com.sleepycat.je.log.entry.LogEntry Maven / Gradle / Ivy
/*-
* Copyright (C) 2002, 2018, Oracle and/or its affiliates. All rights reserved.
*
* This file was distributed by Oracle as part of a version of Oracle Berkeley
* DB Java Edition made available at:
*
* http://www.oracle.com/technetwork/database/database-technologies/berkeleydb/downloads/index.html
*
* Please see the LICENSE file included in the top-level directory of the
* appropriate version of Oracle Berkeley DB Java Edition for a copy of the
* license and additional information.
*/
package com.sleepycat.je.log.entry;
import java.nio.ByteBuffer;
import com.sleepycat.je.dbi.DatabaseId;
import com.sleepycat.je.dbi.DatabaseImpl;
import com.sleepycat.je.dbi.EnvironmentImpl;
import com.sleepycat.je.log.LogEntryHeader;
import com.sleepycat.je.log.LogEntryType;
import com.sleepycat.je.utilint.VLSN;
/**
* A Log entry allows you to read, write and dump a database log entry. Each
* entry may be made up of one or more loggable items.
*
* The log entry on disk consists of a log header defined by LogManager and
* the specific contents of the log entry.
*
*
Log entries that support replication are required to implement {@link
* ReplicableLogEntry}.
*/
public interface LogEntry extends Cloneable {
/**
* Inform a LogEntry instance of its corresponding LogEntryType.
*/
public void setLogType(LogEntryType entryType);
/**
* @return the type of log entry
*/
public LogEntryType getLogType();
/**
* Read in a log entry.
*/
public void readEntry(EnvironmentImpl envImpl,
LogEntryHeader header,
ByteBuffer entryBuffer);
/**
* Print out the contents of an entry.
*/
public StringBuilder dumpEntry(StringBuilder sb, boolean verbose);
/**
* @return the first item of the log entry
*/
public Object getMainItem();
/**
* Construct a complete item from a item entry, fetching additional log
* entries as needed to ensure that a usable main object is available.
*
* For an OldBINDeltaLogEntry, fetches the full BIN and merges the delta
* information. This is necessary to return a Node main object.
* However, for the new BINDeltaLogEntry, the full BIN is not fetched,
* since the partial BIN (the delta) is usable as a Node.
*/
public Object getResolvedItem(DatabaseImpl dbImpl);
/**
* @return the ID of the database containing this entry, or null if this
* entry type is not part of a database.
*/
public DatabaseId getDbId();
/**
* @return return the transaction id if this log entry is transactional,
* 0 otherwise.
*/
public long getTransactionId();
/**
* @return size of byte buffer needed to store this entry.
*/
public int getSize();
/**
* Serialize this object into the buffer.
* @param logBuffer is the destination buffer
*/
public void writeEntry(ByteBuffer logBuffer);
/**
* Returns true if this item should be counted as obsolete when logged.
*/
public boolean isImmediatelyObsolete(DatabaseImpl dbImpl);
/**
* Returns whether this is a deleted LN.
*/
public boolean isDeleted();
/**
* Do any processing we need to do after logging, while under the logging
* latch.
*/
public void postLogWork(LogEntryHeader header,
long justLoggedLsn,
VLSN vlsn);
/**
* @return a shallow clone.
*/
public LogEntry clone();
/**
* @return true if these two log entries are logically the same.
* Used for replication.
*/
public boolean logicalEquals(LogEntry other);
/**
* Dump the contents of the log entry that are interesting for
* replication.
*/
public void dumpRep(StringBuilder sb);
}