Smart Consumer for V2

[ablease]

Ideal Features

• Consumer Context can contain chunk position + offset
• Multiple Codec options, does not have to be external to the client
• Message Handling must not block main thread
• During consumer reconnect we must start at the same offset
• Initial credits, should be configurable, perhaps specifiy a limit range (1-1000)

Description

Expanding on the V1 consumer, while addressing some issues highlighted in this issue #241. Keep the design close to Producer v2 for a more streamlined user experience. For example, the Consumer Options struct contains only optional params

Consumer Options

// ConsumerOpts handles optional parameters only
type ConsumerOpts struct {
    client             *Client
    ConsumerName       string
    streamName         string
    autocommit         bool
    autoCommitStrategy *AutoCommitStrategy
    Offset             OffsetSpecification
        Filter
    CRCCheck           bool
    initialCredits     int16
        sinlgeActiveConsumer bool
        reference string
}

// func (c *Consumer) CreateConsumer(stream string, opts ConsumerOpts) *Consumer {}

Single Active Consumer is created via the singleActiveConsumer bool and reference string in ConsumerOpts