Class LazyFieldLite
- Direct Known Subclasses:
LazyField
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: 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.
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate boolean
private ByteString
A delayed-parsed version of the contents of this field.private ExtensionRegistryLite
AnExtensionRegistryLite
for parsing bytes.private ByteString
The memoized bytes forvalue
.protected MessageLite
The parsed value. -
Constructor Summary
ConstructorsConstructorDescriptionConstructs 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 TypeMethodDescriptionprivate static void
checkArguments
(ExtensionRegistryLite extensionRegistry, ByteString bytes) void
clear()
Clears the value state of this instance.boolean
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
static LazyFieldLite
fromValue
(MessageLite value) Constructs a LazyFieldLite instance with a value.int
Due to the optional field can be duplicated at the end of serialized bytes, which will make the serialized size changed after LazyField parsed.getValue
(MessageLite defaultInstance) Returns message instance.int
hashCode()
(package private) boolean
Returns whether the lazy field was corrupted and replaced with an empty message.void
merge
(LazyFieldLite other) Merges another instance's contents.void
mergeFrom
(CodedInputStream input, ExtensionRegistryLite extensionRegistry) Merges another instance's contents from a stream.private static MessageLite
mergeValueAndBytes
(MessageLite value, ByteString otherBytes, ExtensionRegistryLite extensionRegistry) void
set
(LazyFieldLite other) Overrides the contents of this LazyField.void
setByteString
(ByteString bytes, ExtensionRegistryLite extensionRegistry) Sets this field with bytes to delay-parse.setValue
(MessageLite value) Sets the value of the instance and returns the old value without delay parsing anything.Returns a BytesString for this field in a thread-safe way.(package private) void
Writes this lazy field into aWriter
.
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Field Details
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delayedBytes
A delayed-parsed version of the contents of this field. When this field is non-null, then the "value" field is allowed to be null until the time that the value needs to be read.When delayedBytes is non-null then
extensionRegistry
is required to also be non-null.value
andmemoizedBytes
will be initialized lazily. -
extensionRegistry
AnExtensionRegistryLite
for parsing bytes. It is non-null on a best-effort basis. It is only guaranteed to be non-null if this message was initialized using bytes and anExtensionRegistry
. If it directly had a value set then it will be null, unless it has been merged with anotherLazyFieldLite
that had anExtensionRegistry
. -
value
The parsed value. When this is null and a caller needs access to the MessageLite value, thendelayedBytes
will be parsed lazily at that time. -
memoizedBytes
The memoized bytes forvalue
. This is an optimization for the toByteString() method to not have to recompute its return-value on each invocation. TODO: Figure out whether this optimization is actually necessary. -
corrupted
private volatile boolean corrupted
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Constructor Details
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LazyFieldLite
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.
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Method Details
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fromValue
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
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hashCode
public int hashCode() -
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.
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set
Overrides the contents of this LazyField.LazyField is not thread-safe for write access. Synchronizations are needed under read/write situations.
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getValue
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.
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setValue
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.
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merge
Merges another instance's contents. In some cases may drop some extensions if both fields contain data. If the other field has anExtensionRegistry
but this does not, then this field will copy over thatExtensionRegistry
.LazyField is not thread-safe for write access. Synchronizations are needed under read/write situations.
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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
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mergeValueAndBytes
private static MessageLite mergeValueAndBytes(MessageLite value, ByteString otherBytes, ExtensionRegistryLite extensionRegistry) -
setByteString
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
Returns a BytesString for this field in a thread-safe way. -
writeTo
Writes this lazy field into aWriter
.- Throws:
IOException
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ensureInitialized
Might lazily parse the bytes that were previously passed in. Is thread-safe. -
checkArguments
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isCorrupted
boolean isCorrupted()Returns whether the lazy field was corrupted and replaced with an empty message.
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