Examples

Prerequisite

Install Task

Install Task

Install YoMo CLI

$ task -t ../Taskfile.yml cli:install

All examples can be run by Task, following the Install Task, execute task -l in this directory will list all the examples.

$ task -l |grep example

* example-backflow:                     Backflow usage
* example-basic:                        YoMo basic usage
* example-cascading-zipper:             Cascading zippers
* example-iopipe:                       IO Pipe
* example-multi-sfn:                    Multiple stream functions
* example-pipeline:                     Unix pipeline to cloud
* example-mesh:                         Edge mesh
* example-wasm:                         YoMo Stream Function using WebAssembly
* example-deno:                         YoMo Stream Function using Deno
* example-cli:                          Use the CLI to run stream functions

can run each example directly by task example-basic, task example-cascading-zipper and etc.

Basic example

• 0-basic: process the streams from IoT sound sensor.

Linux Pipeline over cloud

• 1-pipeline: read the local streams (f.e. /dev/urandom) and use yomo-source to send the streams over cloud.
• 2-iopipe: use io.Copy() to pipe the local streams (f.e. /dev/urandom) to yomo-source.

Multiple stream functions

• 3-multi-sfn: use 3 stream functions to process the streams in different cases.
  • stream-fn-1: calculate the sound value in real-time.
  • stream-fn-2: print the warning message when the sound value reaches a threshold.
  • stream-fn-3: calculate the average value in a sliding window.

Cascading zippers

• 4-cascading-zipper: source connect to zipper-1, then zipper-1 will write the streams to the zippers in other regions.

Backflow

• 5-backflow: source can receive stream functions processed results.

This feature is experimental.

Steps:

1. Set observe data tags on source:

   source := yomo.NewSource(
     "yomo-source",
     "127.0.0.1:9000",
     // set observe data tags, 0x34, 0x35 is sfn return data tags
     yomo.WithObserveDataTags(0x34, 0x35), 
   )

1. Set receive handler on source

   // set receive handler
   source.SetReceiveHandler(func(tag byte, data []byte) {
     logger.Printf("[source] ♻️  receive backflow: tag=%#v, data=%s", tag, data)
     // TODO:
   })