Struct rdkafka::message::BorrowedMessage

pub struct BorrowedMessage<'a> { /* fields omitted */ }

A native librdkafka message. The content of the message is stored in the receiving buffer of the consumer, to avoid memory allocations. As such, BorrowedMessage cannot outlive the consumer it is received from. BorrowedMessages are removed from the consumer buffer once they are dropped. Holding references to many messages might cause the memory of the consumer to fill up and stop. To transform a BorrowedMessage into a OwnedMessage, use the detach method.

Methods

impl<'a> BorrowedMessage<'a>

fn new<C, X>(ptr: *mut RDKafkaMessage, _consumer: &'a C) -> BorrowedMessage<'a> where
    X: ConsumerContext,
    C: Consumer<X>, 

Creates a new BorrowedMessage that wraps the native Kafka message pointer. The lifetime of the message will be bound to the lifetime of the consumer passed as parameter.

fn ptr(&self) -> *mut RDKafkaMessage

Returns a pointer to the RDKafkaMessage.

fn topic_ptr(&self) -> *mut RDKafkaTopic

Returns a pointer to the message's RDKafkaTopic

fn key_len(&self) -> usize

Returns the length of the key field of the message.

fn payload_len(&self) -> usize

Returns the length of the payload field of the message.

fn detach(&self) -> OwnedMessage

Clones the content of the BorrowedMessage and returns an OwnedMessage, that can outlive the consumer. This operation requires memory allocation and can be expensive.

Trait Implementations

impl<'a> Debug for BorrowedMessage<'a>

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.

impl<'a> Message for BorrowedMessage<'a>

fn key(&self) -> Option<&[u8]>

Returns the key of the message, or None if there is no key.

fn payload(&self) -> Option<&[u8]>

Returns the payload of the message, or None if there is no payload.

fn topic(&self) -> &str

Returns the source topic of the message.

fn partition(&self) -> i32

Returns the partition number where the message is stored.

fn offset(&self) -> i64

Returns the offset of the message.

fn timestamp(&self) -> Timestamp

Returns the message timestamp for a consumed message if available.

fn payload_view<P: ?Sized + FromBytes>(&self) -> Option<Result<&P, P::Error>>

Converts the raw bytes of the payload to a reference of the specified type, that points to the same data inside the message and without performing any memory allocation

fn key_view<K: ?Sized + FromBytes>(&self) -> Option<Result<&K, K::Error>>

Converts the raw bytes of the key to a reference of the specified type, that points to the same data inside the message and without performing any memory allocation

impl<'a> Drop for BorrowedMessage<'a>

fn drop(&mut self)

A method called when the value goes out of scope.