System.util.zlib.Inflate.inflate C# (CSharp) Method

inflate() private method

private inflate ( ZStream z, int f ) : int
z ZStream
f int
return int
        internal int inflate(ZStream z, int f)
        {
            int r;
            int b;

            if(z == null || z.istate == null || z.next_in == null)
                return Z_STREAM_ERROR;
            f = f == Z_FINISH ? Z_BUF_ERROR : Z_OK;
            r = Z_BUF_ERROR;
            while (true){
                //System.out.println("mode: "+z.istate.mode);
                switch (z.istate.mode){
                    case METHOD:

                        if(z.avail_in==0)return r;r=f;

                        z.avail_in--; z.total_in++;
                        if(((z.istate.method = z.next_in[z.next_in_index++])&0xf)!=Z_DEFLATED){
                            z.istate.mode = BAD;
                            z.msg="unknown compression method";
                            z.istate.marker = 5;       // can't try inflateSync
                            break;
                        }
                        if((z.istate.method>>4)+8>z.istate.wbits){
                            z.istate.mode = BAD;
                            z.msg="invalid window size";
                            z.istate.marker = 5;       // can't try inflateSync
                            break;
                        }
                        z.istate.mode=FLAG;
                        goto case FLAG;
                    case FLAG:

                        if(z.avail_in==0)return r;r=f;

                        z.avail_in--; z.total_in++;
                        b = (z.next_in[z.next_in_index++])&0xff;

                        if((((z.istate.method << 8)+b) % 31)!=0){
                            z.istate.mode = BAD;
                            z.msg = "incorrect header check";
                            z.istate.marker = 5;       // can't try inflateSync
                            break;
                        }

                        if((b&PRESET_DICT)==0){
                            z.istate.mode = BLOCKS;
                            break;
                        }
                        z.istate.mode = DICT4;
                        goto case DICT4;
                    case DICT4:

                        if(z.avail_in==0)return r;r=f;

                        z.avail_in--; z.total_in++;
                        z.istate.need=((z.next_in[z.next_in_index++]&0xff)<<24)&0xff000000L;
                        z.istate.mode=DICT3;
                        goto case DICT3;
                    case DICT3:

                        if(z.avail_in==0)return r;r=f;

                        z.avail_in--; z.total_in++;
                        z.istate.need+=((z.next_in[z.next_in_index++]&0xff)<<16)&0xff0000L;
                        z.istate.mode=DICT2;
                        goto case DICT2;
                    case DICT2:

                        if(z.avail_in==0)return r;r=f;

                        z.avail_in--; z.total_in++;
                        z.istate.need+=((z.next_in[z.next_in_index++]&0xff)<<8)&0xff00L;
                        z.istate.mode=DICT1;
                        goto case DICT1;
                    case DICT1:

                        if(z.avail_in==0)return r;r=f;

                        z.avail_in--; z.total_in++;
                        z.istate.need += (z.next_in[z.next_in_index++]&0xffL);
                        z.adler = z.istate.need;
                        z.istate.mode = DICT0;
                        return Z_NEED_DICT;
                    case DICT0:
                        z.istate.mode = BAD;
                        z.msg = "need dictionary";
                        z.istate.marker = 0;       // can try inflateSync
                        return Z_STREAM_ERROR;
                    case BLOCKS:

                        r = z.istate.blocks.proc(z, r);
                        if(r == Z_DATA_ERROR){
                            z.istate.mode = BAD;
                            z.istate.marker = 0;     // can try inflateSync
                            break;
                        }
                        if(r == Z_OK){
                            r = f;
                        }
                        if(r != Z_STREAM_END){
                            return r;
                        }
                        r = f;
                        z.istate.blocks.reset(z, z.istate.was);
                        if(z.istate.nowrap!=0){
                            z.istate.mode=DONE;
                            break;
                        }
                        z.istate.mode=CHECK4;
                        goto case CHECK4;
                    case CHECK4:

                        if(z.avail_in==0)return r;r=f;

                        z.avail_in--; z.total_in++;
                        z.istate.need=((z.next_in[z.next_in_index++]&0xff)<<24)&0xff000000L;
                        z.istate.mode=CHECK3;
                        goto case CHECK3;
                    case CHECK3:

                        if(z.avail_in==0)return r;r=f;

                        z.avail_in--; z.total_in++;
                        z.istate.need+=((z.next_in[z.next_in_index++]&0xff)<<16)&0xff0000L;
                        z.istate.mode = CHECK2;
                        goto case CHECK2;
                    case CHECK2:

                        if(z.avail_in==0)return r;r=f;

                        z.avail_in--; z.total_in++;
                        z.istate.need+=((z.next_in[z.next_in_index++]&0xff)<<8)&0xff00L;
                        z.istate.mode = CHECK1;
                        goto case CHECK1;
                    case CHECK1:

                        if(z.avail_in==0)return r;r=f;

                        z.avail_in--; z.total_in++;
                        z.istate.need+=(z.next_in[z.next_in_index++]&0xffL);

                        if(((int)(z.istate.was[0])) != ((int)(z.istate.need))){
                            z.istate.mode = BAD;
                            z.msg = "incorrect data check";
                            z.istate.marker = 5;       // can't try inflateSync
                            break;
                        }

                        z.istate.mode = DONE;
                        goto case DONE;
                    case DONE:
                        return Z_STREAM_END;
                    case BAD:
                        return Z_DATA_ERROR;
                    default:
                        return Z_STREAM_ERROR;
                }
            }
        }

Usage Example

Esempio n. 1
0
 public int inflate(int f)
 {
     if (istate == null)
     {
         return(Z_STREAM_ERROR);
     }
     return(istate.inflate(this, f));
 }