Golang ShaHash.SetBytes方法代碼示例

// FetchHeightRange looks up a range of blocks by the start and ending
// heights.  Fetch is inclusive of the start height and exclusive of the
// ending height. To fetch all hashes from the start height until no
// more are present, use the special id `AllShas'.
func (db *LevelDb) FetchHeightRange(startHeight, endHeight int32) (rshalist []wire.ShaHash, err error) {
	db.dbLock.Lock()
	defer db.dbLock.Unlock()

	var endidx int32
	if endHeight == database.AllShas {
		endidx = startHeight + 500
	} else {
		endidx = endHeight
	}

	shalist := make([]wire.ShaHash, 0, endidx-startHeight)
	for height := startHeight; height < endidx; height++ {
		// TODO(drahn) fix blkFile from height

		key := int64ToKey(int64(height))
		blkVal, lerr := db.lDb.Get(key, db.ro)
		if lerr != nil {
			break
		}

		var sha wire.ShaHash
		sha.SetBytes(blkVal[0:32])
		shalist = append(shalist, sha)
	}

	if err != nil {
		return
	}
	//log.Tracef("FetchIdxRange idx %v %v returned %v shas err %v", startHeight, endHeight, len(shalist), err)

	return shalist, nil
}

func parsesha(argstr string) (argtype int, height int32, psha *wire.ShaHash, err error) {
	var sha wire.ShaHash

	var hashbuf string

	switch len(argstr) {
	case 64:
		hashbuf = argstr
	case 66:
		if argstr[0:2] != "0x" {
			log.Infof("prefix is %v", argstr[0:2])
			err = errBadShaPrefix
			return
		}
		hashbuf = argstr[2:]
	default:
		if len(argstr) <= 16 {
			// assume value is height
			argtype = argHeight
			var h int
			h, err = strconv.Atoi(argstr)
			if err == nil {
				height = int32(h)
				return
			}
			log.Infof("Unable to parse height %v, err %v", height, err)
		}
		err = errBadShaLen
		return
	}

	var buf [32]byte
	for idx, ch := range hashbuf {
		var val rune

		switch {
		case ch >= '0' && ch <= '9':
			val = ch - '0'
		case ch >= 'a' && ch <= 'f':
			val = ch - 'a' + rune(10)
		case ch >= 'A' && ch <= 'F':
			val = ch - 'A' + rune(10)
		default:
			err = errBadShaChar
			return
		}
		b := buf[31-idx/2]
		if idx&1 == 1 {
			b |= byte(val)
		} else {
			b |= (byte(val) << 4)
		}
		buf[31-idx/2] = b
	}
	sha.SetBytes(buf[0:32])
	psha = &sha
	return
}

// fetchBlockShaByHeight returns a block hash based on its height in the
// block chain.
func (db *LevelDb) fetchBlockShaByHeight(height int32) (rsha *wire.ShaHash, err error) {
	key := int64ToKey(int64(height))

	blkVal, err := db.lDb.Get(key, db.ro)
	if err != nil {
		log.Tracef("failed to find height %v", height)
		return // exists ???
	}

	var sha wire.ShaHash
	sha.SetBytes(blkVal[0:32])

	return &sha, nil
}

// fetchAddrIndexTip returns the last block height and block sha to be indexed.
// Meta-data about the address tip is currently cached in memory, and will be
// updated accordingly by functions that modify the state. This function is
// used on start up to load the info into memory. Callers will use the public
// version of this function below, which returns our cached copy.
func (db *LevelDb) fetchAddrIndexTip() (*wire.ShaHash, int32, error) {
	db.dbLock.Lock()
	defer db.dbLock.Unlock()

	data, err := db.lDb.Get(addrIndexMetaDataKey, db.ro)
	if err != nil {
		return &wire.ShaHash{}, -1, database.ErrAddrIndexDoesNotExist
	}

	var blkSha wire.ShaHash
	blkSha.SetBytes(data[0:32])

	blkHeight := binary.LittleEndian.Uint64(data[32:])

	return &blkSha, int32(blkHeight), nil
}

func (db *LevelDb) getBlkByHeight(blkHeight int32) (rsha *wire.ShaHash, rbuf []byte, err error) {
	var blkVal []byte

	key := int64ToKey(int64(blkHeight))

	blkVal, err = db.lDb.Get(key, db.ro)
	if err != nil {
		log.Tracef("failed to find height %v", blkHeight)
		return // exists ???
	}

	var sha wire.ShaHash

	sha.SetBytes(blkVal[0:32])

	blockdata := make([]byte, len(blkVal[32:]))
	copy(blockdata[:], blkVal[32:])

	return &sha, blockdata, nil
}