Golang Buffer.Slice方法代碼示例

func identifyRdr(w writer, s *siegfried.Siegfried, r io.Reader, sz int64, path, mime, mod string) {
	lg.set(path)
	c, err := s.Identify(r, path, mime)
	lg.err(err)
	if c == nil {
		w.writeFile(path, sz, mod, nil, err, nil)
		lg.reset()
		return
	}
	var b *siegreader.Buffer
	var cs []byte
	if checksum != nil {
		b = s.Buffer()
		var i int64
		l := checksum.BlockSize()
		for ; ; i += int64(l) {
			buf, _ := b.Slice(i, l)
			if buf == nil {
				break
			}
			checksum.Write(buf)
		}
		cs = checksum.Sum(nil)
		checksum.Reset()
	}
	a := w.writeFile(path, sz, mod, cs, err, idChan(c))
	lg.reset()
	if !*archive || a == config.None {
		return
	}
	var d decompressor
	if b == nil {
		b = s.Buffer()
	}
	switch a {
	case config.Zip:
		d, err = newZip(siegreader.ReaderFrom(b), path, sz)
	case config.Gzip:
		d, err = newGzip(b, path)
	case config.Tar:
		d, err = newTar(siegreader.ReaderFrom(b), path)
	case config.ARC:
		d, err = newARC(siegreader.ReaderFrom(b), path)
	case config.WARC:
		d, err = newWARC(siegreader.ReaderFrom(b), path)
	}
	if err != nil {
		writeError(w, path, sz, mod, fmt.Errorf("failed to decompress, got: %v", err))
		return
	}
	for err = d.next(); err == nil; err = d.next() {
		if *droido {
			for _, v := range d.dirs() {
				w.writeFile(v, -1, "", nil, nil, nil)
			}
		}
		identifyRdr(w, s, d.reader(), d.size(), d.path(), d.mime(), d.mod())
	}
}

func (fs *frameSet) index(buf *siegreader.Buffer, rev bool, quit chan struct{}) chan fsmatch {
	ret := make(chan fsmatch)
	go func() {
		var i int
		for {
			select {
			case <-quit:
				close(ret)
				return
			default:
			}
			if i >= len(fs.set) {
				close(ret)
				return
			}
			f := fs.set[i]
			var match bool
			var matches []int
			if rev {
				slc, err := buf.EofSlice(0, frames.TotalLength(f))
				if err != nil {
					close(ret)
					return
				}
				match, matches = f.MatchR(slc)
			} else {
				slc, err := buf.Slice(0, frames.TotalLength(f))
				if err != nil {
					close(ret)
					return
				}
				match, matches = f.Match(slc)
			}
			if match {
				var min int
				if !rev {
					min, _ = f.Length()
				}
				for _, off := range matches {
					ret <- fsmatch{i, int64(off - min), min}
				}
			}
			i++
		}
		close(ret)
	}()
	return ret
}

func (m Matcher) Identify(n string, b siegreader.Buffer) (chan core.Result, error) {
	res := make(chan core.Result)
	// check trigger
	buf, err := b.Slice(0, 8)
	if err != nil {
		close(res)
		return res, nil
	}
	for _, c := range m {
		if c.trigger(buf) {
			rdr, err := c.rdr(b)
			if err != nil {
				close(res)
				return res, err
			}
			go c.identify(n, rdr, res)
			return res, nil
		}
	}
	// nothing ... move on
	close(res)
	return res, nil
}

//.........這裏部分代碼省略.........
				}
				if v.r {
					checkr = true
				}
			}
		}
		if !checkl && !checkr {
			return res
		}
		// calculate the offset and lengths for the left and right test slices
		var lslc, rslc []byte
		var lpos, rpos int64
		var llen, rlen int
		if st.reverse {
			lpos, llen = st.offset+int64(st.length), t.maxLeftDistance
			rpos, rlen = st.offset-int64(t.maxRightDistance), t.maxRightDistance
			if rpos < 0 {
				rlen = rlen + int(rpos)
				rpos = 0
			}
		} else {
			lpos, llen = st.offset-int64(t.maxLeftDistance), t.maxLeftDistance
			rpos, rlen = st.offset+int64(st.length), t.maxRightDistance
			if lpos < 0 {
				llen = llen + int(lpos)
				lpos = 0
			}
		}
		//  the partials slice has a mirror entry for each of the testTree incompletes
		partials := make([]partial, len(t.incomplete))
		// test left (if there are valid left tests to try)
		if checkl {
			if st.reverse {
				lslc, _ = buf.EofSlice(lpos, llen)
			} else {
				lslc, _ = buf.Slice(lpos, llen)
			}
			left := matchTestNodes(t.left, lslc, true)
			for _, lp := range left {
				if partials[lp.followUp].l {
					partials[lp.followUp].ldistances = append(partials[lp.followUp].ldistances, lp.distances...)
				} else {
					partials[lp.followUp].l = true
					partials[lp.followUp].ldistances = lp.distances
				}
			}
		}
		// test right (if there are valid right tests to try)
		if checkr {
			if st.reverse {
				rslc, _ = buf.EofSlice(rpos, rlen)
			} else {
				rslc, _ = buf.Slice(rpos, rlen)
			}
			right := matchTestNodes(t.right, rslc, false)
			for _, rp := range right {
				if partials[rp.followUp].r {
					partials[rp.followUp].rdistances = append(partials[rp.followUp].rdistances, rp.distances...)
				} else {
					partials[rp.followUp].r = true
					partials[rp.followUp].rdistances = rp.distances
				}
			}
		}
		// now iterate through the partials, checking whether they fulfil any of the incompletes
		for i, p := range partials {