Package convex.core.data

Class MapEntry<K extends ACell,V extends ACell>

java.lang.Object

convex.core.data.AObject

convex.core.data.ACell

convex.core.data.ACountable<E>

convex.core.data.ADataStructure<T>

convex.core.data.ACollection<T>

convex.core.data.ASequence<T>

convex.core.data.AVector<ACell>

convex.core.data.AMapEntry<K,V>

convex.core.data.MapEntry<K,V>

Type Parameters:

K - The type of keys

V - The type of values

All Implemented Interfaces:

IAssociative<CVMLong,ACell>, IValidated, IWriteable, Comparable<MapEntry<K,V>>, Iterable<ACell>, Collection<ACell>, List<ACell>, Map.Entry<K,V>

public class MapEntry<K extends ACell,V extends ACell>
extends AMapEntry<K,V>
implements Comparable<MapEntry<K,V>>

Map.Entry implementation for persistent maps. This is primarily intended as an efficient implementation class for handling entries in Convex maps, and also to support the Java Map.Entry interface for compatibility and developer convenience. From a CVM perspective, a MapEntry is just a regular 2 element Vector. As such, MapEntry is *not* canonical and getting the canonical form of a MapEntry requires converting to a Vector Contains exactly 2 Refs, one for key and one for value Implements Comparable using the Hash value of keys.

Field Summary

Fields inherited from class convex.core.data.ADataStructure

count

Fields inherited from class convex.core.data.ACell

cachedRef, EMPTY_ARRAY

Fields inherited from class convex.core.data.AObject

encoding

Method Summary

Modifier and Type	Method	Description
<R extends ACell> AVector<R>	assoc(long i, R a)	Updates a value at the given position in the sequence.
int	compareTo(MapEntry<K,V> o)
<R extends ACell> AVector<R>	concat(ASequence<R> b)	Concatenates the elements from another sequence to the end of this sequence.
boolean	contains(Object o)
static MapEntry	convertOrNull(AVector v)
protected <R> void	copyToArray(R[] arr, int offset)	Copies the elements of this collection in order to an array at the specified offset
static <K extends ACell, V extends ACell> MapEntry<K,V>	create(K key, V value)	Creates a new MapEntry with the provided key and value
static <K extends ACell, V extends ACell> MapEntry<K,V>	createRef(Ref<? extends K> keyRef, Ref<? extends V> valueRef)
int	encode(byte[] bs, int pos)	Writes this Cell's encoding to a byte array, including a tag byte which will be written first.
static int	encodeCompressed(MapEntry<?,?> me, byte[] bs, int pos)	Writes a MapEntry or null content in compressed format (no count).
int	encodeRaw(byte[] bs, int pos)	Writes the raw MapEntry content.
boolean	equals(ACell o)	Checks for equality with another object.
boolean	equals(MapEntry<K,V> b)
int	estimatedEncodingSize()	Estimate the encoded data size for this Cell.
ACell	get(long i)	Gets the element at the specified index in this vector
Ref<ACell>	getElementRef(long i)	Gets the element Ref at the specified index
K	getKey()
Hash	getKeyHash()	Gets the Hash of the key for this MapEntry
Ref<K>	getKeyRef()
<R extends ACell> Ref<R>	getRef(int i)	Gets a numbered child Ref from within this Cell.
int	getRefCount()	Gets the number of Refs contained within this Cell.
byte	getTag()	Gets the tag byte for this cell.
AType	getType()	Gets the most specific known runtime Type for this Cell.
V	getValue()
Ref<V>	getValueRef()
boolean	isCanonical()	Returns true if this vector is in canonical format, i.e.
boolean	isCVMValue()	Returns true if this Cell represents a first class CVM Value.
boolean	keyEquals(MapEntry<K,V> b)	Checks if the keys of two map entries are equal
<R extends ACell> AVector<R>	map(Function<? super ACell,? extends R> mapper)	Maps a function over a collection, applying it to each element in turn.
static <K extends ACell, V extends ACell> MapEntry<K,V>	of(Object key, Object value)	Create a map entry, converting key and value to correct CVM types.
static <K extends ACell, V extends ACell> MapEntry<K,V>	read(ByteBuffer bb)	Reads a MapEntry from a ByteBuffer.
static <K extends ACell, V extends ACell> MapEntry<K,V>	readCompressed(ByteBuffer bb)	Reads a MapEntry or null from a ByteBuffer.
<R> R	reduce(BiFunction<? super R,? super ACell,? extends R> func, R value)
<R extends ACell> AVector<R>	subVector(long start, long length)	Gets a vector containing the specified subset of this sequence.
ACell	toCanonical()	Converts this Cell to its canonical version.
<R extends ACell> AVector<R>	toVector()	Converts this collection to a canonical vector of elements
MapEntry<K,V>	updateRefs(IRefFunction func)	Updates all Refs in this object using the given function.
void	validate()	Validates the complete structure of this object.
void	validateCell()	Validates the local structure and invariants of this cell.
void	visitElementRefs(Consumer<Ref<ACell>> f)	Visits all elements in this sequence, calling the specified consumer for each.
protected MapEntry<K,V>	withKey(K key)	Create a new MapEntry with an updated key.
MapEntry<K,V>	withValue(V value)	Create a new MapEntry with an updated value.

Methods inherited from class convex.core.data.AMapEntry

allMatch, anyMatch, append, appendChunk, commonPrefixLength, forEach, getChunk, isFullyPacked, iterator, listIterator, listIterator, longIndexOf, longLastIndexOf, next, set, setValue, spliterator, toArray

Methods inherited from class convex.core.data.AVector

appendAll, conj, conjAll, cons, empty, flatMap, get, indexOf, isPacked, lastIndexOf, listIterator, mergeWith, print, reverse, slice, spliterator, toArray

Methods inherited from class convex.core.data.ASequence

add, addAll, assoc, checkRange, containsKey, get, get, remove, subList, toCellArray

Methods inherited from class convex.core.data.ACollection

add, addAll, clear, containsAll, remove, removeAll, retainAll

Methods inherited from class convex.core.data.ADataStructure

count, isEmpty, size, toCVMString

Methods inherited from class convex.core.data.ACell

announce, announce, attachMemorySize, attachRef, cachedEncoding, cachedHash, calcMemorySize, createAnnounced, createEncoding, createPersisted, createPersisted, createRef, equals, getCanonical, getChildRefs, getEncoding, getEncodingLength, getHash, getMemorySize, getRef, hashCode, isCompletelyEncoded, isEmbedded, mark, mark, toString, write

Methods inherited from class convex.core.data.AObject

attachEncoding, print, print

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Collection

parallelStream, removeIf, stream, toArray

Methods inherited from interface java.util.List

add, addAll, clear, containsAll, equals, hashCode, isEmpty, remove, removeAll, replaceAll, retainAll, size, sort

Methods inherited from interface java.util.Map.Entry

equals, hashCode

Method Details

getType

public AType getType()

Description copied from class: ACell

Gets the most specific known runtime Type for this Cell.

Overrides:

getType in class AVector<ACell>

Returns:

The Type of this Call

createRef

public static <K extends ACell,
V extends ACell>
MapEntry<K,V> createRef(Ref<? extends K> keyRef,
 Ref<? extends V> valueRef)

create

public static <K extends ACell,
V extends ACell>
MapEntry<K,V> create(K key,
 V value)

Creates a new MapEntry with the provided key and value

Type Parameters:

K - Type of Key

V - Type of value

Parameters:

key - Key to use for MapEntry

value - Value to use for MapEntry

Returns:

New MapEntry instance

of

public static <K extends ACell,
V extends ACell>
MapEntry<K,V> of(Object key,
 Object value)

Create a map entry, converting key and value to correct CVM types.

Type Parameters:

K - Type of Keys

V - Type of Values

Parameters:

key - Key to use for map entry

value - Value to use for map entry

Returns:

New MapEntry

withValue

public MapEntry<K,V> withValue(V value)

Description copied from class: AMapEntry

Create a new MapEntry with an updated value. Shares old key. Returns the same MapEntry if unchanged

Specified by:

withValue in class AMapEntry<K extends ACell,V extends ACell>

Parameters:

value - Value to update

Returns:

assoc

public <R extends ACell> AVector<R> assoc(long i,
 R a)

Description copied from class: ASequence

Updates a value at the given position in the sequence.

Specified by:

assoc in class AVector<ACell>

Parameters:

i - Index of element to update

a - New element value

Returns:

Updated sequence, or null if index is out of range

withKey

protected MapEntry<K,V> withKey(K key)

Description copied from class: AMapEntry

Create a new MapEntry with an updated key. Shares old value. Returns the same MapEntry if unchanged

Specified by:

withKey in class AMapEntry<K extends ACell,V extends ACell>

Parameters:

key - Key to update

Returns:

getKey

public K getKey()

Specified by:

getKey in interface Map.Entry<K extends ACell,V extends ACell>

Specified by:

getKey in class AMapEntry<K extends ACell,V extends ACell>

map

public <R extends ACell> AVector<R> map(Function<? super ACell,? extends R> mapper)

Description copied from class: ACollection

Maps a function over a collection, applying it to each element in turn.

Specified by:

map in class AVector<ACell>

Type Parameters:

R - Type of element in resulting collection

Parameters:

mapper - Function to map over collection

Returns:

Collection after function applied to each element

reduce

public <R> R reduce(BiFunction<? super R,? super ACell,? extends R> func,
 R value)

Specified by:

reduce in class AVector<ACell>

copyToArray

protected <R> void copyToArray(R[] arr,
 int offset)

Description copied from class: ACollection

Copies the elements of this collection in order to an array at the specified offset

Specified by:

copyToArray in class ACollection<ACell>

Type Parameters:

R - Type of array elements required

getKeyHash

public Hash getKeyHash()

Gets the Hash of the key for this MapEntry

Returns:

the Hash of the Key

getValue

public V getValue()

Specified by:

getValue in interface Map.Entry<K extends ACell,V extends ACell>

Specified by:

getValue in class AMapEntry<K extends ACell,V extends ACell>

getKeyRef

public Ref<K> getKeyRef()

getValueRef

public Ref<V> getValueRef()

read

public static <K extends ACell,
V extends ACell>
MapEntry<K,V> read(ByteBuffer bb)
            throws BadFormatException

Reads a MapEntry from a ByteBuffer. Assumes Tag already handled.

Parameters:

bb - ByteBuffer to read from

Returns:

MapEntry instance

Throws:

BadFormatException - If encoding is invalid

readCompressed

public static <K extends ACell,
V extends ACell>
MapEntry<K,V> readCompressed(ByteBuffer bb)
                      throws BadFormatException

Reads a MapEntry or null from a ByteBuffer. Assumes no Tag.

Parameters:

bb - ByteBuffer to read from

Returns:

MapEntry instance, or null

Throws:

BadFormatException - If encoding is invalid

compareTo

public int compareTo(MapEntry<K,V> o)

Specified by:

compareTo in interface Comparable<K extends ACell>

getRefCount

public int getRefCount()

Description copied from class: ACell

Gets the number of Refs contained within this Cell. This number is final / immutable for any given instance and is defined by the Cell encoding rules. Contained Refs may be either external or embedded.

Specified by:

getRefCount in class AMapEntry<K extends ACell,V extends ACell>

Returns:

The number of Refs in this Cell

getRef

public <R extends ACell> Ref<R> getRef(int i)

Description copied from class: ACell

Gets a numbered child Ref from within this Cell.

Specified by:

getRef in class AMapEntry<K extends ACell,V extends ACell>

Type Parameters:

R - Type of referenced Cell

Parameters:

i - Index of ref to get

Returns:

The Ref at the specified index

updateRefs

public MapEntry<K,V> updateRefs(IRefFunction func)

Description copied from class: ACell

Updates all Refs in this object using the given function. The function *must not* change the hash value of Refs, in order to ensure structural integrity of modified data structures. This is a building block for a very sneaky trick that enables use to do a lot of efficient operations on large trees of smart references. Must return the same object if no Refs are altered.

Specified by:

updateRefs in class AVector<ACell>

Parameters:

func - Ref update function

Returns:

Cell with updated Refs

equals

public boolean equals(ACell o)

Description copied from class: ACell

Checks for equality with another object. In general, data objects should be considered equal if they have the same canonical representation, i.e. an identical encoding with the same hash value. Subclasses SHOULD override this if offer have a more efficient equals implementation. MUST NOT require reads from Store.

Overrides:

equals in class ACell

Parameters:

o - Cell to compare with. May be null??

Returns:

True if this cell is equal to the other object

equals

public boolean equals(MapEntry<K,V> b)

keyEquals

public boolean keyEquals(MapEntry<K,V> b)

Checks if the keys of two map entries are equal

Parameters:

b - MapEntry to compare with this MapEntry

Returns:

true if this entry's key equals that of the other entry, false otherwise.

toVector

public <R extends ACell> AVector<R> toVector()

Description copied from class: ACollection

Converts this collection to a canonical vector of elements

Specified by:

toVector in class ACollection<ACell>

Returns:

This collection coerced to a vector

contains

public boolean contains(Object o)

Specified by:

contains in interface Collection<K extends ACell>

Specified by:

contains in interface List<K extends ACell>

Overrides:

contains in class ASequence<ACell>

get

public ACell get(long i)

Description copied from class: AVector

Gets the element at the specified index in this vector

Specified by:

get in class AMapEntry<K extends ACell,V extends ACell>

Parameters:

i - The index of the element to get

Returns:

The element value at the specified index

getElementRef

public Ref<ACell> getElementRef(long i)

Description copied from class: ASequence

Gets the element Ref at the specified index

Specified by:

getElementRef in class ASequence<ACell>

Parameters:

i - Index of element to get

Returns:

Ref to element at specified index

encode

public int encode(byte[] bs,
 int pos)

Description copied from class: ACell

Writes this Cell's encoding to a byte array, including a tag byte which will be written first. Cell must be canonical, or else an error may occur.

Specified by:

encode in interface IWriteable

Specified by:

encode in class AMapEntry<K extends ACell,V extends ACell>

Parameters:

bs - A byte array to which to write the encoding

pos - The offset into the byte array

Returns:

New position after writing

encodeRaw

public int encodeRaw(byte[] bs,
 int pos)

Writes the raw MapEntry content. Puts the key and value Refs onto the given ByteBuffer

Specified by:

encodeRaw in class AVector<ACell>

Parameters:

bs - Byte array to write to

pos - The offset into the byte array

Returns:

Updated position after writing

encodeCompressed

public static int encodeCompressed(MapEntry<?,?> me,
 byte[] bs,
 int pos)

Writes a MapEntry or null content in compressed format (no count). Useful for embedding an optional MapEntry inside a larger Encoding

Parameters:

me - MapEntry to encode

bs - Byte array to write to

pos - Starting position for encoding in byte array

Returns:

Updated position after writing

isCVMValue

public final boolean isCVMValue()

Description copied from class: ACell

Returns true if this Cell represents a first class CVM Value. Sub-structural cells that are not themselves first class values should return false, pretty much everything else should return true. Note: CVM values might not be in a canonical format, e.g. temporary data structures

Specified by:

isCVMValue in class ACell

Returns:

true if the object is a CVM Value, false otherwise

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.

Specified by:

estimatedEncodingSize in interface IWriteable

Returns:

The estimated size for the binary representation of this object.

visitElementRefs

public void visitElementRefs(Consumer<Ref<ACell>> f)

Description copied from class: ASequence

Visits all elements in this sequence, calling the specified consumer for each.

Specified by:

visitElementRefs in class ASequence<ACell>

Parameters:

f - Function to call for each element

concat

public <R extends ACell> AVector<R> concat(ASequence<R> b)

Description copied from class: ASequence

Concatenates the elements from another sequence to the end of this sequence. Potentially O(n) in size of resulting sequence

Specified by:

concat in class AVector<ACell>

Parameters:

b - A sequence of values to concatenate.

Returns:

The concatenated sequence, of the same type as this sequence.

subVector

public <R extends ACell> AVector<R> subVector(long start,
 long length)

Description copied from class: ASequence

Gets a vector containing the specified subset of this sequence.

Specified by:

subVector in class ASequence<ACell>

Parameters:

start - Start index of sub vector

length - Length of sub vector to produce

Returns:

Sub-vector of this sequence

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 ACell

Throws:

InvalidDataException - If the data Valie is invalid in any way

validateCell

public void validateCell()
                  throws InvalidDataException

Description copied from class: ACell

Validates the local structure and invariants of this cell. Called by validate() super implementation. Should validate directly contained data, but should not validate all other structure of this cell. In particular, should not traverse potentially missing child Refs.

Specified by:

validateCell in class ACell

Throws:

InvalidDataException - If the Cell is invalid

getTag

public byte getTag()

Description copied from class: ACell

Gets the tag byte for this cell. The tag byte is always written as the first byte of the Cell's Encoding

Overrides:

getTag in class AVector<ACell>

Returns:

Tag byte for this Cell

convertOrNull

public static MapEntry convertOrNull(AVector v)

isCanonical

public boolean isCanonical()

Description copied from class: AVector

Returns true if this vector is in canonical format, i.e. suitable as top-level serialised representation of a vector.

Specified by:

isCanonical in class AMapEntry<K extends ACell,V extends ACell>

Returns:

true if the vector is in canonical format, false otherwise

toCanonical

public ACell toCanonical()

Description copied from class: ACell

Converts this Cell to its canonical version. Returns this Cell if already canonical, may be O(n) in size of value otherwise.

Specified by:

toCanonical in class ACell

Returns:

Canonical version of Cell