View Source KafkaEx.Messages.Offset.PartitionOffset (kafka_ex v1.0.0-rc.1)

This module represents Offset value for a specific partition.

Used for three Kafka offset-related APIs:

ListOffsets API (log position queries) - uses timestamp field, always has offset
OffsetFetch API (committed consumer group offsets) - uses metadata field, always has offset
OffsetCommit API (commit operation results) - only has error_code, offset is nil

Summary

Types

error_code()

leader_epoch()

metadata()

offset()

partition()

partition_response()

t()

timestamp()

Functions

build(map)

Builds a PartitionOffset struct from response data.

to_offset_and_metadata(partition_offset)

Converts this PartitionOffset to an OffsetAndMetadata struct.

Types

error_code()

@type error_code() :: KafkaEx.Support.Types.error_code() | atom()

leader_epoch()

@type leader_epoch() :: integer() | nil

metadata()

@type metadata() :: binary() | nil

offset()

@type offset() :: KafkaEx.Support.Types.offset() | nil

partition()

@type partition() :: KafkaEx.Support.Types.partition()

partition_response()

@type partition_response() :: %{
  :partition => partition(),
  :error_code => error_code(),
  optional(:offset) => offset(),
  optional(:timestamp) => timestamp(),
  optional(:metadata) => metadata(),
  optional(:leader_epoch) => leader_epoch()
}

t()

@type t() :: %KafkaEx.Messages.Offset.PartitionOffset{
  error_code: error_code(),
  leader_epoch: leader_epoch(),
  metadata: metadata(),
  offset: offset(),
  partition: partition(),
  timestamp: timestamp()
}

timestamp()

@type timestamp() :: KafkaEx.Support.Types.timestamp() | nil

Functions

build(map)

@spec build(partition_response()) :: t()

Builds a PartitionOffset struct from response data.

Supports three different Kafka APIs:

ListOffsets API (log position queries):

Includes timestamp when the offset was written
For older API versions, timestamp defaults to -1
Always includes offset

OffsetFetch API (committed consumer group offsets):

Includes metadata (consumer-supplied string)
Metadata can be empty string or nil
Always includes offset

OffsetCommit API (commit operation results):

Only includes partition and error_code
No offset (you already know what you committed)
No metadata or timestamp

to_offset_and_metadata(partition_offset)

@spec to_offset_and_metadata(t()) :: KafkaEx.Messages.OffsetAndMetadata.t() | nil

Converts this PartitionOffset to an OffsetAndMetadata struct.

Returns nil if offset is nil (e.g., for OffsetCommit results that don't include offset).

Examples

iex> po = PartitionOffset.build(%{partition: 0, offset: 100, error_code: :no_error, metadata: "v1"})
iex> PartitionOffset.to_offset_and_metadata(po)
%OffsetAndMetadata{offset: 100, metadata: "v1", leader_epoch: nil}