org.apache.pulsar.functions.api

Interface Context

@InterfaceAudience.Public
 @InterfaceStability.Stable
public interface Context

Context provides contextual information to the executing function. Features like which message id we are handling, whats the topic name of the message, what are our operating constraints, etc can be accessed by the executing function

Method Summary

Modifier and Type	Method and Description
void	deleteState(String key) Delete the state value for the key.
CompletableFuture<Void>	deleteStateAsync(String key) Delete the state value for the key, but don't wait for the operation to be completed
long	getCounter(String key) Retrieve the counter value for the key.
CompletableFuture<Long>	getCounterAsync(String key) Retrieve the counter value for the key, but don't wait for the operation to be completed
Record<?>	getCurrentRecord() Access the record associated with the current input value.
String	getFunctionId() The id of the function that we are executing
String	getFunctionName() The name of the function that we are executing.
String	getFunctionVersion() The version of the function that we are executing.
Collection<String>	getInputTopics() Get a list of all input topics.
int	getInstanceId() The id of the instance that invokes this function.
org.slf4j.Logger	getLogger() The logger object that can be used to log in a function.
String	getNamespace() The namespace this function belongs to.
int	getNumInstances() Get the number of instances that invoke this function.
String	getOutputSchemaType() Get output schema builtin type or custom class name.
String	getOutputTopic() Get the output topic of the function.
PulsarAdmin	getPulsarAdmin() Get the pulsar admin client.
PulsarAdmin	getPulsarAdmin(String clusterName) Get the pulsar admin client by cluster name.
String	getSecret(String secretName) Get the secret associated with this key.
ByteBuffer	getState(String key) Retrieve the state value for the key.
CompletableFuture<ByteBuffer>	getStateAsync(String key) Retrieve the state value for the key, but don't wait for the operation to be completed
<S extends StateStore> S	getStateStore(String name) Get the state store with the provided store name in the function tenant & namespace.
<S extends StateStore> S	getStateStore(String tenant, String ns, String name) Get the state store with the provided store name.
String	getTenant() The tenant this function belongs to.
Map<String,Object>	getUserConfigMap() Get a map of all user-defined key/value configs for the function.
Optional<Object>	getUserConfigValue(String key) Get any user-defined key/value.
Object	getUserConfigValueOrDefault(String key, Object defaultValue) Get any user-defined key/value or a default value if none is present.
void	incrCounter(String key, long amount) Increment the builtin distributed counter referred by key.
CompletableFuture<Void>	incrCounterAsync(String key, long amount) Increment the builtin distributed counter referred by key but dont wait for the completion of the increment operation
<O> ConsumerBuilder<O>	newConsumerBuilder(Schema<O> schema) Create a ConsumerBuilder with the schema.
<O> TypedMessageBuilder<O>	newOutputMessage(String topicName, Schema<O> schema) New output message using schema for serializing to the topic
<O> TypedMessageBuilder<O>	newOutputMessage(String clusterName, String topicName, Schema<O> schema) New output message using schema for serializing to the topic in the cluster
<O> CompletableFuture<Void>	publish(String topicName, O object) Deprecated. in favor of using newOutputMessage(String, Schema)
<O> CompletableFuture<Void>	publish(String topicName, O object, String schemaOrSerdeClassName) Deprecated. in favor of using newOutputMessage(String, Schema)
void	putState(String key, ByteBuffer value) Update the state value for the key.
CompletableFuture<Void>	putStateAsync(String key, ByteBuffer value) Update the state value for the key, but don't wait for the operation to be completed
void	recordMetric(String metricName, double value) Record a user defined metric.

Method Detail

getCurrentRecord

Record<?> getCurrentRecord()

Access the record associated with the current input value.

Returns:

getInputTopics

Collection<String> getInputTopics()

Get a list of all input topics.

Returns:

a list of all input topics

getOutputTopic

String getOutputTopic()

Get the output topic of the function.

Returns:

output topic name

getOutputSchemaType

String getOutputSchemaType()

Get output schema builtin type or custom class name.

Returns:

output schema builtin type or custom class name

getTenant

String getTenant()

The tenant this function belongs to.

Returns:

the tenant this function belongs to

getNamespace

String getNamespace()

The namespace this function belongs to.

Returns:

the namespace this function belongs to

getFunctionName

String getFunctionName()

The name of the function that we are executing.

Returns:

The Function name

getFunctionId

String getFunctionId()

The id of the function that we are executing

Returns:

The function id

getInstanceId

int getInstanceId()

The id of the instance that invokes this function.

Returns:

the instance id

getNumInstances

int getNumInstances()

Get the number of instances that invoke this function.

Returns:

the number of instances that invoke this function.

getFunctionVersion

String getFunctionVersion()

The version of the function that we are executing.

Returns:

The version id

getLogger

org.slf4j.Logger getLogger()

The logger object that can be used to log in a function.

Returns:

the logger object

getStateStore

<S extends StateStore> S getStateStore(String name)

Get the state store with the provided store name in the function tenant & namespace.

Type Parameters:

S - the type of interface of the store to return

Parameters:

name - the state store name

Returns:

the state store instance.

Throws:

ClassCastException - if the return type isn't a type or interface of the actual returned store.

getStateStore

<S extends StateStore> S getStateStore(String tenant,
                                       String ns,
                                       String name)

Get the state store with the provided store name.

Type Parameters:

S - the type of interface of the store to return

Parameters:

tenant - the state tenant name

ns - the state namespace name

name - the state store name

Returns:

the state store instance.

Throws:

ClassCastException - if the return type isn't a type or interface of the actual returned store.

incrCounter

void incrCounter(String key,
                 long amount)

Increment the builtin distributed counter referred by key.

Parameters:

key - The name of the key

amount - The amount to be incremented

incrCounterAsync

CompletableFuture<Void> incrCounterAsync(String key,
                                         long amount)

Increment the builtin distributed counter referred by key but dont wait for the completion of the increment operation

Parameters:

key - The name of the key

amount - The amount to be incremented

getCounter

long getCounter(String key)

Retrieve the counter value for the key.

Parameters:

key - name of the key

Returns:

the amount of the counter value for this key

getCounterAsync

CompletableFuture<Long> getCounterAsync(String key)

Retrieve the counter value for the key, but don't wait for the operation to be completed

Parameters:

key - name of the key

Returns:

the amount of the counter value for this key

putState

void putState(String key,
              ByteBuffer value)

Update the state value for the key.

Parameters:

key - name of the key

value - state value of the key

putStateAsync

CompletableFuture<Void> putStateAsync(String key,
                                      ByteBuffer value)

Update the state value for the key, but don't wait for the operation to be completed

Parameters:

key - name of the key

value - state value of the key

deleteState

void deleteState(String key)

Delete the state value for the key.

Parameters:

key - name of the key

deleteStateAsync

CompletableFuture<Void> deleteStateAsync(String key)

Delete the state value for the key, but don't wait for the operation to be completed

Parameters:

key - name of the key

getState

ByteBuffer getState(String key)

Retrieve the state value for the key.

Parameters:

key - name of the key

Returns:

the state value for the key.

getStateAsync

CompletableFuture<ByteBuffer> getStateAsync(String key)

Retrieve the state value for the key, but don't wait for the operation to be completed

Parameters:

key - name of the key

Returns:

the state value for the key.

getUserConfigMap

Map<String,Object> getUserConfigMap()

Get a map of all user-defined key/value configs for the function.

Returns:

The full map of user-defined config values

getUserConfigValue

Optional<Object> getUserConfigValue(String key)

Get any user-defined key/value.

Parameters:

key - The key

Returns:

The Optional value specified by the user for that key.

getUserConfigValueOrDefault

Object getUserConfigValueOrDefault(String key,
                                   Object defaultValue)

Get any user-defined key/value or a default value if none is present.

Parameters:

key -

defaultValue -

Returns:

Either the user config value associated with a given key or a supplied default value

getSecret

String getSecret(String secretName)

Get the secret associated with this key.

Parameters:

secretName - The name of the secret

Returns:

The secret if anything was found or null

getPulsarAdmin

PulsarAdmin getPulsarAdmin()

Get the pulsar admin client.

Returns:

The instance of pulsar admin client

getPulsarAdmin

PulsarAdmin getPulsarAdmin(String clusterName)

Get the pulsar admin client by cluster name.

Parameters:

clusterName - The name of the cluster name for pulsar admin client

Returns:

The instance of pulsar admin client

recordMetric

void recordMetric(String metricName,
                  double value)

Record a user defined metric.

Parameters:

metricName - The name of the metric

value - The value of the metric

publish

<O> CompletableFuture<Void> publish(String topicName,
                                    O object,
                                    String schemaOrSerdeClassName)

Deprecated. in favor of using newOutputMessage(String, Schema)

Publish an object using serDe or schema class for serializing to the topic.

Parameters:

topicName - The name of the topic for publishing

object - The object that needs to be published

schemaOrSerdeClassName - Either a builtin schema type (eg: "avro", "json", "protobuf") or the class name of the custom schema class

Returns:

A future that completes when the framework is done publishing the message

publish

<O> CompletableFuture<Void> publish(String topicName,
                                    O object)

Deprecated. in favor of using newOutputMessage(String, Schema)

Publish an object to the topic using default schemas.

Parameters:

topicName - The name of the topic for publishing

object - The object that needs to be published

Returns:

A future that completes when the framework is done publishing the message

newOutputMessage

<O> TypedMessageBuilder<O> newOutputMessage(String topicName,
                                            Schema<O> schema)
                                     throws PulsarClientException

New output message using schema for serializing to the topic

Type Parameters:

O -

Parameters:

topicName - The name of the topic for output message

schema - provide a way to convert between serialized data and domain objects

Returns:

the message builder instance

Throws:

PulsarClientException

newOutputMessage

<O> TypedMessageBuilder<O> newOutputMessage(String clusterName,
                                            String topicName,
                                            Schema<O> schema)
                                     throws PulsarClientException

New output message using schema for serializing to the topic in the cluster

Type Parameters:

O -

Parameters:

clusterName - the name of the cluster for topic

topicName - The name of the topic for output message

schema - provide a way to convert between serialized data and domain objects

Returns:

the message builder instance

Throws:

PulsarClientException

newConsumerBuilder

<O> ConsumerBuilder<O> newConsumerBuilder(Schema<O> schema)
                                   throws PulsarClientException

Create a ConsumerBuilder with the schema.

Type Parameters:

O -

Parameters:

schema - provide a way to convert between serialized data and domain objects

Returns:

the consumer builder instance

Throws:

PulsarClientException