FSTBinaryOffheapMap (fst 2.12 API)

java.lang.Object
- org.nustaq.offheap.FSTBinaryOffheapMap

Direct Known Subclasses:

FSTCodedOffheapMap
```
public class FSTBinaryOffheapMap
extends Object
```
Baseclass of offheap maps. FST OffHeap Maps enable to store key/value pairs in offheap memory. Additionally it provides and iterator interface for all values. In order to also iterate keys, add each key to its value object, as this OffHeap map does not support iteration of keys out of the box. See subclasses for directly applicable classes (E.g. FSTStringOffheapMap) The base is a generic bytesource to bytesource map. Note that key should be as short as possible (4-20 bytes) and should have their most modified digit at the last character of their value. e.g. [0,0,0,0,123,44] where '44' changes with each new key. Else on-heap memory consumption will grow. Performance of lookup degrades with growing key size. In case entries are updated frequently with values of different size, avoid fragementation by adding extra space to each entry. Override getEntryLengthForContentLength for this.

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static interface FSTBinaryOffheapMap.KeyValIter

Nested Classes
Modifier and Type	Class and Description
`static interface`	`FSTBinaryOffheapMap.KeyValIter`

Field Summary

Fields
Modifier and Type	Field and Description
`protected MallocBytezAllocator`	`alloc`
`protected long`	`bytezOffset`
`static int`	`CORE_HEADER_LEN`
`static int`	`CUSTOM_FILEHEADER_LEN`
`protected Bytez`	`customHeader`
`static int`	`FILE_HEADER_LEN`
`protected FreeList`	`freeList`
`static long`	`GB`
`protected OffHeapByteTree`	`index`
`static int`	`KEY_OFFSET_IN_HEADER`
`protected int`	`keyLen`
`static long`	`MB`
`protected Bytez`	`memory`
`protected int`	`numElem`

Constructor Summary

Constructors
Constructor and Description
`FSTBinaryOffheapMap(int keyLen, long sizeMemBytes, int numberOfElems)`
`FSTBinaryOffheapMap(String mappedFile, int keyLen, long sizeMemBytes, int numberOfElems)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`protected long`	`addEntry(ByteSource key, ByteSource value)`
`protected void`	`addToFreeList(long offset)`
`FSTBinaryOffheapMap.KeyValIter`	`binaryKeys()`
`Iterator<ByteSource>`	`binaryValues()`
`protected void`	`decElems()`
`void`	`dumpIndexStats()`
`protected void`	`finalize()`
`void`	`free()`
`BytezByteSource`	`getBinary(ByteSource key)` get an entry.
`int`	`getCapacityMB()`
`protected int`	`getContentLenFromHeader(long off)`
`Bytez`	`getCustomFileHeader()`
`protected int`	`getEntryLengthForContentLength(long lengthOfEntry)` called upon add, allows to reserve extra space for later growth per entry
`long`	`getFreeMem()`
`protected int`	`getHeaderLen()`
`protected int`	`getLenFromHeader(long off)`
`int`	`getSize()`
`long`	`getUsedMem()`
`protected void`	`incElems()`
`protected void`	`init(int keyLen, long sizeMemBytes, int numberOfElems)`
`protected void`	`initFromFile(String file, int keyLen, long sizeMemBytes, int numberOfElems)`
`String`	`printBinaryKey(ByteSource key)`
`void`	`putBinary(ByteSource key, ByteSource value)`
`void`	`removeBinary(ByteSource key)` remove the key from the binary map
`protected void`	`removeEntry(long offset)`
`protected void`	`setEntry(long off, int entryLen, ByteSource value)`
`protected void`	`writeEntryHeader(long offset, int entryLen, int contentLen, boolean removed)`

Methods inherited from class java.lang.Object
clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

MB
```
public static final long MB
```
See Also:

Constant Field Values

GB
```
public static final long GB
```
See Also:

Constant Field Values

CUSTOM_FILEHEADER_LEN
```
public static final int CUSTOM_FILEHEADER_LEN
```
See Also:

Constant Field Values

CORE_HEADER_LEN
```
public static final int CORE_HEADER_LEN
```
See Also:

Constant Field Values

FILE_HEADER_LEN
```
public static final int FILE_HEADER_LEN
```
See Also:

Constant Field Values

KEY_OFFSET_IN_HEADER
```
public static final int KEY_OFFSET_IN_HEADER
```
See Also:

Constant Field Values

index
```
protected OffHeapByteTree index
```

memory
```
protected Bytez memory
```

customHeader
```
protected Bytez customHeader
```

alloc
```
protected MallocBytezAllocator alloc
```

numElem
```
protected int numElem
```

keyLen
```
protected int keyLen
```

bytezOffset
```
protected long bytezOffset
```

freeList
```
protected FreeList freeList
```

Constructor Detail

FSTBinaryOffheapMap

public FSTBinaryOffheapMap(String mappedFile,
                           int keyLen,
                           long sizeMemBytes,
                           int numberOfElems)
                    throws Exception

Throws:: Exception

FSTBinaryOffheapMap

public FSTBinaryOffheapMap(int keyLen,
                           long sizeMemBytes,
                           int numberOfElems)

Method Detail

getCustomFileHeader
```
public Bytez getCustomFileHeader()
```

initFromFile

protected void initFromFile(String file,
                            int keyLen,
                            long sizeMemBytes,
                            int numberOfElems)
                     throws Exception

Throws:: Exception

init

protected void init(int keyLen,
                    long sizeMemBytes,
                    int numberOfElems)

finalize

protected void finalize()
                 throws Throwable

Overrides:: finalize in class Object
Throws:: Throwable

free
```
public void free()
```

putBinary

public void putBinary(ByteSource key,
                      ByteSource value)

removeEntry

protected void removeEntry(long offset)

addToFreeList

protected void addToFreeList(long offset)

setEntry

protected void setEntry(long off,
                        int entryLen,
                        ByteSource value)

addEntry

protected long addEntry(ByteSource key,
                        ByteSource value)

getBinary
```
public BytezByteSource getBinary(ByteSource key)
```
get an entry. the returned ByteSource must be processed immediately as it will be reused internally on next get Warning: Concurrent Modification (e.g. add remove elements during iteration) is NOT SUPPORTED and NOT CHECKED. Collect keys to change inside iteration and perform changes after iteration is finished.

Parameters:

key -

Returns:

removeBinary
```
public void removeBinary(ByteSource key)
```
remove the key from the binary map

Parameters:

key -

decElems
```
protected void decElems()
```

incElems
```
protected void incElems()
```

getEntryLengthForContentLength
```
protected int getEntryLengthForContentLength(long lengthOfEntry)
```
called upon add, allows to reserve extra space for later growth per entry

Parameters:

lengthOfEntry -

Returns:

writeEntryHeader

protected void writeEntryHeader(long offset,
                                int entryLen,
                                int contentLen,
                                boolean removed)

getHeaderLen
```
protected int getHeaderLen()
```

getLenFromHeader

protected int getLenFromHeader(long off)

getContentLenFromHeader

protected int getContentLenFromHeader(long off)

binaryValues

public Iterator<ByteSource> binaryValues()

printBinaryKey

public String printBinaryKey(ByteSource key)

binaryKeys

public FSTBinaryOffheapMap.KeyValIter binaryKeys()

getFreeMem
```
public long getFreeMem()
```

getUsedMem
```
public long getUsedMem()
```

getCapacityMB
```
public int getCapacityMB()
```

getSize
```
public int getSize()
```

dumpIndexStats
```
public void dumpIndexStats()
```

Class FSTBinaryOffheapMap

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

MB

GB

CUSTOM_FILEHEADER_LEN

CORE_HEADER_LEN

FILE_HEADER_LEN

KEY_OFFSET_IN_HEADER

index

memory

customHeader

alloc

numElem

keyLen

bytezOffset

freeList

Constructor Detail

FSTBinaryOffheapMap

FSTBinaryOffheapMap

Method Detail

getCustomFileHeader

initFromFile

init

finalize

free

putBinary

removeEntry

addToFreeList

setEntry

addEntry

getBinary

removeBinary

decElems

incElems

getEntryLengthForContentLength

writeEntryHeader

getHeaderLen

getLenFromHeader

getContentLenFromHeader

binaryValues

printBinaryKey

binaryKeys

getFreeMem

getUsedMem

getCapacityMB

getSize

dumpIndexStats