com.spotify.sparkey.extra

Class ReloadableSparkeyReader

java.lang.Object

com.spotify.sparkey.extra.ReloadableSparkeyReader

All Implemented Interfaces:

SparkeyReader, Iterable<SparkeyReader.Entry>

public class ReloadableSparkeyReader
extends Object
implements SparkeyReader

A sparkey reader that can switch between log files at runtime. This reader is thread-safe.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ReloadableSparkeyReader.ReloadableSparkeyReaderException

Nested classes/interfaces inherited from interface com.spotify.sparkey.SparkeyReader

SparkeyReader.Entry, SparkeyReader.Type

Method Summary

Methods

Modifier and Type	Method and Description
void	close()
SparkeyReader	duplicate() Create a duplicate of the reader.
static com.google.common.util.concurrent.ListenableFuture<ReloadableSparkeyReader>	fromLogFile(File logFile, com.google.common.util.concurrent.ListeningExecutorService executorService) Creates a new reloadable sparkey reader from a log file.
byte[]	getAsByteArray(byte[] key)
SparkeyReader.Entry	getAsEntry(byte[] key) This is mostly useful for retrieving large values that don't fit in a byte array.
String	getAsString(String key)
IndexHeader	getIndexHeader()
LogHeader	getLogHeader()
Iterator<SparkeyReader.Entry>	iterator() Get an iterator over all the live entries.
com.google.common.util.concurrent.ListenableFuture<ReloadableSparkeyReader>	load(File logFile)

Methods inherited from class java.lang.Object

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

Method Detail

fromLogFile

public static com.google.common.util.concurrent.ListenableFuture<ReloadableSparkeyReader> fromLogFile(File logFile,
                                                                                      com.google.common.util.concurrent.ListeningExecutorService executorService)

Creates a new reloadable sparkey reader from a log file.

Parameters:

logFile - The log file to start with.

executorService - An executor service that is used to run reload tasks on.

Returns:

A future that resolves to the sparkey reader once it has loaded the log file.

load

public com.google.common.util.concurrent.ListenableFuture<ReloadableSparkeyReader> load(File logFile)

getAsString

public String getAsString(String key)
                   throws IOException

Specified by:

getAsString in interface SparkeyReader

Parameters:

key - the key to search for, interpreted as an UTF-8 string.

Returns:

null if the key/value pair was not found, otherwise the value interpreted as an UTF-8 string.

Throws:

IOException

getAsByteArray

public byte[] getAsByteArray(byte[] key)
                      throws IOException

Specified by:

getAsByteArray in interface SparkeyReader

Parameters:

key - the key to search for

Returns:

null if the key/value pair was not found, otherwise the raw byte array value

Throws:

IOException

getAsEntry

public SparkeyReader.Entry getAsEntry(byte[] key)
                               throws IOException

Description copied from interface: SparkeyReader

This is mostly useful for retrieving large values that don't fit in a byte array.

Specified by:

getAsEntry in interface SparkeyReader

Parameters:

key - the key to search for

Returns:

null if the key/value pair was not found, otherwise the entry.

Throws:

IOException

close

public void close()
           throws IOException

Specified by:

close in interface SparkeyReader

Throws:

IOException

getIndexHeader

public IndexHeader getIndexHeader()

Specified by:

getIndexHeader in interface SparkeyReader

getLogHeader

public LogHeader getLogHeader()

Specified by:

getLogHeader in interface SparkeyReader

duplicate

public SparkeyReader duplicate()

Description copied from interface: SparkeyReader

Create a duplicate of the reader. Useful for using the reader from another thread.

Specified by:

duplicate in interface SparkeyReader

Returns:

a duplicate of the reader.

iterator

public Iterator<SparkeyReader.Entry> iterator()

Description copied from interface: SparkeyReader

Get an iterator over all the live entries. The iterator object is not thread safe, and the entry objects are highly volatile and will be invalidated by the next iteration step. Don't leak this entry, copy whatever data you want from it instead.

Specified by:

iterator in interface SparkeyReader

Specified by:

iterator in interface Iterable<SparkeyReader.Entry>

Returns:

an iterator