DataFileReader(Stream stream, Schema readerSchema, CreateDatumReader datumReaderFactory)
{
_readerSchema = readerSchema;
_datumReaderFactory = datumReaderFactory;
Init(stream);
BlockFinished();
}
DataFileReader(Stream stream, Schema readerSchema, CreateDatumReader datumReaderFactory, bool leaveOpen)
{
_readerSchema = readerSchema;
_datumReaderFactory = datumReaderFactory;
_leaveOpen = leaveOpen;
Init(stream);
BlockFinished();
}
private static Decoder OpenReader(Stream inStream, CreateDatumReader datumReaderFactory)
{
if (!inStream.CanSeek)
{
throw new AvroRuntimeException("Not a valid input stream - must be seekable!");
}
return(new Decoder(inStream, datumReaderFactory)); // (not supporting 1.2 or below, format)
}
Decoder(Stream stream, CreateDatumReader datumReaderFactory)
{
_datumReaderFactory = datumReaderFactory;
_stream = stream;
_header = new Header();
_reader = new Reader(stream);
_syncBuffer = new byte[DataFileConstants.SyncSize];
// validate header
byte[] firstBytes = new byte[DataFileConstants.AvroHeader.Length];
try
{
_reader.ReadFixed(firstBytes);
}
catch (Exception)
{
throw new InvalidAvroObjectException("Cannot read length of Avro Header");
}
if (!firstBytes.SequenceEqual(DataFileConstants.AvroHeader))
{
throw new InvalidAvroObjectException("Cannot read Avro Header");
}
// read meta data
long len = _reader.ReadMapStart();
if (len > 0)
{
do
{
for (long i = 0; i < len; i++)
{
string key = _reader.ReadString();
byte[] val = _reader.ReadBytes();
_header.MetaData.Add(key, val);
}
} while ((len = _reader.ReadMapNext()) != 0);
}
// read in sync data
_reader.ReadFixed(_header.SyncData);
// parse schema and set codec
_header.Schema = Schema.Parse(GetMetaString(DataFileConstants.SchemaMetadataKey));
resolver = _datumReaderFactory(_header.Schema, _readerSchema ?? _header.Schema);
_codec = Codec.CreateCodecFromString(GetMetaString(DataFileConstants.CodecMetadataKey));
}
/// <summary>
/// Open a reader for a stream using the reader's schema and a custom DatumReader
/// </summary>
/// <param name="inStream"></param>
/// <returns></returns>
public static IFileReader <T> OpenReader(Stream inStream, Schema readerSchema, CreateDatumReader datumReaderFactory)
{
if (!inStream.CanSeek)
{
throw new AvroRuntimeException("Not a valid input stream - must be seekable!");
}
if (inStream.Length < DataFileConstants.AvroHeader.Length)
{
throw new AvroRuntimeException("Not an Avro data file");
}
// verify magic header
byte[] magic = new byte[DataFileConstants.AvroHeader.Length];
inStream.Seek(0, SeekOrigin.Begin);
for (int c = 0; c < magic.Length; c = inStream.Read(magic, c, magic.Length - c))
{
}
inStream.Seek(0, SeekOrigin.Begin);
if (magic.SequenceEqual(DataFileConstants.AvroHeader)) // current format
{
return(new DataFileReader <T>(inStream, readerSchema, datumReaderFactory)); // (not supporting 1.2 or below, format)
}
throw new AvroRuntimeException("Not an Avro data file");
}
/// <summary>
/// Open a reader for a stream using the reader's schema and a custom DatumReader
/// </summary>
/// <param name="inStream">Stream of file contents</param>
/// <param name="readerSchema">Schema used to read the file</param>
/// <param name="datumReaderFactory">Factory to create datum readers given a reader an writer schema</param>
/// <returns>A new file reader</returns>
public static IFileReader <T> OpenReader(Stream inStream, Schema readerSchema, CreateDatumReader datumReaderFactory)
{
return(new DataFileReader <T>(inStream, readerSchema, datumReaderFactory)); // (not supporting 1.2 or below, format)
}
Reader(Stream stream, CreateDatumReader datumReaderFactory)
{
_datumReaderFactory = datumReaderFactory;
Init(stream);
BlockFinished();
}
