org.iq80.leveldb

Class WriteOptions

java.lang.Object

org.iq80.leveldb.WriteOptions

public class WriteOptions
extends Object

Options that control write operations

Constructor Summary

Constructors

Constructor and Description
WriteOptions()

Method Summary

Modifier and Type	Method and Description
boolean	snapshot() If "snapshot" is true, take a snapshot at the end of this write operation
WriteOptions	snapshot(boolean snapshot)
boolean	sync() If true, the write will be flushed from the operating system buffer cache (by calling WritableFile::Sync()) before the write is considered complete.
WriteOptions	sync(boolean sync)

Methods inherited from class java.lang.Object

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

Constructor Detail

WriteOptions

public WriteOptions()

Method Detail

sync

public boolean sync()

If true, the write will be flushed from the operating system buffer cache (by calling WritableFile::Sync()) before the write is considered complete. If this flag is true, writes will be slower.

If this flag is false, and the machine crashes, some recent writes may be lost. Note that if it is just the process that crashes (i.e., the machine does not reboot), no writes will be lost even if sync==false.

In other words, a DB write with sync==false has similar crash semantics as the "write()" system call. A DB write with sync==true has similar crash semantics to a "write()" system call followed by "fsync()".

In java Implementation if process crash Default: false

sync

public WriteOptions sync(boolean sync)

snapshot

public boolean snapshot()

If "snapshot" is true, take a snapshot at the end of this write operation

snapshot

public WriteOptions snapshot(boolean snapshot)