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private inflate_fast ( int bl, int bd, int tl, int tl_index, int td, int td_index, |
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| bl | int | |
| bd | int | |
| tl | int | |
| tl_index | int | |
| td | int | |
| td_index | int | |
| s | ||
| z | ||
| return | int | |
internal 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{
System.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{
System.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{
System.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;
}
