com.google.protobuf

Class LazyFieldLite

java.lang.Object

com.google.protobuf.LazyFieldLite

Direct Known Subclasses:

LazyField

public class LazyFieldLite
extends Object

LazyFieldLite encapsulates the logic of lazily parsing message fields. It stores the message in a ByteString initially and then parses it on-demand. LazyFieldLite is thread-compatible: concurrent reads are safe once the proto that this LazyFieldLite is a part of is no longer being mutated by its Builder. However, explicit synchronization is needed under read/write situations. When a LazyFieldLite is used in the context of a MessageLite object, its behavior is considered to be immutable and none of the setter methods in its API are expected to be invoked. All of the getters are expected to be thread-safe. When used in the context of a MessageLite.Builder, setters can be invoked, but there is no guarantee of thread safety. TODO(yatin,dweis): Consider splitting this class's functionality and put the mutable methods into a separate builder class to allow us to give stronger compile-time guarantees. This class is internal implementation detail of the protobuf library, so you don't need to use it directly.

Author:

[email protected] (Xiang Li)

Field Summary

Fields

Modifier and Type	Field and Description
protected MessageLite	value The parsed value.

Constructor Summary

Constructors

Constructor and Description
LazyFieldLite() Constructs a LazyFieldLite with no contents, and no ability to parse extensions.
LazyFieldLite(ExtensionRegistryLite extensionRegistry, ByteString bytes) Constructs a LazyFieldLite with bytes that will be parsed lazily.

Method Summary

Modifier and Type	Method and Description
void	clear() Clears the value state of this instance.
boolean	containsDefaultInstance() Determines whether this LazyFieldLite instance represents the default instance of this type.
protected void	ensureInitialized(MessageLite defaultInstance) Might lazily parse the bytes that were previously passed in.
boolean	equals(Object o)
static LazyFieldLite	fromValue(MessageLite value) Constructs a LazyFieldLite instance with a value.
int	getSerializedSize() Due to the optional field can be duplicated at the end of serialized bytes, which will make the serialized size changed after LazyField parsed.
MessageLite	getValue(MessageLite defaultInstance) Returns message instance.
int	hashCode()
void	merge(LazyFieldLite other) Merges another instance's contents.
void	mergeFrom(CodedInputStream input, ExtensionRegistryLite extensionRegistry) Merges another instance's contents from a stream.
void	set(LazyFieldLite other) Overrides the contents of this LazyField.
void	setByteString(ByteString bytes, ExtensionRegistryLite extensionRegistry) Sets this field with bytes to delay-parse.
MessageLite	setValue(MessageLite value) Sets the value of the instance and returns the old value without delay parsing anything.
ByteString	toByteString() Returns a BytesString for this field in a thread-safe way.

Methods inherited from class java.lang.Object

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

Field Detail

value

protected volatile MessageLite value

The parsed value. When this is null and a caller needs access to the MessageLite value, then delayedBytes will be parsed lazily at that time.

Constructor Detail

LazyFieldLite

public LazyFieldLite(ExtensionRegistryLite extensionRegistry,
                     ByteString bytes)

Constructs a LazyFieldLite with bytes that will be parsed lazily.

LazyFieldLite

public LazyFieldLite()

Constructs a LazyFieldLite with no contents, and no ability to parse extensions.

Method Detail

fromValue

public static LazyFieldLite fromValue(MessageLite value)

Constructs a LazyFieldLite instance with a value. The LazyFieldLite may not be able to parse the extensions in the value as it has no ExtensionRegistry.

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

containsDefaultInstance

public boolean containsDefaultInstance()

Determines whether this LazyFieldLite instance represents the default instance of this type.

clear

public void clear()

Clears the value state of this instance.

LazyField is not thread-safe for write access. Synchronizations are needed under read/write situations.

set

public void set(LazyFieldLite other)

Overrides the contents of this LazyField.

LazyField is not thread-safe for write access. Synchronizations are needed under read/write situations.

getValue

public MessageLite getValue(MessageLite defaultInstance)

Returns message instance. It may do some thread-safe delayed parsing of bytes.

Parameters:

defaultInstance - its message's default instance. It's also used to get parser for the message type.

setValue

public MessageLite setValue(MessageLite value)

Sets the value of the instance and returns the old value without delay parsing anything.

LazyField is not thread-safe for write access. Synchronizations are needed under read/write situations.

merge

public void merge(LazyFieldLite other)

Merges another instance's contents. In some cases may drop some extensions if both fields contain data. If the other field has an ExtensionRegistry but this does not, then this field will copy over that ExtensionRegistry.

LazyField is not thread-safe for write access. Synchronizations are needed under read/write situations.

mergeFrom

public void mergeFrom(CodedInputStream input,
                      ExtensionRegistryLite extensionRegistry)
               throws IOException

Merges another instance's contents from a stream.

LazyField is not thread-safe for write access. Synchronizations are needed under read/write situations.

Throws:

IOException

setByteString

public void setByteString(ByteString bytes,
                          ExtensionRegistryLite extensionRegistry)

Sets this field with bytes to delay-parse.

getSerializedSize

public int getSerializedSize()

Due to the optional field can be duplicated at the end of serialized bytes, which will make the serialized size changed after LazyField parsed. Be careful when using this method.

toByteString

public ByteString toByteString()

Returns a BytesString for this field in a thread-safe way.

ensureInitialized

protected void ensureInitialized(MessageLite defaultInstance)

Might lazily parse the bytes that were previously passed in. Is thread-safe.