_BUF_ERROR) r = Z_OK;
// update counters
z.avail_out -= n;
z.total_out += n;
// update check information
if(checkfn != null)
z.adler=check=z._adler.adler32(check, window, q, n);
// copy as far as end of window
System.Array.Copy(window, q, z.next_out, p, n);
p += n;
q += n;
// see if more to copy at beginning of window
if (q == end){
// wrap pointers
q = 0;
if (write == end)
write = 0;
// compute bytes to copy
n = write - q;
if (n > z.avail_out) n = z.avail_out;
if (n!=0 && r == Z_BUF_ERROR) r = Z_OK;
// update counters
z.avail_out -= n;
z.total_out += n;
// update check information
if(checkfn != null)
z.adler=check=z._adler.adler32(check, window, q, n);
// copy
System.Array.Copy(window, q, z.next_out, p, n);
p += n;
q += n;
}
// update pointers
z.next_out_index = p;
read = q;
// done
return r;
}
} internal int proc(InfBlocks s, ZStream z, int 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 (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>>=(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 = 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;
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 = 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;
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);
}
}
}
