yomo build

Build Stream Function to WebAssembly.

When you write StreamFunction in Go, before compiling to WebAssembly, you need to install tinygo (opens in a new tab) first.

Also, you can implement StreamFunction in Rust, Zig, C or other languages can be compiled to WebAssembly, more examples can be found at example/7-wasm/sfn (opens in a new tab)

Tutorial: Write a StreamFunction in Rust
Tutorial: Write a StreamFunction in Zig
Tutorial: Write a StreamFunction in C

Usage

yomo build [flags] app.go

Flags

-m, --modfile - Build with custom go.mod file

Example

Following by last step, we init a accumulator-func project, and try-run it by yomo dev command, now, start to build it to WebAssembly.

ᐅ yomo build app.go
 
ℹ️  YoMo Stream Function file: app.go
⌛  YoMo Stream Function building...
✅  YoMo Stream Function build successful!

List the directory, will see sfn.wasm:

ᐅ exa -Tla .
 
drwxr-xr-x@    - cc 16 Apr 21:58 .
.rw-r--r--@   31 cc 16 Apr 20:39 ├── .env
.rw-r--r--@  378 cc 16 Apr 21:23 ├── app.go
.rwxr-xr-x@ 191k cc 16 Apr 21:58 ├── sfn.wasm

sfn.wasm is the compiled Stream Function.

Remember the yomo dev command in last step? Now you can run it again, and you will see the Stream Function is running:

ᐅ yomo dev sfn.wasm
 
ℹ️ YoMo Stream Function file: sfn.wasm
⌛  Create YoMo Stream Function instance...
⌛  YoMo Stream Function building...
✅  YoMo Stream Function build successful!
ℹ️  YoMo Stream Function is running...
time=2023-04-16T22:02:47.717+08:00 level=INFO msg="use credential" component="Stream Function" client_id=avVuTuuEeOs94VHGUn7mb client_name=yomo-app-demo credential_name=none
time=2023-04-16T22:02:48.594+08:00 level=INFO msg="connected to zipper" component="Stream Function" client_id=avVuTuuEeOs94VHGUn7mb client_name=yomo-app-demo zipper_addr=tap.yomo.dev:9140
sfn received 59 bytes: {"noise":143.39989,"time":1681653768764,"from":"localhost"}
sfn received 58 bytes: {"noise":90.18577,"time":1681653768865,"from":"localhost"}
sfn received 58 bytes: {"noise":42.21701,"time":1681653768966,"from":"localhost"}
sfn received 58 bytes: {"noise":39.78166,"time":1681653769067,"from":"localhost"}
sfn received 59 bytes: {"noise":112.37636,"time":1681653769168,"from":"localhost"}
sfn received 60 bytes: {"noise":101.950584,"time":1681653769268,"from":"localhost"}

Now, we want to calculate the average noise level every time we get new data, and send the result to next processor. Let's modify the app.go file:

app.go

package main
 
import (
	"encoding/binary"
	"fmt"
	"math"
 
	"github.com/tidwall/gjson"
	"github.com/yomorun/yomo/core/frame"
)
 
type NoiseSensorData struct {
	Noise float32 `json:"noise"` // Noise level
	Time  int64   `json:"time"`  // Timestamp (ms)
	From  string  `json:"from"`  // Source IP
}
 
var sum float64
var count int
 
// Handler will handle the raw data
func Handler(data []byte) (frame.Tag, []byte) {
	fmt.Printf("sfn received %d bytes: %s\n", len(data), string(data))
	// get noise field from json string
	noiseLevel := gjson.Get(string(data), "noise").Float()
 
	sum += noiseLevel
	count++
 
	// calculate average noise level
	avg := sum / float64(count)
	fmt.Printf("\t⚡️avg=%f\n", avg)
 
	// send result to next processor with data tag=0x34
	var buf [8]byte
	binary.BigEndian.PutUint64(buf[:], math.Float64bits(avg))
	return frame.Tag(0x34), buf[:]
}
 
func DataTags() []frame.Tag {
	return []frame.Tag{0x33}
}

Now, we can run yomo dev sfn.wasm again to see the execute result:

ᐅ yomo dev sfn.wasm
 
ℹ️  YoMo Stream Function file: sfn.wasm
⌛  Create YoMo Stream Function instance...
⌛  YoMo Stream Function building...
✅  YoMo Stream Function build successful!
ℹ️  YoMo Stream Function is running...
time=2023-04-16T22:29:07.897+08:00 level=INFO msg="use credential" component="Stream Function" client_id=lc-GnzDJQmNyYTwgqrw-l client_name=yomo-app-demo credential_name=none
time=2023-04-16T22:29:08.010+08:00 level=INFO msg="connected to zipper" component="Stream Function" client_id=lc-GnzDJQmNyYTwgqrw-l client_name=yomo-app-demo zipper_addr=tap.yomo.dev:9140
sfn received 58 bytes: {"noise":38.32263,"time":1681655348178,"from":"localhost"}
        ⚡️avg=38.322630
sfn received 59 bytes: {"noise":19.962397,"time":1681655348278,"from":"localhost"}
        ⚡️avg=29.142513
sfn received 58 bytes: {"noise":16.23246,"time":1681655348379,"from":"localhost"}
        ⚡️avg=24.839162
sfn received 58 bytes: {"noise":86.43262,"time":1681655348480,"from":"localhost"}
        ⚡️avg=40.237527
sfn received 58 bytes: {"noise":81.13323,"time":1681655348581,"from":"localhost"}
        ⚡️avg=48.416667
sfn received 59 bytes: {"noise":62.185295,"time":1681655348682,"from":"localhost"}
        ⚡️avg=50.711439
^C

But if you want to make this Stream Function connect to your own Zipper service, should check the yomo run command.

yomo dev <serverless>yomo run <serverless>