Package io.delta.kernel.internal.replay

Class ProtocolMetadataLogReplay

Object

io.delta.kernel.internal.replay.ProtocolMetadataLogReplay

public class ProtocolMetadataLogReplay
extends Object

Static utility class for loading Protocol and Metadata from Delta log files.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	ProtocolMetadataLogReplay.Result	Result of loading Protocol and Metadata from a LogSegment.

Field Summary

Fields

Modifier and Type	Field	Description
static final StructType	PROTOCOL_METADATA_READ_SCHEMA	Read schema when searching for the latest Protocol and Metadata.

Constructor Summary

Constructors

Constructor	Description
ProtocolMetadataLogReplay()

Method Summary

Modifier and Type	Method	Description
static ProtocolMetadataLogReplay.Result	loadProtocolAndMetadata(Engine engine, Path dataPath, LogSegment logSegment, Lazy<Optional<CRCInfo>> lazyCrcInfo, SnapshotMetrics snapshotMetrics)	Loads the latest Protocol and Metadata from the log files in the given LogSegment.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

PROTOCOL_METADATA_READ_SCHEMA

public static final StructType PROTOCOL_METADATA_READ_SCHEMA

Read schema when searching for the latest Protocol and Metadata.

Constructor Details

ProtocolMetadataLogReplay

public ProtocolMetadataLogReplay()

Method Details

loadProtocolAndMetadata

public static ProtocolMetadataLogReplay.Result loadProtocolAndMetadata(Engine engine,
 Path dataPath,
 LogSegment logSegment,
 Lazy<Optional<CRCInfo>> lazyCrcInfo,
 SnapshotMetrics snapshotMetrics)

Loads the latest Protocol and Metadata from the log files in the given LogSegment.

Uses the provided lazy CRC loader to bound how many delta files it reads, and to ensure we only read the CRC file if needed.

We read delta files in reverse order (newest first) searching for the latest Protocol and Metadata. When we reach the version just before (greater than) the CRC file version (if present), we lazily load the CRC file to fill in any missing Protocol or Metadata, avoiding reading older delta files.

Also validates that the Kernel can read the table at the loaded protocol version.