Chunk (Flink : State backends : Heap spillable 1.19.2-cp3 API)

```
public interface Chunk
```
Chunk is a logically contiguous space backed by one or multiple ByteBuffer.
For example: a Chunk of 1G size may be backed by one MappedByteBuffer from a memory-mapped 1G file, or multiple HeapByteBuffer/DirectByteBuffer.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`int`	`allocate(int len)`	Try to allocate size bytes from the chunk.
`void`	`free(int interChunkOffset)`	release the space addressed by interChunkOffset.
`int`	`getChunkCapacity()`
`int`	`getChunkId()`
`org.apache.flink.core.memory.MemorySegment`	`getMemorySegment(int chunkOffset)`
`int`	`getOffsetInSegment(int offsetInChunk)`

- Method Detail
  - allocate
```
int allocate(int len)
```
    Try to allocate size bytes from the chunk.
    
    Parameters:
    
    len - size of bytes to allocate.
    
    Returns:
    
    the offset of the successful allocation, or -1 to indicate not-enough-space
  - free
```
void free(int interChunkOffset)
```
    release the space addressed by interChunkOffset.
    
    Parameters:
    
    interChunkOffset - offset of the chunk
  - getChunkId
```
int getChunkId()
```
    Returns:
    
    Id of this Chunk
  - getChunkCapacity
```
int getChunkCapacity()
```
  - getMemorySegment
```
org.apache.flink.core.memory.MemorySegment getMemorySegment(int chunkOffset)
```
    Returns:
    
    This chunk's backing MemorySegment described by chunkOffset.
  - getOffsetInSegment
```
int getOffsetInSegment(int offsetInChunk)
```
    Parameters:
    
    offsetInChunk - virtual and global address in chunk
    
    Returns:
    
    chunk maybe compose of multi MemorySegments, return the offset in certain one.