jackdaw.streams.describe — net.clojars.savya/jackdaw 1.3.3

->edge clj

(->edge from to)

assign-id clj

(assign-id applicaton-id n)

Assigns a deterministic :id (via gen-id) to graph node n.

assign-ids clj

(assign-ids applicaton-id g)

Assigns deterministic :ids to graph g and each of its nodes, then resolves every edge's :from-id/:to-id from the node names.

base-node clj

(base-node t n)

Returns the base graph fragment {:nodes :edges} for topology node n typed t, with edges connecting it to its predecessor and successor nodes.

collapse-merge-chains clj

(collapse-merge-chains g)

Collapses a chain of pairwise Kafka merge nodes in graph g into a single N-way merge, rewriting edges onto the head merge node and pruning the redundant intermediate nodes.

describe-node clj multimethod

describe-node-dispatch clj

(describe-node-dispatch n)

Dispatch fn for describe-node: the lower-cased simple class name of node n as a keyword (e.g. :source, :sink, :processor, :globalstore, :subtopology).

describe-topology clj

(describe-topology topology streams-config)

Returns a list of the stream graphs in a topology. The passed in topology object must have a describe method, meaning it is one of:

Kafka >= 1.1 : https://kafka.apache.org/21/javadoc/org/apache/kafka/streams/Topology.html Kafka < 1.1 : https://kafka.apache.org/10/javadoc/org/apache/kafka/streams/processor/TopologyBuilder.html#internalTopologyBuilder

Each stream graph takes the form:

{:id <a unique UUID for the stream, deterministic from the encosing topology and its stream name> :type :stream :name <the name that kafka gives this stream> :nodes <a list of all the nodes in the graph> :edges <a list of all the edges in the graph>}

Nodes and edges are represented as:

{:id <a deterministic UUID for the node> :name <the name as assigned by kafka> :type <the type - processor, store, topic &c.>}

{:from <the :name of the node the edge comes from> :from-id <the :id of the node the edge comes from> :to <the :name of the node the edge goes to> :to-id <the :id of the node the edge goes to>}

All identifiers are v5 UUIDs, and are globally unique where objects are distinct and globally equal where objects are the same.

gen-id clj

(gen-id applicaton-id n)

Returns a deterministic v5 UUID for graph node/graph n within applicaton-id (topic nodes use a global namespace instead), so the same node in the same application always gets the same id across describe calls and can be merged across applications.

good-edge clj

(good-edge e)

Returns true if edge e is not a self-loop (:from-id differs from :to-id).

is-merge? clj

(is-merge? n)

Returns true if node name n is a Kafka Streams merge node ("KSTREAM-MERGE...").

parse-description clj

(parse-description applicaton-id d)

Parses a Kafka TopologyDescription d into a sequence of id-assigned, merge-collapsed stream graphs (one per subtopology and per global store) scoped to applicaton-id.

topic? clj

(topic? s)

Returns true if graph node s is a topic node (:type :topic).