diff options
Diffstat (limited to 'vendor/github.com/gogo/protobuf/proto/message_set.go')
-rw-r--r-- | vendor/github.com/gogo/protobuf/proto/message_set.go | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/vendor/github.com/gogo/protobuf/proto/message_set.go b/vendor/github.com/gogo/protobuf/proto/message_set.go new file mode 100644 index 000000000..f48a75676 --- /dev/null +++ b/vendor/github.com/gogo/protobuf/proto/message_set.go @@ -0,0 +1,181 @@ +// Go support for Protocol Buffers - Google's data interchange format +// +// Copyright 2010 The Go Authors. All rights reserved. +// https://github.com/golang/protobuf +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above +// copyright notice, this list of conditions and the following disclaimer +// in the documentation and/or other materials provided with the +// distribution. +// * Neither the name of Google Inc. nor the names of its +// contributors may be used to endorse or promote products derived from +// this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +package proto + +/* + * Support for message sets. + */ + +import ( + "errors" +) + +// errNoMessageTypeID occurs when a protocol buffer does not have a message type ID. +// A message type ID is required for storing a protocol buffer in a message set. +var errNoMessageTypeID = errors.New("proto does not have a message type ID") + +// The first two types (_MessageSet_Item and messageSet) +// model what the protocol compiler produces for the following protocol message: +// message MessageSet { +// repeated group Item = 1 { +// required int32 type_id = 2; +// required string message = 3; +// }; +// } +// That is the MessageSet wire format. We can't use a proto to generate these +// because that would introduce a circular dependency between it and this package. + +type _MessageSet_Item struct { + TypeId *int32 `protobuf:"varint,2,req,name=type_id"` + Message []byte `protobuf:"bytes,3,req,name=message"` +} + +type messageSet struct { + Item []*_MessageSet_Item `protobuf:"group,1,rep"` + XXX_unrecognized []byte + // TODO: caching? +} + +// Make sure messageSet is a Message. +var _ Message = (*messageSet)(nil) + +// messageTypeIder is an interface satisfied by a protocol buffer type +// that may be stored in a MessageSet. +type messageTypeIder interface { + MessageTypeId() int32 +} + +func (ms *messageSet) find(pb Message) *_MessageSet_Item { + mti, ok := pb.(messageTypeIder) + if !ok { + return nil + } + id := mti.MessageTypeId() + for _, item := range ms.Item { + if *item.TypeId == id { + return item + } + } + return nil +} + +func (ms *messageSet) Has(pb Message) bool { + return ms.find(pb) != nil +} + +func (ms *messageSet) Unmarshal(pb Message) error { + if item := ms.find(pb); item != nil { + return Unmarshal(item.Message, pb) + } + if _, ok := pb.(messageTypeIder); !ok { + return errNoMessageTypeID + } + return nil // TODO: return error instead? +} + +func (ms *messageSet) Marshal(pb Message) error { + msg, err := Marshal(pb) + if err != nil { + return err + } + if item := ms.find(pb); item != nil { + // reuse existing item + item.Message = msg + return nil + } + + mti, ok := pb.(messageTypeIder) + if !ok { + return errNoMessageTypeID + } + + mtid := mti.MessageTypeId() + ms.Item = append(ms.Item, &_MessageSet_Item{ + TypeId: &mtid, + Message: msg, + }) + return nil +} + +func (ms *messageSet) Reset() { *ms = messageSet{} } +func (ms *messageSet) String() string { return CompactTextString(ms) } +func (*messageSet) ProtoMessage() {} + +// Support for the message_set_wire_format message option. + +func skipVarint(buf []byte) []byte { + i := 0 + for ; buf[i]&0x80 != 0; i++ { + } + return buf[i+1:] +} + +// unmarshalMessageSet decodes the extension map encoded in buf in the message set wire format. +// It is called by Unmarshal methods on protocol buffer messages with the message_set_wire_format option. +func unmarshalMessageSet(buf []byte, exts interface{}) error { + var m map[int32]Extension + switch exts := exts.(type) { + case *XXX_InternalExtensions: + m = exts.extensionsWrite() + case map[int32]Extension: + m = exts + default: + return errors.New("proto: not an extension map") + } + + ms := new(messageSet) + if err := Unmarshal(buf, ms); err != nil { + return err + } + for _, item := range ms.Item { + id := *item.TypeId + msg := item.Message + + // Restore wire type and field number varint, plus length varint. + // Be careful to preserve duplicate items. + b := EncodeVarint(uint64(id)<<3 | WireBytes) + if ext, ok := m[id]; ok { + // Existing data; rip off the tag and length varint + // so we join the new data correctly. + // We can assume that ext.enc is set because we are unmarshaling. + o := ext.enc[len(b):] // skip wire type and field number + _, n := DecodeVarint(o) // calculate length of length varint + o = o[n:] // skip length varint + msg = append(o, msg...) // join old data and new data + } + b = append(b, EncodeVarint(uint64(len(msg)))...) + b = append(b, msg...) + + m[id] = Extension{enc: b} + } + return nil +} |