func (p *DataPage) createDecoder(rb *bufio.Reader, page *DictionaryPage) (encoding.Decoder, error) {
numValues := uint(p.header.NumValues)
switch p.header.Encoding {
case thrift.Encoding_BIT_PACKED:
case thrift.Encoding_DELTA_BINARY_PACKED:
case thrift.Encoding_DELTA_BYTE_ARRAY:
case thrift.Encoding_DELTA_LENGTH_BYTE_ARRAY:
case thrift.Encoding_PLAIN:
return encoding.NewPlainDecoder(rb, numValues), nil
case thrift.Encoding_RLE:
case thrift.Encoding_RLE_DICTIONARY:
fallthrough
case thrift.Encoding_PLAIN_DICTIONARY:
if page == nil {
return nil, fmt.Errorf("data page in dictionary page format but no dictionary was defined")
}
return encoding.NewPlainDictionaryDecoder(rb, page, numValues), nil
default:
panic("Not supported type for " + p.header.GetEncoding().String())
}
panic("NYI")
}
//Decode Read a dictionary page. There is only one dictionary page for each column chunk
func (p *DictionaryPage) Decode(r io.Reader) error {
// r = dump(r)
count := p.count
_type := p.t
//log.Println("dictionaryPage.Decode:", p.header.GetEncoding(), p.t, count)
switch p.header.GetEncoding() {
case thrift.Encoding_PLAIN_DICTIONARY:
decoder := encoding.NewPlainDecoder(r, count)
switch _type {
case thrift.Type_BOOLEAN:
read, err := decoder.DecodeBool(p.valuesBool)
if err != nil || read != count {
return fmt.Errorf("could not read all dataPage encoded values")
}
case thrift.Type_INT32:
read, err := decoder.DecodeInt32(p.valuesInt32)
if err != nil || read != count {
return fmt.Errorf("could not read all dataPage encoded values")
}
case thrift.Type_INT64:
read, err := decoder.DecodeInt64(p.valuesInt64)
if err != nil || read != count {
return fmt.Errorf("could not read all dataPage encoded values")
}
case thrift.Type_INT96:
read, err := decoder.DecodeInt96(p.valuesInt96)
if err != nil || read != count {
return fmt.Errorf("could not read all dataPage encoded values")
}
case thrift.Type_BYTE_ARRAY:
read, err := decoder.DecodeByteArray(p.valuesByteArray)
if err != nil || read != count {
return fmt.Errorf("could not read all dataPage encoded values")
}
case thrift.Type_FIXED_LEN_BYTE_ARRAY:
read, err := decoder.DecodeFixedByteArray(p.valuesByteArray, p.typeLength)
if err != nil || read != count {
return fmt.Errorf("could not read all dataPage encoded values")
}
case thrift.Type_DOUBLE:
read, err := decoder.DecodeFloat64(p.valuesFloat64)
if err != nil || read != count {
return fmt.Errorf("could not read all dataPage encoded values")
}
case thrift.Type_FLOAT:
read, err := decoder.DecodeFloat32(p.valuesFloat32)
if err != nil || read != count {
return fmt.Errorf("could not read all dataPage encoded values")
}
default:
return fmt.Errorf("dictionary type " + _type.String() + "not yet supported") // FIXME
}
default:
return fmt.Errorf("dictionary encoding " + p.header.GetEncoding().String() + "not yet supported") // FIXME
}
return nil
}