diff options
Diffstat (limited to 'swarm/storage/mru/update.go')
-rw-r--r-- | swarm/storage/mru/update.go | 132 |
1 files changed, 58 insertions, 74 deletions
diff --git a/swarm/storage/mru/update.go b/swarm/storage/mru/update.go index d1bd37ddf..6aa57fce1 100644 --- a/swarm/storage/mru/update.go +++ b/swarm/storage/mru/update.go @@ -17,36 +17,35 @@ package mru import ( - "encoding/binary" - "errors" + "fmt" + "strconv" "github.com/ethereum/go-ethereum/swarm/chunk" - "github.com/ethereum/go-ethereum/swarm/log" - "github.com/ethereum/go-ethereum/swarm/multihash" ) -// resourceUpdate encapsulates the information sent as part of a resource update -type resourceUpdate struct { - updateHeader // metainformationa about this resource update - data []byte // actual data payload +// ProtocolVersion defines the current version of the protocol that will be included in each update message +const ProtocolVersion uint8 = 0 + +const headerLength = 8 + +// Header defines a update message header including a protocol version byte +type Header struct { + Version uint8 // Protocol version + Padding [headerLength - 1]uint8 // reserved for future use } -// Update chunk layout -// Prefix: -// 2 bytes updateHeaderLength -// 2 bytes data length -const chunkPrefixLength = 2 + 2 +// ResourceUpdate encapsulates the information sent as part of a resource update +type ResourceUpdate struct { + Header Header // + ID // Resource update identifying information + data []byte // actual data payload +} -// Header: (see updateHeader) -// Data: -// data (datalength bytes) -// -// Minimum size is Header + 1 (minimum data length, enforced) -const minimumUpdateDataLength = updateHeaderLength + 1 -const maxUpdateDataLength = chunk.DefaultSize - signatureLength - updateHeaderLength - chunkPrefixLength +const minimumUpdateDataLength = idLength + headerLength + 1 +const maxUpdateDataLength = chunk.DefaultSize - signatureLength - idLength - headerLength // binaryPut serializes the resource update information into the given slice -func (r *resourceUpdate) binaryPut(serializedData []byte) error { +func (r *ResourceUpdate) binaryPut(serializedData []byte) error { datalength := len(r.data) if datalength == 0 { return NewError(ErrInvalidValue, "cannot update a resource with no data") @@ -60,26 +59,17 @@ func (r *resourceUpdate) binaryPut(serializedData []byte) error { return NewErrorf(ErrInvalidValue, "slice passed to putBinary must be of exact size. Expected %d bytes", r.binaryLength()) } - if r.multihash { - if _, _, err := multihash.GetMultihashLength(r.data); err != nil { - return NewError(ErrInvalidValue, "Invalid multihash") - } - } - - // Add prefix: updateHeaderLength and actual data length - cursor := 0 - binary.LittleEndian.PutUint16(serializedData[cursor:], uint16(updateHeaderLength)) - cursor += 2 + var cursor int + // serialize Header + serializedData[cursor] = r.Header.Version + copy(serializedData[cursor+1:headerLength], r.Header.Padding[:headerLength-1]) + cursor += headerLength - // data length - binary.LittleEndian.PutUint16(serializedData[cursor:], uint16(datalength)) - cursor += 2 - - // serialize header (see updateHeader) - if err := r.updateHeader.binaryPut(serializedData[cursor : cursor+updateHeaderLength]); err != nil { + // serialize ID + if err := r.ID.binaryPut(serializedData[cursor : cursor+idLength]); err != nil { return err } - cursor += updateHeaderLength + cursor += idLength // add the data copy(serializedData[cursor:], r.data) @@ -89,60 +79,54 @@ func (r *resourceUpdate) binaryPut(serializedData []byte) error { } // binaryLength returns the expected number of bytes this structure will take to encode -func (r *resourceUpdate) binaryLength() int { - return chunkPrefixLength + updateHeaderLength + len(r.data) +func (r *ResourceUpdate) binaryLength() int { + return idLength + headerLength + len(r.data) } // binaryGet populates this instance from the information contained in the passed byte slice -func (r *resourceUpdate) binaryGet(serializedData []byte) error { +func (r *ResourceUpdate) binaryGet(serializedData []byte) error { if len(serializedData) < minimumUpdateDataLength { return NewErrorf(ErrNothingToReturn, "chunk less than %d bytes cannot be a resource update chunk", minimumUpdateDataLength) } - cursor := 0 - declaredHeaderlength := binary.LittleEndian.Uint16(serializedData[cursor : cursor+2]) - if declaredHeaderlength != updateHeaderLength { - return NewErrorf(ErrCorruptData, "Invalid header length. Expected %d, got %d", updateHeaderLength, declaredHeaderlength) - } + dataLength := len(serializedData) - idLength - headerLength + // at this point we can be satisfied that we have the correct data length to read - cursor += 2 - datalength := int(binary.LittleEndian.Uint16(serializedData[cursor : cursor+2])) - cursor += 2 + var cursor int - if chunkPrefixLength+updateHeaderLength+datalength+signatureLength != len(serializedData) { - return NewError(ErrNothingToReturn, "length specified in header is different than actual chunk size") - } + // deserialize Header + r.Header.Version = serializedData[cursor] // extract the protocol version + copy(r.Header.Padding[:headerLength-1], serializedData[cursor+1:headerLength]) // extract the padding + cursor += headerLength - // at this point we can be satisfied that we have the correct data length to read - if err := r.updateHeader.binaryGet(serializedData[cursor : cursor+updateHeaderLength]); err != nil { + if err := r.ID.binaryGet(serializedData[cursor : cursor+idLength]); err != nil { return err } - cursor += updateHeaderLength - - data := serializedData[cursor : cursor+datalength] - cursor += datalength + cursor += idLength - // if multihash content is indicated we check the validity of the multihash - if r.updateHeader.multihash { - mhLength, mhHeaderLength, err := multihash.GetMultihashLength(data) - if err != nil { - log.Error("multihash parse error", "err", err) - return err - } - if datalength != mhLength+mhHeaderLength { - log.Debug("multihash error", "datalength", datalength, "mhLength", mhLength, "mhHeaderLength", mhHeaderLength) - return errors.New("Corrupt multihash data") - } - } + data := serializedData[cursor : cursor+dataLength] + cursor += dataLength // now that all checks have passed, copy data into structure - r.data = make([]byte, datalength) + r.data = make([]byte, dataLength) copy(r.data, data) return nil } -// Multihash specifies whether the resource data should be interpreted as multihash -func (r *resourceUpdate) Multihash() bool { - return r.multihash +// FromValues deserializes this instance from a string key-value store +// useful to parse query strings +func (r *ResourceUpdate) FromValues(values Values, data []byte) error { + r.data = data + version, _ := strconv.ParseUint(values.Get("protocolVersion"), 10, 32) + r.Header.Version = uint8(version) + return r.ID.FromValues(values) +} + +// AppendValues serializes this structure into the provided string key-value store +// useful to build query strings +func (r *ResourceUpdate) AppendValues(values Values) []byte { + r.ID.AppendValues(values) + values.Set("protocolVersion", fmt.Sprintf("%d", r.Header.Version)) + return r.data } |