io.permazen.kv.mvcc

Class Writes

java.lang.Object

io.permazen.kv.mvcc.Writes

All Implemented Interfaces:

Mutations, Cloneable

public class Writes
extends Object
implements Cloneable, Mutations

Holds a set of writes to a KVStore.

Each mutation is either a key/value put, the removal of a key range (possibly containing only a single key), or a counter adjustment.

Instances are not thread safe.

Constructor Summary

Constructors

Constructor and Description
Writes()

Method Summary

Modifier and Type	Method and Description
static void	apply(Mutations mutations, KVStore target) Deprecated. use KVStore.apply(io.permazen.kv.mvcc.Mutations) instead
void	applyTo(KVStore target) Apply all mutations contained in this instance to the given KVStore.
void	clear() Clear all mutations.
Writes	clone() Clone this instance.
static Writes	deserialize(InputStream input) Deserialize a mutable instance created by serialize().
static Writes	deserialize(InputStream input, boolean immutable) Deserialize an instance created by serialize().
static Mutations	deserializeOnline(InputStream input) Create an "online" Mutations view of a serialized Writes instance.
Iterable<Map.Entry<byte[],Long>>	getAdjustPairs() Get the counter adjustments contained by this instance.
NavigableMap<byte[],Long>	getAdjusts() Get the set of counter adjustments contained by this instance.
Iterable<Map.Entry<byte[],byte[]>>	getPutPairs() Get the written key/value pairs contained by this instance.
NavigableMap<byte[],byte[]>	getPuts() Get the written key/value pairs contained by this instance.
NavigableSet<KeyRange>	getRemoveRanges() Get the key ranges removals contained by this instance.
KeyRanges	getRemoves() Get the key ranges removals contained by this instance.
Writes	immutableSnapshot() Return an immutable snapshot of this instance.
boolean	isEmpty() Determine whether this instance is empty, i.e., contains zero mutations.
void	serialize(OutputStream out) Serialize this instance.
long	serializedLength() Calculate the number of bytes required to serialize this instance via serialize().
String	toString()

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Writes

public Writes()

Method Detail

getRemoves

public KeyRanges getRemoves()

Get the key ranges removals contained by this instance.

Returns:

key ranges removed

getPuts

public NavigableMap<byte[],byte[]> getPuts()

Get the written key/value pairs contained by this instance.

The caller must not modify any of the returned byte[] arrays.

Returns:

mapping from key to corresponding value

getAdjusts

public NavigableMap<byte[],Long> getAdjusts()

Get the set of counter adjustments contained by this instance.

The caller must not modify any of the returned byte[] arrays.

Returns:

mapping from key to corresponding counter adjustment

isEmpty

public boolean isEmpty()

Determine whether this instance is empty, i.e., contains zero mutations.

Returns:

true if this instance contains zero mutations, otherwise false

clear

public void clear()

Clear all mutations.

getRemoveRanges

public NavigableSet<KeyRange> getRemoveRanges()

Description copied from interface: Mutations

Get the key ranges removals contained by this instance.

The caller must not invoke Iterator.remove().

Specified by:

getRemoveRanges in interface Mutations

Returns:

key ranges removed

getPutPairs

public Iterable<Map.Entry<byte[],byte[]>> getPutPairs()

Description copied from interface: Mutations

Get the written key/value pairs contained by this instance.

The caller must not modify any of the returned byte[] arrays, nor invoke Iterator.remove().

Specified by:

getPutPairs in interface Mutations

Returns:

mapping from key to corresponding value

getAdjustPairs

public Iterable<Map.Entry<byte[],Long>> getAdjustPairs()

Description copied from interface: Mutations

Get the counter adjustments contained by this instance.

The caller must not modify any of the returned byte[] arrays, nor invoke Iterator.remove().

Specified by:

getAdjustPairs in interface Mutations

Returns:

mapping from key to corresponding counter adjustment

applyTo

public void applyTo(KVStore target)

Apply all mutations contained in this instance to the given KVStore.

Mutations are applied in this order: removes, puts, counter adjustments.

Parameters:

target - target for recorded mutations

Throws:

IllegalArgumentException - if target is null

apply

@Deprecated
public static void apply(Mutations mutations,
                                     KVStore target)

Deprecated. use KVStore.apply(io.permazen.kv.mvcc.Mutations) instead

Apply all the given Mutations to the given KVStore.

Mutations are applied in this order: removes, puts, counter adjustments.

Parameters:

mutations - mutations to apply

target - target for mutations

Throws:

IllegalArgumentException - if either parameter is null

UnsupportedOperationException - if this instance is immutable

serialize

public void serialize(OutputStream out)
               throws IOException

Serialize this instance.

Parameters:

out - output

Throws:

IOException - if an error occurs

serializedLength

public long serializedLength()

Calculate the number of bytes required to serialize this instance via serialize().

Returns:

number of serialized bytes

deserialize

public static Writes deserialize(InputStream input)
                          throws IOException

Deserialize a mutable instance created by serialize().

Equivalent to deserialize(input, false).

Parameters:

input - input stream containing data from serialize()

Returns:

mutable deserialized instance

Throws:

IllegalArgumentException - if input is null

IllegalArgumentException - if malformed input is detected

IOException - if an I/O error occurs

deserialize

public static Writes deserialize(InputStream input,
                                 boolean immutable)
                          throws IOException

Deserialize an instance created by serialize().

Parameters:

input - input stream containing data from serialize()

immutable - true for an immutable instance, otherwise false

Returns:

deserialized instance

Throws:

IllegalArgumentException - if input is null

IllegalArgumentException - if malformed input is detected

IOException - if an I/O error occurs

deserializeOnline

public static Mutations deserializeOnline(InputStream input)

Create an "online" Mutations view of a serialized Writes instance.

This method returns a Mutations instance that decodes the serialized Writes from the given input in an "online" fashion, i.e., it does not load the whole thing into memory. The returned Mutations iterators may only be accessed once, and they must be accessed in this order: removes, puts, adjusts. Any duplicate or out-of-order access will result in an IllegalStateException.

If an IOException is thrown by input, the Iterator being used will throw a RuntimeException wrapping it; if invalid data is encountered, the Iterator being used will throw an IllegalArgumentException.

Parameters:

input - input stream containing data from serialize()

Returns:

online Mutations view of input

Throws:

IllegalArgumentException - if input is null

clone

public Writes clone()

Clone this instance.

This is a "mostly deep" clone: all of the mutations are copied, but the actual byte[] keys and values, which are already assumed non-mutable, are not copied.

The returned clone will always be mutable, even if this instance is not.

Overrides:

clone in class Object

immutableSnapshot

public Writes immutableSnapshot()

Return an immutable snapshot of this instance.

Returns:

immutable snapshot

toString

public String toString()

Overrides:

toString in class Object