Cortical

import "github.com/owulveryck/cortical"

What is Cortical?

Cortical is a go framework middleware piece of code that acts as a message dispatcher. The messages are transmitted in full duplex over a websocket. Cortical is therefore a very convenient way to distribute messages to "processing units" (other go functions) and to get the responses back in a concurrent and asynchronous way.

The "processing units" are called Cortexes and do not need to be aware of any web mechanism.

Cortical? Cortex? is it related to ML?

Actually I have developed this code as a support for my tests with tensorflow, Google Cloud Plafeform and AWS ML services. I needed a way to capture images from my webcam. I have used my chrome browser for this purpose. Every Cortex is a specific ML implementation (eg a Memory Cortex that captures all the images and send them to a cloud storage is needed for training models).

See my blog post "Chrome, the eye of the cloud - Computer vision with deep learning and only 2Gb of RAM" for more explanation.

Cortexes

A cortex is any go code that provides two functions:

• A "send" function that returns a channel of []byte. The content of the channel is sent to the websocket once available (cf GetInfoFromCortexFunc)
• A "receive" method that take a pointer of []byte. This function is called each time a message is received (cf SendInfoToCortex)

A cortex object must therefore be compatible with the cortical.Cortex interface:

ex:

// echo is a dummy type that reads a message, and send back an "ack"
type echo struct{}

func new() *echo {
	return &echo{}
}

// NewCortex is filling the cortical.Cortex interface
func (e *echo) NewCortex(ctx context.Context) (cortical.GetInfoFromCortexFunc, cortical.SendInfoToCortex) {
	c := make(chan []byte)
	return func(ctx context.Context) chan []byte {
			return c
		}, func(ctx context.Context, b *[]byte) {
			c <- *b
		}
}

Cortical take care of extracting and sending the []byte to the websocket and dispatches them through all the cortexes.

Registering the cortexes and creating a http.HandlerFunc

By now, the registration of cortexes is done at the creation of the Cortical object.

WARNING This will probably change in the future

brain := &cortical.Cortical{
     Upgrader: websocket.Upgrader{},
     Cortexes:  []cortical.Cortex{
          &echo{}, // See example in the previous paragraph
     }, 
}
http.HandleFunc("/ws", brain.ServeWS)
log.Fatal(http.ListenAndServe(":8080", nil))

Examples of cortex

See the example in godoc

Why is it coded in go?

1. Because I love go
2. Because I only know how to code in go
3. The real reason: concurrency (take a look at Rob Pike - 'Concurrency Is Not Parallelism' on youtube to truly understand why)

Caution

The API may change a lot; use it at your own risks. PR are welcome.

TODO

• Tests
• Doc
• Benchmarks
• Demo
• More functional tests
• Using the context cancel mechanism instead of my done chan
• Evaluating the opportunity of changing the interface for an io.ReadWriteCloser
• More and better doc