org.nustaq.offheap

Class FSTAsciiStringOffheapMap<V>

java.lang.Object

org.nustaq.offheap.FSTBinaryOffheapMap

org.nustaq.offheap.FSTCodedOffheapMap<K,V>

org.nustaq.offheap.FSTSerializedOffheapMap<String,V>

org.nustaq.offheap.FSTAsciiStringOffheapMap<V>

public class FSTAsciiStringOffheapMap<V>
extends FSTSerializedOffheapMap<String,V>

Created by ruedi on 27.06.14. An offheap hashmap. Keys are strings with a given max length. The longer the strings, the slower lookup will be. Values < 50 are ok'ish. The Map can reside on disk (using mmapped files) or just in offheap. Note that changing stored classes will lead to decoding errors in case of persisted files. You need to make use of FST versioning annotation in order to avoid this.

Nested Class Summary

Nested classes/interfaces inherited from class org.nustaq.offheap.FSTBinaryOffheapMap

FSTBinaryOffheapMap.KeyValIter

Field Summary

Fields inherited from class org.nustaq.offheap.FSTSerializedOffheapMap

buffer, coder, tmpVal

Fields inherited from class org.nustaq.offheap.FSTBinaryOffheapMap

alloc, bytezOffset, CORE_HEADER_LEN, CUSTOM_FILEHEADER_LEN, customHeader, FILE_HEADER_LEN, freeList, GB, index, KEY_OFFSET_IN_HEADER, keyLen, mappedFile, MB, memory, mutationCount, numElem

Constructor Summary

Constructors

Constructor and Description
FSTAsciiStringOffheapMap(int keyLen, long sizeMemBytes, int numberOfEleems)
FSTAsciiStringOffheapMap(int keyLen, long sizeMemBytes, int numberOfEleems, FSTCoder coder) see other mem constructor, additional allows to insert a coder.
FSTAsciiStringOffheapMap(String file, int keylen, long size, int numelem) create a memory mapped offheap hashmap
FSTAsciiStringOffheapMap(String mappedFile, int keyLen, long sizeMemBytes, int numberOfElems, FSTCoder coder) see other mem mapped file constructor + additional allows to insert a coder.

Method Summary

Modifier and Type	Method and Description
ByteSource	encodeKey(String key)

Methods inherited from class org.nustaq.offheap.FSTSerializedOffheapMap

decodeValue, encodeValue, getCoder, getEntryLengthForContentLength

Methods inherited from class org.nustaq.offheap.FSTCodedOffheapMap

get, put, remove, values

Methods inherited from class org.nustaq.offheap.FSTBinaryOffheapMap

addEntry, addToFreeList, binaryKeys, binaryValues, decElems, dumpIndexStats, finalize, free, getBinary, getCapacityMB, getContentLenFromHeader, getCustomFileHeader, getFileName, getFreeMem, getHeaderLen, getLenFromHeader, getSize, getUsedMem, incElems, init, initFromFile, printBinaryKey, putBinary, removeBinary, removeEntry, resizeStore, setEntry, writeEntryHeader

Methods inherited from class java.lang.Object

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

Constructor Detail

FSTAsciiStringOffheapMap

public FSTAsciiStringOffheapMap(int keyLen,
                                long sizeMemBytes,
                                int numberOfEleems,
                                FSTCoder coder)

see other mem constructor, additional allows to insert a coder. Useful to preregister classes (speed+size gain, no classnames written!). E.g. new DefaultCoder(MyValue.class, MyOtherValue.class, .. )

FSTAsciiStringOffheapMap

public FSTAsciiStringOffheapMap(int keyLen,
                                long sizeMemBytes,
                                int numberOfEleems)

Parameters:

keyLen - - maximum len of a key

sizeMemBytes - - size of memory (not bigger than OS heap

numberOfEleems - - estimation on number of key-value pairs (autogrow, just educated guess)

FSTAsciiStringOffheapMap

public FSTAsciiStringOffheapMap(String mappedFile,
                                int keyLen,
                                long sizeMemBytes,
                                int numberOfElems,
                                FSTCoder coder)
                         throws Exception

see other mem mapped file constructor + additional allows to insert a coder. Useful to preregister classes (speed+size gain, no classnames written!). E.g. new DefaultCoder(MyValue.class, MyOtherValue.class, .. )

Throws:

Exception

FSTAsciiStringOffheapMap

public FSTAsciiStringOffheapMap(String file,
                                int keylen,
                                long size,
                                int numelem)
                         throws Exception

create a memory mapped offheap hashmap

Parameters:

file - - the file location. If file exists, it will be loaded Attention: in case classes changed you need to delete files as objects won't be compatible (except you made use of fst versioning features)

keylen - - the maximum len of a key

size - - max size of file (can be GB, check OS settings to avoid eager write-to-disk)

numelem - - estimated number of key-value pairs (will auto-grow, just educated guess)

Throws:

Exception

Method Detail

encodeKey

public ByteSource encodeKey(String key)

Specified by:

encodeKey in class FSTCodedOffheapMap<String,V>