RootAllocator (Apache Arrow Java Root POM 12.0.0 API)

java.lang.Object
- org.apache.arrow.memory.RootAllocator

All Implemented Interfaces:

AutoCloseable, BufferAllocator
```
public class RootAllocator
extends Object
```
A root allocator for using direct memory for Arrow Vectors/Arrays. Supports creating a tree of descendant child allocators to facilitate better instrumentation of memory allocations.

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static class BaseAllocator.Verbosity
Enum for logging verbosity.

Nested Classes
Modifier and Type	Class and Description
`static class`	`BaseAllocator.Verbosity` Enum for logging verbosity.

Field Summary

Fields
Modifier and Type	Field and Description
`static boolean`	`DEBUG`
`static String`	`DEBUG_ALLOCATOR`
`static int`	`DEBUG_LOG_LENGTH`
`static org.apache.arrow.memory.BaseAllocator.Config`	`DEFAULT_CONFIG`
`protected org.apache.arrow.memory.Accountant`	`parent` The parent allocator.
`protected long`	`reservation` The amount of memory reserved for this allocator.

Constructor Summary

Constructors
Constructor and Description
`RootAllocator()`
`RootAllocator(AllocationListener listener, long limit)`
`RootAllocator(AllocationListener listener, long limit, RoundingPolicy roundingPolicy)` Constructor.
`RootAllocator(org.apache.arrow.memory.BaseAllocator.Config config)`
`RootAllocator(long limit)`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`assertOpen()` Asserts (using java assertions) that the provided allocator is currently open.
`ArrowBuf`	`buffer(long initialRequestSize)` Allocate a new or reused buffer of the provided size.
`ArrowBuf`	`buffer(long initialRequestSize, BufferManager manager)` Allocate a new or reused buffer of the provided size.
`void`	`close()` Close this Accountant.
`static ImmutableConfig.Builder`	`configBuilder()` Returns a builder class for configuring BaseAllocator's options.
`static org.apache.arrow.memory.BaseAllocator.Config`	`defaultConfig()` Returns a default `Config` instance.
`boolean`	`forceAllocate(long size)` Increase the accounting.
`long`	`getAllocatedMemory()` Return the current amount of allocated memory that this Accountant is managing accounting for.
`Collection<BufferAllocator>`	`getChildAllocators()` Returns the set of child allocators.
`ArrowBuf`	`getEmpty()` Get a reference to the empty buffer associated with this allocator.
`long`	`getHeadroom()`
`long`	`getInitReservation()` Return the initial reservation.
`long`	`getLimit()` Return the current limit of this Accountant.
`AllocationListener`	`getListener()` Returns the allocation listener used by this allocator.
`String`	`getName()` Return the name of the accountant.
`org.apache.arrow.memory.BaseAllocator`	`getParentAllocator()` Returns the parent allocator.
`long`	`getPeakMemoryAllocation()` The peak memory allocated by this Accountant.
`BufferAllocator`	`getRoot()` Get the root allocator of this allocator.
`RoundingPolicy`	`getRoundingPolicy()` Gets the rounding policy of the allocator.
`static boolean`	`isDebug()`
`boolean`	`isOverLimit()`
`BufferAllocator`	`newChildAllocator(String name, AllocationListener listener, long initReservation, long maxAllocation)` Create a new child allocator.
`BufferAllocator`	`newChildAllocator(String name, long initReservation, long maxAllocation)` Create a new child allocator.
`AllocationReservation`	`newReservation()` Create an allocation reservation.
`void`	`releaseBytes(long size)`
`void`	`setLimit(long newLimit)` Set the maximum amount of memory that can be allocated in the this Accountant before failing an allocation.
`String`	`toString()`
`String`	`toVerboseString()` Provide a verbose string of the current allocator state.
`void`	`verify()` Verify the accounting state of the allocation system.
`ArrowBuf`	`wrapForeignAllocation(ForeignAllocation allocation)` EXPERIMENTAL: Wrap an allocation created outside this BufferAllocator.

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

Methods inherited from interface org.apache.arrow.memory.BufferAllocator
forceAllocate, getAllocatedMemory, getHeadroom, getInitReservation, getLimit, getPeakMemoryAllocation, isOverLimit, releaseBytes, setLimit

- Field Detail
  - DEBUG_ALLOCATOR
```
public static final String DEBUG_ALLOCATOR
```
    See Also:
    
    Constant Field Values
  - DEBUG_LOG_LENGTH
```
public static final int DEBUG_LOG_LENGTH
```
    See Also:
    
    Constant Field Values
  - DEBUG
```
public static final boolean DEBUG
```
  - DEFAULT_CONFIG
```
public static final org.apache.arrow.memory.BaseAllocator.Config DEFAULT_CONFIG
```
  - parent
```
protected final org.apache.arrow.memory.Accountant parent
```
    The parent allocator.
  - reservation
```
protected final long reservation
```
    The amount of memory reserved for this allocator. Releases below this amount of memory will not be returned to the parent Accountant until this Accountant is closed.
- Constructor Detail
  - RootAllocator
```
public RootAllocator()
```
  - RootAllocator
```
public RootAllocator(long limit)
```
  - RootAllocator
```
public RootAllocator(AllocationListener listener,
                     long limit)
```
  - RootAllocator
```
public RootAllocator(AllocationListener listener,
                     long limit,
                     RoundingPolicy roundingPolicy)
```
    Constructor.
    
    Parameters:
    
    listener - the allocation listener
    
    limit - max allocation size in bytes
    
    roundingPolicy - the policy for rounding the buffer size
  - RootAllocator
```
public RootAllocator(org.apache.arrow.memory.BaseAllocator.Config config)
```
- Method Detail
  - verify
```
public void verify()
```
    Verify the accounting state of the allocation system.
  - getListener
```
public AllocationListener getListener()
```
    Description copied from interface: BufferAllocator
    
    Returns the allocation listener used by this allocator.
    
    Specified by:
    
    getListener in interface BufferAllocator
    
    Returns:
    
    the AllocationListener instance. Or AllocationListener.NOOP by default if no listener is configured when this allocator was created.
  - getParentAllocator
```
public org.apache.arrow.memory.BaseAllocator getParentAllocator()
```
    Description copied from interface: BufferAllocator
    
    Returns the parent allocator.
    
    Specified by:
    
    getParentAllocator in interface BufferAllocator
    
    Returns:
    
    parent allocator
  - getChildAllocators
```
public Collection<BufferAllocator> getChildAllocators()
```
    Description copied from interface: BufferAllocator
    
    Returns the set of child allocators.
    
    Specified by:
    
    getChildAllocators in interface BufferAllocator
    
    Returns:
    
    set of child allocators
  - isDebug
```
public static boolean isDebug()
```
  - assertOpen
```
public void assertOpen()
```
    Description copied from interface: BufferAllocator
    
    Asserts (using java assertions) that the provided allocator is currently open. If assertions are disabled, this is a no-op.
    
    Specified by:
    
    assertOpen in interface BufferAllocator
  - getName
```
public String getName()
```
    Return the name of the accountant.
    
    Specified by:
    
    getName in interface BufferAllocator
    
    Returns:
    
    name of accountant
  - getEmpty
```
public ArrowBuf getEmpty()
```
    Description copied from interface: BufferAllocator
    
    Get a reference to the empty buffer associated with this allocator. Empty buffers are special because we don't worry about them leaking or managing reference counts on them since they don't actually point to any memory.
    
    Specified by:
    
    getEmpty in interface BufferAllocator
    
    Returns:
    
    the empty buffer
  - wrapForeignAllocation
```
public ArrowBuf wrapForeignAllocation(ForeignAllocation allocation)
```
    Description copied from interface: BufferAllocator
    
    EXPERIMENTAL: Wrap an allocation created outside this BufferAllocator.
    This is useful to integrate allocations from native code into the same memory management framework as Java-allocated buffers, presenting users a consistent API. The created buffer will be tracked by this allocator and can be transferred like Java-allocated buffers.
    The underlying allocation will be closed when all references to the buffer are released. If this method throws, the underlying allocation will also be closed.
    
    Specified by:
    
    wrapForeignAllocation in interface BufferAllocator
    
    Parameters:
    
    allocation - The underlying allocation.
  - buffer
```
public ArrowBuf buffer(long initialRequestSize)
```
    Description copied from interface: BufferAllocator
    
    Allocate a new or reused buffer of the provided size. Note that the buffer may technically be larger than the requested size for rounding purposes. However, the buffer's capacity will be set to the configured size.
    
    Specified by:
    
    buffer in interface BufferAllocator
    
    Parameters:
    
    initialRequestSize - The size in bytes.
    
    Returns:
    
    a new ArrowBuf, or null if the request can't be satisfied
  - buffer
```
public ArrowBuf buffer(long initialRequestSize,
                       BufferManager manager)
```
    Description copied from interface: BufferAllocator
    
    Allocate a new or reused buffer of the provided size. Note that the buffer may technically be larger than the requested size for rounding purposes. However, the buffer's capacity will be set to the configured size.
    
    Specified by:
    
    buffer in interface BufferAllocator
    
    Parameters:
    
    initialRequestSize - The size in bytes.
    
    manager - A buffer manager to manage reallocation.
    
    Returns:
    
    a new ArrowBuf, or null if the request can't be satisfied
  - getRoot
```
public BufferAllocator getRoot()
```
    Description copied from interface: BufferAllocator
    
    Get the root allocator of this allocator. If this allocator is already a root, return this directly.
    
    Specified by:
    
    getRoot in interface BufferAllocator
    
    Returns:
    
    The root allocator
  - newChildAllocator
```
public BufferAllocator newChildAllocator(String name,
                                         long initReservation,
                                         long maxAllocation)
```
    Description copied from interface: BufferAllocator
    
    Create a new child allocator.
    
    Specified by:
    
    newChildAllocator in interface BufferAllocator
    
    Parameters:
    
    name - the name of the allocator.
    
    initReservation - the initial space reservation (obtained from this allocator)
    
    maxAllocation - maximum amount of space the new allocator can allocate
    
    Returns:
    
    the new allocator, or null if it can't be created
  - newChildAllocator
```
public BufferAllocator newChildAllocator(String name,
                                         AllocationListener listener,
                                         long initReservation,
                                         long maxAllocation)
```
    Description copied from interface: BufferAllocator
    
    Create a new child allocator.
    
    Specified by:
    
    newChildAllocator in interface BufferAllocator
    
    Parameters:
    
    name - the name of the allocator.
    
    listener - allocation listener for the newly created child
    
    initReservation - the initial space reservation (obtained from this allocator)
    
    maxAllocation - maximum amount of space the new allocator can allocate
    
    Returns:
    
    the new allocator, or null if it can't be created
  - newReservation
```
public AllocationReservation newReservation()
```
    Description copied from interface: BufferAllocator
    
    Create an allocation reservation. A reservation is a way of building up a request for a buffer whose size is not known in advance. See
    
    Specified by:
    
    newReservation in interface BufferAllocator
    
    Returns:
    
    the newly created reservation
    
    See Also:
    
    AllocationReservation
  - close
```
public void close()
```
    Close this Accountant. This will release any reservation bytes back to a parent Accountant.
    
    Specified by:
    
    close in interface AutoCloseable
    
    Specified by:
    
    close in interface BufferAllocator
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object
  - toVerboseString
```
public String toVerboseString()
```
    Provide a verbose string of the current allocator state. Includes the state of all child allocators, along with historical logs of each object and including stacktraces.
    
    Specified by:
    
    toVerboseString in interface BufferAllocator
    
    Returns:
    
    A Verbose string of current allocator state.
  - defaultConfig
```
public static org.apache.arrow.memory.BaseAllocator.Config defaultConfig()
```
    Returns a default Config instance.
    
    See Also:
    
    ImmutableConfig.Builder
  - configBuilder
```
public static ImmutableConfig.Builder configBuilder()
```
    Returns a builder class for configuring BaseAllocator's options.
  - getRoundingPolicy
```
public RoundingPolicy getRoundingPolicy()
```
    Description copied from interface: BufferAllocator
    
    Gets the rounding policy of the allocator.
    
    Specified by:
    
    getRoundingPolicy in interface BufferAllocator
  - forceAllocate
```
public boolean forceAllocate(long size)
```
    Increase the accounting. Returns whether the allocation fit within limits.
    
    Parameters:
    
    size - to increase
    
    Returns:
    
    Whether the allocation fit within limits.
  - releaseBytes
```
public void releaseBytes(long size)
```
  - isOverLimit
```
public boolean isOverLimit()
```
  - getLimit
```
public long getLimit()
```
    Return the current limit of this Accountant.
    
    Returns:
    
    Limit in bytes.
  - getInitReservation
```
public long getInitReservation()
```
    Return the initial reservation.
    
    Returns:
    
    reservation in bytes.
  - setLimit
```
public void setLimit(long newLimit)
```
    Set the maximum amount of memory that can be allocated in the this Accountant before failing an allocation.
    
    Parameters:
    
    newLimit - The limit in bytes.
  - getAllocatedMemory
```
public long getAllocatedMemory()
```
    Return the current amount of allocated memory that this Accountant is managing accounting for. Note this does not include reservation memory that hasn't been allocated.
    
    Returns:
    
    Currently allocate memory in bytes.
  - getPeakMemoryAllocation
```
public long getPeakMemoryAllocation()
```
    The peak memory allocated by this Accountant.
    
    Returns:
    
    The peak allocated memory in bytes.
  - getHeadroom
```
public long getHeadroom()
```

Class RootAllocator

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface org.apache.arrow.memory.BufferAllocator

Field Detail

DEBUG_ALLOCATOR

DEBUG_LOG_LENGTH

DEBUG

DEFAULT_CONFIG

parent

reservation

Constructor Detail

RootAllocator

RootAllocator

RootAllocator

RootAllocator

RootAllocator

Method Detail

verify

getListener

getParentAllocator

getChildAllocators

isDebug

assertOpen

getName

getEmpty

wrapForeignAllocation

buffer

buffer

getRoot

newChildAllocator

newChildAllocator

newReservation

close

toString

toVerboseString

defaultConfig

configBuilder

getRoundingPolicy

forceAllocate

releaseBytes

isOverLimit

getLimit

getInitReservation

setLimit

getAllocatedMemory

getPeakMemoryAllocation

getHeadroom