Package convex.core.data

Class RefSoft<T extends ACell>

java.lang.Object

convex.core.data.AObject

convex.core.data.Ref<T>

convex.core.data.RefSoft<T>

Type Parameters:

T - Type of referenced Cell

All Implemented Interfaces:

IValidated, IWriteable, Comparable<Ref<T>>

public class RefSoft<T extends ACell>
extends Ref<T>

Reference class implemented via a soft reference and store lookup. Ref makes use of a soft reference to values, allowing memory to be reclaimed by the garbage collector when not required. A MissingDataException will occur with any attempt to deference this Ref when the value is not present and not stored in the current store. Instances of this class should usually be be STORED, otherwise data loss may occur due to garbage collection. However UNKNOWN RefSoft may exist temporarily (e.g. reading Refs from external messages) SoftRef must always have a non-null hash, to ensure lookup capability in store.

Field Summary

Fields

Modifier and Type	Field	Description
protected SoftReference<T>	softRef	SoftReference to value.
protected AStore	store	SoftReference to value.

Fields inherited from class convex.core.data.Ref

ANNOUNCED, BAD_MASK, EMBEDDING_MASK, FALSE_VALUE, flags, hash, INDIRECT_ENCODING_LENGTH, INTERNAL, INTERNAL_FLAGS, INVALID, KNOWN_EMBEDDED_MASK, MARKED, MAX_STATUS, NON_EMBEDDED_MASK, NULL_VALUE, PERSISTED, STATUS_MASK, STORED, TRUE_VALUE, UNKNOWN, VALIDATED, VERIFICATION_MASK, VERIFIED_MASK

Fields inherited from class convex.core.data.AObject

encoding

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	RefSoft(AStore store, Hash hash)
protected	RefSoft(AStore store, SoftReference<T> ref, Hash hash, int flags)
protected	RefSoft(AStore store, T value, Hash hash, int flags)

Method Summary

Modifier and Type	Method	Description
static <T extends ACell> RefSoft<T>	create(AStore store, T value, int flags)
static <T extends ACell> RefSoft<T>	createForHash(Hash hash)	Create a RefSoft with a Hash reference.
boolean	equalsValue(Ref<T> a)	Checks if two Ref Values are equal.
int	estimatedEncodingSize()	Estimate the encoded data size for this Cell.
Hash	getHash()	Gets the Hash of this ref's value.
T	getValue()	Gets the value from this Ref.
boolean	isDirect()	Return true if this Ref is a direct reference, i.e.
boolean	isMissing()	Checks if this Ref refers to missing data, i.e.
void	validate()	Validates the complete structure of this object.
RefSoft<T>	withFlags(int newFlags)	Create a new Ref of the same type with updated flags
Ref<T>	withValue(T newValue)	Updates the value stored within this Ref.

Methods inherited from class convex.core.data.Ref

accumulateRefSet, addAllToSet, cachedHash, compareTo, createArray, createEncoding, encode, equals, findMissing, flagsWithStatus, forHash, get, get, getEncodingLength, getFlags, getMemorySize, getStatus, hashCode, isEmbedded, isMarked, isPersisted, markEmbedded, mergeFlags, persist, persist, persistShallow, persistShallow, print, readRaw, setFlags, toDirect, toString, updateRefs, withMinimumStatus, write

Methods inherited from class convex.core.data.AObject

attachEncoding, getEncoding, print

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Details

softRef

protected SoftReference<T extends ACell> softRef

SoftReference to value. Might get updated to a fresh instance.

store

protected AStore store

SoftReference to value. Might get updated to a fresh instance.

Constructor Details

RefSoft

protected RefSoft(AStore store,
 SoftReference<T> ref,
 Hash hash,
 int flags)

RefSoft

protected RefSoft(AStore store,
 T value,
 Hash hash,
 int flags)

RefSoft

protected RefSoft(AStore store,
 Hash hash)

Method Details

withFlags

public RefSoft<T> withFlags(int newFlags)

Description copied from class: Ref

Create a new Ref of the same type with updated flags

Specified by:

withFlags in class Ref<T extends ACell>

Parameters:

newFlags - New flags to set

Returns:

Updated Ref

create

public static <T extends ACell> RefSoft<T> create(AStore store,
 T value,
 int flags)

createForHash

public static <T extends ACell> RefSoft<T> createForHash(Hash hash)

Create a RefSoft with a Hash reference. Attempts to get the value will trigger a store lookup, which may in turn cause a MissingDataException if not found.

Type Parameters:

T - Type of value

Parameters:

hash - Hash ID of value.

Returns:

New RefSoft instance

getValue

public T getValue()

Description copied from class: Ref

Gets the value from this Ref. Important notes: - May throw a MissingDataException if the data does not exist in available storage - Will return null if and only if the Ref refers to the null value

Specified by:

getValue in class Ref<T extends ACell>

Returns:

The value contained in this Ref

isMissing

public boolean isMissing()

Description copied from class: Ref

Checks if this Ref refers to missing data, i.e. a Cell that does not exist in the currect store.

Specified by:

isMissing in class Ref<T extends ACell>

Returns:

true if this specific Ref has missing data, false otherwise.

equalsValue

public boolean equalsValue(Ref<T> a)

Description copied from class: Ref

Checks if two Ref Values are equal. Equality is defined as referring to the same data, i.e. have an identical hash.

Specified by:

equalsValue in class Ref<T extends ACell>

Parameters:

a - The Ref to compare with

Returns:

true if Refs have the same value, false otherwise

isDirect

public boolean isDirect()

Description copied from class: Ref

Return true if this Ref is a direct reference, i.e. the value is pinned in memory and cannot be garbage collected

Specified by:

isDirect in class Ref<T extends ACell>

Returns:

true if this Ref is direct, false otherwise

getHash

public Hash getHash()

Description copied from class: Ref

Gets the Hash of this ref's value.

Specified by:

getHash in class Ref<T extends ACell>

Returns:

Hash of the value

validate

public void validate()
              throws InvalidDataException

Description copied from interface: IValidated

Validates the complete structure of this object. It is necessary to ensure all child Refs are validated, so the general contract for validate is:

1. Call super.validate() - which will indirectly call validateCell()
2. Call validate() on any contained cells in this class

Specified by:

validate in interface IValidated

Overrides:

validate in class Ref<T extends ACell>

Throws:

InvalidDataException - If the data Valie is invalid in any way

withValue

public Ref<T> withValue(T newValue)

Description copied from class: Ref

Updates the value stored within this Ref. New value must be equal in value to the old value (identical hash), but may have updated internal refs etc.

Specified by:

withValue in class Ref<T extends ACell>

Parameters:

newValue - New value

Returns:

Updated Ref

estimatedEncodingSize

public int estimatedEncodingSize()

Description copied from interface: IWriteable

Estimate the encoded data size for this Cell. Used for quickly sizing buffers. Implementations should try to return a size that is likely to contain the entire object when represented in binary format, including the tag byte.

Returns:

The estimated size for the binary representation of this object.