//
// readSingleRecord should be called to read a single record from the DBClient connection
// stream (from a db query/command). In particular, this function should be called
// after the resultType has been read from the stream and resultType == 'r' (byte 114).
// When this is called the 'r' byte shown below should have already been read. This
// function will then read everything else shown here - including the serialized record,
// but *NOT* including the byte after the serialized record (which is 0 to indicate
// End of Transmission).
//
// Writing byte (1 byte): 114 [OChannelBinaryServer] <- 'r' (type=single-record)
// Writing short (2 bytes): 0 [OChannelBinaryServer] <- 0=full record (-2=null, -3=RID only)
// Writing byte (1 byte): 100 [OChannelBinaryServer] <- 'd'=document ('f'=flat data, 'b'=raw bytes)
// Writing short (2 bytes): 11 [OChannelBinaryServer] <- cluster-id (RID part 1)
// Writing long (8 bytes): 0 [OChannelBinaryServer] <- cluster-pos (RID part 2)
// Writing int (4 bytes): 1 [OChannelBinaryServer] <- version
// Writing bytes (4+26=30 bytes): [0, 14, 80, 97, 116, ... , 110, 107, 1] <- serialized record
//
// A new single ODocument pointer is returned.
//
// TODO: this method needs to determine how to handle 'f' (flat data) and 'b' (raw bytes)
//
func readSingleRecord(dbc *DBClient) (*oschema.ODocument, error) {
var doc *oschema.ODocument
resultType, err := rw.ReadShort(dbc.conx)
if err != nil {
return nil, oerror.NewTrace(err)
}
if resultType == RecordNull { // null record
// do nothing - return the zero values of the return types
return nil, nil
} else if resultType == RecordRID {
orid, err := readRID(dbc)
if err != nil {
return nil, oerror.NewTrace(err)
}
doc = oschema.NewDocument("")
doc.RID = orid
ogl.Warn(fmt.Sprintf("readSingleRecord :: Code path not seen before!!: SQLCommand resulted in RID: %s\n", orid))
// TODO: would now load that record from the DB if the user (Go SQL API) wants it
return doc, nil
} else if resultType != int16(0) {
_, file, line, _ := runtime.Caller(0)
return nil, fmt.Errorf("Unexpected resultType in SQLCommand (file: %s; line %d): %d",
file, line+1, resultType)
}
// if get here then have a full record, which can be in one of three formats:
// - "flat data"
// - "raw bytes"
// - "document"
recType, err := rw.ReadByte(dbc.conx)
if err != nil {
return nil, oerror.NewTrace(err)
}
if recType == byte('d') {
return readSingleDocument(dbc)
} else if recType == byte('f') {
return readFlatDataRecord(dbc) // ???
} else if recType == byte('b') {
return readRawBytesRecord(dbc) // ???
} else {
_, file, line, _ := runtime.Caller(0)
return nil, fmt.Errorf("Unexpected record type. Expected 'd', 'f' or 'b', but was %v (file: %s; line %d)",
recType, file, line+1)
}
}
//
// TODO: in the Java version there is a "fill" method on ODocument (ORecord)
// to create a record from these entries => maybe move this there?
//
func createDocumentFromBytes(rid oschema.ORID, recVersion int32, serializedDoc []byte, dbc *DBClient) (*oschema.ODocument, error) {
var doc *oschema.ODocument
doc = oschema.NewDocument("") // don't know classname yet (in serialized record)
doc.RID = rid
doc.Version = recVersion
// TODO: here need to make a query to look up the schema of the doc if we don't have it already cached
// the first byte specifies record serialization version
// use it to look up serializer and strip off that byte
serde := dbc.RecordSerDes[int(serializedDoc[0])]
recBuf := obuf.NewReadBuffer(serializedDoc[1:])
err := serde.Deserialize(dbc, doc, recBuf)
if err != nil {
return nil, err
}
return doc, nil
}
//
// The serialization version (the first byte of the serialized record) should
// be stripped off (already read) from the io.Reader being passed in.
//
func (serde ORecordSerializerV0) Deserialize(dbc *DBClient, doc *oschema.ODocument, buf *obuf.ReadBuf) (err error) {
if doc == nil {
return errors.New("ODocument reference passed into ORecordSerializerBinaryV0.Deserialize was null")
}
// temporarily set state for the duration of this Deserialize call
// dbc is allowed to be nil for reentrant (recursive) calls -- in which
// case serde.dbc should already be set (not-nil)
if dbc != nil {
if serde.dbc != nil {
return errors.New("Attempted to set dbc again in Serialize when it is already set")
}
serde.dbc = dbc
defer func() {
serde.dbc = nil
}()
} else if serde.dbc == nil {
return errors.New("dbc *DBClient passed into Deserialize was null and dbc had not already been set in Serializer state")
}
classname, err := readClassname(buf)
if err != nil {
return oerror.NewTrace(err)
}
doc.Classname = classname
header, err := readHeader(buf)
if err != nil {
return oerror.NewTrace(err)
}
serde.refreshGlobalPropertiesIfRequired(header)
for i, prop := range header.properties {
var ofield *oschema.OField
if len(prop.name) == 0 {
globalProp, ok := serde.dbc.GetCurrDB().GlobalProperties[int(prop.id)]
if !ok {
panic(oerror.ErrStaleGlobalProperties) // TODO: should return this instead
}
ofield = &oschema.OField{
ID: prop.id,
Name: globalProp.Name,
Type: globalProp.Type,
}
} else {
ofield = &oschema.OField{
ID: int32(-1),
Name: string(prop.name),
Type: prop.typ,
}
}
// if data ptr is 0 (NULL), then it has no entry/value in the serialized record
if header.dataPtrs[i] != 0 {
buf.Seek(uint(header.dataPtrs[i] - 1)) // -1 bcs the lead byte (serialization version) was stripped off
val, err := serde.readDataValue(buf, ofield.Type)
if err != nil {
return err
}
ofield.Value = val
}
doc.AddField(ofield.Name, ofield)
}
return nil
}
//
// In Progress attempt to rewrite writeSerializedRecord and related fns
// using a seekable/skipping WriteBuf
//
func (serde ORecordSerializerV0) writeSerializedRecord(wbuf *obuf.WriteBuf, doc *oschema.ODocument) (err error) {
nfields := len(doc.FieldNames())
ptrPos := make([]int, 0, nfields) // position in buf where data ptr int needs to be written
currDB := serde.dbc.GetCurrDB()
oclass, ok := currDB.Classes[doc.Classname]
docFields := doc.GetFields()
for _, fld := range docFields {
var oprop *oschema.OProperty
if ok {
oprop = oclass.Properties[fld.Name]
}
// FROM THE JAVA CLIENT:
// if (properties[i] != null) {
// OVarIntSerializer.write(bytes, (properties[i].getId() + 1) * -1);
// if (properties[i].getType() != OType.ANY)
// pos[i] = bytes.alloc(OIntegerSerializer.INT_SIZE);
// else
// pos[i] = bytes.alloc(OIntegerSerializer.INT_SIZE + 1); // TODO: why does ANY required an additional byte?
// } else {
// writeString(bytes, entry.getKey());
// pos[i] = bytes.alloc(OIntegerSerializer.INT_SIZE + 1);
if oprop != nil {
// if property is known in the global properties, then
// just write its encoded id
varint.EncodeAndWriteVarInt32(wbuf, encodeFieldIDForHeader(oprop.ID))
ptrPos = append(ptrPos, wbuf.Len())
wbuf.Skip(4)
// Note: no need to write property type when writing property ID
} else {
// property Name
err = varint.WriteString(wbuf, fld.Name)
if err != nil {
return oerror.NewTrace(err)
}
ptrPos = append(ptrPos, wbuf.Len())
wbuf.Skip(4)
// property Type
err = rw.WriteByte(wbuf, byte(fld.Type))
if err != nil {
return oerror.NewTrace(err)
}
}
}
wbuf.WriteByte(0) // End of Header sentinel
// now write out the data values
for i, fld := range docFields {
currPos := wbuf.Len()
wbuf.Seek(uint(ptrPos[i]))
err = rw.WriteInt(wbuf, int32(currPos))
if err != nil {
return oerror.NewTrace(err)
}
wbuf.Seek(uint(currPos))
err = serde.writeDataValue(wbuf, fld.Value, fld.Type)
if err != nil {
return oerror.NewTrace(err)
}
}
return nil
}