examples

Zenoh Kotlin examples

---

Start instructions

  gradle <example> --args="<arguments>"

for instance

  gradle ZPub --args="-h"

will return

> Task :examples:ZPub
Usage: zpub [<options>]

  Zenoh Pub example

Options:
  -k, --key=<key>             The key expression to write to [default:
                              demo/example/zenoh-kotlin-pub]
  -c, --config=<config>       A configuration file.
  -e, --connect=<connect>...  Endpoints to connect to.
  -l, --listen=<listen>...    Endpoints to listen on.
  -m, --mode=<mode>           The session mode. Default: peer. Possible values:
                              [peer, client, router]
  -v, --value=<value>         The value to write. [Default: "Pub from Kotlin!"]
  -a, --attach=<attach>       The attachments to add to each put. The key-value
                              pairs are &-separated, and = serves as the
                              separator between key and value.
  --no-multicast-scouting     Disable the multicast-based scouting mechanism.
  -h, --help                  Show this message and exit

The connect and listen parameters (that are common to all the examples) accept multiple repeated inputs. For instance:

  gradle ZPub --args="-l tcp/localhost:7447 -l tcp/localhost:7448 -l tcp/localhost:7449"

There is the possibility to provide a Zenoh config file as follows

  gradle ZPub --args="-c path/to/config.json5"

In that case, any other provided configuration parameters through the command line interface will not be taken into consideration.

One last comment regarding Zenoh logging for the examples, remember it can be enabled through the environment variable RUST_LOG as follows:

  RUST_LOG=<level> gradle ZPub

where <level> can be either info, trace, debug, warn or error.

---

Examples description

ZPub

Declares a resource with a path and a publisher on this resource. Then puts a value using the numerical resource id. The path/value will be received by all matching subscribers, for instance the ZSub example.

Usage:

gradle ZPub

or

gradle ZPub --args="-k demo/example/test -v 'hello world'"

ZSub

Creates a subscriber with a key expression. The subscriber will be notified of each put made on any key expression matching the subscriber's key expression, and will print this notification.

Usage:

gradle ZSub

or

gradle ZSub --args="-k demo/example/test"

ZGet

Sends a query message for a selector. The queryables with a matching path or selector (for instance ZQueryable) will receive this query and reply with paths/values that will be received by the query callback.

gradle ZGet

or

gradle ZGet --args="-s demo/example/get"

ZPut

Puts a path/value into Zenoh. The path/value will be received by all matching subscribers, for instance the ZSub.

Usage:

gradle ZPut

or

gradle ZPut --args="-k demo/example/put -v 'Put from Kotlin!'"

ZDelete

Performs a Delete operation into a path/value into Zenoh.

Usage:

gradle ZDelete

or

gradle ZDelete --args="-k demo/example/delete"

ZQueryable

Creates a queryable function with a key expression. This queryable function will be triggered by each call to a get operation on zenoh with a selector that matches the key expression, and will return a value to the querier.

Usage:

gradle ZQueryable

or

gradle ZQueryable --args="-k demo/example/query"

ZPubThr & ZSubThr

Pub/Sub throughput test. This example allows to perform throughput measurements between a publisher performing put operations and a subscriber receiving notifications of those puts.

Subscriber usage:

gradle ZSubThr

Publisher usage:

gradle ZPubThr <payload_size>