Package com.google.common.flogger.context

Class ContextMetadata

java.lang.Object

com.google.common.flogger.backend.Metadata

com.google.common.flogger.context.ContextMetadata

public abstract class ContextMetadata
extends Metadata

Immutable Metadata implementation intended for use in nested contexts. Scope metadata can be concatenated to inherit metadata from a parent context. This class is only expected to be needed by implementations of ScopedLoggingContext and should not be considered a stable API.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	ContextMetadata.Builder	A builder to collect metadata key/values pairs in order.

Method Summary

Modifier and Type	Method	Description
static ContextMetadata.Builder	builder()	Returns a new ScopeMetadata builder.
abstract ContextMetadata	concatenate(ContextMetadata metadata)	Concatenates the given context metadata after this instance.
MetadataKey<?>	getKey(int n)	Returns the key for the Nth piece of metadata.
Object	getValue(int n)	Returns the non-null value for the Nth piece of metadata.
static ContextMetadata	none()	Returns the empty ScopeMetadata.
static <T> ContextMetadata	singleton(MetadataKey<T> key, T value)	Returns a space efficient ScopeMetadata containing a single value.

Methods inherited from class com.google.common.flogger.backend.Metadata

empty, findValue, size

Methods inherited from class java.lang.Object

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

Method Detail

builder

public static ContextMetadata.Builder builder()

Returns a new ScopeMetadata builder.

singleton

public static <T> ContextMetadata singleton(MetadataKey<T> key,
                                            T value)

Returns a space efficient ScopeMetadata containing a single value.

none

public static ContextMetadata none()

Returns the empty ScopeMetadata.

concatenate

public abstract ContextMetadata concatenate(ContextMetadata metadata)

Concatenates the given context metadata after this instance. Key value pairs are simply concatenated (rather than being merged) which may result in multiple single valued keys existing in the resulting sequence.

Whether this is achieved via copying or chaining of instances is an implementation detail.

Use MetadataProcessor to process metadata consistently with respect to single valued and repeated keys, and use Metadata.findValue(MetadataKey) to lookup the "most recent" value for a single valued key.

getKey

public MetadataKey<?> getKey(int n)

Description copied from class: Metadata

Returns the key for the Nth piece of metadata.

Specified by:

getKey in class Metadata

getValue

public Object getValue(int n)

Description copied from class: Metadata

Returns the non-null value for the Nth piece of metadata.

Specified by:

getValue in class Metadata