Golang util.NewCRC函数代码示例

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本文整理汇总了Golang中github.com/syndtr/goleveldb/leveldb/util.NewCRC函数的典型用法代码示例。如果您正苦于以下问题：Golang NewCRC函数的具体用法？Golang NewCRC怎么用？Golang NewCRC使用的例子？那么恭喜您, 这里精选的函数代码示例或许可以为您提供帮助。

在下文中一共展示了NewCRC函数的9个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于我们的系统推荐出更棒的Golang代码示例。

示例1: randomData

func randomData(dst []byte, ns, prefix byte, i uint32, dataLen int) []byte {
	if dataLen < (2+4+4)*2+4 {
		panic("dataLen is too small")
	}
	if cap(dst) < dataLen {
		dst = make([]byte, dataLen)
	} else {
		dst = dst[:dataLen]
	}
	half := (dataLen - 4) / 2
	if _, err := rand.Reader.Read(dst[2 : half-8]); err != nil {
		panic(err)
	}
	dst[0] = ns
	dst[1] = prefix
	binary.LittleEndian.PutUint32(dst[half-8:], i)
	binary.LittleEndian.PutUint32(dst[half-8:], i)
	binary.LittleEndian.PutUint32(dst[half-4:], util.NewCRC(dst[:half-4]).Value())
	full := half * 2
	copy(dst[half:full], dst[:half])
	if full < dataLen-4 {
		if _, err := rand.Reader.Read(dst[full : dataLen-4]); err != nil {
			panic(err)
		}
	}
	binary.LittleEndian.PutUint32(dst[dataLen-4:], util.NewCRC(dst[:dataLen-4]).Value())
	return dst
}

开发者ID:syndtr，项目名称:goleveldb，代码行数:28，代码来源:main.go

示例2: writeBlock

func (w *Writer) writeBlock(buf *util.Buffer, compression opt.Compression) (bh blockHandle, err error) {
	// Compress the buffer if necessary.
	var b []byte
	if compression == opt.SnappyCompression {
		// Allocate scratch enough for compression and block trailer.
		if n := snappy.MaxEncodedLen(buf.Len()) + blockTrailerLen; len(w.compressionScratch) < n {
			w.compressionScratch = make([]byte, n)
		}
		compressed := snappy.Encode(w.compressionScratch, buf.Bytes())
		n := len(compressed)
		b = compressed[:n+blockTrailerLen]
		b[n] = blockTypeSnappyCompression
	} else {
		tmp := buf.Alloc(blockTrailerLen)
		tmp[0] = blockTypeNoCompression
		b = buf.Bytes()
	}

	// Calculate the checksum.
	n := len(b) - 4
	checksum := util.NewCRC(b[:n]).Value()
	binary.LittleEndian.PutUint32(b[n:], checksum)

	// Write the buffer to the file.
	_, err = w.writer.Write(b)
	if err != nil {
		return
	}
	bh = blockHandle{w.offset, uint64(len(b) - blockTrailerLen)}
	w.offset += uint64(len(b))
	return
}

开发者ID:lessos，项目名称:lessdb，代码行数:32，代码来源:writer.go

示例3: randomData

func randomData(dst []byte, ns, prefix byte, i uint32) []byte {
	n := 2 + dataLen + 4 + 4
	n2 := n*2 + 4
	if cap(dst) < n2 {
		dst = make([]byte, n2)
	} else {
		dst = dst[:n2]
	}
	_, err := rand.Reader.Read(dst[2 : n-8])
	if err != nil {
		panic(err)
	}
	dst[0] = ns
	dst[1] = prefix
	binary.LittleEndian.PutUint32(dst[n-8:], i)
	binary.LittleEndian.PutUint32(dst[n-4:], util.NewCRC(dst[:n-4]).Value())
	copy(dst[n:n+n], dst[:n])
	binary.LittleEndian.PutUint32(dst[n2-4:], util.NewCRC(dst[:n2-4]).Value())
	return dst
}

开发者ID:Richardphp，项目名称:noms，代码行数:20，代码来源:main.go

示例4: fillHeader

// fillHeader fills in the header for the pending chunk.
func (w *Writer) fillHeader(last bool) {
	if w.i+headerSize > w.j || w.j > blockSize {
		panic("leveldb/journal: bad writer state")
	}
	if last {
		if w.first {
			w.buf[w.i+6] = fullChunkType
		} else {
			w.buf[w.i+6] = lastChunkType
		}
	} else {
		if w.first {
			w.buf[w.i+6] = firstChunkType
		} else {
			w.buf[w.i+6] = middleChunkType
		}
	}
	binary.LittleEndian.PutUint32(w.buf[w.i+0:w.i+4], util.NewCRC(w.buf[w.i+6:w.j]).Value())
	binary.LittleEndian.PutUint16(w.buf[w.i+4:w.i+6], uint16(w.j-w.i-headerSize))
}

开发者ID:Blueprint-Marketing，项目名称:syncthing，代码行数:21，代码来源:journal.go

示例5: readRawBlock

func (r *Reader) readRawBlock(bh blockHandle, verifyChecksum bool) ([]byte, error) {
	data := r.bpool.Get(int(bh.length + blockTrailerLen))
	if _, err := r.reader.ReadAt(data, int64(bh.offset)); err != nil && err != io.EOF {
		return nil, err
	}

	if verifyChecksum {
		n := bh.length + 1
		checksum0 := binary.LittleEndian.Uint32(data[n:])
		checksum1 := util.NewCRC(data[:n]).Value()
		if checksum0 != checksum1 {
			r.bpool.Put(data)
			return nil, r.newErrCorruptedBH(bh, fmt.Sprintf("checksum mismatch, want=%#x got=%#x", checksum0, checksum1))
		}
	}

	switch data[bh.length] {
	case blockTypeNoCompression:
		data = data[:bh.length]
	case blockTypeSnappyCompression:
		decLen, err := snappy.DecodedLen(data[:bh.length])
		if err != nil {
			return nil, r.newErrCorruptedBH(bh, err.Error())
		}
		decData := r.bpool.Get(decLen)
		decData, err = snappy.Decode(decData, data[:bh.length])
		r.bpool.Put(data)
		if err != nil {
			r.bpool.Put(decData)
			return nil, r.newErrCorruptedBH(bh, err.Error())
		}
		data = decData
	default:
		r.bpool.Put(data)
		return nil, r.newErrCorruptedBH(bh, fmt.Sprintf("unknown compression type %#x", data[bh.length]))
	}
	return data, nil
}

开发者ID:tendermint，项目名称:functional-tester，代码行数:38，代码来源:reader.go

示例6: verifyChecksum

func verifyChecksum(data []byte) bool {
	n := len(data) - 4
	checksum0 := binary.LittleEndian.Uint32(data[n:])
	checksum1 := util.NewCRC(data[:n]).Value()
	return checksum0 == checksum1
}

开发者ID:Blueprint-Marketing，项目名称:syncthing，代码行数:6，代码来源:reader.go

示例7: dataChecksum

func dataChecksum(data []byte) (uint32, uint32) {
	checksum0 := binary.LittleEndian.Uint32(data[len(data)-4:])
	checksum1 := util.NewCRC(data[:len(data)-4]).Value()
	return checksum0, checksum1
}

开发者ID:syndtr，项目名称:goleveldb，代码行数:5，代码来源:main.go

示例8: nextChunk

// nextChunk sets r.buf[r.i:r.j] to hold the next chunk's payload, reading the
// next block into the buffer if necessary.
func (r *Reader) nextChunk(first bool) error {
	for {
		if r.j+headerSize <= r.n {
			checksum := binary.LittleEndian.Uint32(r.buf[r.j+0 : r.j+4])
			length := binary.LittleEndian.Uint16(r.buf[r.j+4 : r.j+6])
			chunkType := r.buf[r.j+6]

			if checksum == 0 && length == 0 && chunkType == 0 {
				// Drop entire block.
				m := r.n - r.j
				r.i = r.n
				r.j = r.n
				return r.corrupt(m, "zero header", false)
			} else {
				m := r.n - r.j
				r.i = r.j + headerSize
				r.j = r.j + headerSize + int(length)
				if r.j > r.n {
					// Drop entire block.
					r.i = r.n
					r.j = r.n
					return r.corrupt(m, "chunk length overflows block", false)
				} else if r.checksum && checksum != util.NewCRC(r.buf[r.i-1:r.j]).Value() {
					// Drop entire block.
					r.i = r.n
					r.j = r.n
					return r.corrupt(m, "checksum mismatch", false)
				}
			}
			if first && chunkType != fullChunkType && chunkType != firstChunkType {
				m := r.j - r.i
				r.i = r.j
				// Report the error, but skip it.
				return r.corrupt(m+headerSize, "orphan chunk", true)
			}
			r.last = chunkType == fullChunkType || chunkType == lastChunkType
			return nil
		}

		// The last block.
		if r.n < blockSize && r.n > 0 {
			if !first {
				return r.corrupt(0, "missing chunk part", false)
			}
			r.err = io.EOF
			return r.err
		}

		// Read block.
		n, err := io.ReadFull(r.r, r.buf[:])
		if err != nil && err != io.EOF && err != io.ErrUnexpectedEOF {
			return err
		}
		if n == 0 {
			if !first {
				return r.corrupt(0, "missing chunk part", false)
			}
			r.err = io.EOF
			return r.err
		}
		r.i, r.j, r.n = 0, 0, n
	}
}

开发者ID:Blueprint-Marketing，项目名称:syncthing，代码行数:65，代码来源:journal.go

示例9: nextChunk

// nextChunk sets r.buf[r.i:r.j] to hold the next chunk's payload, reading the
// next block into the buffer if necessary.
func (r *Reader) nextChunk(wantFirst, skip bool) error {
	for {
		if r.j+headerSize <= r.n {
			checksum := binary.LittleEndian.Uint32(r.buf[r.j+0 : r.j+4])
			length := binary.LittleEndian.Uint16(r.buf[r.j+4 : r.j+6])
			chunkType := r.buf[r.j+6]

			var err error
			if checksum == 0 && length == 0 && chunkType == 0 {
				// Drop entire block.
				err = DroppedError{r.n - r.j, "zero header"}
				r.i = r.n
				r.j = r.n
			} else {
				m := r.n - r.j
				r.i = r.j + headerSize
				r.j = r.j + headerSize + int(length)
				if r.j > r.n {
					// Drop entire block.
					err = DroppedError{m, "chunk length overflows block"}
					r.i = r.n
					r.j = r.n
				} else if r.checksum && checksum != util.NewCRC(r.buf[r.i-1:r.j]).Value() {
					// Drop entire block.
					err = DroppedError{m, "checksum mismatch"}
					r.i = r.n
					r.j = r.n
				}
			}
			if wantFirst && err == nil && chunkType != fullChunkType && chunkType != firstChunkType {
				if skip {
					// The chunk are intentionally skipped.
					if chunkType == lastChunkType {
						skip = false
					}
					continue
				} else {
					// Drop the chunk.
					err = DroppedError{r.j - r.i + headerSize, "orphan chunk"}
				}
			}
			if err == nil {
				r.last = chunkType == fullChunkType || chunkType == lastChunkType
			} else {
				if r.dropper != nil {
					r.dropper.Drop(err)
				}
				if r.strict {
					r.err = err
				}
			}
			return err
		}
		if r.n < blockSize && r.n > 0 {
			// This is the last block.
			if r.j != r.n {
				r.err = io.ErrUnexpectedEOF
			} else {
				r.err = io.EOF
			}
			return r.err
		}
		n, err := io.ReadFull(r.r, r.buf[:])
		if err != nil && err != io.ErrUnexpectedEOF {
			r.err = err
			return r.err
		}
		if n == 0 {
			r.err = io.EOF
			return r.err
		}
		r.i, r.j, r.n = 0, 0, n
	}
	panic("unreachable")
}

开发者ID:pombredanne，项目名称:goleveldb，代码行数:77，代码来源:journal.go

注：本文中的github.com/syndtr/goleveldb/leveldb/util.NewCRC函数示例由纯净天空整理自Github/MSDocs等源码及文档管理平台，相关代码片段筛选自各路编程大神贡献的开源项目，源码版权归原作者所有，传播和使用请参考对应项目的License；未经允许，请勿转载。