public MetaInfoObjExtractor(CompressionKind compressionKind, int bufferSize, int metadataSize,
ByteBuffer footerBuffer)
{
this.compressionKind = compressionKind;
this.bufferSize = bufferSize;
this.codec = WriterImpl.createCodec(compressionKind);
this.metadataSize = metadataSize;
int position = footerBuffer.position();
int footerBufferSize = footerBuffer.limit() - footerBuffer.position() - metadataSize;
this.metadata = extractMetadata(footerBuffer, position, metadataSize, codec, bufferSize);
this.footer = extractFooter(
footerBuffer, position + metadataSize, footerBufferSize, codec, bufferSize);
footerBuffer.position(position);
this.inspector = OrcStruct.createObjectInspector(0, footer.TypesList);
}
/** Extracts the necessary metadata from an externally store buffer (fullFooterBuffer). */
public static FooterInfo extractMetaInfoFromFooter(ByteBuffer bb, string srcPath)
{
// Read the PostScript. Be very careful as some parts of this historically use bb position
// and some use absolute offsets that have to take position into account.
int baseOffset = bb.position();
int lastByteAbsPos = baseOffset + bb.remaining() - 1;
int psLen = bb.get(lastByteAbsPos) & 0xff;
int psAbsPos = lastByteAbsPos - psLen;
OrcProto.PostScript ps = extractPostScript(bb, srcPath, psLen, psAbsPos);
Debug.Assert(baseOffset == bb.position());
// Extract PS information.
int footerSize = (int)ps.FooterLength, metadataSize = (int)ps.MetadataLength,
footerAbsPos = psAbsPos - footerSize, metadataAbsPos = footerAbsPos - metadataSize;
CompressionKind compressionKind = (CompressionKind)Enum.Parse(typeof(CompressionKind), ps.Compression.ToString(), true);
CompressionCodec codec = WriterImpl.createCodec(compressionKind);
int bufferSize = (int)ps.CompressionBlockSize;
bb.position(metadataAbsPos);
bb.mark();
// Extract metadata and footer.
OrcProto.Metadata metadata = extractMetadata(
bb, metadataAbsPos, metadataSize, codec, bufferSize);
List <StripeStatistics> stats = new List <StripeStatistics>(metadata.StripeStatsCount);
foreach (OrcProto.StripeStatistics ss in metadata.StripeStatsList)
{
stats.Add(new StripeStatistics(ss.ColStatsList));
}
OrcProto.Footer footer = extractFooter(bb, footerAbsPos, footerSize, codec, bufferSize);
bb.position(metadataAbsPos);
bb.limit(psAbsPos);
// TODO: do we need footer buffer here? FileInfo/FileMetaInfo is a mess...
FileMetaInfo fmi = new FileMetaInfo(
compressionKind, bufferSize, metadataSize, bb, extractWriterVersion(ps));
return(new FooterInfo(stats, footer, fmi));
}
